ONSITE WASTEWATER TREATMENT SYSTEMS MANUAL

Transcription

1 ONSITE WASTEWATER TREATMENT SYSTEMS MANUAL Draft April 2016 Alameda County Department of Environmental Health 1131 Harbor Bay Parkway Alameda, CA 94502

2 1.1 INTRODUCTION CHAPTER 1 MANUAL OVERVIEW This Manual provides the procedural and technical details for implementation of the provisions of the Alameda County Onsite Wastewater Systems Ordinance, codified in Chapter of the Alameda County General Ordinance. The provisions within this Manual are designed to protect public health, groundwater sources and surface water bodies from contamination, and provide safely operating Onsite Wastewater Treatment Systems (Onsite Systems or Systems) through proper design, siting, installation, maintenance, and monitoring. This Manual is intended to provide technical guidance for Property Owners, Designers, Installers, Contractors, and Service Providers of Systems. The Onsite Wastewater Systems Manual is divided into the following main chapters as follows: Chapter 2: Qualified Professionals Chapter 3: Site Evaluation Requirements Chapter 4: General System Design Criteria & Design Submittal Requirements Chapter 5: Tanks - Design Requirements Chapter 6: Supplemental Treatment Systems - Design Requirements Chapter 7: Subsurface Dispersal Systems - Design Requirements Chapter 8: Non-Discharging Toilet Units & Graywater Systems Design Requirements Chapter 9: Construction Materials & Installation Specifications Chapter 10: Site Modifications and Stabilization Criteria Chapter 11: System Installation and Abandonment Inspection Requirements Chapter 12: System Operation, Maintenance, Monitoring and Reporting Requirements Chapter 13: Existing System Evaluation, Repair & Replacement Criteria Chapter 14: Complaint Investigations Chapter 15: Definition of Terms

3 CHAPTER 1 MANUAL OVERVIEW 1.2 AMENDMENTS TO THE MANUAL The Alameda County Department of Environmental Health (the Department) is the agency responsible for the enforcement of the Alameda County Onsite Wastewater Treatment Systems Ordinance and provisions in this Manual. The California Regional Water Quality Control Boards (San Francisco Bay Region and Central Valley Region) are the state agencies responsible for the protection of ground and surface water quality in Alameda County. While the Department administers the local program, the Regional Boards retain the authority to issue permits for any discharge of Wastewater that may affect water quality, including discharges from Individual Systems. The regular review and update of this Manual is necessary to keep pace with new issues, policies, procedures, and technologies affecting the use and management of Onsite Systems. Any substantive changes in requirements will require review and approval by the San Francisco Bay Regional Water Quality Control Board (Regional Water Board) and adoption by Resolution of the Alameda County Board of Supervisors. The amendments may include recommended changes originating from the Department, Regional Water Board, Zone 7 Water Agency, other departments or agencies, contractors and consultants working in the OWTS industry, or other affected groups or individuals. As changes are made to this manual, cross references throughout this Manual are also subject to change. Failure of a cross-reference to indicate the appropriate chapter of requirements due to these changes does not void the applicability of the requirements. The general format for considering changes to this Manual are as follows: 1. On an annual basis the Department will announce its intent to review proposed changes, including a due date for submission of proposals. Proposals received shall include a description of the proposed change(s) along with supporting rationale, technical information, and specific language/text additions or changes. 2. The Department will conduct a preliminary internal review to determine the completeness and general merit of the proposal, and request additional information, as applicable. 3. The Department will circulate the proposal(s) for review by local consultants, contractors and maintenance providers, and others as deemed appropriate. The Department will convene a workshop/meeting with interested parties to review and discuss the proposals. 4. Based on the Department s review and workshop findings, proposals acceptable to the Department and warranting further consideration will be forwarded to the Regional Water Board for review and approval. If approved by the Regional Water Board changes will be incorporated following adoption by the Board of Supervisors.

4 2.1 SECTION OVERVIEW CHAPTER 2 QUALIFIED PROFESSIONALS This Chapter provides an overview of the professionals, contractors and other service providers that are qualified to perform site evaluations, system design, and system installation, repair, abandonment, and operations, maintenance and monitoring. The chapter is organized in the following sections: Section 2.2: Professional, Contractors, and Maintenance Providers Qualifications Section 2.3: System Designer Annual Registration Requirements Section 2.4: System Operations, Maintenance and Monitoring (OM&M) Annual Registration Requirements Section 2.5: Septage Pumper Operating Permits

5 CHAPTER 2 QUALIFIED PROFESSIONALS 2.2 PROFESSIONAL, CONTRACTOR AND MAINTENANCE PROVIDER QUALIFICATIONS A. QUALIFIED PROFESSIONALS 1. Qualified professionals as defined by this manual include the following: a. Professional Civil Engineers b. Professional Geotechnical Engineers c. Certified Engineering Geologists d. Professional Geologists e. Certified Hydrogeologists f. Professional Land Surveyors g. Registered Environmental health Specialists h. Certified Professional Soil Scientists i. Licensed Contractors j. Registered Septage Pumpers k. Onsite Wastewater System Maintenance Providers 2. Information on the qualifications and licenses, registrations, and certifications are provided in Table 2-1 and Table Additional information on qualified professional requirements is provided in subsequent sections and chapters of this manual. 4. The department shall provide oversight of qualified professionals conducting work within the county by maintaining the following programs: a. A registration program for System designers and System OM&M service providers as outlined in Section 2.4. b. A permitting program for septage pumper trucks as outlined in section 2.5 of this chapter. 5. The Department shall maintain a list of qualified professionals on the Departments website at

6 CHAPTER 2 QUALIFIED PROFESSIONALS 2.3 SYSTEM DESIGNER REQUIREMENTS A. GENERAL Qualified professionals performing site evaluations, existing system performance evaluations, and system design shall be registered with the Department. B. ANNUAL REGISTRATION REQUIRED 1. Requirements for initial System designer registration and reregistration when annual registration has lapsed without renewal, shall include the following: a. The designer shall successfully complete a written examination on the county s ordinance and manual to assure knowledge of the procedures, policies and technical regulations; b. The designer shall provide verification to the Department of the applicant s current licensure and/or registration status as required in this section; and 2. Requirements for annual registration renewal shall include the following: a. The designer shall demonstrate to the Department an ongoing minimum annual attendance of eight hours of classes dealing with subject matter related to application, design, and construction of onsite wastewater systems. b. Attendance shall be demonstrated to the Department by certification of completion provided by the instructor or sponsor of said educational activity.

7 CHAPTER 2 QUALIFIED PROFESSIONALS 2.4 SYSTEM OPERATION, MAINTENANCE & MONITORING SERVICE PROVIDER A. GENERAL Qualified professionals performing System operation, monitoring, and maintenance (OM&M) and reporting shall be registered with the Department. B. ANNUAL REGISTRATION REQUIRED 1. Requirements for initial System OM&M service provider registration and for reregistration when the registration has lapsed without renewal shall include the following: a. The OM&M specialist shall successfully complete a written examination and certification by a third-party entity approved by the Department; and b. Successful passage of a written examination provided by the Department, demonstrating the applicant s knowledge of the policies, procedures, technical requirements in the ordinance and this manual. 2 Requirements for annual registration renewal shall include the following: a. The designer shall demonstrate to the Department an ongoing minimum annual attendance of eight hours of classes dealing with subject matter related to application, design, and construction of onsite wastewater systems. b. Attendance shall be demonstrated to the Department by certification of completion provided by the instructor or sponsor of said educational activity.

8 CHAPTER 2 QUALIFIED PROFESSIONALS 2.5 SEPTAGE PUMPER TRUCK REQUIREMENTS A. GENERAL Business that perform the service of pumping or cleaning septic tanks, chemical toilets, cesspools, seepage pits, or other sewage containments are regulated under the California Health and Safety Code, division 104, part 13, sections and chapter of the Alameda County General Ordinance require a permit to operate. Each septage pumper truck that is used for this purpose requires a pumper truck annual operating permit from the Department. B. OPERATING PERMIT REQUIRED 1. A Pumper truck annual operating permit is required for each of the following: a. A vehicle that pumps wastewater from septic tanks, cesspools, grease traps, grease interceptors, seepage pits, wastewater holding tanks, wastewater ponds, or other wastewater source; or b. A business that cleans portable toilets; or c. A vehicle that disposes of wastewater from these activities in Alameda County. 2. A pumper truck annual operating permit is required for each septage pumper truck that performs liquid waste pumping and cleaning services as provided above. 3. No permit is required if the entity providing the service is a city, town, county, sanitary district, sanitation district, sewer maintenance district, or any agency or institution of the state or federal government. C. OPERATING PERMIT APPLICATION 1. An application for a pumper truck annual operating permit shall include the name and address of the business, the names and addresses of all owners, (if a partnership, then all names and addresses of all partners shall be disclosed), vehicle license number, vehicle identification number, and the exact location(s) where wastes will be disposed. 2. The application shall be submitted to the Department with the required fee established by resolution of the Board of Supervisors. D. SEPTAGE PUMPER TRUCK OPERATOR KNOWLEDGE The septage pumper truck owner, operator and all employees shall demonstrate knowledge of sanitary principles, and of the requirements and restrictions of septage pumper truck business operation and waste disposal. The Department may require demonstration of knowledge, such as employee training, pumping procedure, spill procedures, etc. E. SEPTAGE PUMPER TRUCK BUSINESS COMPLIANCE The septage pumper truck business shall demonstrate reliability in observing sanitary laws, ordinances and directions. Failure of the permitted business to operate in compliance may result in permit revocation.

9 CHAPTER 2 QUALIFIED PROFESSIONALS F. SEPTAGE PUMPER TRUCK INSPECTION PROCEDURES 1. The applicant and operator(s) of the septage tank pumper truck shall schedule an inspection of each vehicle to be permitted with the Department. During the inspection the applicant shall be required to demonstrate compliance with the following requirements for each vehicle being permitted: a. Vehicle Identification. The business name and phone number shall be permanently affixed on both sides of the vehicle in plain, legible letters and numbers at least four inches high, and shall be visible at all times. The certified capacity of the tank in gallons shall be permanently affixed on both sides of the tank in plain, legible numbers a minimum of four inches high and shall be visible at all times. The capacity as shown shall be that approved and certified by the sealer of weights and measures of the county, or other approved sealer of weights and measures. b. Vehicle in Good Repair. Vehicle and all hoses are leak proof and do not show signs of deterioration that could lead to leaking. c. Vehicle Equipment. A minimum of fifty (50) feet of pumping hose, a bucket and detergent shall be carried on each pumping vehicle. All pumping hoses must be cleaned out into the truck tank or into the septic tank, chemical toilet or other receptacle being pumped, and not on the surface of the ground. The customer's hose shall not be used. d. Vehicle Spill Kit. There shall be a spill kit carried on each vehicle at all times which shall include, but not be limited to a sufficient quantity of chloride of lime or other chlorine product for disinfection of hose, absorbent material such as kitty litter, garbage bags, gloves of an impervious material, shovel, and absorbent spill containment barrier. G. REPORTING REQUIREMENTS 1. On a quarterly basis, the owner of the permitted septage pumper truck shall report the following to Department. a. The name and address of the owner and tenant of each and every one of the premises where a wastewater septic tank, holding tank, cesspool, sewage pit, pond, chemical toilet has been pumped or cleaned out; b. The date of service; c. Gallons pumped; d. The reason for the pumping or work performed; e. Incidents where sewage is surfacing or there are other signs of System failure; f. The condition of the System and recommendations for repairs if any; and g. The locations where the pumped contents were disposed. 2. This information may be used to conduct outreach or observations regarding potential System failures or other problems. This information will also be used to assess the demand for septage pumper truck effluent disposal facilities in Alameda County. Facilitates that receive waste from septage pumper trucks in Alameda County will be assessed for capacity to receive the waste.

10 3.1 CHAPTER OVERVIEW CHAPTER 3 SITE EVALUATION REQUIREMENTS A Site Evaluation is an assessment of the characteristics of a lot sufficient to determine its suitability for the installation, use, and sustainability of a System meeting the requirements of this Manual and Ordinance. The site evaluation takes into consideration soil texture, soil percolation rate, depth to groundwater, distance from natural land features and structures, site topography, and usable space. A site evaluation is performed by a qualified professional in coordination with the Department so that Department personnel may be present for any facet of the process. This chapter presents the site assessment, field investigation, and reporting requirements for site evaluations associated with the permitting of Systems. Administrative aspects of when site evaluations are required and the Service Request Application process are presented in chapter 1. The requirements of sections 3.2 through 3.4 are applicable to the siting of all Systems, whereas sections 3.5 through 3.7 are applicable only if dictated by site-specific conditions. Section 3.2: Section 3.3: Section 3.4: Section 3.5 Section 3.6: Section 3.7: Topographic Base Map Soil Profile Study Percolation Testing Groundwater Monitoring (if required) Cumulative Impact Assessment (if required) Geotechnical Evaluation (if required)

11 3.2 TOPOGRAPHIC MAP CHAPTER 3 SITE EVALUATION REQUIREMENTS A. TOPOGRAPHIC MAP OVERVIEW 1. The first step in the site evaluation process is the preparation of a topographic map to identify physical features of the lot and adjacent lots that may impact or limit: a. Siting and performance requirements of a new System; b. Siting and performance requirements of an existing System; c. Proposed work associated with a local building agency permit for grading, demolition, or new site construction with respect to potential impact to existing Systems and reserve/replacement dispersal field areas. d. Proposed land use projects including lot creation, lot line adjustments, subdivisions and conditional use permits with respect to new System design or potential impact to existing Systems and reserve/replacement dispersal field areas. 2. The topographic map shall include data obtained by field inspection and survey, and review of information from the Department files, local building agency files, well permitting agency databases, Federal Emergency Management Act (FEMA) flood maps, United States Geological Survey (USGS) maps, and other available databases. 3. The topographic map shall be used as the base map for System evaluation and design. B. QUALIFED PROFESSIONAL Topographic maps shall be prepared, signed and Wet Stamped by a California Registered Civil Engineer or a licensed Land Surveyor to verify the following critical aspects of the siting and design of Systems. This requirement may be waived by the Department if not warranted by the lot configuration and topography. C. TOPOGRAPHIC MAP GENERAL REQUIREMENTS Topographic maps shall be prepared in accordance with the following general requirements. 1. Size. The plans shall be clearly and legibly drawn to scale on American National Standards Institute (ANSI) D sized sheets measuring twenty-two (22) inches by thirtyfour (34) inches. 2. Scale. The scale of the Map shall not be smaller than one (1) inch equals twenty (20) feet. The map shall include a statement of the nominal scale as a ratio or fraction and provide a bar scale to represent the nominal scale. 3. Title Block. The title block shall be include the following information: a. Assessor s Parcel Number and address of the lot. b. Name, address, telephone number of the preparer.

12 CHAPTER 3 SITE EVALUATION REQUIREMENTS c. Date of plans and subsequent revisions. d. Name, address, and telephone number of the property owner. 4. Vicinity Sketch. The map shall include a vicinity sketch (not at map scale) indicating the location of the lot relative to the principal roadways, lakes, and watercourses in the area. 5. Assessor s Parcel Map. The map shall include a copy of the current Assessor s parcel map. 6. North Arrow. The map shall include a north arrow. 7. Lot Dimensions and Boundaries. The map shall show property boundaries and lengths and compass bearings of property lines. 8. Property Line Location. Property lines in the vicinity of System components shall be verified through pin location or boundary surveys (if required). 9. Contour Lines, Spot Elevations, and Slope Designations. The map shall provide spot elevations, slope designations (percent and direction) and contours of the earth s surface of existing terrain and proposed grading in the vicinity of existing and proposed Systems to facilitate evaluation, siting and design. Contour interval lines shall not be greater than two (2) feet. D. TOPOGRAPHIC BASE MAP REQUISITE ELEMENTS The following information obtained during the site evaluation shall be included on the topographic map to facilitate System evaluation, siting, and design and compliance with requisite horizontal setbacks from System components. 1. Features on the Lot a. System Related Field Investigation Activities. The map shall show the locations of soil profile test pits, percolation test holes, geotechnical evaluation test pits or borings, and groundwater observation and monitoring wells, and any other areas of the lot and adjacent lots investigated during site evaluation activities. b. Existing Onsite Wastewater Systems. The map shall show the location of the components of all existing Systems on the lot including: i. Prohibited wastewater Systems (cesspools, seepage pits); ii. iii. iv. Non-discharging wastewater Systems (holding tanks, vault toilets, portable toilets); Onsite Wastewater Treatment Systems with subsurface dispersal fields; Wastewater ponds; and v. Graywater Systems. c. Buildings and Structures. The map shall show the location and footprint of all existing and proposed buildings and detached structures on the lot.

13 CHAPTER 3 SITE EVALUATION REQUIREMENTS 2. Features within fifty (50) feet of existing and proposed Systems a. Property lines; b. Storm water and groundwater drainage structures (infiltration trenches, interceptor drains, roof run-off piping, sumps, swales, v-ditches, canals, culverts, energy dissipaters, outfalls, etc.); c. Vehicle traffic and storage areas (paved or unpaved); d. Utility lines (existing and proposed electrical, sewer, water, gas, etc.); e. Landscaped/irrigated areas; f. Easements, access agreements, and public right-of-ways (underground utility easements, above ground utility easements, public roadway right-of-ways, private potable water supply access agreements and easements, Onsite Wastewater Treatment System access agreements and easements, etc.); g. Graded/fill areas (building pads, berms, etc.); h. Retaining walls; i. Hazardous materials storage areas including above ground and underground storage tanks. j. General location and character of vegetation; and k. Large trees with a trunk diameter of twelve (12) inches or more, measured at a point three feet above average ground level. l. Other site development related features and appurtenances including but not limited to patios, decks, gazebos, walkways, children s play structures, fences, driveways, bridges, decorative ponds, hot tubs/spas, pools, pool houses, ground mounted solar installations, animal pens/corrals, animal wash pads, crush pads, garbage enclosures, etc.). 3. Features within One Hundred (100) Feet of Existing and Proposed Systems a. Drainage ways, drainage swales, and ephemeral streams (measured from the edge of flow path) b. French drains or groundwater interceptor drains 4. Features within one hundred and fifty (150) feet of existing and proposed Systems a. Steep slopes (measured from the break of slope); b. Cut or steep embankments (measured from the top of cut); c. Unstable land masses or any other areas subject to earth slides identified by a seismic hazard zone map or a registered Civil Engineer or other qualified professional;

14 CHAPTER 3 SITE EVALUATION REQUIREMENTS d. Private existing, abandoned, and proposed potable water supply sources (springs or wells) associated appurtenances including water storage and treatment facilities (storage tanks, pump houses, water softener ponds); e. Watercourses defined as a body of running water flowing over the earth in a natural water course, where the movement of water is readily discernable or if water is not present it is apparent from review of the geology that when present it does flow (measured from the natural or levied top of bank); f. Reservoirs, lakes, ponds, or other non-flowing surface water bodies (measured from the high water mark); g. Springs; h. Floodplain Boundaries (100-year); and i. Wetlands. 5. Features within two hundred (200) feet of existing and proposed systems Public water wells. 6. Features within two Hundred and fifty (250) feet of existing and proposed systems Surface water bodies (measured from high water mark of the reservoir, lake or flowing water body) located more than one-thousand two hundred (1,200) feet but less than two thousand five hundred (2,500 feet) from a public water system intake. 7. Features within four hundred and fifty (450) feet of existing and proposed dispersal systems Surface water bodies (measured from high water mark of the reservoir, lake or flowing water body) located within two thousand five hundred (2,500) feet from a public water system intake.

15 3.3 SOIL PROFILE STUDY A. PURPOSE CHAPTER 3 SITE EVALUATION REQUIREMENTS The purpose of the soil profile study is to: 1. Determine the suitability of the soil for absorption of wastewater in the area of a dispersal System to: a. Ensure that proper soil conditions exist to allow appropriate effluent retention, treatment, and filtration. b. Prevent wastewater from discharging to the ground surface or contaminating groundwater or surface water resources. 2. Verify that there is adequate vertical separation between the bottom of the dispersal System and bedrock, groundwater, or impermeable soil strata. B. QUALIFED PROFESSIONAL Soil profile studies shall be conducted by a California State Registered Civil Engineer, Registered Environmental Health Specialist, or Registered Geologist, or a Soil Scientist certified by the Soil Science Society of America. C. DEPARTMENT OVERSIGHT 1. The Department shall be notified forty-eight (48) hours in advance of conducting the soil profile study and the time of the Department field observation, arranged through mutual consent with Department staff. 2. All soil test pits shall be dug prior to the Department field observation appointment time. D. SOIL PROFILE PITS NUMBER, DEPTH, AND DISTRIBUTION 1. Test pits shall be sufficient in number and adequately spaced to encompass and represent the soil conditions of the entire area of the primary and secondary/reserve dispersal System areas. 2. A minimum of two (2) soil profiles are required: a. One (1) profile in the primary dispersal System area. b. One (1) profile in the secondary/reserve dispersal System area. 3. Additional soil profiles may be required if the initial two soil profiles show conditions which are dissimilar to the extent that they do not provide sufficient information for design and/or determination of code compliance. E. SOIL PROFILE TEST PIT EXCAVATIONS 1. Soil profiles shall be performed when the soil conditions are dry as defined below: a. When soil particles pass freely through a #10 sieve; and

16 CHAPTER 3 SITE EVALUATION REQUIREMENTS b. A clear visual identification of the soil structure in the test pit sidewalls can be observed. 2. If the soil moisture content does not allow for these criteria, the soil profile study shall not be performed. 3. The qualified professional shall be responsible for assuring soil conditions are dry enough to perform the soil profiles prior to inspection by Department staff. 4. Soil profile test pits are generally excavated by a backhoe or excavator, but hand dug holes are acceptable when dug to proper dimensions and with adequate setbacks. 5. The test pits shall be constructed in accordance with the trenching and excavation safety requirements of Title 29 of the Code of Federal Regulations sections and or comparable California Occupational Health and Safety (OSHA) approved state plan requirements. 6. Test pits shall not be less than twenty-four (24) inches wide and shall be gently sloped or stepped and shall not be excavated so as to require the use of a ladder for entry. 7. Soil profile test pits shall be excavated to the appropriate depth to verify that there is adequate vertical separation and effective soil beneath the bottom of the dispersal system. 8. Effective soil is the undisturbed unsaturated natural soil located above the seasonal high water table, fractured or fissured rock, or any layer that impedes movements of water, air, or growth of plant roots. 9. The measurement of effective soil depth is taken from natural grade and must not consider fill material or imported soil. 10. The types of layers that differ from overlying soil material enough to limit effective soil depth include hardpans, claypans, impermeable soil, fragipans, compacted soil, bedrock, fractured bedrock, saprolite, clay soil, soil containing more than 50 percent rock or consolidated material (by volume as retained on a #10 sieve), or seasonal high groundwater. 11. The qualified professional shall ensure that the soil profiles are advanced to sufficient depths to enable verification of vertical separation to groundwater and effective soil depths beneath the proposed dispersals system design. Soil profile test pit and percolation hole depth requirements for standard and alternative system configurations approved for use in the County are shown on Table 3-1. System configurations are further discussed in Chapter 4 of this Manual. 12. Dispersal systems approved for use in the County include: Shallow In-Ground Trench Dispersal Systems, Conventional Trench Dispersal Systems, Deep Trench Dispersal Systems, Pressure Dosed Sand Trench Dispersal Systems, Subsurface Drip Dispersal Systems, At-Grade Dispersal Systems, Mound Dispersal Systems, Raised Sand Bed Filter Systems and Engineered Fill Drip Dispersal Systems. The effective soil depth and vertical separation to groundwater requirements beneath each of the above listed dispersal systems is dependent on the level of treatment (primary or supplemental) preceding the dispersal system.

17 F. AUGER TEST HOLES CHAPTER 3 SITE EVALUATION REQUIREMENTS 1. Auger test holes may be an acceptable alternative to backhoe or hand-dug test pits under the following conditions: a. The use of a backhoe or similar excavating machinery is impractical due to site access constraints or fragile soils; or b. It is necessary only to verify conditions based on prior soils investigations; OR c. Soil profiles are required to be no greater than 3-feet deep; or d. It is done in connection with geologic investigation; or e. Where verification of groundwater separation requires additional deeper subsurface exploration. 2. When the auger method is used, at least three test holes in the primary and three test holes in the secondary/reserve dispersal field are required. G. SOIL PROFILE OBSERVATIONS 1. The excavated sidewall shall be picked away with a sharp instrument to expose the natural soil structure. 2. The qualified professional shall identify each soil horizon from ground surface to the bottom of the soil profile. 3. Soil profile observations shall be recorded on the Form 3-1 (Soil Profile Observations) using the abbreviations provided with the instructions. The Soil Profile form shall include a description of the following soil features: a. Soil texture, color, structure, consistency, plasticity, and porosity, for each soil horizon in the excavation utilizing the United States Department of Agriculture (USDA) soil classification system and Soil Textural Triangle (see Figure 3-3). b. Depth and type of limiting condition, including but not limited to bedrock, hardpan, impermeable soil layers, observed free water, saturated soils, or groundwater. c. Depth of soil mottling, gleying or other evidence of periodic soil saturation. d. Other prominent soil features including but not limited to percentage of rock or coarse fragments, root porosity, dampness, or depth and type of fill or imported soil in the profile. H. HYDROMETER TESTING 1. If the classification of the soil is in question, the Department staff may require the qualified professional to provide hydrometer test data to verify the actual classification of the soil. 2. Hydrometer analysis is a laboratory test that measures the percentage of sand, silt, and clay in the soil. The data can be plotted on an USDA Soil Textural Triangle to confirm the field classification.

18 CHAPTER 3 SITE EVALUATION REQUIREMENTS 3. The soil sample for the hydrometer analysis shall be taken from the most restrictive layer within the soil profiles. 4. All samples shall be appropriately labeled and analyzed for soil structure by hydrometer testing in accordance with an approved American Society of Testing and Materials (ASTM) method or California Test Method by a soils mechanics laboratory. 5. The hydrometer analysis cannot be used exclusively since the hydrometer test will not show presence of highly compacted soil or soil structures that limit infiltrative properties. I. REFERENCES A. USDA, Natural Resources Conservation Service. Field Book for Describing and Sampling Soils. September 2002 B. USDA, Natural Resources Conservation Service. Soil Survey Manual. C. USEPA, Design Manual Onsite Wastewater Treatment and Disposal Systems (pages 28-38).

19 CHAPTER 3 SITE EVALUATION REQUIREMENTS 3.4 SOIL PERCOLATION TESTING A. PURPOSE 1. Percolation testing shall normally be conducted at the time of or shortly following the soil profile investigation and is performed to provide supplemental information required to determine the potential absorption rate of soil in the primary and secondary/reserve areas of dispersal fields. 2. Percolation testing does not replace the need or requirement for soil profile study, soil textural determination, and determination of evidence of high seasonal groundwater. B. QUALIFED PROFESSIONAL Percolation tests shall be conducted by a California State Registered Civil Engineer, Registered Environmental Health Specialist, or Registered Geologist, or a Soil Scientist certified by the Soil Science Society of America. C. DEPARTMENT OVERSIGHT 1. The Department will determine the level of oversight required and may elect to witness the installation of the percolation holes, verify presoaking, and be present during all or part of the testing. 2. The Department shall be notified forty-eight (48) hours in advance prior to performing percolation tests and Department field observation (if required) arranged through mutual consent with Department staff. D. PERCOLATION TESTS NUMBER, DEPTH AND DISTRIBUTION 1. Percolation tests shall be sufficient in number and adequately spaced to encompass and represent the soil conditions of the entire area of the primary and secondary/reserve dispersal system areas. 2. A minimum of six (6) percolation tests shall be conducted; three (3) in the primary dispersal area and three (3) in the secondary/reserve dispersal field area. 3. The location of the percolation test holes shall be evenly distributed horizontally and vertically in the dispersal field areas to provide a reasonable representation of conditions within the dispersal field bottom infiltration zone and the sidewall infiltration zone (if applicable). 4. Additional percolation tests may be required if the initial tests show conditions which are dissimilar to the extent that they do not provide sufficient information for design or to refine an exclusion area represented by failed percolation tests.

20 CHAPTER 3 SITE EVALUATION REQUIREMENTS E. PERCOLATION TEST HOLE CONSTRUCTION 1. Percolation test holes shall be hand augured or machine augered per the specifications provided below: a. Test holes shall be six inches (6) inches in diameter. b. Test hole sides shall be kept as straight as possible. c. Test holes shall be installed in accordance with the depth requirements in Table 3-1. d. The bottom and sides of the test holes shall be carefully scarified with a blunt edged instrument to remove smeared soil particles and remove all loose soil material. e. The native soil structure shall be visible on the bottom ten (10) to twelve (12) inches of the side wall. f. Two (2) inches of pea-size gravel shall be placed in the bottom of the hole to protect the bottom from scouring and sediment. g. The test hole shall be stabilized by placing a four (4) inch perforated pipe and a one (1) inch sidewall gravel pack (1/2 to 3/4 inch clean washed drain rock) in the test hole to prevent silting of the bottom of the hole and sidewall cave-in. F. PERCOLATION TEST HOLE PRESOAKING 1. All percolation test holes shall be presoaked before the test begins. 2. Presoaking shall consist of filling each percolation hole with clean water to a minimum depth of twelve (12) inches above the base of the hole for a four (4) hour period. 3. The presoak shall be maintained for a minimum of four (4) hours, refilling approximately once per hour or as necessary. 4. Areas of high clay content may require a presoak twelve (12) hours or longer. 5. In sandy soils with little or no clay content, pre-soaking is not necessary. If, after filling the hole twice with twelve (12) inches of water, the water seeps completely away in less than ten minutes, the test can proceed immediately. 6. If more than six (6) inches of water remains above the bottom of the hole after presoaking and prior to the start of the test, this constitutes a failure and no further testing of the hole is warranted. 7. If less than six (6) inches of water remains in the test hole after presoaking percolation testing of the hole is warranted. G. CONDUCTING THE PERCOLATION TESTS 1. Conduct the test in accordance with the instructions on Form 3-2 by adding clean water to bring the depth of water in the test hole to approximately six (6) inches above the bottom of the hole. Maintain approximately six (6) inches of water in the hole throughout the test. Water shall be added through the pipe rather than into the gravel.

21 CHAPTER 3 SITE EVALUATION REQUIREMENTS 2. Water level measurements shall be measured from the top of the pipe and shall be recorded with a 1/8 inch accuracy. 3. Percolation tests results shall be recorded on Form 3-2 (Soil Percolation Test Recorded Measurements). H. CALCULATING PERCOLATION RATES 1. Individual Test Hole Percolation Rates a. An Average Stabilized Percolation Rate shall be determined for each test hole by averaging the last three successive stabilized readings varying by no more than 10 percent or 1/8-inch of each other. b. An Adjusted Percolation Rate shall be calculated using the equation below to adjust for the displacement of water by the gravel pack: Adjusted Percolation Rate (mpi) = Average Percolation Rate (mpi) x Correction Factor Correction Factor = 1.59 for a six (6) inch diameter hole with a four (4) inch perforated pipe and one (1) inch thick gravel pack. 2. Average Adjusted Stabilized Mean Percolation Rate a. An Average Adjusted Stabilized Mean Percolation Rate shall be calculated as the sum of the Adjusted Stabilized Percolation Rates for each individual percolation test hole divided by the total number of percolation test holes completed. b. The Average Percolation Rate is used as the basis for Dispersal Field design I. ALTERNATIVE PERCOLATION TEST PROCEDURES Alternate methods of measuring the percolation rate may be approved by the Department if the proposed procedures can be shown to produce a stabilized rate as defined in this section.

22 CHAPTER 3 SITE EVALUATION REQUIREMENTS 3.5 GROUNDWATER MONITORING A. HIGH GROUNDWATER LEVELS 1. Some locations in Alameda County are subject to high groundwater levels which can have an adverse impact on the performance of the System by eliminating or minimizing the zone of aeration in soils that is critical for optimal wastewater treatment. 2. Installing a system on a site that appears to have adequate separation to groundwater in the dry season but experiences shallow groundwater during the rainy season may result in a System which functions properly only part of the year. 3. Failure to provide the required separation to seasonal high groundwater may potentially result in System failure resulting in: a. Introducing untreated wastewater to the groundwater which could affect area water wells, water quality and public health. b. Effluent surfacing on the ground. c. Sewage backing up into the house fixtures. 4. If there are site characteristics or historical documentation indicating that a shallow groundwater table is likely to occur during the rainy season, a wet weather groundwater investigation shall be required. B. AREAS OF NITRATE IMPACTED GROUNDWATER 1. Some locations in Alameda County have been identified as having nitrate impacted groundwater (see Chapter 4). 2. Installation of groundwater monitoring wells to assess the current groundwater nitrate conditions beneath the site and/or monitor nutrient loading from the System may be required as part of the System installation approval. C. QUALIFIED PROFESSIONAL Hydrogeologic and wet weather groundwater investigations shall be conducted by a California State Registered Civil Engineer or Registered Geologist. D. DEPARTMENT OVERSIGHT Department staff will determine the level of oversight required during wet weather testing if applicable. E. DEPTH TO GROUNDWATER DETERMINATION 1. The anticipated highest level of groundwater in the vicinity of System shall be estimated by:

23 CHAPTER 3 SITE EVALUATION REQUIREMENTS a. The highest extent of soil mottling and/or gleying to natural grade observed in a soil profiles study b. Data from nearby soil evaluations or groundwater observations; or c. Direct observation of groundwater levels during the time of year when the highest groundwater conditions are expected or known to occur (i.e., during the wet weather period defined in this manual) 2. Where there is a discrepancy between soil profile indications (mottling or gleying) and direct observations, the direct observations shall govern. F. FIELD OBSERVATIONS INDICATING NEED FOR WET WEATHER TESTING Field observations on parcels or lots with suspected seasonal groundwater issues requiring wet weather season monitoring include: 1. Visual indication of seasonal groundwater, such as mottling or gleying in soil profiles 2. Visual evidence of soil shrinkage cracks. Expansive, high shrink-swell soils may exhibit suitable soil percolation rates during the dry season due to shrinkage cracks in the soil; but, when they become wet, the same soils may swell to the point of providing little or no percolation 3. Soil exhibiting high clay content (e.g., exceeding 40 percent) in combination with massive, columnar or angular blocky soil structure 4. Sandy soil lacking the necessary iron compounds to exhibit redoximorphic features 5. Site location at the base of a hill, near a creek or otherwise located where water is likely to accumulate 6. Springs or other indications, such as swampy/marshy appearance or presence of riparian or water-loving vegetation such as cattails, willows, or perennial grasses indicating prolonged soil moisture 7. History of seasonal groundwater in the vicinity of site 8. The presence of any other condition that may indicate a seasonal high groundwater table G. WET WEATHER TESTING WINDOW 1. Seasonal wet weather groundwater monitoring shall be conducted when sufficient rainfall has occurred in the area to establish the normal seasonal groundwater table. 2. Minimum rainfall shall be fifty (50) percent of average for the observation months of October through April. 3. Data from local rainfall-monitoring stations shall be used to determine when sufficient rainfall has occurred.

24 H. RAINFALL DATA SOURCE CHAPTER 3 SITE EVALUATION REQUIREMENTS 1. California Irrigation Management Information system (CIMIS) at: 2. The wet weather period may be extended earlier or later depending on weather patterns and with approval of the Department. 3. The qualified professional may propose a different source of historical data. I. WET WEATHER TESTING FREQUENCY Groundwater level data collection shall occur at the following frequency: 1. At least every two weeks. 2. If there is a significant rainfall event (i.e., when there have been one (1) or more inches of rainfall within a twenty-four (24) hour period additional readings shall be taken within two (2) days following the event. 3. Daily observations may be necessary during elevated groundwater periods to identify maximum groundwater levels. 4. In areas that experience high groundwater due to flood irrigation, monitoring shall be done when flooding is at its maximum. 5. Monitoring ports shall be staked and flagged so that they can be readily located by the Department staff for periodic confirmatory observations. J. LOW RAINFALL YEARS 1. During years of low rainfall, such as drought conditions, a secondary source of seasonal high groundwater determination may be considered. 2. After completion of at least one groundwater observation period that does not reach the average rainfall requirement for certification, a complete groundwater report prepared by a California Registered Civil Engineer, Registered Geologist, or Registered Hydrogeologist may be submitted to the Department for review and approval. 3. The report shall contain supporting data for groundwater elevation conclusions and include an analysis of expected maximum groundwater elevations for dispersal field area. 4. Elements for the report shall include: a. Topographical and geographical characteristics of the site including slope of the land that could affect surface and subsurface drainage characteristics. b. Soil classification and hydraulic conductivity of the soil. c. Restrictive layers in the soil profile. d. Indicators of seasonal groundwater (e.g., soil mottling).

25 CHAPTER 3 SITE EVALUATION REQUIREMENTS e. Depth of observed groundwater in relationship to minimum soil depth requirements and depth of Dispersal Field. K. WORK PLAN REQUIRED 1. If groundwater monitoring is required to assess groundwater conditions beneath the site or if soil profiles and field observations indicate the need for wet weather testing to determine highest anticipated level of groundwater in the dispersal field areas, a groundwater monitoring work plan shall be prepared by the qualified professional and submitted to the Department for review and approval. 2. The Work Plan shall contain: a. Proposed piezometer or monitoring well and network system design b. Proposed sample collection and analysis procedures c. Proposed sample collection or wet weather testing frequency d. Proposed rainfall data source e. Reporting schedule 3. Monitoring well design for wet weather observation a. Direct observation of groundwater shall be done with piezometers or monitoring wells at the time of year when the maximum groundwater elevation is expected to occur. b. Monitoring wells sufficient in number and adequately spaced to encompass and represent the entire primary and secondary/reserve dispersal field areas shall be constructed. c. At least one port or piezometer shall be constructed in each dispersal field area (primary and secondary/reserve). d. Monitoring well depth shall be equal or greater than the required depth from the bottom of the dispersal fields to groundwater for System approval (see Table 3-1). e. Where a conflict exists between the depth of groundwater observed through direct observation during wet weather conditions and the depth at which soil mottles are observed, the direct observation of actual groundwater levels shall govern. f. For larger flow systems, deeper groundwater monitoring wells may be required to assess groundwater mounding.

26 CHAPTER 3 SITE EVALUATION REQUIREMENTS 3.6 CUMULATIVE IMPACT ASSESSMENT A. PURPOSE 1. Certain projects require the completion of additional technical studies, termed Cumulative Impact Assessment in situations where cumulative impacts on groundwater and/or watershed conditions from Systems are of potential concern. 2. Cumulative impact issues (mainly groundwater mounding and nitrogen loading) from Systems may occur due to the following factors: a. the constituent levels in wastewater (e.g., nitrogen content); b. the volume of wastewater flow; c. the density of System discharges in a given area; and/or d. the sensitivity and beneficial uses of water resources in a particular location 3. These issues are not necessarily addressed by conformance with standard siting and design criteria. B. QUALIFIED PROFESSIONAL 1. Cumulative impact assessment shall be performed by or under the supervision of a California State Registered Civil Engineer, a Registered Geologist, or a Registered Hydrogeologist. 2. The licensed professional assuming responsibility for the cumulative impact assessment should have education, training and experience in the fields of water quality and hydrogeology. C. CUMULATIVE IMPACT ISSUES 1. The primary issues to be addressed in cumulative impact assessments include: a. Groundwater Mounding - A rise in the water table, referred to as "groundwater mounding", that may occur beneath or down-gradient of System or Systems as a result of the concentrated or high volume of hydraulic loading from one or more Systems in a limited area. b. Groundwater Nitrogen Loading: Discharges from Systems contain high concentrations of nitrogen that may contribute to rises in the nitrate level of local and regional aquifers. 2. Analysis of cumulative impact issues, other than those listed above which could pose potential water quality, public health, or safety risks may also be required.

27 CHAPTER 3 SITE EVALUATION REQUIREMENTS D. PROJECTS REQUIRING CUMULATIVE IMPACT ASSESSMENT 1. Projects where cumulative impact assessments shall be required are listed in Table Criteria for assessing hydrological impacts for groundwater mounding or nitrogen loading will be considered on a case-by-case basis. The Department may rely upon Regional Water Board staff or a third-party consultant to assist in the review. Costs for retaining a third-party consultant would be the responsibility of the project applicant. E. GROUNDWATER MOUNDING ANALYSIS 1. Analysis of groundwater mounding effects shall be conducted using accepted principles of groundwater hydraulics. The specific methodology shall be described and supported with accompanying literature references, as appropriate. 2. Assumptions and data used for the groundwater mounding analysis shall be stated along with supporting information. A map of the project site showing the location and dimensions of the proposed system(s) and the location of other nearby System, wells and relevant hydrogeological features (e.g., site topography, streams, drainage channels, subsurface drains, etc.) shall be provided. 3. The wastewater flow used for groundwater mounding analyses shall be the design daily sewage flow, unless supported adequately by other documentation or rationale. 4. Groundwater mounding analyses shall be used to predict the highest rise of the water table and shall account for background groundwater conditions during the wet weather season. 5. All relevant calculations necessary for reviewing the groundwater mounding analysis shall accompany the submittal. 6. Any measures proposed to mitigate or reduce the groundwater mounding effects shall be presented and described as to their documented effectiveness elsewhere, special maintenance or monitoring requirements or other relevant factors. 7. For Systems located less than two hundred (200) feet from and within the catchment area of surface water, an annual water balance analysis will also ordinarily be required to assess the extent of potential System impacts on hydrology of a sensitive habitat. 8. The maximum acceptable rise of the water table for short periods of time [e.g., one (1) to two (2) weeks] during the wet weather season, as estimated from groundwater mounding analyses, shall be such that the minimum two (2) feet separation to the groundwater is maintained for all Systems. F. NITROGEN LOADING ANALYSIS 1. Analysis of nitrate loading effects shall, at a minimum, be based upon construction of an annual chemical-water mass balance. The specific methodology shall be described and supported with accompanied literature references as appropriate.

28 CHAPTER 3 SITE EVALUATION REQUIREMENTS 2. Assumptions and data for the mass balance analysis shall be stated, along with supporting information. Such supporting information should include, at a minimum: a. Climatic data (e.g., precipitation, evapotranspiration rates); b. Groundwater occurrence, depth and flow direction(s); c. Background groundwater quality data, if available; d. Soils conditions and runoff factors; e. Wastewater characteristics (i.e., flow and nitrogen content); and, f. Other significant nitrogen sources in the impact area (e.g., livestock, other waste discharges, etc.). 3. A map of the project siting showing the location and dimensions of the proposed system(s) and the location of other nearby System, wells and relevant hydrogeological features (e.g., site topography, streams, drainage channels, subsurface drains, etc.) shall be provided. 4. The wastewater flow (average) used for nitrogen loading analyses shall be submitted with adequate backup documentation to support estimated average flows. 5. Minimum values used for the total nitrogen concentration of septic tank effluent shall be as follows, unless supported adequately by other documentation or rationale: a. Residential wastewater: 70 milligrams per liter (mg/l) b. Non-residential wastewater: as determined from sampling of comparable system(s) or from literature values. 6. The Department may require the use of more conservative values than cited above if the values are not likely to be representative of the proposed System(s). 7. All relevant calculations necessary for reviewing the nitrogen loading analysis shall accompany the submittal. 8. Any measures proposed to mitigate or reduce the nitrogen loading effects shall be presented and described as to their documented effectiveness elsewhere, special maintenance or monitoring requirements or other relevant factors. 9. The minimum criteria for evaluating the cumulative nitrogen loading from the proposed System for areas served by individual water wells shall be as follows: a. Existing lots of record: New Systems on existing lots of record shall not cause the groundwater nitrate-nitrogen concentration to exceed 7.5 mg-n/l at the nearest existing or potential point of groundwater withdrawal (e.g., water well location); and b. New subdivisions: The total loading of nitrate from new subdivisions shall not result in an average groundwater nitrate-nitrogen concentration over the geographical extent of the subdivision that exceeds 7.5 mg-n/l.

29 CHAPTER 3 SITE EVALUATION REQUIREMENTS 10. The minimum criteria for evaluating the cumulative nitrogen loading from the proposed System for areas not served by individual water wells shall be as follows: a. Existing lots of record: New system on existing lots of record shall not cause the groundwater nitrate-nitrogen concentration to exceed 7.5 milligrams of Nitrate per liter (mg-n/l) at the nearest existing or potential point of groundwater withdrawal (e.g., water well location); and b. New Subdivisions: The total loading of nitrate from new subdivisions shall not result in an average groundwater nitrate-nitrogen concentration over the geographical extent of the subdivision that exceeds 7.5 mg-n/l. 11. The Department reserves the right to require, in any individual case, more stringent nitrate-nitrogen compliance criteria where deemed necessary for protection of public health, or based upon specific requirements or recommendations of the Zone 7 Water Agency or San Francisco Regional Water Board.

30 CHAPTER 3 SITE EVALUATION REQUIREMENTS 3.7 GEOTECHNICAL EVALUATION A. PURPOSE 1. Geotechnical/geological investigations shall be required in accordance with the provision of chapter of the Alameda County General Ordinance and in any of the following circumstances: a. When dispersal systems are proposed on sites with natural ground slopes greater than thirty (30) percent; b. When a proposed system is located within an earthquake fault zone or a seismic hazard zone, as delineated on the official maps published for that purpose by the California Geologic Survey, or when such hazards are otherwise known or suspected in the location of the System; c. For proposed reductions in horizontal setbacks from cuts, embankments, steep slopes or an unstable land mass; or d. When grading includes a cut or fill exceeding five (5) feet in depth at any point and the slope of the natural ground within thirty (30) feet of the cut or fill exceeds ten (10) percent. 2. The geotechnical evaluation shall assess slope stability, drainage, and other factors and demonstrate through a geotechnical report and engineering installation plan that the use of the subsurface dispersal field will not permit wastewater to surface, degrade water quality, create a nuisance, affect soil stability, or present a threat to the public health or safety.. B. QUALIFIED PROFESSIONAL The geotechnical evaluation shall be conducted by a California State Registered Civil Engineer or Registered Geotechnical Engineer or Certified Engineering Geologist. C. GEOTECHNICAL REPORT REQUIRMENTS 1. The geotechnical report shall include, but not be limited to, soil percolation rates, contours, soil depth, seasonal groundwater elevation(s), location of all existing or proposed ground cuts, rock formations, soil stability, drainage, and other data as determined by the Geotechnical Engineer. 2. The report must specially reference the engineering installation plan. 3. If at some future date, the System is appreciably modified an amended report must be submitted that references the modified plan. 4. The geotechnical report must discuss the following: a. Geology b. Slope stability and seismic hazards

31 c. Soil d. Groundwater e. Drainage f. Percolation Rate g. Topography h. Cuts i. Vegetation CHAPTER 3 SITE EVALUATION REQUIREMENTS j. Other pertinent site features 5. The report shall include any recommendations deemed appropriate or necessary to mitigate potential slope stability, drainage or seepage concerns associated with the System Installation and operation including as applicable recommended horizontal setback(s) from any cut banks, embankments, steep slopes or unstable land masses. 6. The report shall state specifically in the conclusion that the proposed system will not (or other wording such as not likely to, risk is very low, etc.): a. Permit sewage effluent to surface b. Degrade water quality c. Affect soil stability d. Present a threat to public health or safety e. Create a public nuisance 7. The report shall be wet-stamped and signed by the qualified professional. D. ENGINEERING INSTALLATION PLAN REQUIREMENTS 1. The plan must be wet-stamped by the system designer and initialed or signed. 2. The plan must include cross section(s) through the dispersal field that show dispersal line depths and details, and any benching that will be necessary to install the system. 3. Any System proposed for installation on slopes between thirty (30) percent and forty (40) percent shall require the use of pressure distribution methods. 4. Any system proposed for installation on slopes between forty (40) percent and fifty (50) percent shall require the use of subsurface drip dispersal methods. 5. The plan must include an erosion control plan, incorporating measures consistent with guidelines and requirements contained in chapter (grading, erosion and sediment control) of the Alameda County General Ordinance. 6. The plans shall incorporate applicable recommendation contained in the geotechnical report regarding the avoidance or mitigation of slope stability concerns, including, as applicable, recommended horizontal setback distance(s) from cut banks, embankments, steep slopes, or any identified unstable land mass within one hundred (100) feet of the System.

32 4.1 CHAPTER OVERVIEW CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS This chapter presents general design criteria used for designing all systems and for selecting system components in the treatment train including tanks, supplemental treatment systems, and subsurface dispersal systems. This Chapter is organized in the following sections: Section 4.2: Section 4.3: Section 4.4: Section 4.5: Section 4.6: Section 4.7: System Types and Treatment Train Overview Wastewater Design Flow Criteria Wastewater Strength Design Criteria Wastewater Application Rates System Siting Criteria System Design Submittal Requirements

33 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 4.2 SYSTEM TYPES AND TREATMENT TRAIN OVERVIEW A. TYPES OF SYSTEMS 1. Systems can be designed as individual systems, cluster systems or community systems. a. An Individual System is a System serving one (1) dwelling or other building on a lot. b. A Cluster System is a System serving at least two (2) but not more than four (4) dwellings or other buildings that are sources of wastewater discharge on the same lot and under the same ownership. c. A Community System is a System that accepts wastewater discharges from two or more lots, or a System shared by dwellings under separate ownership whether or not they are on the same lot. A Community System is not a public sewer system. 2. Types of Systems include: a. Standard Systems. A Standard System is a type of onsite wastewater treatment system consisting of a septic tank for primary treatment of sewage followed by a system of drainfield trenches for subsurface dispersal of wastewater effluent into the soil. A standard system may utilize gravity flow or a pump system to convey effluent from the septic tank to the drainfield. b. Alternative Systems: An Alternative System is a type of onsite wastewater treatment system that utilizes either a method of wastewater treatment or supplemental treatment other than a septic tank and/or a method of wastewater dispersal other than a standard drainfield trench. Alternative systems are designed to produce a higher quality wastewater effluent and improved performance of and siting option for effluent dispersal where a standard system is not suitable. c. Other Systems. (1) Non-Discharging Disposal Units. A Non-Discharging Wastewater Disposal Unit is a self-contained, watertight container designed to hold Wastewater until it is pumped and/or cleaned. Non-Discharging Wastewater Disposal Units includes holding tanks, vault privies, portable toilets, and waterless toilets. (2) Graywater Systems. A Graywater System is a type of system designed to collect graywater and transport it out of the structure for distribution in an irrigation field. A Graywater System may include tanks, valves, filter, pumps, or other appurtenances along with piping and receiving landscape. B. SYSTEM SELECTION OVERVIEW 1. Selection of the appropriate system type, size, and location at the site shall be based on the wastewater flow and composition, site evaluation, performance requirements, and evaluation of the available technology options approved for use in the County as outlined in Figure 4-1 and Figure 4-2.

34 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 2. The main criteria used in selection of the treatment train components includes the level of wastewater treatment required prior to discharging to the dispersal system, wastewater application and loading rates to infiltrative surfaces, wastewater dispersal mechanisms (gravity fed or pressure dosed), and siting constraints (including horizontal setbacks requirements, vertical separation to groundwater requirements, effective soil depth, soil classification and percolation rate, site topography, and available area on a parcel for a dispersal system). 3. Where multiple treatment trains (system designs) meeting the prescribed siting and design requirements are feasible and technically equivalent, the System designer shall discuss the options with the owner and users of the System and evaluate each option with respect to aesthetics, operation and maintenance requirements, cost, and reliability. a. Aesthetics include such considerations as System location preferences, space requirements, appearance, and disruption during construction, equipment and alarm noise, and odor potential for owners, users and adjacent property owners. b. Operations and maintenance requirements include specific operation and maintenance tasks and frequency necessary for a System to perform properly over its intended service life. c. Costs of feasible alternatives shall be presented to the owner and shall be based on the total cost of each alternative including capital costs incurred in planning, designing, and construction the System and the long-term costs associated with maintaining the System over its design life. d. Reliability of the treatment train components and considerations such as individual component longevity, overall System reliability, and potential risks to the owner, the public and the environment if the proposed System malfunctions or failures occur, shall be presented to the owner. C. MAJOR SYSTEM COMPONENTS (TREATMENT TRAIN) 1. The major components commonly utilized in the treatment trains of Systems designed for sanitary waste generated from residential and commercial facilities include tanks, supplemental treatment systems, and dispersal systems. A schematic of the treatment train or sequence of the treatment components shall be shall be included on the design plans. 2. The types of tanks approved for use in the County are listed below. Design requirements for tanks are provided in Chapter 5 of this Manual. a. Septic Tanks b. Holding Tanks c. Pump Tanks d. Dosing Tanks e. Flow Equalization Tanks f. Grease Interceptor Tanks

35 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 3. The types of Supplemental Treatment Systems approved for use in the County are listed below. Design requirements for Supplemental Treatment systems are provided in Chapter 6 of this Manual. a. Proprietary Treatment Units (manufactured or package units) b. Intermittent Sand Filters c. Recirculating Sand Filters d. Other Supplemental Treatment systems approved by the Department and the Regional Water Quality Control Board. 4. The types of subsurface dispersal Systems approved for use in the County are listed below. Design requirements for dispersal Systems are provided in Chapter 7 of this Manual. a. Gravity Distribution Conventional Trench Systems b. Gravity Distribution Shallow In-Ground Trench Systems c. Pressure Distribution Conventional Trench Systems d. Pressure Distribution Shallow In-Ground Trench Systems e. Pressure-dosed Sand Trench Systems f. Drip Dispersal systems g. At-Grade Systems h. Mound Systems i. Gravity Distribution Grid Conventional Trench Systems (repair or replacement Systems only) j. Gravity Distribution Deep Trench Systems (repair or replacement Systems only) k. Pressure Distribution Deep Trench Systems (repair or replacement Systems only) l. Raised Sand Filter Bed Systems (repair or replacement Systems only) m. Engineered Fill with Subsurface Drip Systems (repair or replacement Systems only) n. Other alternative dispersal systems approved by the Department and Regional Water Quality Control Board. 5. The types of non-discharging toilets approved for use in the County are listed below. Design requirements for non-discharging units are provided in Chapter 8 of this Manual. a. Vault toilet or privies b. Portable toilets c. Waterless toilets 6. The types of graywater systems approved for use in the County are specified in the Uniform Plumbing Code, California Code of Regulations, Title 24, Part 5, Chapter 16A, Part 1. General design requirements are specified in Chapter 8 of this Manual.

36 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 4.3 WASTEWATER DESIGN FLOW CRITERIA A. SINGLE FAMILY RESIDENCES AND SECONDARY UNITS 1. System sizing for residential dwellings shall be based on the maximum daily flow rate. 2. Wastewater flows used for design of Systems for single family residences and secondary units shall be based on a factor of one hundred and fifty (150) gallons per day (gal/day) per bedroom for the first three (3) bedrooms, plus seventy-five (75) gal/day for each additional bedroom, as indicated in Table The design flows for a primary residence and secondary dwelling unit shall be determined independently, regardless of whether the flows are treated separately or combined in a single System. B. MULTIUNIT RESIDENCES AND NON-RESIDENTIAL FACILITIES 1. System sizing shall be based on the maximum daily flow rate. 2. Wastewater flows used for the design of Systems for multiunit residences and nonresidential projects shall be developed based on full consideration of projected activities, occupancy, and facilities. 3. Table 4-2 provides guidelines for use in estimating design wastewater flows. 4. For facilities not listed in Table 4-2 the wastewater design flow shall be estimated based on either: (a) appropriate literature references (e.g., US EPA) for the type of facility proposed; or (b) documented wastewater flow monitoring data for a comparable facility. 5. The Department may consider adjustment to the criteria listed in Table 4-2 for specific facilities based upon documented wastewater flow monitoring data. 6. In all cases, the design proposal shall include sufficient technical information to support the proposed design flow estimate. 7. Notwithstanding the above, minimum design flow for any System shall not be less than one hundred and fifty (150) gpd. 8. Systems with wastewater flows in excess of one thousand five hundred (1,500) gallons per day will require an annual operating permit. 9. For some non-residential units where flow rate is questionable, an effluent flow meter may be required. C. WINE PROCESSING FACILITIES 1. Wastewater flows from wine processing facilities are based on such factors as annual wine production, duration of the harvest period and anticipated peak flow during the harvest period. 2. Sanitary flows from winery processing facilities shall be calculated using Table Winery process and sanitary wastewater flows must be calculated separately and collected in separate septic tanks. See chapter 12 for winery process waste facility sizing.

37 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 4.4 WASTEWATER STRENGTH DESIGN CRITERIA A. GENERAL 1. The System designer is responsible for ensuring that wastewater in each project is properly characterized. 2. Whenever possible, waste streams should be sampled and actual values used in the design. B. WASTEWATER TYPES 1. Blackwater a. Blackwater is defined as wastewater contaminated with human or kitchen wastes, generally originating from toilets and kitchen sinks. b. Blackwater includes, but is not limited to, wastewater discharges from kitchen sinks, garbage grinders, water closets, toilets, urinals or similar fixtures alone or in combination with other wastewater. 2. Graywater a. Graywater is defined as untreated wastewater that has not been contaminated by any toilet discharge, and has not been affected by infectious, contaminated, or unhealthy bodily wastes, and does not present a threat from contamination by unhealthful processing, manufacturing, or operating wastes (Health and Safety Code section ). b. Graywater includes but is not limited to Wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs. c. Graywater does not include wastewater from kitchen sinks or dishwashers. 3. Process Wastewater. Process wastewater is generated from any manufacturing, processing institution, commercial, or agricultural operation, or any operation that discharges other than sanitary wastewater. C. PRIMARY PARAMETERS USED TO EVALUATE THE QUALITY OF WASTEWATER 1. Biological Oxygen Demand (BOD). BOD measures oxygen required for biochemical degradation of organic and inorganic material. High BOD causes an increased biological demand on downstream System components and may shorten the life of the System. 2. Chemical Oxygen Demand (COD). COD measures the oxygen equivalent of the organic content of a sample. Samples from a specific source can be related to BOD. 3. Total Suspended Solids (TSS). TSS are a constituent of total solids. TSS is residue retained on a filter after drying the sample and is a measure of the level of treatment being achieved. TSS can be inorganic particles, which are difficult for biological processes to break down, resulting in mechanical clogging. In wastewater with high TSS, inorganics are less easily broken down and can accelerate mechanical clogging of the infiltrative surface of the dispersal system.

38 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 4. Fats, Oil and Grease (FOG). FOG measures biological lipids and mineral hydrocarbons. The analytical test for FOG does not measure an absolute quantity, but is useful in making comparisons of wastewater. High FOG results in a highly increased biological demand on downstream System components and may drastically shorten the life of the System. 5. Nitrogen. Nitrogen is of concern due to its impact on groundwater and surface water. Nitrogen can change form as it moves through a treatment system and into the receiving environment. Nitrogen acts as a potentially limiting nutrient for photosynthetic autotrophs in surface water and as a potential health risk in groundwater. The principal forms of nitrogen found in wastewater are organic nitrogen (Organic-N), ammonia nitrogen (NH 3- N), ammonium nitrogen (NH 4-N), nitrite nitrogen (NO 2-N), and nitrate nitrogen (NO 3-N). These forms of nitrogen are expressed either individually or as components of the following: a. Total Kjeldahl Nitrogen (TKN), which is the sum of (Organic-N) + (NH 3-N) b. Total Inorganic Nitrogen (TIN), which is the sum of (NH 3-N) + (NO 2-N) + (NO 3-N) c. Total Nitrogen (TN), which is the sum of (TKN) + (NO 2-N) + (NO 3-N) D. WASTEWATER STRENGTH 1. Domestic Strength Wastewater a. Domestic strength wastewater is defined as wastewater with a measured strength less than high-strength wastewater (see Table 4-3) and is defined as having a thirty (30) day average concentration of the following constituents prior to a septic tank or supplemental treatment component: i. BOD less than or equal to 300 milligrams per liter (mg/l); or ii. iii. iv. TSS less than or equal to 330 mg/l; or FOG less than or equal to 100 mg/l; or TN less than 75 mg/l. b. Domestic wastewater is normally discharged from, or similar to, that discharged from plumbing fixtures, appliances and other household devices including, but not limited to toilets, bathtubs, showers, laundry facilities, dishwashing facilities, and garbage disposals. c. Domestic wastewater may include wastewater from commercial buildings such as office buildings, retail stores, and some restaurants or from industrial facilities where the domestic wastewater is segregated from the industrial wastewater. d. Domestic wastewater may include incidental recreational vehicle (RV) holding tank dumping but does not include wastewater consisting of a significant portion of RV holding tank wastewater such as at RV dump stations. e. Domestic wastewater does not include wastewater from industrial processes.

39 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 2. High Strength Wastewater a. High strength wastewater is defined as wastewater with a measure strength greater than domestic wastewater (see Table 4-3) and is defined as having a thirty (30) day average concentration of the following constituents prior to the septic tank or a supplemental treatment component: i. BOD greater than 300 milligrams per liter (mg/l); or ii. iii. iv. TSS greater than 330 mg/l; or FOG greater than 100 mg/l; or TN greater than 75 mg/l. b. High strength wastewater shall receive supplemental treatment to lower the waste strength to the level commonly found in domestic residential septic tank effluent before discharge into the dispersal field. 3. High Strength Commercial Facility Wastewater. Wastewater from commercial facilities can be classified into five (5) general categories as described below. Wastewater characteristics for each of the categories are provided in Table 4-4 and are based on the type of business or facility, waste streams and usage characteristics. a. Type 1 Wastewater. Type 1 Wastewater is associated with wastewater generated from businesses or facilities such as apartments, condominiums, mobile home parks, residential subdivisions and work camps. i. Waste streams are domestic (blend of black and grey waters) in nature. ii. iii. iv. Contributions come from both black and grey wastewater sources. Some facilities have flow contributions that bias them toward another application type (e.g., communities serving primarily commercial core areas with minimal residential connections, or work camps with commercial kitchens serving meals for workers from other camps). Primary-treated (septic tank) effluent characteristics for BOD 5, TSS, and TKN are listed in Table 4-4. b. Type 2 Wastewater. Type 2 Wastewater is associated with wastewater generated from businesses or facilities such as airports, campgrounds, fire departments, golf courses, manufacturing facilities, offices, parks, public toilets/rest areas, RV parks, and visitor centers. i. Waste streams are commercial in nature; ii. iii. Contributions come from primarily black wastewater sources; Some facilities have flow contributions that bias them toward another application type (e.g., facilities with restaurants or RV parks or campgrounds with flow contributions from dump stations exceeding twenty (20) percent of the daily flow).

40 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS iv. Primary-treated (septic tank) effluent characteristics for BOD 5, TSS, and TKN are listed in Table 4-4. c. Type 3 Wastewater. Type 3 Wastewater is associated with wastewater generated from businesses or facilities such as churches and schools. i. Waste streams are commercial in nature and primarily from black wastewater sources. ii. iii. iv. Flows and primary treated effluent quality are heavily dependent on the facilities (e.g., schools with cafeterias and shower facilities vary significantly from those without). Due to variations in daily waste volumes, flow equalization tankage should be strongly considered in order to optimize the treatment process and reduce the dispersal field area. Primary-treated (septic tank) effluent characteristics for BOD 5, TSS, and TKN are listed in Table 4-4. d. Type 4 Wastewater. Type 4 Wastewater is associated with wastewater generated from businesses or facilities such as hospitals, retirement facilities and veterinary clinics. i. Waste streams are commercial in nature and primarily from black wastewater sources. ii. iii. iv. Antibiotics and other pharmaceutical products in the waste stream may impair microorganism health in the primary tank and advanced treatment units. The System designer shall note on the plan set and in the operations manual that the wastewater treatment system can be negatively affected by the introduction of these substances and care should be taken to limit their discharge. Primary-treated (septic tank) effluent characteristics for BOD 5, TSS, and TKN are listed in Table 4-4. e. Type 5 Wastewater. Type 5 Wastewater is associated with wastewater generated from businesses or facilities such as bars, casinos, delis, gas stations, hotels/motels, restaurants, resorts, shopping centers and strip malls. i. Waste streams are commercial in nature. ii. iii. iv. Contributions range from primarily black water with some kitchen sources to primarily kitchen sources with some black wastewater. Raw wastewater has significant oil and grease contributions. Careful evaluation is required to properly size advanced treatment units.

41 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS v. Waste strength varies significantly depending on the hours of business, menu, take-out versus dine-in eating, dining seat turnover rate, catering and event hosting activities, etc. vi. vii. viii. ix. Restaurants and applications with greater than a 50% flow contribution form restaurants and BOD 5 values greater than 800 mg/l may require the use of pre-aeration and clarification. Grease tanks must be sized to ensure that the maximum O&G contribution to the secondary treatment system does not exceed manufacturer s recommendations. Kitchen dishwashing appliances used in conjunction with secondary treatment systems may need to be high-temperature appliances. For existing systems with low-temperature, chemical-type appliances, preaeration may be necessary. x. Primary-treated (septic tank) effluent characteristics for BOD 5, TSS, and TKN are listed in Table High Strength Process Wastewater High Strength Process Wastewater is associated with wastewater generated from businesses and facilities such as wineries, breweries, dairies, food processing facilities, and slaughterhouses. a. Process wastewater consists of complex waste streams requiring careful evaluation. b. Chemical cleaning processes used in facilities that produce high-strength process waste must be evaluated to ensure they are compatible with secondary treatment systems. c. Additional treatment processes, such as pre-aeration, clarification and bioaugmentation (the addition of necessary nutrient required to speed up the rate of degradation of a contaminant) are often necessary in addition to the secondary treatment system.

42 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 4.5 WASTEWATER APPLICATION RATES A. GENERAL 1. Subsurface Dispersal Systems shall be sized based on wastewater application rates that are representative of the soil classification and percolation rates for the soil zone corresponding to the sidewall and bottom of the dispersal system. B. WASTEWATER APPLICATION RATES BASED ON PERCOLATION RATE 1. The maximum soil application rate for conventional gravity trench dispersal fields in Standard Systems shall be in accordance with the criteria in Table The maximum soil application rate for At-Grade Dispersal Systems shall be in accordance with the criteria in Table 4-6. Soil with average percolation rates greater than sixty (60) mpi shall utilize supplemental treatment. 3. Increased (or enhanced) maximum soil application rates may be utilized for Advanced Systems with supplemental treatment due to the reduction in Biological Oxygen Demand (BOD) in the treated effluent. a. Enhanced wastewater application rates for Pressure Distribution Trench Systems, Pressure-dosed Sand Trench Systems, Mound Systems, and Raised Sand Filter Beds are provided in Table 4-7. b. Enhanced wastewater application rates for Drip Dispersal Systems are provided in Table 4-8. C. SOIL PERCOLATION RATES BASED ON SOIL CLASSIFICATION 1. The stabilized percolation rates shall be compared to the United States Department of Agriculture (USDA) soil texture classification provided in Table The System designer shall resolve discrepancies in the application rates derived based on the soil classification and the percolation rates and collect additional field data if necessary.

43 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 4.6 SYSTEM SITING CRITERIA A. MINIMUM HORIZONTAL SETBACK DISTANCES FROM SITE FEATURES TO SYSTEM COMPONENTS 1. The System design and installation shall meet the minimum horizontal setback distances provided in Table 4-10 and depicted on Figure Incorporated cities may also have their own requirements for setbacks that are not included in this manual. Applicants are encouraged to check with the local jurisdiction Planning and Building Departments. B. DUAL DISPERSAL SYSTEM REQUIREMENT 1. Standard Systems. A primary and a secondary dispersal system shall each be designed to accept one hundred (100) percent of the peak daily design flow. Both primary and secondary systems shall be installed, and shall be equipped with an approved (manual) diversion device to allow alternating use of the two systems, typically switching between systems every 6 to 12 months. 2. Alternative Systems. A replacement area with suitable site conditions for a new System installation shall be identified and preserved for future use. The replacement area must be: a. Equal to one hundred (100) percent of the size required for the primary (installed) System, with the exception of commercial systems which shall have a two hundred (200) percent replacement area identified and preserved for future use. b. Totally separate from the primary System area; c. Able to meet all current design requirements for the type of replacement System proposed; and d. Fully protected to prevent damage to Soil and any adverse impact on the immediate surrounding that may affect the installation of the Replacement System and its function. C. MINIMUM VERTICAL SEPARATION DISTANCES & EFFFECTIVE SOIL DEPTH FOR DISPERSAL AREA 1. Dispersal systems shall be designed to meet the minimum effective soil depth and vertical separation distances from high seasonal groundwater or limiting layer such as impermeable soil or bedrock. 2. The vertical separation and effective soil depth requirements depend on the soil characteristics and groundwater observations as discussed in Chapter 3.

44 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 3. Where alternative Systems are utilized, the minimum effective soil depth and the vertical separation to groundwater distance may be reduced from the requirements that apply to Standard Systems. 4. Minimum vertical separation distances to groundwater and minimum effective soil depth requirements for Standard and Alternative System configurations approved for use in the County are provided in Table 3-1. D. DISPERSAL AREA SLOPE REQUIREMENTS 1. Dispersal systems shall be designed to comply with the maximum slope requirements allowable for the specific type of System. 2. Maximum ground slope for Standard and Alternative System configurations approved for use in the County are provided in Table Geotechnical/geological investigations shall be required in accordance with the requirements of chapter 4 of this manual and chapter of the Alameda County General Ordinance in any of the following circumstances: a. Dispersal systems on sites with slopes greater than thirty (30) percent; b. When the System is located within an earthquake fault zone or a seismic hazard zone, as delineated on the official maps published for that purpose by the California Geologic Survey, or when such hazards are otherwise known or suspected in the location of the System; or c. When grading includes a cut or fill exceeding five (5) feet in depth at any point and the slope of the natural ground within thirty (30) feet of the cut or fill exceeds the (10) percent. E. FLOODPLAINS AND FLOODWAYS 1. Setbacks from floodplains and floodways as designated on the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) shall be in accordance with the provisions of Chapter and Chapter of the Alameda County General Ordinance Code in order to prevent damage to System components by associated flood events. 2. All new and replacement Systems located in areas subject to flooding, shall include design features to prevent infiltration of flood waters into the System or discharge from the System into flood waters. The analysis and design features must include: a. Protecting System components from flood damage using structural tie-downs and/or elevating critical components above the one hundred (100) year flood level; and b. Preventing discharge of wastewater into flooded dispersal areas from pump systems (e.g., using flood-activated float switches to override/disable pump operation during high water conditions); and c. Providing additional emergency storage capacity for flood periods.

45 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS F. UPPER ALAMEDA CREEK WATERSHED ABOVE NILES 1. Additional siting requirements apply to new, upgraded, or replacement Systems located in the Upper Alameda Creek Watershed above Niles in accordance with Zone 7 Water Agency s 2015 Nutrient Management Plan for the Livermore Valley Groundwater Basin, issued by Zone 7 in February 2015 and adopted by the San Francisco Bay Regional Water Board in March The Nutrient Management Plan identifies designated areas of concern within the Upper Alameda Creek Watershed above Niles. a. Happy Valley, Pleasanton b. Buena Vista, Livermore c. Mines Road, Livermore d. May School, Livermore e. Greenville, Livermore 3. The additional requirements do not apply to existing, properly-working and properly-sized Systems. 4. The additional requirements are dependent on the total size of the parcel and whether the Lot is located inside or outside of the limits of five designated Areas of Concern (see Figure 4-4) and include: a. Outside Areas of Concern. Minimization of nitrogen loading from new systems by applying one rural residential equivalence of wastewater (RRE) per five (5) acre maximum provisions. b. Inside Areas of Concern. i. Minimization of nitrogen loading from new systems by applying one (1) RRE per ten (10) acre maximum provisions and requiring Alternative Systems with nitrogenreducing treatment for new, upgraded, or replacement Systems; or ii. Preparation of a hydrogeological study that assesses exisitng groundwater nitrate conditions beneath the site and demonstrates that nitrate concentration of total System recharge does not exceed 36 mg/l (80 percent of the maximum contaminant concentration for drinking water) or the maximum concentration at the site, whichever is lower. c. High Strength and High Flow Systems. Installation of groundwater monitoring wells to monitor nutrient loading from onsite operations.

46 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 4.7 SYSTEM DESIGN SUBMITTAL REQUIREMENTS A. SYSTEM DESIGN PLANS 1. The System design plans shall include sheets with legible and scaled plan views, cross sections, and details sufficient to allow: a. Review by Department staff for compliance with the requirements of the Ordinance and this manual. b. System installation. 2. The design plans shall include the signature and wet stamp of the System designer and shall provide the name of the qualified professional who prepared the topographic base map and the date of the survey. 3. The design plans shall show the layout of all System components including reserve areas on a Topographic Base Map prepared in accordance with the requirements of Chapter 3 of this Manual. The topographic base map shall include all information obtained from the Site Evaluation and sufficient spot elevation data to confirm the siting and hydraulic design of the System. 4. The design plans shall be dimensioned to show at a minimum all requisite setback designations to System components, slope designations in the vicinity of System components (percent and arrows for direction), and surface water flow direction (arrows). 5. The design plans shall include cross sections in the vicinity of the System components showing at a minimum: a. Elevations of building sewers as they exit buildings or structures connected to the System to demonstrate adequate fall to the septic tank or other appurtenance; b. Tank depths and slope of original grade and proposed grading (if applicable) to prevent storm water infiltration; c. Effluent piping from the tank to the dispersal system; d. Dispersal system components and vertical separation to groundwater and effective soil depths relative to the bottom of the dispersal system; e. Effluent pipe crossings with site utilities to verify minimum vertical setback requirements; f. Surface water diversion structures; g. Curtain drains; h. Storm water infiltration galleries; and i. Other pertinent features that could affect System installation and performance.

47 CHAPTER 4 GENERAL SYSTEM DESIGN CRITERIA & DESIGN SUBMITTAL REQUIREMENTS 6. The design plans shall include: a. All relevant elevation data and hydraulic calculations; b. Make and model of all components; c. Pump system components, float settings, and dosing calculations; d. Control panel programming; e. Erosion control plan; f. Specific step-by-step construction guidelines and notes for use by the installation Contractor; and g. An inspection schedule listing critical control points. 7. The plans submitted with the System design documents must be identical or incorporated into the plans submitted to the authority issuing a building permit. B. SYSTEM BASIS OF DESIGN REPORT 1. The system design plans shall be accompanied by a bound design report documenting the basis of the System design. The design report shall include but not be limited to the following: a. Legible field data sheets documenting the results of the soil profile and percolation tests; b. Manufacturer spec sheets for all system components; c. Hydraulic calculation sheets; d. Other pertinent data required to support the System design. 2. Reports documenting geotechnical evaluations, cumulative impact assessments, hydrogeological studies, or other evaluations shall be appended to the Basis of Design Report. C. OPERATIONS, MAINTENANCE AND MONITORING PLAN 1. An Operations, Maintenance & Monitoring Plan (OM&M Plan) shall be submitted with the System design plans and the Basis of Design Report. 2. The OM&M Plan shall include requisite maintenance, monitoring and reporting activities for the System per the requirements of chapter 14 of this manual and any manufacturer recommendations. 3. The OM&M Plan shall be revised following System installation to include an As-built Plan of the System and updated information to documenting changes to the Department approved design during System installation.

48 5.1 SECTION OVERVIEW CHAPTER 5 TANKS - DESIGN CRITERIA The guidelines presented in this chapter provide general design guidelines for the different types of tanks that may be utilized as part of the treatment train prior to effluent dispersal into a Supplemental Treatment System or the Dispersal System. Onsite wastewater treatment systems employ various buried and/or above ground tanks such as septic, flow equalization, grease interceptor, holding, pump and dosing tanks. The chapter is organized in the following sections: Section 5.2: General Performance Requirements Section 5.3: Septic Tank Design Criteria Section 5.4: Flow Equalization Tank Design Criteria Section 5.5: Grease Interceptor Tank Design Criteria Section 5.6: Holding Tank Design Criteria Section 5.7: Pump and Dosing Tank Design Criteria Section 5.8: Tank Installation and Destruction/Removal Requirements

49 CHAPTER 5 TANKS - DESIGN CRITERIA 5.2 GENERAL PERFORMANCE REQUIREMENTS A. APPROVED TANKS 1. All tanks in the treatment train (e.g., septic, flow equalization, pump, dosing, grease interceptor, treatment tanks) must have a current International Association of Plumbing and Mechanical Officials (IAPMO) or an American National Standards Institute (ANSI) accredited testing organization approval listing. 2. An exception to IAPMO or ANSI approval listing may be granted where structural design calculations for the septic tank are provided by a California Registered Civil Engineer. 3. Each tank shall be permanently marked on the uppermost surface with the manufacturer s name and/or trademark, and the nominal working volume. 4. Permanent markings shall be adequately protected from corrosion so as to remain permanent and readable over the life of the tank. The product shall also bear the Uniform Plumbing Code certification mark (UPC ). 5. Heavy cement-based sealants are approved for sealing concrete tanks and may be required. B. MATERIALS 1. Tanks shall be constructed of reinforced concrete, heavyweight reinforced concrete blocks, fiberglass or other durable, non-corrodible materials as approved by the Department. 2. Wood and metal tanks are prohibited. 3. Tanks shall be monolithic or if not, tank seams shall be located above the effluent level. C. WATERTIGHT 1. Prevention of Infiltration and Exfiltration. Tanks shall be watertight while installed and operating to prevent infiltration (or inflow) of groundwater and storm water and exfiltration (or outflow) of wastewater. a. Inflow of Groundwater or Storm Water. Systems are designed to return a predetermined volume and quality of wastewater to the environment. A tank allowing inflow of groundwater or surface water into the System can overwhelm the capacity of the downstream System components and lead to hydraulic overload of the System and/or inadequate wastewater treatment. Surges of inflow can also displace solids from the tank adversely affecting the operation and operating life expectancy of downstream System components. b. Outflow of Wastewater. Leaking tanks can create a public health hazard and contaminant surface water and groundwater due to bypassing the downstream components of the Treatment Train.

50 CHAPTER 5 TANKS - DESIGN CRITERIA 2. New Tank Test Procedures. Watertight testing for new tanks shall be done in accordance with the following procedures: a. Tanks, inlet and outlet connections, risers and riser covers shall be completely watertight. b. Watertight tests shall be conducted under the oversight of the System Designer. A watertight test certification form shall be submitted by the System Designer prior to the Department granting final approval of the System. c. The watertight test shall be performed after tank installation is complete including connecting inlet and outlet piping (with caps) and installing risers (if applicable). d. Whenever possible, risers shall be installed as one continuous piece. e. Backfill may or may not be in place depending on whether the backfill is integral to the structural design of the tank. f. The tank shall be filled with water to two (2) inches above the highest connecting inlet or outlet piping or the tank and riser connection (if installed). If multiple riser connections or concrete grade rings are used, water shall be added to two (2) inches above the highest riser connection. The level of the water in the tank or riser shall be marked and after a predetermined test time applicable to the material or assembly, the water level in the tank (or riser) shall be checked and a visual inspection shall be made on the outside of the tank for leakage (if possible). If no visual evidence of leaking is observed and water is at mark the tank shall be considered watertight. i. Fiberglass or Plastic Tanks. If there is no measurable loss of water for one (1) hour and no visual signs of leakage, the tank is considered watertight. ii. Concrete Tanks. Concrete tanks shall be left for twenty-four (24) hours after filling the tank to allow for a period of time for natural absorption into the material prior to beginning the watertight test. After twenty-four (24) hours the tank(s) shall be refilled to two (2) inches above the piping or riser connection). If there is no measurable loss after one (1) hour and no visual signs of leakage, the tank is considered watertight. g. If the bedding under the tank is uneven or has rocks protruding, the tank may crack causing failure of the test. 3. Existing Tank Test Procedures. In watertight testing for existing tanks undergoing modifications or repairs, the tank shall be pumped by a licensed septic pumper to remove its contents prior to conducting the test (as described in item 2 above). 4. Repairs. Repairs can be made to tanks failing the watertight test provided the structural integrity has not been compromised.

51 D. STRUCTURALLY SOUND CHAPTER 5 TANKS - DESIGN CRITERIA 1. Tanks shall be designed to be structurally sound to withstand the live and dead loads experienced at the site to prevent cracking or collapse. 2. The potential impacts due to structurally unsound tanks include safety of people in the area of the tank, the operation of the treatment system and the formation of cracks or other openings that cause leaks. 3. Tanks shall be designed and certified by a Professional Engineer, licensed and qualified to perform structural design. 4. Tank selection shall be based on all reasonably expected loading conditions, including burial depth, hydrostatic forces when tank is full or empty, and any other reasonable expected loading conditions. E. TANK ACCESS 1. Access to tanks shall be designed to allow maintenance and prevent injury or death caused to a human or animal due to unintended entry into the System. 2. Access at ground level or above shall be provided for all tanks and/or components contained therein. 3. Access to each compartment of a tank for maintenance shall be provided by a minimum twenty (20) inch diameter opening or equivalent. 4. Tanks shall be installed so that manhole covers are within twenty-four (24) inches of the ground surface. 5. Access shall be secured by bolting or locking lids or by lids that weigh a minimum of 59 pounds (ASTM C 1227, 7.6.1) and are set to prevent sliding. Covers, risers and lids shall be capable of bearing the expected live and dead loads. Potential loads could include people, lawn equipment, or vehicles. 6. Access openings shall be located to provide visual inspection, maintenance and/or repair of sanitary tees, effluent filters, baffles, and pump assemblies. 7. Tanks with influent compartments twelve (12) feet in length or greater shall have an additional access opening located over the baffle. F. TANK RISERS 1. All access openings on tanks shall have risers extended a minimum of two (2) inches above the finished grade. 2. Except for concrete grade rings, risers shall be installed in one continuous piece without seams. 3. All traffic rated tanks shall have traffic rated risers and lids installed flush with the finished grade.

52 CHAPTER 5 TANKS - DESIGN CRITERIA 4. All risers shall be securely attached by means of a watertight collar and/or other sealant material applied according to the manufacturer s instructions. 5. All risers shall be fitted with gastight, watertight, vermin proof, securely fastened covers that are removable with standard hand tools. 6. All covers shall be of durable construction, manufactured specifically for their intended use. G. TANK CONNECTIONS 1. All connections from buildings and structures to tanks shall conform to construction standards as required by the local building official. 2. A cleanout at finished grade shall be provided between each structure and/or building directly connected to a tank. H. HORIZONTAL SETBACKS All tanks shall meet the horizontal setbacks for septic tanks provided in Table 4-10.

53 CHAPTER 5 TANKS - DESIGN CRITERIA 5.3 SEPTIC TANK DESIGN CRITERIA B. GENERAL 1. The primary purpose of the septic tank is to clarify the wastewater (i.e., separate constituents that float and sink from the other wastewater constituents). 2. A second benefit of the septic tank is that decomposition of organic material begins in the septic tank. Raw waste is reduced to sludge, scum, gases, and effluent with the aid of beneficial microbes that reduce the organic material without outside energy sources. 3. The septic tank is extremely beneficial at a nominal cost when compared to the overall System cost. 4. The operating environment of most septic tanks is: buried below ground, in or above ground water, empty or full of sewage. 5. The septic tank system consists of the tank, riser(s) and inlet/outlet ports (see Figure 5-1). C. MINIMUM CAPACITY 1. Adequate septic tankage will anaerobically digest organic material, remove settleable and floatable solids, help modulate flow, and consistently discharge effluent that meets the primary treatment standards. 2. The minimum capacity of septic tanks for residential Systems shall be determined by the number of bedrooms in the dwelling as follows: No. of Bedrooms Minimum Septic Tank Capacity (gallons) 1 to 2 1,000 3 to 4 1,200 5 to 6 1,500 7 to 8 2,000 9 to 10 2, The minimum capacity of septic tanks for non-residential systems with Type 1 residential quality waste (see Chapter 4) shall be one thousand two hundred (1,200) gallons or two (2) times the peak daily wastewater flow for the facility served, whichever is greater. Larger tankage is required for Type 2 through Type 5 waste for optimal System performance. Recommended guidelines for minimum and preferred tank sizing for certain facility types is provided in Table 5-1. B. SEPTIC TANK COMPARTMENTS 1. Septic tanks shall have a minimum of two (2) compartments. 2. The inlet compartment shall be a minimum of two-thirds (2/3) of the total liquid capacity of the tank.

54 CHAPTER 5 TANKS - DESIGN CRITERIA 3. Septic tank compartments shall be separated by a baffle that is permanently affixed, constructed of a solid durable material, and extends a minimum of four (4) inches above the working liquid level. 4. The septic tank baffle shall provide an air vent that connects the two compartments above the working liquid level. 5. A baffle fitting specified by the septic tank manufacturer to prevent the transfer of solids from the first compartment to the second, shall be in place. 6. Single compartment septic tanks may be used in series for high flow systems that incorporate multiple tanks. C. INLETS, OUTLETS AND SANITARY TEES 1. The invert of the inlet of all septic tanks shall be a minimum of two (2) inches higher than the invert of the outlet. 2. In no case shall the inlet and outlet openings be less in diameter than the connecting influent and effluent lines. 3. All inlets of septic tanks shall be fitted with sanitary tees which have an internal diameter equivalent to the inlet piping. 4. The upper end of inlet sanitary tees shall extend a minimum of four (4) inches above the working liquid level and a minimum of two (2) inches below the soffit of the tank top. 5. The lower end of all sanitary tees shall extend a minimum of twelve (12) inches below the working liquid level. 6. For multiple septic tanks in series, outlet sanitary tees may be used in lieu of an effluent filter except for the last septic tank where an effluent filter is required. D. EFFLUENT FILTERS 1. Effluent discharged from a new septic tank(s) directly to a dispersal area or dosing tank must pass through an effluent filter sized based upon the type of facility (residential or commercial) and the estimated peak daily flow. 2. The outlet of the septic tank shall be fitted with an effluent filter capable of screening solids in excess of three-sixteenths (3/16) of an inch in diameter and conforming to NSF/ANSI Standard 46 or as otherwise approved by the Department. 3. All effluent filters shall be located in the outlet compartment of the septic tank, and shall be easily inspected, cleaned and maintained. 4. For multiple tank configurations, only the last septic tank shall be required to be equipped with an effluent filter. 5. All effluent filters shall be appropriately sized, manufactured for their specific use.

55 CHAPTER 5 TANKS - DESIGN CRITERIA 5.4 FLOW EQUALIZATION TANK DESIGN CRITERIA A. GENERAL 1. Flow Equalization is the process of controlling the rate of Wastewater flow through a System by providing surge capacity storage and timed-dosing of the incoming flow. 2. Flow Equalization may be used for non-residential and mixed use facilities that experience significant, regular and predictable fluctuations in Wastewater flows. 3. Examples of applicable facilities include, but are not limited to churches, schools, and special-event venues. 4. Flow Equalization Tanks are installed following the Septic Tank to aid in better System performance by allowing peak surges in Wastewater flow (e.g., from a weekend event) to be temporarily stored and metered into the Supplemental Treatment System and/or Dispersal Field at a relatively even ( average ) rate over an extended number of days (e.g., during the subsequent week). B. FLOW EQUALIZATION REQUIREMENTS 1. Where Flow Equalization is proposed to be incorporated in a System, the following shall apply: a. The Septic Tank capacity shall be sized based on the peak daily flow for the facility; b. The Design Flow used for sizing Supplemental Treatment unit(s) and/or the Dispersal Field may be based on the equalized ( average ) flow rate rather than the peak daily flow rate for the facility; c. Design calculations and specifications must be submitted to substantiate the proposed design and operation of the Flow Equalization System; and 2. Depending on the size and complexity of the System, an Operating Permit may be required.

56 CHAPTER 5 TANKS - DESIGN CRITERIA 5.5 GREASE INTERCEPTOR TANK DESIGN CRITERIA A. GENERAL 1. Grease interceptors are required at all facilities connected to an onsite wastewater treatment system that generate more than two hundred (200) gallons per day of wastewater and provide foodservice and/or food preparation producing wastewater containing floatable oil, wax, fats, or grease. B. EXEMPTIONS 1. A food facility or other commercial operation that demonstrates that the discharge of grease, floatable oil, wax or fats is less than one hundred (100) milligrams per liter (mg/l) may be exempt from the minimum grease interceptor sizing, installation or maintenance requirements of this Chapter. 2. Sampling and testing, if required by the Department, shall be performed at the owner s expense and by and independent certified testing organization using accepted testing methods. 3. An under counter type grease trap may be used in lieu of a grease interceptor if justifiable based on the proposed food facility menu. C. PLUMBING FIXTURE CONNECTIONS 1. Wastewater from plumbing fixtures where floatable oil, wax, fats or a grease may be introduced shall be plumbed separately from other plumbing fixtures into the grease trap/interceptor first and then into the septic tank. 2. The following plumbing fixtures shall be connected to a grease interceptor: a. Dishwashers (kitchen dishwashing appliances should be high-temperature disinfection models only; low temperature chemical disinfection dishwashers are not recommended); b. Three-compartment sinks; c. Floor sinks; d. Mop sinks; e. Other fixtures as determined by the Department. 3. Garbage disposals are prohibited for commercial establishments. 4. Plans and specifications for the plumbing system shall be submitted to the Department.

57 CHAPTER 5 TANKS - DESIGN CRITERIA D. MINIMUM CAPACITY 1. Grease interceptors shall be sized according to the following formula: Required Grease Interceptor Capacity (gallons) = P * WF * RT * SF Where, P = Peak number of meals per hour WF = Design wastewater flow rate (from Table 4-2) RT = Retention Time RT = 1.5 (for single-service/disposable utensils) RT = 2.5 (for multi-service utensils) SF = Storage Factor (minimum capacity of 750 gallons) SF = 1 (for hours of operation 8 hours) SF = 2 (for hours of operation between 9 and 16 hours) SF = 3 (for hours of operation between 17 and 24 hours) 2. The minimum capacity of the grease interceptor shall be eight hundred and ten (810) gallons. Larger tankage is required for optimal System performance. Recommended guidelines for minimum and preferred tank sizing for certain facility types is provided in Table An interior grease trap/interceptor meeting the requirements of Chapter of the Alameda County General Ordinance may be approved at the discretion of the Department. E. MAINTENANCE 1. Grease interceptors shall be located, installed and constructed so that the temperature of wastewater will be reduced to allow separation of grease and to allow easy access for cleaning. 2. Grease interceptors shall be cleaned regularly by licensed septage and/or grease- pumping companies permitted by the Department so as to ensure efficient operation. 3. Written receipts of all grease interceptor and grease trap pumping and maintenance events shall be included in annual operating permit reports submitted to the Department. The receipts shall indicate the following: a. Name and address of the company performing the work; b. Date the work was performed; and c. Volume of grease removed

58 CHAPTER 5 TANKS - DESIGN CRITERIA 5.6 HOLDING TANK DESIGN CRITERIA A. GENERAL 1. A holding tank is a watertight container designed to receive and store wastewater for disposal at another location. B. RESIDENTIAL DWELLINGS 1. Holding tanks for lots for existing residential dwellings may be permitted under the following conditions: a. The site cannot be approved for the installation of a replacement system due to severe site constraints; and b. No public sewer system is legally and physically available. c. The owner of the property shall record a deed restriction agreeing to be served by public sewer system if at any time a connection becomes legally available within two hundred (200) feet of the dwelling property. d. No dwelling shall be served by more than one (1) holding tank. e. A single parcel or lot of record may be served by no more than one (1) holding tank. f. Holding tanks shall not be used for accommodating home expansions or additions. g. Holding tanks shall not be used as a method for wastewater disposal for creating lots and parcels. C. NON-RESIDENTIAL FACILITIES Holding tanks may be permitted for industrial, commercial, or recreational facilities where installation of an onsite wastewater treatment system for sanitary or process wastewater is not feasible or allowed. D. DESIGN REQUIRMENTS 1. The holding tank and piping shall be designed by a Qualified Professional. 2. The holding tank and piping shall be structurally sound and water tight. 3. The holding tank shall have a minimum liquid capacity of fifteen hundred (1,500) gallons and shall be sized to accommodate two hundred (200) percent of the estimated flow between anticipated pumping events: Holding Tank Capacity (gallons) = 2 * (Daily Peak Design Wastewater Flow, GPD) * (#Days between Pumping Events)

59 CHAPTER 5 TANKS - DESIGN CRITERIA 4. The tank shall be located and designed to facilitate visual inspection and removal of contents by pumping. 5. The tank shall be equipped with both an audible and visual alarm, placed in a location acceptable to Department to indicate when the tank is seventy-five (75) percent full. Only the audible alarm may be user cancelable. 6. The tank shall have no overflow vent at an elevation lower than the overflow level of the lowest fixture served. E. PERMIT REQUIRMENTS 1. An operating permit shall be required prior to issuance of the final approval of the installation permit. 2. The Owner shall provide the Department with: a. A copy of a contract with a licensed septage pumper (with a current County operating permit) that shows the tank shall be pumped at regular intervals or as needed to prevent use of greater than seventy-five (75) percent of the tank's capacity. b. A record of pumping dates and amounts pumped that shall be maintained by the property owner and included in the annual operating report and made available to the Department upon request.

60 CHAPTER 5 TANKS - DESIGN CRITERIA 5.7 PUMPING & DOSING TANK DESIGN CRITERIA A. WASTEWATER PUMPING SYSTEMS 1. Wastewater pumping systems may be considered when they offer a better alternative for the protection of public health and safety or are required for parcel development. Due to the problems inherent in mechanical devices, effluent pumps shall be considered only after gravity feed options have been explored and shown to be infeasible. 2. Wastewater pumping systems shall be utilized to enable: a. Installation of a dispersal system hydraulically upgradient of the structure to be served; b. Pressure dosing of effluent to the dispersal system; and/or c. Transporting of wastewater or solids from a sump tank serving non-dwelling units to a septic tank. 3. All wastewater pumping systems shall be separate from the septic tank. 4. Any effluent pumping system transporting wastewater or solids to a septic tank shall have its own penetration into the septic tank with a three (3) inch minimum diameter sanitary tee. The pressure line from the dosing/pump tank shall be connected to a minimum three (3) inch diameter pipe at least ten (10) feet before entering the septic tank in order to prevent effluent entering the septic tank under pressure that could cause turbulence in the septic tank. B. DOSING TANK SIZING REQUIREMENTS 1. The minimum dosing tank size shall have sufficient capacity to hold the following volumes: a. Dosing volume and the displacement volume of the pump required to deliver the design dose. b. Emergency reserve storage volume in case of a power outage equal to one (1) day s peak wastewater design flow between the high level alarm and the invert of the tank inlet. 2. In lieu of providing reserve storage capacity equal to one day s peak flow, a dual pump system may be installed where the alternate pump become operational automatically if the primary pump fails. Dual pump systems may be required for commercial Systems. C. SUMP TANK SIZING REQUIREMENTS The minimum capacity of sump tank installed to serve non-dwelling units (e.g., bathrooms in barns or garages) shall have a minimum capacity of seventy (70) gallons. D. EFFLUENT PUMPS REQUIREMENTS 1. The pump system shall be designed by a Qualified Professional. 2. The pump shall be rated for wastewater applications.

61 CHAPTER 5 TANKS - DESIGN CRITERIA 3. Motors shall be continuous-duty with overload protection. 4. Pumps shall have durable impellers of bronze, cast iron, or other materials approved by the Department. 5. Pumps installed in sump tanks serving non-dwelling units (e.g., bathrooms in barns, garages, etc.) shall be rated as a solids handling pump and shall be able to pass two (2) inch solids. 6. The pump shall be sized to meet the hydraulic design requirements of the System and shall be able to provide the required gallons per minute (gpm) at the design head. 7. Pumps shall be automatically controlled with mechanical switches (or floats) that are compatible with the specified pump and control panel. 8. All pumps shall be equipped with a high level alarm float. Setting the off float arbitrarily low to maximize emergency storage capacity is discouraged. The off float shall not be set as to expose any portion of the pump. 9. Float switches shall be installed such that the float switches or wires do not become entangled. Clamps shall be of non-corrosive material. 10. Pumps shall be provided with an easy, readily accessible means of electrical and plumbing disconnect, and a noncorrosive lifting device as a means of removal for servicing. 11. A check valve shall be required at the pump. 12. The pump shall be seated on a level and stable platform of poured concrete or cement block or placed in suspended pump assemblies. 13. The pump or suspended pump assembly shall be installed in accordance with the manufacturer s requirements and shall be located no less than four (4) inches above the tank bottom. 14. There shall be sufficient distance from the tank bottom to the pump inlet to allow space for any solids to settle without interfering with the pump operation. 15. The pump intake port shall be placed in the clear liquid zone. 16. The minimum liquid level shall be set no lower than what is necessary to provide the minimum required emergency storage volume plus the dosing volume. 17. Dosing tanks and pump systems shall be selected to optimize the use of the tank volume during operation and not compress the clear liquid level. The minim liquid level shall be kept as high as practical to minimize the exposed interior surface of the tank to corrosive gases and stress from exterior hydrostatic and earth pressures. 18. The pump discharge rate shall not exceed a rate that causes the pump to stir the liquid or solids in the tank.

62 E. CONTROLS AND ALARMS CHAPTER 5 TANKS - DESIGN CRITERIA 1. All pumps shall be connected to, and operated from, control panel assemblies manufactured specifically for their intended use. 2. Electrical components used in systems shall comply with the Chapter (Electrical Code) of the Alameda County General Ordinance all applicable local Building code. 3. Pump controls and alarms shall be contained in an exterior rated, water proof, non- corrosive, tamper proof control panel box that can be opened with standard hand tools. Control panels in areas accessible to the public shall be locked to prevent unauthorized access. 4. Control panels shall be equipped with a visible and audible alarm and located in accordance with the following provisions: a. The control panel shall be easily accessible for service and inspection. b. The control panel shall not be located in an environment that may damage the components. c. The control panel shall be mounted no more than fifty (50) feet away from the residence served by the System or the common area of a commercial building. d. In cases where there are multiple residential buildings, the alarm shall be located at the residence that is most often occupied. e. A remote visible and audible alarm shall be required if the primary alarm is not located as required above. 5. Pumps shall have automatically resetting audible and visual high water level alarms with a manual silence switch. Only the audible alarm may be user cancelable. 6. Each pump shall have a non-resettable dose counter and/or elapsed time meter included in the control panel. Systems serving commercial facilities shall have a flow meter installed in addition to a dose counter. 7. Wiring shall be of proper construction and gauge and permanently fixed to a supporting structure under permit from the local building authority. 8. Conduits entering pump control and service panels shall be sealed against gas vapor and moisture with silicone or other method or material approved by the National Electrical Manufacturers Association (NEMA). Control panels located where electrical conduits are installed on a slope must have a pull box located near the electrical panel. 9. The pump control and alarm float shall be connected to separate electrical circuits. 10. There shall be a manual override switch in the electrical box to facilitate dosing control during inspections.

63 CHAPTER 5 TANKS - DESIGN CRITERIA F. DESIGN SPECIFICATIONS AND CALCULATIONS 1. The following minimum information shall be provided on the System design plans and on the Pump Tank Diagram (Form 5-1) and Pump System Worksheet (Form 5-2) to be included in the Design Report submittal: a. Specification sheets for the pump tank, tank risers, and pump, including the pump performance curve. b. Float switch specification sheets and placement indicating the storage capacity, audio/visual alarms. c. The elevation of the pump and drain field pipe at the highest elevation. d. Calculations for total dynamic head including friction losses through the effluent piping and valves. The System Designer shall provide friction loss tables to support the total dynamic head calculations. Friction loss values for PVC pipe and fittings are provided in Table 5-2 and Table 5-3 and can be used where applicable. e. Dosing volume and emergency storage volume calculations supported by manufacturer nominal tank sizing charts.

64 CHAPTER 5 TANKS - DESIGN CRITERIA 5.8 TANK INSTALLATION & DESTRUCTION/REMOVAL REQUIREMENTS A. INSTALLATION REQUIREMENTS 1. Excavations for tanks shall be made according to the manufacturer s requirements. 2. Excavations shall provide a level, uniform load-bearing surface free of imbedded rock formations or large boulders. 3. Tanks shall be set on a level and compacted bed according to the manufacturer s requirements. 4. Wet and/or unstable beds shall be over-excavated, backfilled and compacted with an approved material suitable to stabilize and support the tank. 5. Backfilling and compaction shall be performed according to the manufacturer s requirements. 6. Backfill material shall be friable, not contain stones larger than three (3) inches in diameter or debris of any type. 7. Installation depth for tanks shall be no greater than the manufacturer s specification. 8. The manufacturer s specification sheet, installation instructions and warranty information must be submitted with the System design documents. 9. When multiple septic tanks are proposed, they shall be placed in series. 10. The separation between any two septic tanks shall be a minimum of two (2) feet unless a closer distance is approved by the tank manufacturer. 11. In areas where the Site Evaluation has determined that the high seasonal groundwater level is within six (6) feet or less from original grade, tanks shall be made non-buoyant according to the manufacturer s recommendations. B. TANK DESTRUCTION OR REMOVAL 1. Abandoned tanks that have not been properly destroyed or removed can pose hazards and create undesirable situations. a. Tanks that have collapsed pose safety hazards for people, pets and other animals. b. Tanks that are not properly destroyed may fill with water over time and cause an entrapment or drowning hazard. 2. Improperly destroyed tanks may not be able to support the weight of vehicular traffic, building foundations, or other structures built on the property. 3. Tanks shall be destroyed or removed under permit and inspection of the Department within thirty (30) days from the date of one of the following circumstances:

65 CHAPTER 5 TANKS - DESIGN CRITERIA a. When the system is permanently disconnected from the structure served and has not been approved for subsequent use by another structure. b. When the building sewer has been connected to a sanitary sewer that is part of a municipal treatment works. c. When the system has been determined to be failing and cannot be repaired. 4. The procedures for abandonment of tanks shall be as follows: a. The tank shall be pumped by a Septic Tank Pumper with a valid Operating Permit from the Department and all contents removed and disposed of at a permitted facility. b. All equipment shall be removed. c. Electrical connections shall be disconnected. d. For tank abandonments, the tank lid shall be completely broken and several holes shall be made in the tank bottom. e. For tank removals, the tank lid and tank shall be completely removed from the excavation. f. Hydrated lime or chorine shall be spread over the tank and the void or excavation area. g. After inspection by the Department, the tank or void shall be completely filled with soil, sand, gravel, concrete or other suitable inert material and then completely covered with soil or material similar to that at the surface in the immediate surrounding area. h. When the tank is to be destroyed or removed and subsequently covered with a foundation or other structure, a structural engineer shall determine the method of destruction. i. Future construction in the area of the abandoned tank may require special construction considerations. j. Tank pieces not removed from the excavation shall be taken to a permitted sanitary landfill or appropriate facility for recycling. A copy of the receipt shall be submitted to the Department. k. The building or structure wastewater plumbing system shall be permanently capped unless the building or structure is connected to an approved onsite wastewater treatment system or a public sewer system. If the building or structure is not connected to a wastewater disposal system the building shall be recorded as a non-habitable structure. If the building or structure is to continue to be used as a non-habitable structure all plumbing fixtures and all water inlets shall be removed. l. Subsequent connection of a building or structure to a new tank or public sewer system shall be inspected by the local building authority having jurisdiction.

66 6.1 SECTION OVERVIEW CHAPTER 6 SUPPLEMENTAL TREATMENT The guidelines presented in this chapter provide general design guidelines for Supplemental Treatment Units approved for use in the County. Supplemental Treatment Units may be proprietary Treatment units and/or engineered filter systems that provide a specified level of Treatment prior to effluent dispersal into the Dispersal Field. Guidelines are provided for the following Supplemental Treatment Systems: Intermittent Sand Filters Recirculating Sand Filters; and Proprietary Treatment Units. Other Supplemental Treatment Systems may utilized provided they are approved by the Department and the San Francisco Bay Regional Water Board. The chapter is organized in the following sections: Section 6.2: General Performance Requirements for Supplemental Treatment Units Section 6.3: Guidelines for Intermittent Sand Filters & Recirculating Sand Filter Systems Section 6.4: Guidelines for Proprietary Treatment Units

67 CHAPTER 6 SUPPLEMENTAL TREATMENT 6.2 GENERAL PERFORMANCE REQUIREMENTS FOR SUPPLEMENTAL TREATEMENT UNITS A. QUALIFIED PROFESSIONAL AND INSTALLATION CONTRACTOR All Supplemental Treatment Systems must be designed by a Qualified Professional and installed by a Contractor, as defined, with specific training in the installation of the type of System utilized. B. PERFORMANCE REQUIREMENTS Supplemental Treatment Units must be designed to meet the following Biological Oxygen Demand (BOD) and Total Suspended Solids (TSS) concentrations and, where nitrogen is identified as a water quality concern, the following nitrogen reducing performance: 1. Thirty (30) day average BOD concentration shall not exceed thirty (30) milligrams per liter (mg/l), or alternately, a carbonaceous BOD (CBOD) in excess of twenty-five (25) mg/l. 2. Thirty (30) day average TSS concentration will not exceed 30 mg/l. 3. Thirty (30) day average Total Nitrogen concentration will not exceed ten (10) mg/l as nitrogen; or as an alternative, the reduction in total nitrogen shall meet or exceed up to fifty (50) reduction as measured between the influent prior to Supplemental Treatment and Effluent after Supplemental Treatment. Nitrogen reduction of up to seventy (70) percent may be required depending on the site location. C. EFFLUENT QUALITY STANDARDS Testing to comply with these performance levels must be conducted based on Effluent analysis with the following minimum detection limits: Parameter BOD TSS Total Nitrogen Detection Limit 2 mg/l 5 mg/l 1 mg/l D. DISINFECTION 1. Disinfection may be required when: a. The soil texture indicates a coarse sand or the percolation rate is 5 minutes per inch (5 mpi) or faster, and seasonal high groundwater is within eight (8) feet of the bottom of the dispersal field; or b. Replacement Systems located within the minimum horizontal setback distances from a surface water body or a well and requiring maximum extent practicable technology.

68 CHAPTER 6 SUPPLEMENTAL TREATMENT 2. Add-on components performing disinfection must be designed to achieve an Effluent total coliform bacteria concentration, at the 95th percentile, not greater than the following: a. Ten (10) Most Probably Number (MPN) per 100 ml prior to discharge into the Dispersal Field where the Soils exhibit percolation rates of 1 to 10 mpi or where the Soil Texture is sand; or b. One thousand (1,000) MPN per one hundred (100) ml prior to discharge into the Dispersal Field where the Soils exhibit percolation rates greater than 10 mpi or consist of a Soil Texture other than sand. E. REMOTE NOTIFICATION Where feasible, Supplemental Treatment components shall be equipped with a remote notification mechanism that notifies the Owner and Service Provider in the event of System malfunction. F. SYSTEM PERFORMANCE System performance shall be demonstrated through the Operation, Maintenance and Monitoring (OM & M) Program as described in Chapter 12 of this Manual.

69 CHAPTER 6 SUPPLEMENTAL TREATMENT 6.3 GUIDELINES FOR INTERMITTENT SAND FILTERS & RECIRCULATING SAND FILTER SYSTEMS A. DESCRIPTION 1. Intermittent Sand Filters (ISF) and Recirculating Sand Filters (RSF) are used to provide Supplemental Treatment of Septic Tank Effluent prior to discharge to the Dispersal System. They are used to improve or restore the capacity of the Dispersal Field, reduce pathogenic bacteria loading and can provide additional nitrogen removal. 2. An ISF consists of a packed-bed filter of medium-grained sand, designed for single passthrough Treatment of Septic Tank Effluent; it is sometimes referred to as a single pass filter. 3. An RSF utilizes coarse-grained sand and a recirculation system, usually controlled by a timer that causes the effluent to pass through the sand media several times prior to final dispersal. RSFs have the ability to produce Effluent quality similar to ISFs, except that they are less effective in bacteria removal. However, RSFs typically provide greater nitrogen removal than ISFs, on the order of 50-percent reduction as compared with Standard Tank Effluent. 4. Effluent from sand filters may be discharged to Standard Dispersal Fields and to any type of alternative Dispersal System identified in this Manual. Effluent from an ISF or RSF designed and operated in accordance with these guidelines will be considered to meet the criteria for Supplemental Treatment. 5. Schematic and cross-section diagrams are provided in Figure 6-1, Figure 6-2 and Figure 6-3 to illustrate the key design features of Intermittent Sand Filters Systems and Recirculating Sand Filters. B. QUALIFIED PROFESSIONAL Intermittent Sand Filters and Recirculating Sand Filters shall be designed by a California Registered Civil Engineer. C. CONTRAINTS ADDRESSED Sand filters can be applied to address the following onsite Wastewater constraints when used in combination with the appropriate type of Dispersal System: 1. High Groundwater; 2. Shallow Soil over Fractured Rock or Coarse alluvium; 3. Shallow Soil over Impermeable Soil or Bedrock; 4. Slow percolation at standard Dispersal Trench depths; 5. Steep Slopes; 6. Limited dispersal area; and 7. Nitrogen limitations (RSFs)

70 D. SITING REQUIREMENTS CHAPTER 6 SUPPLEMENTAL TREATMENT 1. Sand Filter Treatment Unit. All siting criteria for Septic Tanks, as specified in Chapter 4, shall also apply to intermittent and recirculating sand filters and associated tanks and pumping units. 2. Dispersal Systems Receiving Sand Filter Effluent. Dispersal Systems receiving sand filter effluent are subject to the siting criteria in Chapter 7 for the specific type of alternative dispersal system proposed, including any allowances for the incorporation of Supplemental Treatment. Allowances for Supplemental Treatment may include reduced Vertical Separation distances or increased Wastewater Application Rates. E. TREATMENT REQUIRMENTS 1. Sand Filter Systems are designed for treating residential strength Wastewater. The wastewater applied to the sand filter (influent) must not be higher in strength than two hundred twenty (220) mg/l BOD 5 or one hundred and forty five (145) mg/l TSS. Lower Wastewater strengths, without increased flow rates are preferable for assuring long term operation of Sand Filter Systems. 2. The following treatment requirements shall apply in connection with the use of sand filter systems: a. Primary (septic tank) treatment shall be the minimum level of treatment. b. Supplemental treatment, using an approved alternative treatment system identified in this Manual, shall be required for High Strength Wastewater in order to reduce its strength prior to introduction into the sand filter. F. PRESSURE DOSING 1. Septic Tank Effluent shall be applied to the Sand Filter Treatment unit by Pressure Dosing, utilizing either an automatic dosing siphon (intermittent filter only) or pump. 2. The Pressure Distribution System shall be designed in accordance with accepted industry practices to achieve, at a minimum: a. Uniform dosing of Effluent over the surface application area of the sand filter distribution bed; b. Adequate flow rate, screening of Effluent and suitable piping network to preclude solids accumulation in the pipes or clogging of discharge orifices; c. Suitable access provisions for inspection, testing and adjustment of the Pressure Distribution System; d. Dosing volume as follows: i. Intermittent Sand Filters: Dosing volume to achieve a minimum of 3 to 5 doses per day at design flow conditions; ii. Recirculating Sand Filters: Timed dosing to achieve a recirculation rate of approximately five to 1 (5:1) at design flow conditions; or

71 CHAPTER 6 SUPPLEMENTAL TREATMENT iii. Alternatively, the timer must be set to dose a minimum of twelve (12) times a day to assure that the appropriate dose volumes are delivered to the sand filter. e. At least one distribution lateral for every thirty-six (36) inches of bed width. 3. Pump or siphon system designed in accordance with the pump system requirements provided in Chapter 5 of this Manual. 4. Additional requirements for the design and construction of Pressure Distribution Systems contained in Chapter 7 shall also apply. 5. Where a sand filter is used in conjunction with a gravity-fed Dispersal System, the dosing pump system for the sand filter shall provide emergency storage capacity equal to at least one (1) times the daily wastewater flow, consistent with requirements for pump systems provided in Chapter 5 of this Manual. G. SAND FILTER BED CONTAINMENT STRUCTURE 1. Containment Liner. The sand filter shall be provided with an impermeable containment liner along all sides of the filter bed to prevent lateral leakage out of or into the filter. a. The liner shall consist of either: i. 30 mil plastic; ii. iii. reinforced poured-in-placed concrete; or an equivalent impermeable structure or barrier. 2. Finished Grade and Structural Support. The finished grade of the sand filter shall be above the surrounding ground elevation and shall be structurally supported with retaining wall(s), as required. 3. Bed Dimensions. The sand filter shall not be restricted as to its shape in plan view. 4. Multiple Units. The raised sand filter bed may be divided into compartments or multiple units. H. SAND FILTER MEDIA 1. Sand Specifications. The sand media shall be a medium to coarse sand which meets the gradation specifications for ISFs or RSFs in Table 9-1. Documentation of laboratory sieve analysis results for the proposed sand filter media material shall be supplied to the Department to verify conformance with the above specifications. 2. Additional Sand Specifications for RSF. The following additional sand specifications apply for RSF: a. Effective size of sand/gravel, D 10: 1.5 to 2.0 millimeters (mm) b. Uniformity coefficient, U c < 2.5

72 CHAPTER 6 SUPPLEMENTAL TREATMENT 3. Sand Depth. The minimum depth of sand fill, below the gravel distribution bed, shall be twenty-four (24) inches. I. SAND FILTER SURFACE AREA SIZING The surface area of the sand filter shall be sized as follows: 1. Wastewater Flow. The wastewater flow used for sizing the surface area of the sand filter shall be the design wastewater flow for the system. 2. Wastewater Application Rate. Wastewater application rates used for sizing the surface area of the sand filter shall be as follows: Sand Filter Type Individual Residential Systems Commercial, Industrial, Institutional, and Multi- Residential Systems ISF 1.2 gpd/ft gpd/ft 2 RSF Maximum 5.0 gpd/ft 2 Maximum 4.0 gpd/ft 2 Reduction in the above wastewater loading rates or other provisions to insure the longterm integrity and performance of the sand filter may be required for High Strength Wastewater flows. 3. Minimum Sizing. The minimum size (square feet) of the basal area of the raised sand filter bed shall be determined by dividing the design wastewater flow (in gpd) by the applicable wastewater application rate. Sand Filter Surface Area (ft2) = Design Wastewater Flow Rate (gpd) Wastewater Application Rate (gpd/ft2) J. GRAVEL DISTRIBUTION BED 1. Material. The distribution bed shall consist of three-eighth (3/8) inch double-washed pea gravel, substantially free of fines. 2. Depth. Pea gravel shall extend a minimum of six (6) inches below the invert and two (2) inches above the top of the distribution piping. If the distribution piping is installed with chambers, the pea gravel depth below the distribution pipe may be reduced from six (6) inches to four (4) inches, and the two (2) inch pea gravel cover may be eliminated. 3. Silt Barrier. a. Intermittent Sand Filters. The gravel distribution bed shall be covered in its entirety with a geotextile ("filter fabric") silt barrier. Filter fabric shall either be polyester, nylon or polypropylene, or any combination thereof, and shall be suitable for underdrain applications. Filter fabric shall be non-woven, shall not act as a wicking agent and shall be permeable.

73 CHAPTER 6 SUPPLEMENTAL TREATMENT b. Recirculating Sand Filters. RSFs do not require a silt barrier. K. UNDERDRAIN 1. Material. The underdrain beneath the sand media shall consist of three-eighths (3/8) inch washed pea gravel with four (4) inch diameter perforated drain pipe, installed with perforations oriented down. 2. Depth. The pea gravel underdrain shall have a minimum depth of nine (9) inches. 3. Grade. The underdrain shall be constructed and the drain pipe set with a minimum grade of one (1) percent toward the outlet point. 4. Watertight Outlet "Boot". The sand filter underdrain shall be equipped with a watertight outlet "boot" for connection of piping to the dosing tank. An exception to this is for intermittent sand filters that are equipped with an internal pump system for direct dosing to the disposal field (see Section M below). 5. Clean-out Riser. For clean-out and inspection purposes the upslope end of the perforated drain pipe in the underdrain shall be equipped with a vertical riser constructed of non-perforated pipe of equal diameter. The riser shall extend to finished grade of the sand filter. L. AIR MANIFOLD 1. An air manifold shall be installed within the pea gravel underdrain for the purpose of introducing forced air into the sand filter media, as needed, for maintenance or drainage rehabilitation. 2. The air manifold shall consist of small diameter PVC piping, with drilled perforations (pointed down), and positioned above the perforated underdrain pipe. 3. The manifold shall be connected to a vertical leader pipe that extends to the surface of the sand filter, fitted with a threaded pipe cap or plug at the top where a portable air-line can be connected. M. INTERNAL PUMP SYSTEM (ISF ONLY) 1. In lieu of gravity flow from the sand filter to the dispersal field (or dispersal field dosing system), an internal pump system may be installed within the intermittent sand filter for dosing directly to the dispersal field. 2. In such applications: a. The pump chamber shall be seated at or below the bottom of the underdrain; b. The pump operating depth shall be entirely within the depth of the underdrain; and, c. The storage volume equal to at least 50 percent of the disposal field dose volume shall be provided in the network of perforated drain pipes within the underdrain.

74 CHAPTER 6 SUPPLEMENTAL TREATMENT N. COVER 1. Intermittent Sand Filters a. Material. A continuous soil cover consisting of a medium, loamy-textured soil shall be placed over the entire distribution bed. b. Depth. Soil cover depth shall be a minimum of twelve (12) inches and a maximum of eighteen (18) inches over the top of the distribution bed. Soil cover shall be crowned or sloped to promote rainfall runoff. 2. Recirculating Sand Filters c. Material. A granular media cover shall be place over the distribution bed, consisting of clean gravel that may range in size from three-eighths (3/8) inch pea gravel to two and one half (2 ½) inch rounded rock. d. Depth. Cover depth shall be a minimum of twelve (12) inches and a maximum of eighteen (18) inches over the top of the distribution bed. O. INSPECTION PORTS A minimum of one (1) inspection port shall be installed within the gravel distribution bed of each sand filter compartment in accordance with the requirements in Table 6-1 for the purpose of checking water quality sampling. P. REFERENCE GUIDELINES In addition to the requirements set forth herein, design and construction of sand filter systems shall utilize applicable guidelines contained in the following references: a. "Onsite Wastewater Treatment Systems Manual", U.S. Environmental Protection Agency, February 2002 and as amended. b. Design Manual Onsite Wastewater Treatment and Disposal Systems, U.S. Environmental Protection Agency, October 1980.

75 CHAPTER 6 SUPPLEMENTAL TREATMENT 6.4 PROPRIETARY TREATMENT UNITS A. DESCRIPTION 1. Propriety treatment units cover a category of manufactured or package Supplemental Treatment Units specifically developed for residential and other small-scale Wastewater Treatment applications. Most proprietary treatment units currently available fall into the following two general categories: a. Aerobic Treatment Units (ATUs). ATUs utilize forced air to oxidize the Wastewater, promoting aerobic decomposition of the Wastewater solids. These systems provide Supplemental Treatment of Wastewater for improvement in dispersal field performance; they also provide varying degrees of nitrogen removal. In general, ATUs can be relied on to produce secondary quality effluent, better than 30 mg/l BOD and TSS. ATUs are generally not as effective in reducing pathogen levels as are systems that incorporate media filtration. However, some ATUs provide reduction in nitrogen levels equal to or greater than that provided by sand filters and other media filters. b. Media Filters. Media Filters include proprietary designs that function similar to sand filters. In these systems the sand is replaced with an alternate media including but not limited to peat, gravel or textile. Textile and other media filters have been found to produce effluent quality reasonably similar to recirculating sand filters, and provide similar capabilities in overcoming various soil and site constraints. 2. Effluent from proprietary treatment units may be discharged to Standard Dispersal Fields and to any type of Alternative Dispersal System identified in Chapter 7 of this Manual. Effluent from proprietary treatment units designed and operated in accordance with these guidelines will be considered to meet the criteria for Supplemental treatment. B. CONSTRAINTS ADDRESSED Proprietary treatment units can be used in combination with the appropriate type of dispersal system to address the following constraints: 1. High groundwater; 2. Shallow soil over fractured rock or coarse alluvium; 3. Slow percolation at standard dispersal trench depths; 4. Steep slopes; 5. Limited dispersal area; and 6. Nitrogen limitations.

76 CHAPTER 6 SUPPLEMENTAL TREATMENT C. SITING CRITERIA 1. Treatment Unit. All siting criteria for septic tanks, as specified in Chapter 7 of this Manual shall also apply to proprietary treatment units and associated tanks and pumping units. 2. Dispersal Systems Receiving Proprietary Treatment Effluent. Dispersal systems receiving effluent from a proprietary treatment unit are subject to the siting criteria for the specific type of alternative dispersal system proposed, including any allowances for the incorporation of supplemental treatment. Allowances for supplemental treatment may include reduced vertical separation distances, increased wastewater application rates or modified slope restrictions. Refer to Chapter 7 of this Manual for the adopted guidelines for the specific type of dispersal system for applicable requirements and supplemental treatment allowances. D. DESIGN AND CONSTRUCTION REQUIREMENTS 1. NSF Standard 40. a. Proprietary treatment units shall be listed by the National Sanitation Foundation (NSF) as meeting the NSF Standard 40, Class 1 performance evaluation. b. Proprietary treatment units shall be manufactured and installed in accordance with the design specifications used to determine compliance to NSF Standard 40. c. The NSF Standard 40 listing shall be applicable to treatment units for wastewater flows of up to 1,500 gpd and is based on compliance with United States Environmental Protection Agency (USEPA) standards for secondary treatment of municipal wastewater, including 30-day average effluent limits of twenty-five (25) mg/l for CBOD 5 and thirty (30) mg/l for TSS. d. Treatment units for flows in excess of 1,500 gpd will require certification by a thirdparty listing agency listing agency as complying with NSF Standard 40 performance requirements. 2. Design Sewage Flow. Sizing and design of proprietary treatment units shall be based on the projected wasewater flow for the structure(s) or facility(s) being served, determined in accordance with wastewater flow estimation guidelines in Chapter 4 of this Manual. 3. Tanks. All tanks housing a proprietary treatment unit shall be structurally sound, watertight and capable of withstanding one-thousand (1,000) pounds of weight. 4. Controls. Control panels shall be designed and configured in such a manner that, in the event of a treatment unit malfunction, an alarm system will be triggered and discharge from the treatment system to the dispersal field will be interrupted until the treatment unit malfunction is rectified. At a minimum, the alarm system shall include an audible and visual alarm located within the building served by the system.

77 CHAPTER 6 SUPPLEMENTAL TREATMENT 5. Emergency Storage Provisions. Where a proprietary treatment unit is used in conjunction with a gravity-fed dispersal system, the system shall provide emergency storage capacity equal to at least one (1) times the daily wastewater flow, consistent with requirements for pump systems provided in Chapter 5 of this Manual. 6. Compliance with Manufacturer Requirements. The System designer and installer shall follow the proprietary manufacturer s design, installation, construction, and operations procedures. 7. Engineering Plans. Engineering plan submittals for proprietary treatment units shall provide documentation of compliance with manufacturer requirements and sufficient design analysis to verify the appropriateness of the treatment unit for the proposed application. Engineering plans shall contain specific step-by-step construction guidelines and notes for use by the installer, including any manufacturer instructions. 8. Installer Requirements. Anyone installing a proprietary treatment unit shall be trained and certified by the system manufacturer. Documentation verifying conformance to this requirement shall be provided to the Department prior to system installation. 9. Maintenance Contract. The applicant must demonstrate that a written maintenance agreement with a qualified service provider has been obtained for the proposed proprietary treatment unit to ensure satisfactory post-construction operation and maintenance. A maintenance agreement must be maintained valid for the life of the treatment unit.

78 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.1 CHAPTER OVERVIEW The guidelines presented in this chapter provide the design criteria for subsurface dispersal systems approved for use in the County. The criteria apply to new systems and modifications or repairs to existing systems. The dispersal system types presented in Sections 7.9 through 7.12 shall be used only for repair or replacement of existing systems on severely constrained sites. This chapter is organized in the following sections: Section 7.2: Standard Trench Dispersal Systems Section 7.3: Pressure Distribution Dispersal Systems Section 7.4: Pressure Dosed Sand Trench Dispersal Systems Section 7.5: Drip Dispersal Systems Section 7.6: Cover Fill Dispersal Systems Section 7.7: At-Grade Dispersal Systems Section 7.8: Mound Dispersal Systems Section 7.9: Raised Sand Filter Bed Systems Section 7.10: Standard Trench Dispersal Grid Systems Section 7.11: Deep Trench Dispersal Systems Section 7.12: Engineered Fill with Drip Dispersal Systems

79 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.2 STANDARD (GRAVITY) TRENCH DISPERSAL SYSTEMS A. DESCRIPTION Standard trench dispersal systems consist of a series of gravity-fed drainfield trenches for subsurface dispersal of effluent into the soil. Standard trench dispersal systems include conventional trenches and shallow in-ground trenches with cover soil configurations. Schematic and cross-section diagrams are provided in Figure 7-1, Figure 7-2, Figure 7-3 and Figure 7-4 to illustrate the key design features of standard trench dispersal systems. B. DUAL SYSTEM REQUIREMENT 1. Primary and Secondary Dispersal Area. Two dispersal fields (primary and secondary), each with one hundred (100) percent of the total size required for the design wastewater flow shall be installed. 2. Diversion Valve. The dispersal system shall be equipped with an approved manual diversion device to allow alternating use of the two fields, typically switching between fields every six (6) to twelve (12) months. C. SITING REQUIREMENTS Siting requirements for conventional and shallow in-ground standard gravity trench dispersal systems are provided in Table 3-1, Table 4-10 and Table 4-11, respectively. 1. Vertical Separation Requirements. a. Depth to Groundwater. Minimum depth to seasonal high groundwater for standard gravity trench dispersal systems, as measured from the trench bottom, shall vary according to soil percolation rate as shown in Table 3-1. b. Effective Soil Depth. Minimum depth of effective soil, as measured from the trench bottom to impermeable soil or rock, for standard trench dispersal systems shall be five (5) feet as shown in Table Maximum Ground Slope. a. The maximum ground slope in areas used for conventional trench dispersal systems shall be thirty (30) percent (see Table 4-11). b. The maximum ground slope in areas used for shallow in-ground trench dispersal systems with cover fill shall be 20 percent (see Table 4-11). D. WASTEWATER APPLICATION RATES Wastewater application rate(s) used for determining the required infiltrative surface area and overall trench length of Standard Trench Dispersal Systems are provided in Table 4-5.

80 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN E. EFFECTIVE INFILTRATIVE AREA AND TRENCH SIZING a. Effective Infiltrative Area Requirement. The Effective Infiltrative Area for trench dispersal systems shall be limited to four (4) square feet per lineal foot of trench length, which may include any combination of trench bottom area and trench sidewall area below the invert of the perforated distribution pipe. b. Trench Infiltrative Surface Calculation. The required square footage of trench infiltrative surface shall be calculated based on the design flow and the applicable wastewater application rate as provided in Table 7-1. c. Trench Length Calculation. The required trench length for one hundred (100) percent capacity dispersal field shall be calculated as provided in Table 7-1. F. TRENCH SPECIFICATIONS Standard Dispersal Trench Systems shall be constructed with drainrock and perforated pipe and shall meet the specifications in Table 7-2 (Conventional Trenches), Table 7-3 (Shallow In-Ground Trenches) and Chapter Conventional Trench Depths. Conventional trench depths shall range between 30 inches and 60 inches below the native ground surface. Trenches shall be kept as shallow as possible to take advantage of those soil horizons that best provide oxygen and promote microbiological activity; and within the root zone of plants to take advantage of nitrogen uptake in plants. 2. Shallow In-Ground Trench Depths with Cover Fill. Shallow in-ground trench depths shall range from eighteen (18) inches to thirty (30) inches below the native ground surface. The shallow construction of the trenches allows for installation where a limiting layer or groundwater is closer to ground surface. The trench is installed entirely below grade, with to 12 inches of soil fill place on top of native grade to provide the required backfill cover over the pipe and drain rock. The wastewater is dispersed into the native soils, no into the fill soil. Shallow in-ground trenches provide for improved use of absorption capacity of the near surface soils, which tend to be most permeable and most effective for absorption and treatment of wastewater effluent. 3. Drainrock Alternatives. Other material may be substituted for drainrock in the dispersal trenches if they have been approved by the Department. All substitute material shall serve the same function as drainrock as follows: a. Support the trench sidewalls and maintain the integrity of the infiltrative surface; b. Provide adequate storage for septic tank effluent surges c. Provide equivalent effective infiltrative surface consistent with the trench sizing requirement for trenches with drainrock. d. Plastic dispersal chamber systems shall be accepted for use in sewage dispersal systems and shall be certified by IAPMO, UPC, NSF or other nationally recognized certification organization. e. Reduction in trench sizing requirement up to thirty (30) percent may be approved by the Department for IAPMO-certified dispersal systems.

81 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 4. Trench Spacing. Trench spacing shall be in accordance with the requirements in Table 7-4. G. INSPECTION WELLS 1. A minimum of one (1) inspection wells shall be installed within each trench in accordance for the purpose of checking ponded water levels periodically. 2. Inspection wells shall be constructed of two (2) inch to four (4) inch diameter pipe, equipped with a wrench-tight cap or pipe plug and a bottom cap. All wells shall be perforated beginning at a depth of eighteen (18) inches below grade and extending to the bottom of the pipe. Perforations shall consist of hacksaw slots at nominal one (1) inch spacing, or equivalent commercially-slotted pipe. To prevent surface water infiltration, inspection wells shall be sealed with a bentonite or concrete annular seal (or equivalent), extending from the ground surface to depth of twelve (12) inches, minimum (see Figure 6-4). H. DISPERSAL TRENCH GENERAL DESIGN CONSTRUCTION CRITERIA 1. Trenches shall be placed in undisturbed earth, in an accessible area, and shall not be covered by paving or other impermeable or compacted surface. Natural topography shall not be graded to modify slope. 2. Trenches shall be installed on contour (i.e., aligned parallel to the ground surface contours) to the greatest extent practicable. 3. The bottom of a trench shall be level, with a variation of no more than two (2) inches per one hundred (100) lineal feet of trench; trenches shall be aligned parallel to the ground surface contours to the greatest extent practicable. 4. Adjacent trenches on slopes shall be connected with a watertight overflow line ( relief line ) in a manner that allows each trench to be filled with wastewater effluent to the depth of the rock before the wastewater flows to the next lower trench (see Figure 7-4). Alternatively, a distribution box (D-box) may be used to equally divide the flow amongst the trenches. 5. Trenches shall not be excavated when the soil is so wet that smearing or compaction occurs. 6. In clay soils when glazing occurs, the trench surfaces shall be scarified to the depth of the glazing and the loose material removed. 7. Rock material in the trench shall be washed and free of fines. 8. A minimum of two (2) inches of rock shall be placed over the drain pipe. 9. Prior to backfilling the trench, the drain rock shall be covered with geotextile filter fabric. 10. Backfill shall be carefully placed to prevent damage to the system.

82 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 11. Backfill shall be native soil. Backfill shall be free of large stones, frozen clumps of earth, masonry, stumps, waste construction materials, or other materials that could damage the System. 12. The slope shall not exceed percent in the dispersal areas (primary and secondary). 13. For purposes of determining effective soil depth and vertical separation, the depth of limiting layer shall be measured from the upslope side of the dispersal trench bottom. 14. Erosion control measures shall be implemented following installation. 15. Additional requirements for the design and placement of cover fill for shallow in-ground trenches are provided in Section 7.6 of this Chapter. I. REFERENCE GUIDELINES In addition to the requirements set forth herein, design and construction of Standard Trench Distribution Systems shall utilize applicable guidelines contained in the following references: 1. "Onsite Wastewater Treatment Systems Manual", U.S. Environmental Protection Agency, February 2002 and as amended. 2. Design Manual Onsite Wastewater Treatment and Disposal Systems, U.S. Environmental Protection Agency, October 1980.

83 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.3 PRESSURE DISTRIBUTION TRENCH DISPERSAL SYSTEMS A. DESCRIPTION Pressure Distribution Trench Dispersal Systems are an alternative to a Standard Trench Dispersal System that use a pump and small-diameter pressure piping to achieve broad and uniform distribution of Wastewater for improved Soil absorption and better Treatment of percolating Effluent. Pressure Distribution Systems may be installed in shallow or deep trenches. Schematic and cross-section diagrams are provided in Figure 7-5 and Figure 7-6 to illustrate the key design features of Pressure Distribution Trench Dispersal Systems. B. CONSTRAINTS ADDRESSED 1. High groundwater; 2. Shallow soil over impermeable soil or bedrock; 3. Shallow soil over fractured rock or coarse alluvium; 4. Slow percolation at standard dispersal trench depths; and 5. Steep terrain. C. PRIMARY AND RESERVE AREA REQUIRED 1. Primary Dispersal Area. A Primary Pressure Distribution Dispersal System designed to treat one hundred percent of the design wastewater flow shall be installed. 2. Reserve Dispersal Area. A reserve area having suitable site conditions and sufficient area for full, one-hundred (100) percent replacement of the primary Pressure Distribution System shall be identified during the Site Evaluation and reserved for use when the Pressure Distribution dispersal system fails. D. SITING REQUIREMENTS Siting requirements for Pressure Distribution Systems in Shallow In-Ground Trenches, Conventional Trenches and Deep Trench Dispersal Systems are provided in Table 3-1, Table 4-10 and Table 4-11, respectively. 1. Vertical Separation Requirements a. Depth to Groundwater. Minimum depth to seasonal high groundwater for shallow PD systems, as measured from trench bottom, shall vary according to soil percolation rate as shown in Table 3-1. b. Effective Soil Depth. Minimum depth of soil, as measured from trench bottom to impermeable soil or rock, for shallow PD systems shall vary according to soil percolation rate and the level of treatment provided as shown in Table 3-1.

84 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 2. Maximum Ground Slope. a. The maximum ground slope in areas used for shallow trench pressure distribution systems shall be forty (40) percent (see Table 4-11). The maximum ground slope in areas used for deep trench pressure distribution systems shall be twenty (20) percent (see Table 4-11). b. Any pressure distribution system located on slopes greater than thirty (30) percent shall require the completion of a geotechnical report and slope stability analysis as specified in Chapter 3 of this Manual. E. TREATMENT REQUIREMENTS The following treatment requirements shall apply in connection with the use of pressure distribution systems: 1. Primary (septic tank) treatment shall be the minimum level of treatment, and shall be acceptable where the applicable vertical separation distances are met per Tables Supplemental treatment, using an approved alternative treatment system identified in this Manual, may be used to allow compliance with reduced vertical separation distances as provided in Tables 3-1. F. WASTEWATER APPLICATION RATES Wastewater application rate(s) used for determining the required infiltrative surface area and overall trench length of Pressure Distribution Dispersal Systems are provided in the following tables: 1. Table 4-5 (Standard Wastewater Application Rates). Standard Wastewater Application rates shall be used in Pressure Distribution Systems receiving wastewater effluent from Primary Treatment (Septic Tank) where the minimum Vertical Separation to Groundwater and/or Effective Soil Depth for Standard Trench Dispersal Systems provided in Table 3-1 are met. 2. Table 4-7 (Enhanced Wastewater Application Rates). Enhanced Wastewater Application Rates may be used in Pressure Distribution Systems receiving wastewater effluent from Supplemental Treatment where the minimum Vertical Separation to Groundwater and/or Effective Soil Depth for Standard Trench Dispersal Systems provided in Table 3-1 are met. 3. A further reduction in the wastewater application rates may be required for high strength wastewater flows or other site constraints. G. TRENCH DESIGN 1. Pressure distribution trenches shall conform to the same design and construction requirements as Standard Trench Dispersal Systems, per Section 7.2 of this Chapter and Table 7-1, Table 7-2, and Table 7-3, with the exception that the piping system shall consist of pressure piping rather than gravity piping.

85 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 2. Cover fill may also be used in conjunction with shallow in-ground pressure distribution trenches. H. PRESSURE DISTRIBUTION PIPING Pressure distribution piping shall comply with the material specifications provided in Chapter 9 and the following criteria: 1. Pipe Sizing. All pressure distribution pipes and fittings, including transport lines, manifolds, laterals and valves, must be adequately sized for the design flow, and shall be designed to minimize frictional losses to the maximum extent practicable. 2. Pipe Support. All PD transport piping must be uniformly supported along the trench bottom and bedded in sand or other material approved by the Department. 3. Thrust Blocks. Concrete thrust blocks, or equivalent restraint, shall be provided at sharp changes in piping directions. 4. Shut-off Valves. The distribution lateral for each trench shall be fitted with a shut-off valve to adjust or terminate the flow to individual trenches. Shut-off valves may be ball or gate valves, and shall be located in a utility/valve box. 5. Dosing Tank Valves: A gate valve or ball valve must be placed on the pressure transport pipe inside or outside of the pump riser of the dosing tank. 6. Pump Check Valve: A check valve shall be placed between the pump and the gate valve when required. A check valve is not required if the pump has an internal check valve. All check valves and gate valves shall be in an accessible and protected location for maintenance and repair. 7. Lateral End Riser. The end of each lateral shall be fitted with a ninety (90) degree long sweep to facilitate line cleaning and hydraulic testing. The end riser pipe shall also be fitted with a ball valve and/or threaded end cap or plug, housed in a valve box. 8. Anti-siphon Valve. An anti-siphon valve shall be placed between the pump and Dispersal Field when the Dispersal Field is down Slope of the pump. 9. Valve Boxes. All valves must be placed in boxes accessible for maintenance from the surface. I. PRESSURE DOSING 1. A pressure distribution system shall be hydraulically designed in accordance with accepted industry practices to provide an adequate flow rate, screening of effluent, and a suitable piping network to preclude solids accumulation in the pipes or clogging of discharge orifices and to achieve uniform dosing of septic tank effluent throughout the pressure distribution trenches.

86 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 2. Orifices shall have a minimum diameter of one-eighth (1/8) inch and shall be evenly spaced at a distance between two (2) and six (6) feet. Orifices larger than one-eighth (1/8) inch shall be evaluated on a case by case basis due to design constraints related to dose volume, Effluent quality, and dispersal Field size. 3. A minimum of five (5) feett of head at the orifice farthest from the manifold and no more than 10 percent head variation within a Dispersal Trench. 4. Effluent shall be applied to the PD system by pressure dosing, utilizing either an automatic dosing siphon or pump system. 5. The pressure distribution system shall be designed to drain following a dose. 6. The dose volume shall be sufficient to refill any part of the pressure distribution system including supply line and lateral lines. 7. Dosing volumes shall be designed to deliver sufficient additional volume to disperse the daily Design flow in an appropriate number of doses per day at design flow conditions. Dispersal Field performance is enhanced when the daily flow is dispersed in smaller, more frequent doses throughout the day. In most applications, between twelve (12) and twentyfour (24) doses per day per zone is appropriate, although a number outside that range may be appropriate in some cases. 8. Pumps shall comply with the material specifications provided in Chapter 9 and designed and constructed in accordance with pump system requirements provided in Chapter 5 of this Manual. J. INSPECTION WELLS 1. Groundwater Monitoring Wells. A minimum of three (3) groundwater monitoring wells shall be installed within and around the PD Dispersal System in accordance with the requirements in Table 7-5 for the purpose of checking groundwater levels periodically and water quality sampling, if needed. 2. Trench Inspection Wells. A minimum of two (2) inspection wells shall be installed within each trench for the purpose of checking ponded water levels periodically (see Figure 7-5 and Figure 7-6). a. Inspection wells shall be constructed of two (2) inch to four (4) inch diameter pipe, equipped with a wrench-tight cap or pipe plug and a bottom cap. All wells shall be perforated beginning at a depth of eighteen (18) inches below grade and extending to the bottom of the pipe. Perforations shall consist of hacksaw slots at nominal one (1) inch spacing, or equivalent commercially-slotted pipe. To prevent surface water infiltration, inspection wells shall be sealed with a bentonite or concrete annular seal (or equivalent), extending from the ground surface to depth of twelve (12) inches, minimum (see Figure 6-4).

87 K. REFERENCE GUIDELINES CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN In addition to the requirements set forth herein, design and construction of PD systems shall utilize applicable guidelines contained in the following references: 1. "Onsite Wastewater Treatment Systems Manual", U.S. Environmental Protection Agency, February 2002 and as amended. 2. Design Manual Onsite Wastewater Treatment and Disposal Systems, U.S. Environmental Protection Agency, October 1980.

88 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.4 PRESSURE DOSED SAND TRENCH DISPERSAL SYSTEMS A. DESCRIPTION Pressure Dosed Sand Trench (PDST) Dispersal Systems are a variation of a shallow pressure distribution system that utilizes a medium-grade sand in place of a portion of the gravel backfill in the dispersal trench, to improve treatment of effluent and normalize the flow of effluent before it reaches the trench bottom. Treatment occurring in the sand fill can enhance the acceptance rate of native soils beneath the trench. This type of design can also be used with supplemental treatment, and is well suited for conditions where underlying soils are highly permeable and/or groundwater beneath a system is especially vulnerable to wastewater contaminants. Schematic and cross-section diagrams are provided in Figure 7-7 to illustrate the key design features of Pressure Dosed Sand Trench dispersal Systems. B. CONSTRAINTS ADDRESSED 1. High groundwater; and 2. Rapid percolation. C. SITING REQUIREMENTS Siting requirements for Pressure Dosed Sand Trench Distribution Systems are provided in Table 3-1, Table 4-10 and Table Vertical Separation Requirements. a. Depth to Groundwater. The minimum depth to seasonal high groundwater for PDST systems, as measured from trench bottom, shall vary according to soil percolation rate, level of treatment provided, and sand fill thickness as shown in Table 3-1. a. Effective Soil Depth. The minimum depth of soil, as measured from trench bottom to impermeable soil or rock, for shallow PDST systems shall be two (2) feet as shown in Table Maximum Ground Slope. a. Maximum ground slope in areas used for shallow PDST systems shall be forth (40) percent. b. Any PDST system located on slopes greater than thirty (30) percent shall require the completion of a geotechnical report and slope stability analysis as specified in Chapter 3 of this Manual. D. PRIMARY AND RESERVE AREA REQUIRED 1. Primary Dispersal Area. A Primary PDST Dispersal System designed to treat one hundred percent of the design wastewater flow shall be installed.

89 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 2. Reserve Dispersal Area. A reserve area having suitable site conditions and sufficient area for full, one-hundred (100) percent replacement of the primary PDST Dispersal System shall be identified during the Site Evaluation and reserved for use when the PDST Dispersal System fails. E. TREATMENT REQUIREMENTS The following treatment requirements shall apply in connection with the use of PDST systems: 1. Primary (septic tank) treatment shall be the minimum level of treatment, and shall be acceptable where the applicable vertical separation distances are met per Table Supplemental treatment, using an approved alternative treatment system identified in this Manual, may be used to allow compliance with reduced vertical separation distance provided in Table 3-1. F. PRESSURE DOSING Septic tank effluent shall be applied to the PDST system by pressure dosing, utilizing either an automatic dosing siphon or pump system. The pressure distribution system shall be designed in accordance with accepted engineering practices to achieve, at a minimum: 1. Uniform dosing of septic tank effluent throughout the PDST Dispersal System trenches. 2. Adequate flow rate, screening of effluent and suitable piping network to preclude solids accumulation in the pipes or clogging of discharge orifices; 3. Suitable access provisions for inspection, testing and adjustment of the pressure distribution system; and 4. Dosing volume to achieve minimum of three (3) to five (5) doses per day at design flow conditions. 5. Pump system designed in accordance with the pump system requirements provided in Chapter 8 of this Manual. 6. Additional requirements for design and construction of pressure distribution piping systems contained in the guidelines for Pressure Distribution Systems in Section 7.3 of this Manual, as applicable. G. WASTEWATER APPLICATION RATES Wastewater application rates used for system sizing shall include consideration of both the pea gravel-sand interface and the sand-soil interface using the bottom area of the trench only. The more restrictive criterion shall govern system sizing.

90 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 1. Pea Gravel-Sand Interface. The wastewater application rate used for sizing the pea gravel-sand interface shall be: Facility Type Wastewater Application Rate Individual Residential Systems 1.2 gpd/ft 2 Commercial, Industrial, Institutional and Multi-Residential Systems 1.0 gpd/ft 2. Sand-Soil Interface. The Wastewater Application Rate for sizing the sand-soil interface (considering bottom area only) shall be based upon representative percolation test results for the soil zone corresponding with the trench bottom depth. Standard or Enhanced Wastewater Application Rates shall be used as provided in Table 4-5 and Table 4-7, respectively. Reduction in the above Wastewater Application Rates or other provisions to insure the longterm integrity and performance of the PDST trenches may be required for high strength waste flows. H. DRAINFIELD TRENCH DESIGN PDST Dispersal Systems shall conform to the same general design and construction requirements as Pressure Distribution Dispersal Systems per Section 7.3 of this Chapter, with the following exceptions as specified in Table 7-6 and Table Cover Fill. Cover fill may also be used in conjunction with pressure-dosed sand trenches. 2. Trench Filter Material. The trench filter material (below the distribution pipe) shall consist of a minimum of six (6) inches of double-washed pea gravel underlain by six (6) to twentyfour (24) inches of medium sand fill. a. The sand media shall be a medium to coarse sand that meets the gradation specifications provided in Chapter 6. Documentation of laboratory sieve analysis results for the proposed sand fill material shall be supplied to the Department to verify conformance with the above specifications. b. The minimum depth of sand below the pea gravel shall is dependent on the level of wastewater effluent treatment (Primary or Supplemental) and the soil percolation rate as specified in Table Trench Sizing. a. Effective Infiltration Area. The required square footage of trench infiltrative surface shall be calculated based on the design flow and the applicable wastewater application rates as provided in Table 7-6. b. Trench Length. The required length of trench shall be calculated based on the bottom area only, up to a maximum of three (3) square feet of effective infiltrative surface per lineal foot of trench per the requirements of Table Trench Spacing. PDST trench spacing shall comply with the requirements of Table 7-4.

91 I. INSPECTION WELLS CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 1. Groundwater Monitoring Wells. A minimum of three (3) groundwater monitoring wells shall be installed within and around the PDST Dispersal System in accordance with the requirements in Table 7-5 for the purpose of checking groundwater levels periodically and water quality sampling, if needed. 2. Trench Inspection Wells. A minimum of two (2) inspection wells shall be installed within each trench for the purpose of checking ponded water levels periodically (see Figure 7-5 and Figure 7-6). a. Inspection wells shall be constructed of two (2) inch to four (4) inch diameter pipe, equipped with a wrench-tight cap or pipe plug and a bottom cap. All wells shall be perforated beginning at a depth of eighteen (18) inches below grade and extending to the bottom of the pipe. Perforations shall consist of hacksaw slots at nominal one (1) inch spacing, or equivalent commercially-slotted pipe. To prevent surface water infiltration, inspection wells shall be sealed with a bentonite or concrete annular seal (or equivalent), extending from the ground surface to depth of twelve (12) inches, minimum (see Figure 6-4). J. REFERENCE GUIDELINES In addition to the requirements set forth herein, design and construction of PD systems shall utilize applicable guidelines contained in the following references: 3. "Onsite Wastewater Treatment Systems Manual", U.S. Environmental Protection Agency, February 2002 and as amended. 4. Design Manual Onsite Wastewater Treatment and Disposal Systems, U.S. Environmental Protection Agency, October 1980.

92 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.5 SUBSURFACE DRIP DISPERSAL SYSTEM DESIGN A. DESCRIPTION Subsurface drip dispersal is a method for disposal of treated wastewater that uses special drip tubing designed for use with wastewater. The dripline is placed normally eight (8) to twelve (12) inches below ground surface and makes use of the most biologically active soil zone for distribution, nutrient uptake and evapotranspiration of the wastewater. A drip dispersal system is comprised of small-diameter (½ to 1 ) laterals ( driplines ), usually spaced about 24 inches apart, with small-diameter emitters (1/8 ) located at twelve (12) to twenty-four (24) inches on-center along the dripline. Effluent is conveyed under pressure to the laterals, normally with timed doses. Prior to dispersal the effluent requires supplemental treatment. Schematic and cross-section diagrams are provided in Figure 7-8 and Figure 7-9 to illustrate the key design features of Drip Dispersal Systems. B. CONTRAINTS ADDRESSED 1. High groundwater; 2. Shallow soil over impermeable soil or bedrock; 3. Shallow soil over fractured rock or coarse alluvium; 4. Slow percolation at standard dispersal trench depths; 5. Steep slopes; 6. Limited dispersal area; and 7. Large and/or dense tree cover. C. PRIMARY AND RESERVE AREA REQUIRED 1. Primary Dispersal Area. A Primary Drip Dispersal System designed to treat one hundred percent of the design wastewater flow shall be installed. 2. Reserve Dispersal Area. A reserve area having suitable site conditions and sufficient area for full, one-hundred (100) percent replacement of the primary Drip Dispersal System shall be identified during the Site Evaluation and reserved for use when the Primary Drip Dispersal System fails. D. SITING REQUIRMENTS Siting requirements for Drip Dispersal Systems are provided in Table 3-1, Table 4-10 and Table Advantages. Drip dispersal has several advantages, including: a. It can be effective in very shallow soil conditions since it distributes the wastewater very uniformly to substantially all of the available soil in the field;

93 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN b. It can be installed in multiple small discontinuous zones, allowing the hydraulic load to be spread widely rather than concentrated in one main area; c. It can be installed on steeper slopes causes less soil disturbance and erosion or slope stability hazards; and d. Water movement away from the drip emitters is substantially by unsaturated/capillary flow, which maximizes contact with and treatment by the soil. 2. Vertical Separation Requirements. a. Depth to Groundwater. The minimum depth to seasonal high groundwater, as measured from the bottom of the dripline, shall vary according to soil percolation rate as specified in Table 3-1. b. Effective Soil Depth. The minimum depth of soil, as measured from the bottom of the dripline to impermeable soil or rock, shall be two (2) feet. 3. Maximum Ground Slope. a. Maximum ground slope in areas used for Drip Dispersal Systems shall be forty (40) percent. b. Any Drip Dispersal System located on slopes greater than thirty (30) percent shall require the completion of a geotechnical report and slope stability analysis as specified in Chapter 3 of this Manual. E. TREATMENT REQUIREMENTS The following treatment requirements shall apply in connection with the use of Drip Dispersal Systems: 1. Wastewater effluent discharged to a Drip Dispersal System shall be treated to at least a secondary level through an approved supplemental treatment system. 2. All drip dispersal systems shall include a filtering device capable of filtering particles larger than one-hundred (100) microns; this device shall be located downstream of the supplemental treatment system. F. WASTEWATER APPLICATION RATES Wastewater application rates used for sizing Drip Dispersal Systems shall be based on soil percolation rate in accordance with the criteria in Table 4-8. In applying these criteria, the wastewater application area refers to the ground surface area encompassed by the drip dispersal field. G. DRIPFIELD SIZING AND DESIGN 1. Minimum sizing of the dripfield area shall be equal to the design wastewater flow divided by the applicable wastewater application rate.

94 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 2. For sizing purposes, the effective ground surface area used for drip field sizing calculations shall be limited no more than four (4) square feet per drip emitter. For example, two hundred (200) lineal feet of dripline with emitters at two (2) foot spacing would provide a total of one-hundred (100) emitters (200/2) and could be used for dispersal to an effective area of up to four-hundred (400) square feet (100 emitters x 4 ft 2 /emitter). Conversely, if wastewater flow and percolation design information indicate the need for an effective area of one-thousand (1,000) square feet, the dripline design and layout would have to be configured to provide a minimum of two hundred and fifty (250) emitters spaced over the required one-thousand (1,000) square foot dispersal area. 3. Dripfields may be divided into multiple zones which may be located in different areas of a site, as desired or needed to provide the required dripfield size. A single continuous dripfield area is not required. However, any areas proposed for drip dispersal shall be supported by field observations/measurements to verify conformance with soil suitability and other site requirements. Differences in soil conditions and percolation characteristics from one zone to another may require the use of correspondingly different wastewater application rates and dripfield sizing for each zone. 4. Dripline shall be manufactured and intended for use with secondary quality wastewater, with minimum forty-five (45) mil tubing wall thickness, bacterial growth inhibitor(s), and means of protection against root intrusion. 5. The bottom of each dripline row shall be level and parallel to the slope contour. 6. The dripline depth shall be installed at a depth between eight (8) and twelve (12) inches below native grade. Deeper placement of driplines may be considered by the Department on a case-by-case basis. 7. The maximum dripline length shall be designed in accordance with accepted industry practices and in accordance with the manufacturer s criteria and recommendations. 8. Line and emitter spacing shall be designed as appropriate for soil conditions, slope, and contour. Emitters shall be located at no less than twelve (12) inches from the supply and return manifolds. H. PRESSURE DOSING Effluent treated by a Supplemental Treatment System/Unit shall be delivered to the dripfield by pressure, employing a pump system and timed dosing. The pressure distribution system shall be designed in accordance with accepted industry practices and manufacturer recommendations for drip dispersal systems to achieve, at a minimum: 1. Uniform dosing of treated effluent; 2. An adequate dosing volume and pressure per manufacturer s guidelines; 3. Adequate flow rate, final filtering of effluent and suitable piping network to preclude solids accumulation in the pipes and driplines or clogging of discharge emitters; 4. A means of automatically flushing the filter and driplines at regular intervals; and 5. Suitable access provisions for inspection, testing and adjustment of the dripfield and components.

95 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 6. Pump system designed in accordance with the pump system requirements provided in Chapter 5 of this Manual. 7. Additional requirements for design and construction of pressure distribution piping systems contained in the guidelines for Pressure Distribution Systems in Chapter 10 of this Manual, as applicable. I. COVER FILL Cover fill may also be used in conjunction with subsurface drip dispersal systems. J. INSPECTION WELLS A minimum of three (3) inspection wells shall be installed within and around the Drip Dispersal System area for the purpose of checking groundwater levels periodically and water quality sampling, if needed. K. REFERENCE GUIDELINES Installation of subsurface drip dispersal systems shall be in accordance with applicable manufacturer guidelines and recommendations.

96 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.6 COVER FILL DISPERSAL SYSTEMS A. DESCRIPTION 1. The term cover fill refers to a dispersal trench system where the trenches are excavated entirely below grade, but up to twelve (12) inches of soil fill is placed on top of native grade to provide the required backfill cover over the pipe and drain rock. 2. The wastewater is dispersed into the native soils, not into the fill soil. The purpose is to allow for shallower trench depths where necessary or desirable to meet soil depth and groundwater separation requirements. 3. It provides for improved use of the absorption capacity of the near surface soils, which tend to be most permeable and most effective for absorption and treatment of wastewater effluent. 4. Cover fill can be used in conjunction with Standard Shallow Trench Dispersal Systems, Shallow Pressure Distribution Systems, Pressure-Dosed Sand Trench Dispersal Systems, and Drip Dispersal Systems presented in this Chapter. 5. Schematic and cross-section diagrams of cover fill trench systems are provided in Figure 7-2 to illustrate the key design features of Cover Fill Dispersal Systems. B. SITING REQUIREMENTS 1. Horizontal Setback Requirements. The minimum horizontal setback distances specified in Table 4-10 apply to Cover Fill Systems (as measured from the edge of cover soil). 2. Vertical Separation Requirements. Soil depth, groundwater separation and percolation rates shall conform to the requirements applicable to the type of the dispersal system (shallow in-ground trench, pressure dosed trench, pressure-dosed sand trench, subsurface drip) as provided in Table Maximum Ground Slope. The maximum ground slope in areas used for Cover Fill Systems shall be twenty (20) percent. 4. DESIGN AND CONSTRUCTION REQUIREMENTS 1. Dispersal Trenches. The drain rock and perforated pipe sections shall be installed entirely within native soil, and all other aspects of the dispersal trench design shall be in conformance with requirements for Standard Trench Dispersal Systems, or in the case of an Alternative Dispersal System, in accordance with requirements for the particular type of system (e.g., Shallow Pressure Distribution Trench, Drip Dispersal System, etc.) as specified in this Chapter. 2. Site Preparation. Prior to placement of fill material, all vegetation shall be removed and the ground surface ripped or ploughed to a depth approximately six (6) to ten (10) inches to permit good mixing of native soil and fill material. 3. Fill Material. The soil used for fill shall be similar in texture to the native surface soil in the dispersal field area. Sand, gravel or rock do not qualify as acceptable material for cover fill. Particle size analysis (hydrometer method) of the dispersal site soils and fill soil shall be required for the Department review and acceptance of the proposed fill soil, except in cases where the fill is obtained from similar soils at the project site.

97 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 4. Sequencing. The fill shall be placed prior to dispersal trench excavation and installation of dispersal piping and appurtenances. 5. Areal Coverage. The fill shall be continuous and constructed to provide a uniform soil cover of at least twelve (12) inches over the dispersal trenches. The fill shall extend a minimum distance of fifteen (15) feet from the edge of trench in the down-slope direction and ten (10) feet in the upslope and side-slope directions. On a level site, the fill shall extend a minimum of 10 feet in all directions. The toe of the fill shall be tapered at no less than a three horizontal to 1 vertical (3:1) grade, beginning at the above required fifteen (15) foot or ten (10) foot distance, as applicable. Where the primary and secondary dispersal fields are adjacent to one another, the cover fill should be continuous over both fields. 6. Fill Compaction. Fill shall be placed in layers ( lifts ) of not more than six (6) inches, and compacted to approximately the same dry density as the native soil. Normal compaction procedures to achieve this requirement shall consist of track-rolling each lift, two passes minimum. Alternative compaction procedures may be allowed by the Department in accordance with recommendations and supporting technical data supplied by a registered civil engineer.

98 7.7 AT-GRADE SYSTEM A. DESCRIPTION CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN At-grade Systems are similar to Mound Systems, except that they do not include the sand bed; the gravel distribution bed is placed directly on the scarified (i.e., plowed) soil surface. They are often used in conjunction with a supplemental treatment system. They can be used in the same types of situations as Mound Systems to overcome shallow soil depths and high groundwater. Schematic and cross-section diagrams are provided in Figure 7-10 and Figure 7-11 to illustrate the key design features of At-Grade Dispersal Systems. B. CONSTRAINTS ADDRESSED 1. High groundwater; 2. Shallow soil over impermeable soil or bedrock; 3. Shallow soil over fractured rock or coarse alluvium; and 4. Limited Dispersal System area. C. PRIMARY AND RESERVE AREA REQUIRED 1. Primary Dispersal System. A Primary At-Grade Dispersal System designed to treat one hundred percent of the design wastewater flow shall be installed. 2. Reserve Dispersal System Area. A reserve area having suitable site conditions and sufficient area for full, one-hundred (100) percent replacement of the primary At-Grade Dispersal System shall be identified during the Site Evaluation and reserved for use when the Primary At-Grade Dispersal System fails. 3. Dispersal System Overlap. In determining the necessary space for the primary and secondary (reserve) field, the required gravel distribution bed area of the primary and secondary At-grade shall not overlap. The surplus soil fill run-out shall also not overlap unless the primary and secondary At-grades are both installed (i.e., as a dual system). 4. Dual At-Grade Dispersal System. Dual At-grade Dispersal Systems shall be required for any system where, due to space constraints, the soil cover run-out of the primary At-grade overlaps the soil cover run-out area of the secondary At-grade. B. SITING REQUIREMENTS 5. Horizontal Setback Requirements. The minimum horizontal setback distances specified in Table 4-10 apply to the At-Grade System (as measured from the edge of cover soil) except where modified below for buildings, structures, property and underground utility easements: a. Upgradient and laterally: Ten (10) feet b. Downgradient: Twenty five (25) feet

99 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 6. Vertical Separation Requirements. Vertical separation and slope requirements for At- Grade Systems are provided in Table 3-1. a. Depth to Groundwater. Minimum depth to seasonal high groundwater for At- Grade systems, as measured from ground surface, shall vary according to soil percolation rate and the level of treatment. b. Effective Soil Depth. Minimum depth of soil, as measured from ground surface to impermeable soil or rock, for At-Grade systems shall vary according to soil percolation rate and the level of treatment. These soil depth requirements shall apply within the dispersal field and in the adjacent area extending a distance of twenty-five (25) feet down-slope of the At-grade system on sloping sites, and a distance of fifteen (15) feet on all sides on level sites. 7. Maximum Ground Slope. a. Soil Percolation Rates between one (1) and sixty (60) mpi: The maximum ground slope in areas used for Mound Systems with average soil percolation rates between one (1) and sixty (60) mpi shall be twenty (20) percent. b. Soil Percolation Rates greater than 60 mpi: At-Grade systems shall not be sited where the dispersal area soil has an average percolation rate greater than 60 mpi. C. TREATMENT REQUIREMENTS The following treatment requirements shall apply in connection with the use of At-Grade Systems: 1. Primary (septic tank) treatment shall be the minimum level of treatment, and shall be acceptable where the applicable vertical separation distances are met per Table Supplemental treatment, using an approved alternative treatment system identified in this Manual, may be used to allow compliance with reduced vertical separation distance provided in Table 3-1. D. PRESSURE DOSING Wastewater Effluent, from the Septic Tank or Supplemental Treatment System, shall be applied to the At-Grade Dispersal System by pressure dosing, utilizing a pump system. The pressure distribution system shall be designed in accordance with accepted industry practices to achieve, at a minimum: 1. Uniform dosing of treated effluent over the surface application area of the At-grade distribution bed; 2. Adequate flow rate, screening of effluent and suitable piping network to preclude solids accumulation in the pipes or clogging of discharge orifices; 3. Suitable access provisions for inspection, testing and adjustment of the pressure distribution system;

100 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 4. At least one distribution lateral for every thirty-six (36) inches of distribution bed width; and 5. Pump system designed in accordance with the pump system requirements provided in Chapter 5 of this Manual. 6. Additional requirements for design and construction of pressure distribution piping systems contained in the guidelines for Pressure Distribution Systems in Section 7.3 of this Chapter, as applicable. E. AT-GRADE SYSTEM PLACEMENT 1. On sloping sites (greater than 2 percent), the At-Grade System shall be aligned with its longest dimension parallel to the site contours so as not to concentrate the effluent into a small area as it moves laterally down slope. 2. The At-Grade System shall not be aligned perpendicular to the contours. 3. The At-Grade System shall not be placed in a concave landscape position. 4. The gravel distribution bed shall be as long and narrow as possible to limit the linear loading rate of effluent to assure that all the effluent infiltrates into the natural soil before it reaches the toe of the At-Grade System. 5. Site drainage shall be provided so that rainfall and runoff is directed away from or around the At-Grade System. On sloped sites curtain drains may be required to divert runoff away from the At-Grade System. F. GRAVEL DISTRIBUTION BED 1. Material. The distribution bed shall consist of 3/8-inch double-washed pea gravel, substantially free of fines (defined as less than one (1) percent fines, dust, sand and/or silts passing the #200 seive). 2. Depth. Pea gravel shall extend a minimum of six (6) inches below the invert and two (2) inches above the top of the distribution piping. 3. Slope Contour. The toe of the gravel distribution bed shall follow contour and not deviate more than three (3) inches vertically per one-hundred (100) feet horizontally. 4. Gravel Bed Sizing. The minimum gravel distribution bed area shall be sized to meet the maximum wastewater application rates and linear loading requirements in accordance with the criteria provided in Table 7-8. G. SOIL COVER 1. Material. A continuous soil cover shall be placed over the entire distribution bed. The soil cover shall consist of a medium, loamy-textured soil. 2. Silt Barrier. The gravel distribution bed shall be covered in its entirety with a geotextile ("filter fabric") silt barrier. Filter fabric shall either be polyester, nylon or polypropylene, or any combination thereof, and shall be suitable for underdrain applications. Filter fabric shall be non-woven, shall not act as a wicking agent and shall be permeable.

101 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 3. Depth. Soil cover depth shall be a minimum of twelve (12) inches and a maximum of eighteen (18) inches over the top of the distribution bed. Soil cover over the distribution bed shall be crowned to promote rainfall runoff, and compacted by track-rolling, minimum two passes. 4. Lateral Extension. The soil cover shall extend a minimum of four (4) feet beyond the perimeter edge of the gravel bed in all directions on level sites. On sloping sites (greater than 2 percent), the soil cover extension beyond the down-slope edge of the gravel bed shall increase according to slope length correction factors for Mound Systems in Table H. DUAL AT-GRADE DISPERSAL SYSTEMS 1. Distribution Bed Placement. Dual At-grade systems shall have at least two (2) distinctly separate distribution beds. The beds may be placed with one continuous soil cover fill or with independent soil cover fill. The distribution beds may be placed end-to-end or upslope/down-slope of one another, subject to meeting minimum sizing requirements determined from basal area and linear loading criteria above. 2. Distribution Bed Separation. The minimum lateral (i.e., end-to-end) separation between distribution beds for dual At-grade systems shall be six feet. 3. Alternate Dosing. The distribution beds for At-grade systems shall be designed and operated to provide alternate dosing and resting of the beds. I. INSPECTION WELLS A minimum of three (3) inspection wells shall be installed within and around the Drip Dispersal System area in accordance with the requirements in Table 7-5 for the purpose of checking groundwater levels periodically and water quality sampling, if needed. J. REFERENCE GUIDELINES Additional guidelines for At-grade Dispersal Systems shall be in accordance with guidelines contained in the following references: 1. "Wisconsin At-grade Soil Absorption System Siting, Design and Construction Manual, Small Scale Waste Management Project, University of Wisconsin-Madison, "Onsite Wastewater Treatment Systems Manual", U.S. Environmental Protection Agency, February At-grade Component Using Pressure Distribution Manual for Private Onsite Wastewater Treatment Systems, State of Wisconsin, Department of Commerce, 1999.

102 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.8 MOUND DISPERSAL SYSTEMS A. DESCRIPTION A Mound Dispersal System consists of an elevated sand bed with a gravel distribution bed covered by soil fill. Mound systems are intended to raise the soil absorption system above grade and provide further treatment (sand filtration) of effluent before it reaches native soils. It utilizes the shallow surface soils for broad distribution of effluent, and is used to mitigate high water table and shallow soil conditions on flat or gently sloping terrain. Schematic and cross-section diagrams are provided in Figure 7-12 through Figure 7-18 to illustrate the key design features of Mound Dispersal Systems. B. CONSTRAINTS ADDRESSED 1. High groundwater; 2. Shallow soil over impermeable soil or bedrock; 3. Shallow soil over fractured rock or coarse alluvium; 4. Slow percolation at Standard Dispersal Trench depths; and 5. Limited Dispersal System area. C. PRIMARY AND RESERVE AREA REQUIRED 1. Primary Mound System. A Primary Mound Dispersal System designed to treat one hundred percent of the design wastewater flow shall be installed. 2. Reserve Mound System Area. A reserve area having suitable site conditions and sufficient area for full, one-hundred (100) percent replacement of the primary Mound Dispersal System shall be identified during the Site Evaluation and reserved for use when the Primary Mound Dispersal System fails. 3. Overlap of Dispersal Areas. In determining the necessary space for the primary and secondary (reserve) field, the required sand fill basal area of the primary and secondary Mound shall not overlap. The surplus sand run-out and soil fill shall also not overlap. D. SITING REQUIREMENTS 1. Horizontal Setback Requirements. The minimum horizontal setback distances specified in Table 4-10 apply to the Mound system (as measured from the edge of cover soil) except where modified below for buildings, structures, property and underground utility easements: c. Upgradient and laterally: Ten (10) feet d. Downgradient: Twenty five (25) feet 2. Vertical Separation and Slope Requirements. Vertical separation and slope requirements for Mound Dispersal Systems are provided in Table 3-1.

103 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN a. Depth to Groundwater. Minimum depth to seasonal high groundwater for Mound Systems, as measured from ground surface, shall vary according to soil percolation rate. b. Effective Soil Depth. Minimum depth of soil, as measured from ground surface to impermeable soil or rock, for mound systems shall be two (2) feet. This soil depth requirement shall apply within the mound fill area and in the adjacent area extending a distance of twenty-five (25) feet down-slope of the Mound system. 3. Maximum Ground Slope. a. Soil Percolation Rates between one (1) and sixty (60) mpi: The maximum ground slope in areas used for Mound Systems with average soil percolation rates between one (1) and sixty (60) mpi shall be twenty (20) percent. b. Soil Percolation Rates greater than 60 mpi: The maximum ground slope in areas used for Mound Systems with average soil percolation rates greater than sixty (60) mpi shall be fifteen (15) percent. E. TREATMENT REQUIREMENTS 1. Mound Systems are designed for treating residential strength wastewater. The wastewater applied to the Mound System shall meet the definition of residential-strength wastewater (or less) per the criteria provided in Chapter The Mound Dispersal System shall be preceded by a septic tank sized for the design wastewater flow. 3. High strength wastewater shall require Supplemental Treatment in order to reduce its strength to residential waste strength or less prior to introduction into the Mound System. F. PRESSURE DOSING Septic Tank Effluent shall be applied to the Mound Dispersal System by pressure dosing, utilizing a pump system. The pressure distribution system shall be designed in accordance with accepted industry practices to achieve, at a minimum: 1. Uniform dosing of treated effluent over the surface application area of the Mound distribution bed; 2. Adequate flow rate, screening of effluent and suitable piping network to preclude solids accumulation in the pipes or clogging of discharge orifices; 3. Suitable access provisions for inspection, testing and adjustment of the pressure distribution system; 4. Dosing volume to achieve a minimum of three (3) to five (5) doses per day at design flow conditions; 5. At least one distribution lateral for every thirty-six (36) inches of distribution bed width;

104 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 6. Pump system designed in accordance with the pump system requirements provided in Chapter 5 of this Manual; and 7. Additional requirements for design and construction of pressure distribution piping systems contained in the guidelines for Pressure Distribution Systems in Section 7.3 of this Chapter, as applicable. G. MOUND PLACEMENT 1. On sloping sites (greater than 2 percent), the mound shall be aligned with its longest dimension parallel to the site contours so as not to concentrate the effluent into a small area as it moves laterally down slope. 2. The mound shall not be aligned perpendicular to the contours. 3. The mound shall not be placed in a concave landscape position. 4. The infiltration bed shall be as long and narrow as possible to limit the linear loading rate of effluent to assure that all the effluent infiltrates into the natural soil before it reaches the toe of the filter media. 5. Site drainage shall be provided so that rainfall and runoff is directed away from or around the mound system. On sloped sites curtain drains may be required to divert runoff away from the mound. H. GRAVEL DISTRIBUTION BED 1. Material. The gravel distribution bed shall consist of three-eighth (3/8) inch doublewashed pea gravel, substantially free of fines (defined as less than one (1) percent fines, dust, sand and/or silts passing the #200 seive). 2. Depth. Pea gravel shall extend a minimum of six (6) inches below the invert and two (2) inches above the top of the distribution piping. 3. Level. The bottom of the distribution bed shall be level. 4. Slope Contour. The down-slope side of the gravel distribution bed shall be parallel to the slope contour. The bed shall be installed within a tolerance of three (3) inches vertically per one-hundred (100) feet horizontally. 5. Gravel Bed Sizing. The minimum gravel distribution bed area shall be sized to meet the maximum wastewater application rates and linear loading requirements in accordance with the criteria provided in Table 7-9. I. SAND FILL MEDIA 1. Sand Specifications. The sand media shall be a medium to coarse sand which meets the gradation specifications in Table 9-1. Documentation of laboratory sieve analysis results for the proposed sand fill material shall be supplied to the Department to verify conformance with the above specifications.

105 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 2. Sand Depth. a. The minimum depth of sand fill below the gravel distribution bed shall be twelve (12) inches. b. The minimum depth of sand fill shall be increased to twenty-four (24) inches for sites where the average percolation rate is between one (1) and five (5) mpi; such sites also require a three (3) foot separation to groundwater below sand-soil interface. 3. Slope Contour. The toe of the sand fill shall follow contour and not deviate more than three (3) inches vertically per one-hundred (100) feet horizontally. 4. Sand Fill Area Sizing. The minimum basal area of the sand fill (i.e., sand/soil interface area) shall be sized to meet the maximum basal wastewater application rates and linear loading requirements in accordance with the criteria provided in Table Effective Sand Fill Basal Wastewater Application Area. The effective sand fill basal wastewater application area shall be determined based on the slope of the native ground surface as follows. Slope (%) Effective Basal Wastewater Application Area 0 to 2 The entire sand fill basal area The sand basal area immediately below and directly down-slope (at >2 right angles to the natural slope contours) of the gravel distribution bed. 7. Lateral Dimensions. a. On level sites the top of the sand fill shall extend horizontally beyond the gravel distribution bed a minimum of twenty-four (24) inches in all directions, then slope uniformly as determined by the mound dimensions. b. On slopes greater than 2 percent, the twenty-four (24) inch sand fill dimension on the upslope side of the distribution bed may be reduced to 12 inches, then slope uniformly as determined by the mound dimensions. c. The maximum side slope of the top of the sand surface shall be three (3) horizontal to one (1) vertical. J. SOIL COVER 1. Material. A continuous soil cover shall be placed over the entire distribution bed and sand fill. The soil cover shall consist of a medium, loamy-textured soil. 2. Silt Barrier. The gravel distribution bed shall be covered in its entirety with a geotextile ("filter fabric") silt barrier. Filter fabric shall either be polyester, nylon or polypropylene, or any combination thereof, and shall be suitable for underdrain applications. Filter fabric shall be non-woven, shall not act as a wicking agent and shall be permeable.

106 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 3. Depth. Soil cover depth shall be a minimum of twelve (12) inches and a maximum of eighteen (18) inches over the top of the gravel distribution bed, and twelve (12) inches minimum over the sand fill portion of the mound. Soil cover over the distribution bed shall be crowned to promote rainfall runoff, and compacted by track-rolling, minimum two passes. 4. Lateral Extension. The soil cover shall extend a minimum of four (4) feet beyond the perimeter edge of the sand fill in all directions. In the down-slope direction. K. INSPECTION WELLS A minimum of six (6) inspection wells shall be installed within and around the Mound Dispersal System area in accordance with the requirements in Table 7-5 for the purpose of checking groundwater levels periodically and water quality sampling, if needed. L. REFERENCE GUIDELINES Additional guidelines for mound system design are contained in the following references: 1. "Design and Construction Manual for Wisconsin Mounds", Small Scale Waste Management Project, University of Wisconsin, Madison, January 2000, including any amendments. 2. "Onsite Wastewater Treatment Systems Manual", U.S. Environmental Protection Agency, February 2002.

107 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.9 RAISED SAND FILTER BED SYSTEMS A. DESCRIPTION 1. Raised sand filter beds shall be used only for repair or replacement of Existing Systems on severely constrained sites where site specific conditions limit treatment and dispersal options. 2. A raised sand filter bed, sometimes referred to as a bottomless sand filter, combines features of an intermittent sand filter and a mound system. It consists of a raised or terraced sand bed, commonly supported by a low retaining wall or bulkhead, where the bottom surface is even with or slightly below ground surface and forms the absorption surface. The raised sand filter bed provides additional polishing treatment of effluent and final dispersal of wastewater into native soil. 3. The System may be designed for use with supplemental treatment ahead of the raised sand bed when required for very shallow soil or very highly permeable soils. 4. Schematic and cross-section diagrams are provided in Figure 7-19 to illustrate the key design features of Mound Dispersal Systems. B. QUALIFIED PROFESSIONAL A Raised Sand Filter Bed system shall be designed by a California Registered Civil Engineer. C. CONSTRAINTS ADDRESSED 1. High groundwater; 2. Shallow soil over impermeable soil or bedrock; 3. Shallow soil over fractured rock or coarse alluvium; 4. Slow percolation at Standard Dispersal Trench depths; 5. Moderately steep slopes; and 6. Limited Dispersal System area. D. SITING REQUIREMENTS Siting requirements for Raised Sand Filter Beds are provided in Table 3-1, Table 4-10 and Table Vertical Separation Requirements a. Depth to Groundwater. Minimum depth to seasonal high groundwater for Raised Sand Filter Bed Systems, as measured from ground surface, shall vary according to soil percolation rate.

108 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN b. Effective Soil Depth. Minimum depth of soil, as measured from ground surface to impermeable soil or rock, for mound systems shall be 2 feet. This soil depth requirement shall apply within the dispersal field area beneath the Raised Sand Filter Bed and in the adjacent area extending a distance of twenty-five (25) feet down-slope of the Raised Sand Filter Bed. c. Permeable Soil Requirements. Raised Sand Filter Beds are suitable for permeable Soils in USDA Soil Textural Classification of coarse sand, medium sand, fine sand, loamy sand, sandy loam, loam, sandy clay loam, and silt loam. 2. Maximum Ground Slope. Maximum ground slope in areas used for Mound Dispersal Systems shall be twenty (20) percent. E. TREATMENT REQUIREMENTS The following treatment requirements shall apply in connection with the use of raised sand filter bed systems: 1. Primary (septic tank) treatment shall be the minimum level of treatment, and shall be acceptable where the design includes sand fill depth of twenty-four (24) inches. 2. Supplemental treatment, using an approved Supplemental Treatment Unit may be used to allow reduction of the sand fill depth to twelve (12) inches. F. PRESSURE DOSING Septic Tank Effluent shall be applied to the Mound Dispersal System by pressure dosing, utilizing a pump system. The pressure distribution system shall be designed in accordance with accepted industry practices to achieve, at a minimum: 1. Uniform dosing of treated effluent over the surface application area of the Raised Sand Filter Bed; 2. Adequate flow rate, screening of effluent and suitable piping network to preclude solids accumulation in the pipes or clogging of discharge orifices; 3. Suitable access provisions for inspection, testing and adjustment of the pressure distribution system; 4. Dosing volume to achieve a minimum of three (3) to five (5) doses per day at design flow conditions; 5. At least one distribution lateral for every thirty-six (36) inches of distribution bed width; and 6. Pump system designed in accordance with the pump system requirements provided in Chapter 8 of this Manual. 7. Additional requirements for design and construction of pressure distribution piping systems contained in the guidelines for Pressure Distribution Systems in Section 7.3 of this Chapter, as applicable.

109 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN G. RAISED SAND FILTER BED CONTAINMENT STRUCTURE 1. Containment Liner. The raised sand filter bed shall be provided with an impermeable containment liner along all sides of the filter bed to prevent lateral leakage out of or into the filter. a. The liner shall extend a minimum of twelve (12) inches below native grade. b. The liner shall consist of either: i. 30 mil plastic; ii. iii. reinforced poured-in-placed concrete; or an equivalent impermeable structure. 2. Retaining Wall. The finished grade of the raised sand filter bed shall be above the surrounding ground elevation and shall be structurally supported with retaining wall(s), as required. 3. Bed Dimensions. The maximum width of the sand bed shall be ten (10) feet. The raised sand filter bed shall not be restricted as to its shape in plan view. 4. Multiple Units. The raised sand filter bed may be divided into compartments or multiple units. H. SAND FILTER MEDIA 1. Sand Specifications. The sand media shall be a medium to coarse sand which meets the gradation specifications for Raised Sand Filter Beds in Table 9-1. Documentation of laboratory sieve analysis results for the proposed sand filter media material shall be supplied to the Department to verify conformance with the above specifications. 2. Sand Depth. The minimum depth of sand fill, below the gravel distribution bed, shall be: a. Twenty-four (24) inches for septic tank effluent. b. Twelve (12) inches for supplement treatment. I. SAND FILL BASAL AREA SIZING The basal area of the sand filter bed (i.e., area of the sand-soil interface) shall be sized to meet the maximum basal wastewater application rates and linear loading requirements provided in Table Wastewater Flow. The wastewater flow used for sizing the basal area of the sand filter bed shall be the design wastewater flow for the system. 2. Wastewater Application Rate. Wastewater application rates used for sizing the basal area of the sand filter bed shall be based on soil percolation rates in the upper (12) to twentyfour (24) inches of soil depth in accordance with the criteria in Table 4-5 (Standard Wastewater Application Rates) if primary treatment only is utilized, or Table 4-7 (Enhanced Wastewater Application Rates) if Supplemental Treatment is utilized. Reduction in the

110 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN wastewater loading rates or other provisions to insure the long-term integrity and performance of the raised sand filter bed may be required for high strength waste flows. 3. Minimum Sizing. The minimum size (square feet) of the basal area of the raised sand filter bed shall be determined by dividing the design wastewater flow (in gpd) by the applicable wastewater application rate per Table 4-5 or 4-7. Sand Fill Basal Area (ft2) = Design Wastewater Flow Rate (gpd) Wastewater Application Rate (gpd/ft2) 4. Effective Length. The effective length (L) of the Raised Sand Filter Bed shall be the total length of the raised bed along the downslope edge. Effective Length (ft) = Design Wastewater Flow Rate (gpd) Linear Loading Rate (gpd/lineal foot) a. Linear Loading Rate. Maximum linear loading rates for raised sand filter bed systems sizing shall vary according to soil depth, ground slope, and percolation rate as indicated in Table If a variance from these criteria is proposed, it must be supported by detailed groundwater mounding analysis carried out in accordance with accepted methodology and/or scientific references dealing with water movement in soils and utilizing site specific hydraulic conductivity data. b. Wastewater Flow (Q). The wastewater flow used for determining the linear loading rate shall be as follows: System Type Q (gpd) Residential Systems 100 gpd/bedroom 1 Commercial, Institutional, Industrial and Multi-residential Systems Design wastewater flow rate Note: 1 One hundred and fifty (150) gpd shall be used for System design J. GRAVEL DISTRIBUTION BED 1. Material. The distribution bed shall consist of three-eighth (3/8) inch double-washed pea gravel, substantially free of fines.

111 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 2. Depth. Pea gravel shall extend a minimum of six (6) inches below the invert and two (2) inches above the top of the distribution piping. If the distribution piping is installed with chambers, the pea gravel depth below the distribution pipe may be reduced from six (6) inches to four (4) inches, and the two (2) inch pea gravel cover may be eliminated. 3. Silt Barrier. The gravel distribution bed shall be covered in its entirety with a geotextile ("filter fabric") silt barrier. Filter fabric shall either be polyester, nylon or polypropylene, or any combination thereof, and shall be suitable for underdrain applications. Filter fabric shall be non-woven, shall not act as a wicking agent and shall be permeable. K. SOIL COVER 1. Material. A continuous soil cover consisting of a medium, loamy-textured soil shall be placed over the entire gravel distribution bed. 2. Depth. Soil cover depth shall be a minimum of twelve (12) inches and a maximum of eighteen (18) inches over the top of the gravel distribution bed. Soil cover shall be crowned or sloped to promote rainfall runoff. L. INSPECTION PORTS A minimum of four (4) inspection ports shall be installed within and around the Raised Sand Filter Bed in accordance with the requirements in Table 7-5 for the purpose of checking groundwater levels periodically and water quality sampling, if needed.

112 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.10 STANDARD TRENCH GRID DISPERSAL SYSTEM 1. Standard trench grid dispersal systems shall be used only for repair or replacement of existing systems on severely constrained sites where site specific conditions limit treatment and dispersal options. 2. A Schematic diagram is provided in Figure 7-1 to illustrate the key design features of a standard trench grid dispersal system. 3. Maximum ground slope in areas used for grid systems shall be less than five (5) percent. 4. A cross-section of the entire disposal field area must be shown on the design plans to verify trench depths. Trench depths must comply with requirements for Standard conventional trenches as listed in Table Drainfield trench bottoms must be installed level, with a tolerance of zero (0) to two (2) inches maximum per one-hundred (100) lineal feet. 2. For each crossover connection (at the ends of the grid and in the middle of drainlines longer than 100 lineal feet), four (4) lineal feet will be counted towards the required lineal footage of drainlines due to the loss of absorption area in the corners of the grids. For example, with a 10-foot separation between drain lines, only six (6) lineal feet would be counted. 3. Any drainfield proposed in areas where the slope is five (5) percent or more shall utilize relief lines ( popovers ) or an approved D-box. This may result in a drainfield design that utilizes both grid and popover (or D-Box) systems on the same side of the diversion valve. 4. All percolation tests must be conducted at the level of the deepest trench depth proposed in the drainfield design. An alternative method would be to allow the percolation test holes to be at a depth midway between the shallowest trench depth proposed and the maximum trench depth proposed, providing the soil is of a consistent type throughout the trench depth range. 5. The area proposed for a grid system may not be graded to achieve a slope of less than five (5) percent. Slope calculations will be based on the original, natural slope.

113 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.11 DEEP TRENCH DISPERSAL SYTEMS

114 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 7.12 ENGINEERED FILL DISPERSAL SYSTEMS A. DESCRIPTION Engineered fill is a soil bed that has been designed, placed and compacted in accordance to approved design criteria for purposes of elevating the dispersal field above natural grade. Engineered fill dispersal fields must be designed by a California Registered Civil Engineer. Engineered fill dispersal fields do not have a high success rate and have a tendency to fail. Therefore these types of dispersal fields will only be considered in repair or replacement situations where site specific conditions limit dispersal options and where there is no other viable alternative. B. CONSTRAINTS ADDRESSED 1. High groundwater; 2. Shallow soil over impermeable soil or bedrock; 3. Shallow soil over fractured rock or coarse alluvium; 4. Slow percolation at standard dispersal trench depths; and 5. Limited dispersal area. C. SITING REQUIRMENTS Siting requirements for engineered fill systems are provided in Table Vertical Separation Requirements. a. Depth to Groundwater. Minimum depth to seasonal high groundwater for engineered fill systems, as measured from ground surface, is dependent on the level of wastewater treatment and the soil percolation rate. i. Effective Soil Depth. Minimum depth of native soil, as measured from ground surface to impermeable soil or rock, shall be twelve (12) inches (after removal of the organic top Soil layer) in all areas of the proposed dispersal system. ii. If the limiting layer consists of material coarser than sand, or fractured material, the system designer shall demonstrate that there will be no saturated soil conditions formed at the soil/limiting layer interface due to capillary forces in the soil. 2. Maximum Ground Slope. Maximum ground slope in areas used for Engineered Fill Systems shall be ten (10) percent.

115 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN D. TREATMENT REQUIREMENTS Supplemental treatment, using pressure dosing and an approved alternative treatment system identified in this manual, shall be used to allow compliance with reduced vertical separation distance provided in Table E. ENGINEERED FILL SPECIFICATION 1. Site preparation and placement of fill must be under the direct supervision of a California Registered Civil Engineer. 2. Engineered fill shall be evaluated after stabilization by a California Registered Civil Engineer for adequate permeability and percolation. 3. At least three (3) percolation tests shall be performed within the consolidated fill soil after placement and stabilization. 4. A minimum of two sieve analyses shall be conducted prior to fill placement to test for oversize material. 5. Fill shall compensate for the lack of in-place soil at a one and one half to one (1.5:1) ratio so that a one foot deficiency in soil column depth shall require one and one half feet of fill. A minimum of twelve (12) inches of compensating fill shall be required. 6. Fill will be engineered to the specifications of loamy sand with no more than 15 percent fines. At least seventy-five (75) percent of fill material shall pass the two (2) millimeter (mm) sieve. Any sieve analysis falling outside of a loamy sand specification shall be cause for rejection of all fill material. All organic material and material over one (1) inch in diameter shall be removed from fill. 7. Engineered fill, after stabilization, must have a percolation rate between five (5) and sixty (60) mpi. F. DRIP DISPERSAL 1. Wastewater effluent shall be applied by drip irrigation at a maximum application rate of 0.2 gallons/square foot/day. 2. The drip line layout design shall be reviewed by the approved sub-surface drip system manufacturer's factory trained designer. 3. The emitters will be placed at the top of the compensating fill layer, with an additional minimum twelve (12) inches of cover material over the emitters. G. CONSTRUCTION SPECIFICATIONS 1. The organic top soil layer shall be removed from the native soil. Grubbed, native soil shall be worked with a chisel or shank plow with crawler or tracked equipment (no rubber tired vehicles allowed) to scarify the top four (4) inches. All stumps and roots in excess of onequarter (¼) inch in diameter shall be removed from the native soil.

116 CHAPTER 7 SUBSURFACE DISPERSAL SYSTEM DESIGN 2. If fill soil must be transported to the fill site over long distances, care shall be taken to prevent excessive segregation of soil separates. 3. Fill shall be placed as dry as possible and when its moisture content will not cause excessive compaction. 4. An initial fill soil lift of six (6) inches shall be blended into the scarified native Soil. Subsequent lifts of fill shall be no greater than six (6) inches. The top two (2) to (3) inches of each subsequent lift shall be scarified prior to addition of subsequent lifts. 5. After placement, soil shall be consolidated by a means chosen by the design engineer (e.g. light compaction by tracked equipment, by allowing the soil to consolidate naturally over a rainy season, or by watering with at least the estimated pore volume of the fill). 6. Side slopes of any soil mound shall be a three vertical to one horizontal (3:1) slope. For low transmissivity soils a certified design consultant may design shallower slopes. The side slopes shall begin forty-eight (48) inches from any dispersal line. 7. After fill is placed and approved, system shall be crowned with a loam or sandy loam soil type to create a final cap. The bed cap shall be seeded with shallow rooted grass. Seeded areas shall be watered as necessary to establish and maintain vegetation over the life of the unit. 8. "Toes" of built areas shall remain accessible and visible with no vegetation taller than two inches high. 9. Each system shall be provided with one up gradient and two down gradient shallow monitoring wells finished into the limiting layer.

117 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS 8.1 OVERVIEW The chapter presents specifications for non-discharging wastewater toilet units and graywater systems. A non-discharging wastewater toilet unit is a self-contained, watertight container designed to hold wastewater until it is pumped and/or cleaned. A non-discharging wastewater toilet unit includes but is not limited to a Vault Privy, Portable Toilet, and Waterless Toilet. These methods may be subject to the requirements of an Operating Permit. A graywater system is designed to collect graywater and transport it out of the structure for distribution in an irrigation field. A Graywater System may include tanks, valves, filter, pumps, or other appurtenances along with piping and receiving landscape. This chapter is organized in the following sections: Section 8.2: Vault Toilets Section 8.3: Portable Toilets Section 8.4: Waterless Toilets Section 8.5: Graywater Systems

118 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS 8.2 VAULT TOILET REQUIRMENTS A. DESCRIPTION 1. A Vault Toilet (or Privy) is a structure used for disposal of human waste without the aid of water. 2. A Vault Toilet consists of a shelter built above a subsurface vault into which human waste falls. 3. The Vault Privy has no water connection. B. SITING CRITERIA 1. The Vault Privy shall only serve non-residential and non-commercial, limited use applications, such as primitive type picnic grounds, campsites, camps and recreation areas where Septic Tank and leach field systems are not practicable as determined by DEH. Approval to permit Vault Privies will be considered by the Department on a case-bycase basis. 2. Vault Privies shall not be used for seasonal dwellings, commercial facilities, or singlefamily dwellings. C. GENERAL REQUIREMENTS 1. The vault shall be watertight and tested for water tightness at the time of installation using the same methods as found in Section 5 for tank water tightness. 2. The vault shall be constructed in substantial compliance with the specifications for Holding Tanks (See Section 5) and designed to facilitate the removal of the wastes. 3. The vault shall meet the same setbacks requirements as a Septic Tank found in Chapter The capacity of the vaults shall be adequately sized to accommodate the proposed use. 5. Vault Privies shall not be located in a floodway or areas subject to seasonal flooding. 6. Structures must be free of hazardous surface features, such as exposed nail points, splinters, sharp edges, and rough or broken boards, and will provide privacy and protection from the elements. 7. Building ventilation must be equally divided between the bottom and top halves of the room. All vents must be screened with sixteen (16) mesh screen of durable material. 8. Buildings must be fly and rodent resistant, and will have self-closing doors with an inside latch. 9. Vaults must be vented to the outside atmosphere by a flue or vent stack having a minimum inside diameter of four (4) inches.

119 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS 10. Interior floors, walls, ceilings, partitions, and doors must be finished with readily cleanable impervious material resistant to wastes, cleansers and chemicals. Floors and risers must be constructed of impervious material and in a manner that will prevent entry of vermin. 11. The seat opening must be covered with attached, open-front toilet seats with lids, both of which can be raised to allow use as a urinal. 12. A toilet tissue holder must be provided for each seat. 13. Vents must be sized to equal in area to a minimum of three (3) square feet. 14. A minimum clear space of twenty-four (24) inches between multiple unit installations and a clear space of twelve (12) inches from the seat opening to the side building wall in single and multiple units. 15. No water-carried sewage shall be piped to or be placed in vault privies. D. PERMIT REQUIREMENTS 1. An Operating Permit shall be required. 2. Inspections and enforcement shall take place on a complaint response basis. 3. Vault Privies shall be maintained to prevent health hazards and pollution of public waters. 4. The Vault Privy shall not be allowed to become filled with excreta to a point within two (2) feet of the ground surface. 5. The excreta in the vault shall be pumped out as necessary to fulfill these by a Septage Pumper that is permitted to perform such work in Alameda County requirements. 6. The property Owner or Septage Pumper shall submit the Septage Pumper s receipt to the Department within thirty (30) days of its pumping. 7. The privy shall be maintained in a sanitary condition and in good repair. 8. A caustic shall be added routinely to vault chambers to control odors. 9. Contents of Vault Privies shall not be discharged into storm sewers, on the surface of the ground or into public waters. 10. Vault toilet shelters shall display the business name of the Owner, manager or licensed sewage disposal service that is responsible for servicing them. 11. Proof of regular maintenance may be required.

120 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS 8.3 PORTABLE TOILET REQUIRMENTS A. DESCRIPTION 1. A Portable Toilet is any self-contained Chemical Toilet Facility that is housed within a Portable Toilet Shelter. 2. The Portable Toilet has no direct water connection. B. SITING CRITERIA 1. Portable Toilets may be allowed for temporary or limited use areas, such as construction Sites (for use by onsite employees), mobile or temporary agricultural uses, temporary campsites, and special events, provided the Portable Toilets meet the same setbacks requirements as a Septic Tank provided in Chapter When associated with a Use Permit, a Plot Plan may be required which indicates the placement of the Portable Toilets relative to required setbacks. 3. When associated with a Use Permit, the minimum number of Portable Toilets shall be determined based on estimated attendees and duration of event and relevant published industry guidance, such as the Portable Sanitation Association International Special Event Extended Chart Breakdown. 4. Portable Toilets shall not be allowed for seasonal dwellings, commercial facilities or singlefamily dwellings. C. GENERAL REQUIREMENTS 1. Portable Toilet Shelters shall display the business name and contact information of the Owner or licensed sewage disposal service that is responsible for servicing them. 2. All surfaces subject to Soiling shall be impervious, easily cleanable, and readily accessible. 3. No water-carried sewage may be piped to or placed in Portable Toilets. 4. Portable shelters shall provide screened ventilation to the outside atmosphere having a minimum area of one (1) square foot per seat; 5. Portable Toilets shall provide separate compartments with doors and partitions or walls of sufficient height to ensure privacy. 6. Toilets will have toilet bowls constructed of stainless steel, plastic, fiberglass, or ceramic or of other material approved by the Department. 7. Waste passages will have smooth surfaces and be free of obstructions, recesses or cross braces that would restrict or interfere with flow of sewage. 8. Chambers and receptacles will provide a minimum storage capacity of fifty (50) gallons per seat.

121 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS 9. Portable Toilets shall be maintained to prevent health hazards and pollution of protected waters. 10. Contents of Portable Toilets will not be discharged into storm sewers, on the surface of the ground or into protected waters. 11. Biocides and oxidants must be added to waste detention chambers at rates and intervals recommended by the manufacturer. 12. Wastes shall be removed from the chamber as necessary to prevent overflow. D. PERMIT REQUIREMENTS An Operating Permit will not be required for temporary use (less than 7 days) of Portable Toilets and in agricultural field activities.

122 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS 8.4 WATERLESS TOILET REQUIRMENTS A. DESCRIPTION A Waterless Toilet includes a composting toilet, an incinerating toilet or similar device for the holding and processing of Wastewater from a toilet. B. PROHIBITIONS 1. Minimum Lot size for the use of Waterless Toilets shall be two (2) acres. 2. The excrement from Waterless Toilets shall not create a public nuisance. 3. The use of a Waterless Toilet shall not replace the requirement for a System that meets all of the requirements of this Manual. C. HEALTH CONCERNS 1. Waterless Toilets have been showed to be capable of deactivating and/or killing pathogens through the internal processes that take place. 2. Due to external conditions of operational irregularities, the conditions in the unit may not always be optimal for pathogen reduction and improper handling and disposal of the product could adversely impact public health. D. FUTURE OWNERSHIP 1. Properties may change ownership. 2. One family that is fully educated on how to operate and maintain their Waterless Toilet and is highly motivated to do so may be replaced by another family that does not share the previous owners expertise and values. 3. Therefore, the Onsite Wastewater Treatment System must be properly sized to accommodate one hundred (100) percent of the wastewater estimated for the structure served by the System regardless if Waterless Toilets. E. REQUIREMENTS 1. A Site Evaluation shall be conducted in the area of the proposed disposition of Waterless toilet wastes. The Site Evaluation shall verify at least five (5) feet of separation to groundwater or other limiting layer from the bottom of the disposition pit. 2. Waterless toilets should only be considered for owner occupied dwellings on Lots that are at least two (2) acres in size. 3. Waterless toilets may be considered agricultural field settings to replace the use of a Portable Toilet.

123 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS 4. The Lot to be served by the Waterless Toilet shall first be shown to be capable of supporting an Onsite Wastewater Treatment System meeting the requirements of this Manual. 5. The Waterless Toilet shall be installed, maintained, and replaced in accordance with the manufacture s recommendations. 6. No material shall be placed in a Waterless Toilet other than the material for which it has been designed. 7. Installation of the Waterless Toilet has been inspected by the Building Official having jurisdiction, or designee, in consultation with Department. 8. The Waterless Toilet shall be specifically designed for holding and processing liquid and solid human waste, generally associated with toilet usage, and employs the process of biological degradation and/ or heat incineration in which organic material is converted to a compost-like substance. 9. The Waterless Toilet shall be certified and currently listed by the National Sanitation Foundation (NSF) under NSF/ ANSI Standard The model of the Waterless Toilet selected shall be appropriate for the number of users and intended demand. The assumed number of users of the Waterless Toilets shall be provided by the Applicant by estimating the maximum number of people living in the dwelling or if not a residential setting, then estimating the maximum number of people using the toilet on a daily basis. The manufacturer specification sheet shall be provided and shall demonstrate the toilet is appropriately sized for the planned use. 11. The product of the Waterless Toilet shall only be handled and disposed of after the digestion process is complete as specified in the manufacturer s instructions and in this Section. 12. Waterless Toilets have been shown to be capable of deactivating and/or killing pathogens through the internal processes that take place. Due to external conditions or operational irregularities, the conditions in the unit may not always be optimal for pathogen destruction and improper handling and disposal of the product could adversely impact public health by allowing transmission of a variety of enteric diseases and parasitic illnesses. The product of the Waterless Toilet digestion must, therefore, be transported and disposed of in a manner that does not create a public nuisance and is in accordance with the requirements of the Operating Permit and the Owner s operation and maintenance manual, and the following requirements: a. Transportation needs to be by a licensed Septage Pumper to an approved solid waste disposal facility capable of accepting human waste; or b. Disposition by the Owner of the property where the Waterless Toilet is located shall meet the following conditions: i. Bury the waste under a minimum of six (6) inches of compacted soil; and ii. The location of the burial shall be shown on a site plan submitted to the DEH during the Site Assessment process; and

124 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS iii. iv. The waste shall not be buried in any present or planned food crop growing areas or dairy pasture; and The waste should not be buried where there is less than 5 feet of native, undisturbed Soil between the bottom of the burial excavation and the seasonal High Groundwater table or in an area subject to runoff where the discharge could flow into surface or subsurface water. 13. A site plan and Site Assessment for the site proposed for the disposal of the Waterless Toilet product of composting digestion is required. 14. Setback requirements for the Waterless Toilet shall be the same as for Septic Tank in this Manual. And setback requirements for the burial site shall be the same as Dispersal Field as provided in this Manual. F. OPERATING PERMITS 1. Use of a Waterless Toilet shall require an Operating Permit issued by the Department. 2. A Person selling a parcel on which there is an approved Operating Permit for a Waterless Toilet shall notify the Department of the transfer and disclose to the prospective purchaser of the presence of the Waterless Toilet and the requirements to obtain an Operating Permit. The property seller as well as the Department shall notify the purchaser of the approved locations of the disposal of the Waterless Toilet waste product. 3. Operating Permits are non-transferrable. 4. An Operating Permit for a Waterless Toilet may be revoked under any of the following conditions: a. An unsanitary condition has been caused by the Waterless Toilet or its use; b. The waste product of the Waterless Toilet digestion has been improperly transported, disposed of or used; c. The toilet is not operated or maintained as specified in the Operating Permit or the Operating and Maintenance Manual. d. Continued use of the toilet poses a public health threat. 3. No person shall install, maintain, or replace a composting toilet unless an Operating and Maintenance Manual is maintained and available for reference on the premises. The Operating and Maintenance Manual shall at a minimum contain all of the following information: a. Potential health risks from improper use or maintenance of the Waterless Toilet; b. Manufacturer s name and model number; c. Manufacturer s NSF listing and certification;

125 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS d. Manufacturer s recommended operational capacity; e. Manufacturer s operation and maintenance guidance; f. Trouble-shooting information; g. Method of handling and site for disposal of the waste product of the Waterless Toilet; and e. Contact information in case of the need of repair or replacement. G. RECORD DISCLOSURE DOCUMENT Notification shall be recorded on the deed informing future property Owners of the following: 1. The potential health risks associated with the product of composting digestion; 2. The property owner s responsibility to maintain an Operating Permit and operate the Waterless Toilet in compliance with conditions of approval and the Operating and Maintenance Manual; and 3. Notification to DEH at time of property sale or transfer.

126 CHAPTER 8 NON-DISCHARGING TOILETS & GRAYWATER SYSTEMS 8.5 GRAYWATER SYSTEM REQUIRMENTS 1. A Graywater System is designed to collect Graywater and transport it out of the structure for distribution in shallow soil or mulch. A Graywater System may include tanks, valves, filter, pumps, or other appurtenances along with piping and receiving landscape. 2. The provisions for Graywater Systems specified in the Uniform Plumbing Code, California Code of regulations, Title 24, Part 5, Chapter 16A, Part 1 (Graywater Standards) are adopted by reference in the Alameda County Plumbing Code, unless otherwise noted below. 4. No Graywater System shall be approved, designed, constructed, or maintained except for residences that are owner occupied, unless the Owner obtains an Installation Permit. 3. No person shall construct or maintain a Graywater System unless the building is also served by an Onsite Wastewater Treatment System that is functioning properly, as verified by the Department. 5. Graywater Systems designed to receive Graywater from a single laundry waste discharge require prior plan approve from the Department, however an Installation Permit is not required. 6. Notwithstanding paragraph A5, unless otherwise authorized by the Department, all other Graywater Systems require plan review and an Installation Permit. 7. Review of the Installation Permit will include: a. Unless waived, a Site Evaluation including Soil Profile Tests as provided in this Manual b. Design review c. Inspection of construction and installation. 8. Unless otherwise approved by the Department, the application rates for Graywater Systems are the same as the application rates for Standard Systems. 8. No person shall alter or replace an approved Graywater System s components without first notifying the Department. 9. A Graywater System cannot be used to reduce the size of the Onsite Wastewater Treatment System because proper use of a Graywater System prohibits discharging into the Graywater System during saturated conditions (wet season). 10. Kitchen wastewater shall be excluded from Graywater Systems and discharged into an approved System. 11. Graywater Systems do not require Operating Permits unless the Department determines it is required because of the size or complexity of the System.

127 CHAPTER 9 CONSTRUCTION MATERIALS & INSTALLATION SPECIFICATIONS 9.1 CHAPTER OVERVIEW The chapter presents specifications for construction materials and installation. The criteria apply to new systems and modifications or repairs to existing systems. This chapter is organized in the following sections: Section 9.2: Pipes Section 9.3: Distribution Boxes and Diversion Valves Section 9.4: Drain Rock, Sand and Filter Fabric

128 CHAPTER 9 CONSTRUCTION MATERIALS & INSTALLATION SPECIFICATIONS 9.2 PIPES Unless otherwise specified, piping shall consist of materials and be constructed in conformance with the standards outlined below. All connection of pipes of different diameters shall be made with the proper fittings. 1. Labeling. All pipe throughout the System shall be clearly labeled and installed so that the labeling can be readily identified by the Department inspectors. Labeling, consisting of durable ink, must cover at least fifty (50) percent of the length of the pipe. Labeling may consist of a solid line, letters, or a combination of the two. Intervals between markings must not exceed twelve (12) inches. 2. Solid Pipe, Joints and Connections: Solid (non-perforated) pipe for Systems must conform to the standards of the most recent edition of the Uniform Plumbing Code, which is adopted by reference into the county's building ordinances. All solid pipe joints and connections must be glued, cemented or made with an elastomeric seal so as to be watertight. 3. Tightlines under Residential Driveways: Tightlines in residential traffic areas must be installed with schedule 40 Polyvinyl Chloride (PVC). An alternative is to sleeve (i.e., double pipe) the thin wall tightline pipe within an outer pipe consisting of schedule 40 PVC, Acrylonitrile-Butadiene- Styrene (ABS) or suitable alternative and rated by the Uniform Plumbing Code. 4. Distribution Pipe: Perforated pipe for standard Dispersal Systems must conform to the most recent edition of the Uniform Plumbing Code, which is adopted by reference into the county's building ordinances. The pipe diameter must be four (4) inches. 5. Effluent Sewer Pipe, Header Pipe, and Fittings: The Header Pipe shall extend a minimum of five (5) feet out to the Distribution Box. Effluent Sewer, Header Pipe and fittings shall be a minimum of three (3) inch diameter, watertight, and one of the following: a. Schedule 40 PVC that meets the most current ASTM D-1785 for three (3) inch pipe and D for minimum four (4) inch pipe. b. Schedule 40 ABS that meets the most current ASTM Specification D c. ASTM SDR 35 with solvent-welded joints. d. Other material approved by the Department. 6. Perforated Pipe. Perforated pipe shall have two (2) rows of holes spaced one hundred and twenty (120) degrees apart and sixty (60) degrees on either side of a centerline. The holes of each row shall not be more than five (5) inches on-center and must have a minimum diameter of one-half inch. 7. Gravelless Chambers. Gravelless chambers, may be used provided the products meet IAPMO standard PS Building Sewer Requirements: The Building sewer pipe extends from the house to the Septic Tank, and shall meet the following criteria: a. Supported by sand or compacted soil along entire length.

129 CHAPTER 9 CONSTRUCTION MATERIALS & INSTALLATION SPECIFICATIONS b. Sloped one-quarter (¼) inch per foot for three (3) inch diameter pipe; one-eight (1/8) inch per foot for four (4) inch diameter pipe. c. No horizontal bends greater than forty-five (45) degrees. d. Two-way clean-out extended to grade (Building Division inspects this) e. Special installation and materials required under vehicle crossings. 9. Pressure Transport Pipe. Pressure transport pipe, pressure distribution manifolds, and pressure distribution laterals (piping and fittings), must meet the most current requirements for schedule 40 PVC pressure pipe as identified in ASTM Specifications D-1785, or other material approved by the Department. All pressure distribution laterals and all pressure transport and manifold piping must be adequately sized for the design flow. 10. Curtain Drain Pipe. Curtain drain pipe must meet the requirements specified in the Manual for gravity drainfield pipe. Other types of pipe may be approved by the Department, provided it can be demonstrated that the selected pipe has the structural strength for the application proposed.

130 CHAPTER 9 CONSTRUCTION MATERIALS & INSTALLATION SPECIFICATIONS 9.3 DISTRIBUITON BOXES & DIVERSION VALVES A. DISTRIBUTION BOXES 1. Distribution boxes shall be constructed of concrete or other materials. 2. Distribution boxes shall be designed to accommodate the necessary distribution laterals and expected flows. 3. The top, walls, and bottom of concrete distribution boxes shall be at least one and one-half (1-1/2) inches thick. 4. Distribution boxes shall be installed for equal distribution to the drainfield trenches. 5. Each distribution box shall be provided with a sump extending at least one (1) inch below the invert of the outlets. 6. The box design, materials and construction shall comply with all requirements of the Uniform Plumbing Code. 7. All distribution boxes must be installed level on bedding material. B. DIVERSION VALVES 1. Diversion valves shall be constructed of durable material and be of a design. 2. Diversion valves shall be corrosion resistant, watertight, and designed to accommodate the inlet and outlet pipes. 3. Each diversion valve shall have a positive stop. 4. The valve design, materials and construction shall comply with all requirements of the Uniform Plumbing Code.

131 CHAPTER 9 CONSTRUCTION MATERIALS & INSTALLATION SPECIFICATIONS 9.4 DRAINROCK, SAND & FILTER FABRIC A. GRAVEL 1. Gravel used for drainrock shall be three quarter (¾) inch to two and one half (2½) inches in diameter. 2. Uniformly graded material is recommended to maximize pore space. 3. Drainrock shall be clean, washed, non-deteriorating gravel, with the percent by weight passing the U.S. No. 200 sieve no greater than one half (0.5) percent. 4. Alternatives to drainrock including gravelless systems, bundled aggregates may be substituted for drainrock. B. SAND 1. All filter materials used in single-pass sand filters, raised and intermittent sand filters, mound systems, pressure dosed sand trench systems and recirculating sand filters shall fall within the limits of the specifications shown in Table 9-1 for the amounts of material retained/passing (by weight). 2. The material shall also have a uniformity coefficient of four (4) or less. The uniformity coefficient is calculated by dividing D60 (the size of screen opening where sixty (60) percent of a sample passes and forty (40) percent is retained) by D10 (the size of screen opening where ten (10) percent of a sample passes and ninety (90) percent is retained). For sands with a D10 less than mm, the designer should consider a loading of no greater than 1.0 gallon/square foot-day, and specify frequent dosing. A sieve analysis, (done in accordance with ASTM D 136 for dry product, or ASTM C-117 for wet product), of the material is required prior to transport to the construction site. 3. A report of the sieve analysis and on-site analysis results must be available for the Department prior to system approval and for inclusion in the system's permanent file. C. FILTER FABRIC 1. Filter fabric shall meet or exceed the specifications described in the following table: Property Requirement Test Method Grab Strength 80 lbs. ASTM D4632 Puncture Strength 25 lbs. ASTM D4833 Trapezoid Tear 25 lbs. ASTM D4533 Apparent Opening Size Permeability AOS < mm, or > #50 US Standard Sieve > #50 US Standard Sieve 0.4 cm/sec for Soil Types 1, cm/sec for Soil Types >2 2. Examples of filter fabrics meeting this specification include: Mirafi 140 NSL. ASTM D4751 ASTM D4491

132 CHAPTER 10 SITE MODIFICATION & STABILIZATION MEASURES 10.1 OVERVIEW The chapter presents site modifications and stabilization measures used to controlling surface water and shallow perched groundwater and stabilize the site to protect the integrity and performance of System components in certain situations. This chapter is organized in the following sections: Section 10.2: Curtain Drains Section 10.3: Stormwater Diversion Structures Section 10.4: Erosion Control Measures

133 CHAPTER 10 SITE MODIFICATION & STABILIZATION MEASURES 10.2 CURTAIN DRAINS A. BACKGROUND A particular situation of concern is in areas where rainfall readily percolates through very permeable surface soils and perches along the contact with the less permeable substrata. Dispersal trenches can act as a collection area for this transient subsurface water flow, and in the worst case may be flooded during heavy rain events or throughout the rainy season. This reduces the dispersal capacity during the wet season; and it can also contribute to a long-term decline in the dispersal system effectiveness and potential surface failures. One of the most effective drainage measures is a curtain drain (also called subdrain or french drain ), which consists of a gravel-filled trench installed uphill of a drainfield system, designed to intercept shallow perched groundwater flow and divert it away from or around the dispersal field. The installation of curtain drains may be considered for new system installations as well as to rehabilitate a failing system affected by higher than anticipated groundwater. B. SITING CRITERIA AND INVESTIGATION REQUIREMENTS 1. Ground Slope. Curtain drains are only to be used on sites with a slope of greater than five (5) percent. The use of curtain drains to de-water a flat site will not be allowed. 2. Setbacks. Curtain drains may be positioned upslope or to the side of a dispersal field to intercept and drain subsurface water away from dispersal trenches in accordance with the horizontal setback requirements in Chapter 4.. Curtain drains are not to be used as underdrains located downslope from the dispersal field in an attempt to lower the groundwater table. 3. Site Investigation and Engineering Plan. a. Prior to approval of a curtain drain, a site investigation shall be conducted and an engineering plan for the installation shall be developed by a California Registered Civil Engineer. b. The engineering plan for the curtain drain shall include drawings, supporting data and calculations, as applicable, and a plan for groundwater monitoring, as applicable. c. The site investigation shall be conducted to: i. prepare a suitable map of the site, including slope contours, drainage and other pertinent site features; ii. iii. document soil, geologic and groundwater conditions on the site; assess the subsurface conditions to determine the feasibility and means of controlling groundwater levels with a curtain drain; evaluate whether or not the groundwater of concern is a perched condition above a clearly definable restrictive/impermeable soil layer;

134 CHAPTER 10 SITE MODIFICATION & STABILIZATION MEASURES iv. determine the appropriate depth and location for the proposed curtain drain and outlet point, based on soil, groundwater, and other site conditions. 4. Approval Process. The process for approval of the curtain drain will depend on the site conditions and the supporting information supplied with the engineering plan, as follows: a. No Field Demonstration Required. For cases where the site investigation shows the groundwater condition to be mitigated is perched water above a clearly definable restrictive/impermeable layer (e.g., stiff, plastic, clayey subsoil), the curtain drain plan may be approved without the need for field demonstration of its effectiveness. b. Pilot Demonstration Required. For cases where the site investigation shows the groundwater condition to be mitigated is most probably perched water but there is some level of uncertainty about the extent or degree of impermeability of the identified restrictive layer, then the Department may require a pilot test of a portion of the proposed curtain drain prior to approval. The pilot test, conducted by the applicant, would involve the installation of a section of curtain in accordance with the proposed design, along with installation of monitoring wells in appropriate locations (upslope and downslope of the drain) as needed to provide evidence of the effectiveness in lowering the water table during the wet season. The system designer/consultant would be responsible for presenting the details of the pilot demonstration, overseeing the installation, monitoring the performance, and reporting the results to the Department. c. Full-scale Demonstration Required. For cases where the site investigation shows limited or questionable evidence that the groundwater condition to be mitigated is perched water above a defined restrictive/impermeable layer, then the Department may require a full-scale installation and monitoring of the proposed curtain drain prior to approval. The full-scale test, conducted by the applicant, would involve the installation of the entire curtain in accordance with the proposed design, along with installation of monitoring wells in appropriate locations (upslope and downslope of the drain) as needed to provide evidence of the effectiveness in lowering the water table during an entire wet weather season. The system designer/consultant would be responsible for presenting the details of the monitoring plan, overseeing the installation, monitoring the performance, and reporting the results to the Department. C. DESIGN AND CONSTRUCTION REQUIREMENTS A curtain drain shall consist of a gravel-filled trench constructed as shown in the attached schematic diagram and designed in accordance with the following specifications: 1. Trench Width: Twelve (12) inches minimum. 2. Trench Depth: Shall extend to a depth of at least six (6) inches into the underlying impermeable layer.

135 CHAPTER 10 SITE MODIFICATION & STABILIZATION MEASURES 3. Filter/Backfill Material: Filter material shall be clean, durable 3/4 to 1½-inch drain rock, extending from trench bottom to within six (6) to twelve (12) inches of grade; backfill to grade with native soil. 4. Filter Fabric: A geotextile filter fabric envelope shall surround the drain rock. 5. Perforated Collection Pipe: Collection pipe shall consist of four (4) inch diameter perforated drain pipe, oriented with holes down and installed on top of the drain rock, approximately two (2) to four (4) inches above trench bottom. 6. Outlet Pipe: The outlet pipe shall consist of minimum four (4) inch diameter solid (nonperforated) drain pipe. 7. Cleanouts. Provide cleanouts to grade: (a) at the upslope end of the drain; (b) at bends of forty-five (45) degrees or greater; and (c) at least every four hundred (400) feet along the length of the drain. 8. Slope: The trench and pipe shall be sloped for gravity flow at a minimum one (1) percent gradient throughout the trench and extending to the outlet point. The curtain drain must drain by gravity only. 9. Outlet. The outlet must be on the property being developed, and located so the flow does not adversely affect the drainage or any existing or proposed System on the subject parcel or neighboring parcels. Protect downslope outlet against blockage or damage through the use of screening, rock cover, junction box or other suitable means. 10. Erosion Control. Provide erosion protection at drain outlet point.

136 CHAPTER 11 SYSTEM INSPECTIONS & FINAL INSTALLATION APPROVAL 11.1 OVERVIEW The chapter presents the requirements for Department inspections of System installation, modifications, and abandonment and final system approval requirements. This chapter is organized in the following sections: Section 11.2: System Installation and Abandonment Inspection Requirements Section 11.3: Issuance of Final System Installation Approval

137 CHAPTER 11 SYSTEM INSPECTIONS & FINAL INSTALLATION APPROVAL 11.2 SYSTEM INSTALLATION & ABANDONMENT INSPECTION REQUIREMENTS A. GENERAL PERFORMANCE CRITERIA 1. To ensure installation of a safe, effective System and conformance with the standards in this Manual, inspections of the System are required. The System must be ready for the type of inspection requested. 2. If extra inspections are needed, an additional inspection fee will be charged. 3. No portion of the System shall be covered without inspection by this Division unless the Department has given specific authorization. B. NOTIFICATION 1. Installers are required to provide at least forty-eight (48) hours notification to the Department prior to beginning construction of a System, and at least forty-eight (48) hours advance notice prior to reaching specified construction inspections (see below). 2. Notification must include Applicant s name, Assessor s parcel number, street address, and Permit number. Failure to provide sufficient notice may result in delay of construction or duplication of work. C. REQUIRED CONSTRUCTION INSPECTIONS 1. The inspection steps required for the installation of a System will vary with the type and complexity of the System installed. 2. The Department may combine one or more required inspections into a single field visit if possible. 3. An approved copy of the Permit shall be available during each inspection. 4. The following inspections shall be required unless the Applicant demonstrates good cause for not requiring a particular inspection: a. Preconstruction Meeting. Unless waived, the preconstruction meeting shall have the marked layout of the proposed System onto the ground. If not already existing, include any proposed footprints of buildings, pools, or other structures which could affect the System and Replacement Area. Minimum horizontal setbacks shall be in accordance with the approved System Design. b. Open Trench Inspection. Open trench inspections shall be performed by jointly by the System Designer and Department. At the time of the open trench inspection, all the following shall be completed: i. All excavations necessary for the System at designed depth, width, and length. ii. iii. All smeared or compacted surfaces shall be corrected. Bottom of the trenches shall be level.

138 CHAPTER 11 SYSTEM INSPECTIONS & FINAL INSTALLATION APPROVAL c. Rock and Pipe Inspection. The connection of the Septic Tank, all distribution piping and the quality of the rock will be inspected. i. For Alternative System, this inspection will also include inspection of the dosing tank, pump and filter assembly, and hydraulic squirt test for Pressure Distribution System in conjunction with the System Designer. d. Final Inspection. At the time of final inspection by the Department, all the following shall be completed: i. The trenches filled with rock to the specified level with the filter material in place or the gravel-less chambers installed. ii. iii. iv. Approved Distribution Boxes, with covers, installed level on undisturbed Soil and at the proper elevation. Approved tank risers and inspection ports. All pipe, other than in trenches, must be installed on grade (1/8 in./ft. minimum) and grouted to Septic Tank or Distribution Boxes. v. All pipe in trenches installed level (maximum drop of three (3) inches in one-hundred (100) feet) in the full length of trenches with ends capped. Sealing around pipe is also to be completed at the Distribution Boxes. vi. vii. The Septic Tank set level in place on undisturbed soil. All trenches must be uncovered to the filter material and visible for inspection and pipes ends exposed. e. Tank Water Tightness Tests. Tanks or other primary components may be required to be filled with water to the flow line prior to requesting inspection. All seams or joints shall be left exposed (except the bottom) and the tank shall remain watertight. f. Flow Test. A flow test may be required to be performed through the System to the point of Effluent disposal. All lines and components shall be watertight and distribution shall be according to the approved System Design. g. Other Inspections. Other inspections may be required as a Permit condition by the Department depending upon the type of System proposed. Owner-installed Systems may require additional inspections to verify workmanship during the construction. The costs of additional inspections and related services beyond services normally covered by the Permit fee may be charged to the Applicant. 4. Systems must be backfilled within ten (10) days of written approval for backfill from the Department and Qualified Professional (if required), or as specified by the approved System Design. D. SYSTEM MODIFICATIONS/ABANDONMENT INSPECTIONS Depending on the type of work being conducted, inspections may include any of those specified above and will be disclosed at time of Permit approval.

139 CHAPTER 11 SYSTEM INSPECTIONS & FINAL INSTALLATION APPROVAL 11.2 ISSUANCE OF FINAL SYSTEM INSTALLATION APPROVAL 1. General. Final Approval is a document issued by the Department that indicates the System was installed in compliance with this Manual and relevant County Codes, and all Permit conditions of approval have been fulfilled, including issuance of any required Operating Permit. 2. Requirements for Standard System. Prior to issuance of a Final Approval for a Standard System, the following shall be completed: a. The System installation has received final approval by the Department. b. An approved, scaled As-Built Drawing of the parcel, the System and all relevant Site features has been submitted to the Department and received approval. c. The Contractor shall provide with Owner with an Owner s operation and maintenance guide. 3. Requirements for Alternative System. In addition to the minimum requirements for a Final Approval required for a Standard System the following shall be provided to the Department: a. The Qualified Professional shall submit written certification that the System has been installed in accordance with the approved System Design and Permit conditions. b. Appropriate notice of the required Operating Permit, the initial Operating Permit, and other required documents have been recorded on the property deed as described in Section 5 of this Manual. c. The Owner shall obtain an Operating Permit, and where required, the contracted services of a Service Provider. d. The Qualified Professional shall provide the Owner with an operations and maintenance manual that outlines the operation of the system, including the Owner s responsibilities for maintaining the system. A copy of the maintenance manual shall be provided to the Department for archiving. 4. Requirements of submitting As-Built Drawings. At completion of construction and prior to receiving acceptance Final Approval by the Department, the Contractor and/or Qualified Professional shall provide to the Department and system Owner, a set of As- Built drawings of the completed septic system installation.

140 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS 12.1 OVERVIEW The chapter presents an overview of the Operations, Maintenance & Monitoring Program (OM&M) and System performance and monitoring requirements for Standard and Alternative Systems. This chapter is organized in the following sections: Section 12.2: Applicability and Administration Section 12.3: Operations, Maintenance and Monitoring Program Section 12.4: System Performance Requirements Section 12.5: Operating Permit Requirements Section 12.6: Corrective Action

141 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS 12.2 APPLICABILITY AND ADMINISTRATION A. APPLICABILITY 1. The Operating, Monitoring, and Maintenance (OM&M) requirements apply to all Alternative Systems in the County. 2. Owners of Standard Systems are encouraged to voluntarily opt into the OM&M program. 2. Prior to issuance of a Final Approval for an Alternative System, the property Owner shall obtain an Operating Permit from the Department. a. The Operating Permit shall be renewed annually and any required fees shall be paid. The Owner of the property shall keep the Operating Permit valid for the life of the System. b. The Department may suspend or revoke an Operating Permit for failure to comply with any operational, monitoring, or maintenance requirements. Upon revocation or suspension of an Operating Permit further operation of the Alternative System shall cease until the suspension is lifted or a new permit is issued. B. ADMINISTRATION 1. The OM & M program will be administered county-wide by the Department. 2. Any required OM&M inspections will be performed by or under the supervision of an approved Service Provider. C. NOTICE ON PROPERTY DEED 1. In order to provide notice to any future owners of the property, a Notice of Onsite Wastewater Treatment System shall be recorded by the Department after approval of a System. 2. The Department may also record notice of any failed System. A certified copy of the following shall be recorded against the property in the office of the County Recorder of Alameda County: a. initial operating permit issued for the system; b. reissuance of operating permit to new owners; and c. notices of withdrawal of any operating permit.

142 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS 12.3 OPERATION, MAINTENANCE & MONITORING PROGRAM 1. Homeowner Education: The Department will establish methods of increasing public understanding about the proper use and care of onsite Systems. The program goal is to provide Owners with the information they need to properly operate and maintain their Systems. 2. The Department will track the maintenance and performance of all Systems in the OM& M Program. 3. Homeowners will be provided with an OM&M Manual for Systems approved after the adoption of this Manual. The OM&M Manual shall include: a. For Standard System, the Department or the System installer will provide an informational packet to new Owners at the time of installation. b. For Alternative Systems, the Qualified Professional will provide the homeowner with an OM & M Manual and provide an electronic version to the Department for archival purposes. The OM&M Manual will be supplemented or updated by the Service Provider when needed due to System misuse, Repairs, or Modifications. c. The OM & M Manual will include the following elements as applicable and available: (1) Diagrams of the System components (2) Accurate, fully dimensioned as-built drawing of the System (3) Explanation of general System function, operational expectations, Owner responsibility, etc. (3) Routine maintenance schedule (5) Names and phone numbers of the Qualified Profession, installation Contractor, and Service Provider (4) List of proprietary system components, including manufacturer name and model number (7) Information on troubleshooting common operational problems that might occur with the specific System.

143 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS 12.4 GENERAL SYSTEM PERFORMANCE REQUIREMENTS A. ALL SYSTEMS 1. All Systems shall be operated in compliance with applicable performance requirements particular to the type of system, the facility served, and the site conditions. 2. All Systems shall function in such a manner as to: a. Be sanitary and not create a health hazard or nuisance; b. Prevent backup or release of wastewater or wastewater effluent into the structure(s) being served by the onsite wastewater system; and c. Not discharge wastewater or wastewater effluent onto the ground surface or into surface water, or in such a manner that groundwater may be adversely impacted. 3. All onsite wastewater systems and the individual components shall meet the performance requirements for the specific site conditions and application for which they are approved. B. CONVENTIONAL SYSTEMS 1. All components of the System shall be functional and in proper working order. 2. All septic tanks shall be: a. structurally sound b. Watertight c. provide clarified effluent d. have adequate space available for sludge and scum storage e. operate in such a manner as to not create odors or vector attraction f. be properly vented, g. have a functional baffle(s). 3. Dispersal systems shall: a. have adequate dispersal capacity for the structures and/or uses served; b. not result in seepage or saturated soil conditions within 12 inches of ground surface in or adjacent to the dispersal field; c. be free from soil erosion or instability;

144 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS d. not have effluent continuously pond at a level above the invert (bottom) of the perforated distribution pipe in the dispersal trench or serial distribution overflow line, as applicable. C. ALTERNATIVE DISPERSAL SYSTEMS In addition to the requirements in A and B above, alternative dispersal systems shall also comply with the following. 1. Pressure Distribution Systems. a. Pump tanks, risers and lids shall be structurally sound, watertight and store wastewater effluent in such a manner as to not create odors or vector attraction. b. Pumps, floats, alarms and associated controls shall be in good condition and operate in accordance with design specifications. c. Dispersal field and components shall: i. be operable and in good condition; ii. iii. iv. maintain uniform distribution of effluent throughout the dispersal field; not result in continuously ponded effluent in the dispersal trench (or bed) to a level above the invert (bottom) of the distribution pipe; and in the case of pressure-dosed sand trenches, not result in continuously ponded effluent above the sand interface. 2. Mound, At-Grade and Raised Sand Bed Systems. Mound, at-grade and raised sand bed systems shall: a. not result in seepage or saturated soil conditions within twelve (12) inches of ground surface anywhere along the perimeter toe or edge of the system; b. be free from erosion, slumping or damage to the soil cover; c. not result in continuously ponded effluent within the gravel distribution bed or in the sand fill (for mounds and raised sand bed systems); and d. conform to applicable requirements for pressure distribution in C.1 above. 3. Subsurface Drip Dispersal Systems. Subsurface drip dispersal systems and components shall: a. not result in seepage or saturated soil conditions above the depth of the dripline within or anywhere along the perimeter of the dripfield; b. be free from erosion, slumping or other soil disturbance that threatens to expose or cause damage to drip dispersal tubing or appurtenances; c. conform to applicable requirements for pressure distribution in D.1 above; and d. be operated and maintained in accordance with manufacturer recommendations.

145 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS 13.5 OPERATING PERMIT REQUIRMENETS A. GENERAL REQUIREMENTS 1. An Alternative System and other wastewater Systems as required by the Ordinance shall be operated, maintained, and monitored pursuant to the requirements of the standards found in the Ordinance and Manual and the issued Operating Permit. 2. A monitoring program will be established for each alternative System as a condition of the operating permit at the time of permit issuance, and may be amended at the time of permit renewal. Said monitoring shall be performed to ensure that the alternative System is functioning satisfactorily to protect water quality and public health and safety. 3. The Owner of record shall obtain an Operating Permit prior to final System approval and issuance of a Final Approval. 4. Under the terms of the Operating Permit, the Department shall conduct an annual review of the performance and condition of the System. This review may include onsite inspections, sampling, review of submitted maintenance and sampling reports, and other activity deemed necessary to assure the proper maintenance and operation of the System. 5. The Operating Permit shall require maintenance and performance monitoring to be performed by the property Owner or the property Owner s agent, an approved Service Provider, Septage Pumper, or Proprietary Device Licensee at a frequency of once per year or more often as determined by the Department. 6. Operating Permits shall be renewed annually with payment of an annual fee which shall cover the cost of the administration of the OM&M Program. 7. Inspection frequency shall be performed as outlined in Table B. MONITORING ELEMENTS 1. The monitoring requirements will vary depending on the specific type of alternative system, typically including the following: a. Recording of wastewater flow based on water meter readings, pump event counter, elapsed time meter, in-line flow meter, or other approved methods; b. Measurement and recording of water levels in inspection/monitoring wells in the dispersal field; c. Inspection and observation of pump operation and other mechanical equipment; d. Water quality of selected water samples taken from points in the treatment process, from groundwater monitoring wells, or from surface streams or drainages; typical water quality parameters include total and fecal coliform, nitrate, BOD, and suspended solids; e. General review and inspection of treatment and dispersal area for evidence of seepage, effluent surfacing, erosion or other indicators of system malfunction; and f. Other monitoring as recommended by the system designer or equipment manufacturer.

146 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS C. MINIMUM INSPECTION AND MONITORING REQUIRMENTS System components shall be inspected and monitored in accordance with the criteria below and listed in Table 12-2 and Table Septic Tank a. Inspection frequency should be once every three (3) to seven (7) years. b. Scum and sludge measurements (pumped as needed) c. Water intrusion (dissolved oxygen measured by the Service Provider only) d. Integrity of tank, including observation for: cracks or indications of structural deterioration; condition of inlet and outlet tees; condition of lids and risers; indication of leaks in risers e. Presence and condition of Effluent filter. 2. Pump and Dosing Chamber a. Scum and sludge measurements, pumping as needed b. Indication of water intrusion (dissolved oxygen measured by the Service Provider only) c. Integrity of tank, including observation for: cracks or indications of structural deterioration; condition of inlet and outlet T s; condition of lids and risers; indication of leaks in risers d. Condition of and correct operation of all floats e. Orderly wrap of float cords f. Condition of pump intake screen g. Verification of pump cycle h. Siphon sitter functioning, if applicable 3. Control Panel a. Timer and digital counter readings recorded by the Service Provider during the inspection. For control panels that record pump activity electronically, manual recordings are not necessary. b. Pump cycle counter operation verified by the Service Provider in the field by manual operation of the pump. For control panels that record pump activity electronically, counter operation can be verified remotely. c. Audible and visual alarms functioning

147 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS d. Run time appropriate, if demand dose e. Electrical box free from moisture and secure connections 4. Supplemental Treatment Systems 1. Supplemental treatment systems shall comply with the additional performance requirements listed below and shall be monitored annually for performance in the following manner. 2. Treated Effluent and, where applicable, untreated Effluent will be sampled and tested at least annually for total and fecal coliform, BOD, and TSS. Influent and Effluent of Systems with Operating Permits requiring nitrogen reduction shall also be tested for total nitrogen. Wastewater treated by Disinfection Units shall be tested for total fecal coliform. 3. When Effluent quality monitoring results indicate that the Supplemental Treatment and/or disinfection did not meet the minimum Treatment levels specified in this Manual, a second sample will be taken within three months. If the follow up sampling results indicate that the Supplemental Treatment and/or disinfection unit is not performing to the Treatment levels specified in this Manual, the Department shall be informed and the Owner or Owner s agent shall take corrective action necessary to achieve the Treatment levels specified in this Manual. Correction of Treatment problems will be verified by two consecutive compliant results within a three month period. a. Effluent Quality. Effluent produced by all supplemental treatment systems shall comply with the following minimum constituent limitations: Constituent Biochemical Oxygen Demand (BOD), mg/l Total Suspended Solids (TSS), mg/l (1) For Use with Trenches and At-grade Systems (2) For Use with Drip Dispersal Systems (3) Where Pathogen Removal Required Per (1) or (2), as applicable Per (1) or (2), as applicable Fecal Coliform, MPN/100 ml N/A N/A 200 Pathogen removal shall be required due to proximity to state small water or public water supply well or surface water intake per Chapter 4 of this Manual. b. Proprietary Treatment Units. Proprietary treatment units shall comply with the following: i. The unit and its components shall be structurally sound, free from defects, be watertight, and not create odor or vector attraction nuisance. ii. The unit shall be operated in accordance with the approved manufacturer and certification/listing organization standards.

148 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS c. Sand Filters. Sand filters shall: i. be operated to maintain uniform effluent distribution throughout the sand filter bed; ii. iii. iv. not result in continuously ponded effluent on the distribution bed infiltrative surface; be operated and maintained to prevent channeling of flow, erosion of the sand media or other conditions that allow short-circuiting of effluent through the system; not result in leakage of effluent through the sand filter liner or supporting structure; and v. conform to applicable requirements for pressure distribution in D.1 below. 5. Gravity Drainfield (Conventional or Gravelless) a. Depth of Effluent ponding within trench b. Indication of Effluent breakout or discharge to surface of the ground c. Upkeep and accessibility of observation port and inspection ports d. Area verified as free from road, structures, vehicular traffic, surface water drainage with downspouts and landscape drainage properly diverted e. Results of hydraulic loading test, if test is needed. 4. Pressure Distribution Systems. a. Pump tanks, risers and lids shall be structurally sound, watertight and store wastewater effluent in such a manner as to not create odors or vector attraction. b. Pumps, floats, alarms and associated controls shall be in good condition and operate in accordance with design specifications. c. Dispersal field and components shall: i. be operable and in good condition; ii. iii. iv. maintain uniform distribution of effluent throughout the dispersal field; not result in continuously ponded effluent in the dispersal trench (or bed) to a level above the invert (bottom) of the distribution pipe; and in the case of pressure-dosed sand trenches, not result in continuously ponded effluent above the sand interface.

149 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS D. INSPECTION FREQUENCY AND MAINTENANCE CHECKS 1. Inspection Frequency: Systems requiring an Operating Permit pursuant to this Manual, shall meet the inspection frequencies and maintenance checks as specified in Table 12-1, or as otherwise required by the Operating Permit. 2. Nothing contained in this provision shall prevent the Department from requiring more frequent inspections and maintenance checks as deemed necessary to ensure optimal System performance. 3. Complexity and frequency of inspection will be related to the complexity and maintenance requirements of the System components, recommendations of the manufacturer and industry standards. E. REPORTING REQUIRMENTS For Alternative System, the property Owner or his/her agent must submit an annual report to the Department, or as otherwise required by the Operating Permit, for review with the following information as a condition of any Operating Permit: 1. Twelve months actual flows into the System. If this cannot be obtained then the best reasonable estimate shall be provided. 2. Inspection findings of the dosing tank and pump system, including: a. Elapsed time meter readings b. Dosing counter meter reading d. Pump run cycle time c. Proper operation of the alarm system; and d. Proper water tightness of all tanks 3. Inspection findings of the System, including: a. Evidence of breakout or surfacing of sewage Effluent onto the ground. b. Evidence of erosion or degraded erosion control on Slopes and mounds e. Testing and condition of adjusting and purge valves c. Testing and condition of inspection ports e. Results of Effluent sampling.

150 CHAPTER 12 SYSTEM OPERATION, MAINTENANCE, MONITORING & REPORTING REQUIREMENTS 12.6 CORRECTIVE ACTION 1. Corrective Action for non-compliance with System maintenance shall result in administrative fines and penalties. If access is not voluntarily granted, the Department may obtain a warrant to conduct necessary inspections and maintenance of the System at the Owner s expense. 2. Corrective Action for non-compliance with Treatment standards may include the following: a. Notification of non-compliance sent to the System Owner, Qualified Professional, Service Provider, and System proprietor. b. An administrative hearing with the Director of Environmental Health shall be conducted to set forth required corrective action. d. Additional testing and inspections for increased monitoring until the System returns to compliance. d. Restricted or prohibition of the use of the System.

151 CHAPTER 13 EXISTING SYSTEM EVALUATION, REPAIR & REPLACEMENT CRITERIA The chapter will present criteria for existing System performance evaluation, repair and replacement. The criteria in this chapter will be developed after conducting workshops with stakeholders.

152 CHAPTER 14 COMPLAINT INVESTIGATIONS 14.1 COMPLAINTS & INVESTIGATIONS A. COMPLAINTS Complaints about odors, vectors, surfacing effluent, cesspools, seepage pits, illegal installations, or other illegal wastewater discharge will be responded to by the Department with high priority. All violations of the Ordinance and Manual are determined to be unlawful, and declared to be detrimental to the public health, safety and welfare, and are Public Nuisances. B. INVESTIGATIONS Upon receipt of a complaint, the Department will conduct a complaint investigation. If the Department determines that public health and/or the environment may be at risk, or that a system has been installed or repaired illegally, the property Owner shall be responsible for all subsequent costs associated with the complaint. 1. Right of Entry: The Department is authorized to enter property/ premises at any reasonable hour as may be necessary for investigation of complaints and enforcement of the Ordinance and Manual. The Department will make attempts to contact the property Owner and Occupant prior to making the investigation. If entry is refused, the Department may obtain a warrant to enter and inspect. 2. Right to Investigate: No person(s) shall obstruct, impede or interfere with the investigation performed by the Department in the performance of code enforcement and nuisance abatement duties. 3. Collection of Evidence: The Department may take photographs and videos during the investigation as evidence of conditions found on the Site. C. ILLEGAL SYSTEM INSTALLATION OR REPAIR WORK If complaint investigation results in a finding of an illegal system installation or work is being conducted without necessary permits, or outside of issued permit conditions, the Department may issue a Stop Work Order. Once the order is issued, no further work shall be conducted until the Stop Work Order is released by the Department. If a licensed Contractor is found performing work without necessary Permits,they will be reported to the State Contractors License Board in addition to being charged double the permit fee as a penalty for the violation. Any Person conducting work without necessary Permits shall pay double the Permit fee as a penalty. The penalty is separate from required fees for Permits and services to bring the System or condition into compliance.

153 CHAPTER 14 COMPLAINT INVESTIGATIONS 14.2 FAILED SYSTEMS & ABATEMENT A. The Department will require the Owner to immediately abate conditions that pose a threat to human health and/or the environment due to a failing System on all properties that have been impacted by surfacing effluent. At a minimum the Owner will be required to hire a Qualified Professional to immediately implement the following interim abatement measures: 1. Stop all wastewater flows to the System until a permanent solution has been permitted and installed or an interim solution has been implemented. Interim solutions may include but are not limited to hiring a Qualified Professional to install plugs in the outlet of the existing septic tank if it is watertight or install a holding tank and pump the tank at appropriate intervals to dispose of wastewater coming from site structures. 2. Collect surfacing or ponding wastewater with a Vactor Truck. 3. Contain surfacing wastewater as close as practical to the failed System through the use of berms or other measures. 4. Isolate storm drain collection systems if wastewater has the potential to enter inlets. 5. Conduct general cleanup measures including removing all impacted debris. 6. Prevent public contact with wastewater by covering impacted areas with clean soil and/or installing fencing or hazard tape and warning signs around the impacted area. 7. Wash down impacted impervious surfaces and collect and dispose of wash water in a sanitary sewer. 8. Notify adjacent property owners that have the potential to be directly affected by the failed system and or cleanup activities. B. Depending on the extent of the failed system impacts the Department may require the Owner to hire a Qualified Professional to implement additional measures including but not limited to: 1. Investigation and/or monitoring the source and or movement of wastewater. 2. Collection of water well, surface water, and/or soil samples for analysis of fecal indicator bacteria to determine the extent of the release and threat to public health and the environment. 3. Identification of appropriate cleanup action. Depending on the extent of impact of the wastewater release to the environment, oversight by other regulatory agencies may be required including but not limited to the Regional Water Board, State Water Board, California Department of Fish and Wildlife, or the U.S. Army Corp of Engineers. 4. Implementation of additional soil cleanup measures including but not limited to covering the impacted area with clean soil, excavation, aeration, or disinfection of the impacted soil.

154 14.3 ENFORCMENT CHAPTER 14 COMPLAINT INVESTIGATIONS A. NOTICE OF VIOLATION When the Department finds a violation of the Ordinance or Manual, the Department representative shall issue a Notice of Violation to the property Owner, and any or all Persons which may be a part of the violations (such as the Contractor or Occupant). Responsibility of the violations shall be joint and several. The Notice of Violation shall indicate the specific violation found to exist or that was observed. B. FALSIFICATION If it is found that false information was provided for the Site Evaluation, Permit Application or other supporting documentation that is relevant to the System performance, the Installation Permit may be suspended or revoked. C. CONDEMNATION The Department in conjunction with the local building department may condemn any building that is found to be causing or may result in the accumulation or disposal of wastewater in a manner that would be detrimental to the public health, safety, and welfare. The Department may in conjunction with the Sheriff or Police department impound any vehicle found to be illegally discharging wastewater. D. FINES AND PENALTIES Any Person found violating any provisions of the Ordinance and Manual shall be subject to all fines or penalties that may apply as provided in Article VII of the Ordinance.

155 CHAPTER 15 DEFINITION OF TERMS Definitions are provided for terms used in this Manual. Abandoned System: A septic System that will no longer be used to receive Effluent because the Dwelling has been connected to an approved sewer system or the Department has issued a notice or order to destroy the System under Permit. Abandoned Well: A well whose original purpose and use has been permanently discontinued or which is in such a state of disrepair that it cannot be used for its original purpose. If an Abandoned Well has been properly destroyed so that it will not produce water nor act as a conduit for the movement of water, it will not be subject to well setback requirements. Alternative System: A type of Wastewater disposal or System component(s) that utilizes either a method of Wastewater Treatment other than a standard Septic Tank and/or a method of Wastewater dispersal other than a standard Dispersal Field in native Soil. Applicant: A property Owner or the property Owner s Authorized Representative. Artificial Drain: Any Artificial Drainage feature or structure that intercepts and concentrates Groundwater or surface water. For example: driveways, roads, road ditches, agricultural drain tile, Cut banks, and Curtain Drains. As-Built Drawing: A scaled drawing of features on the lot where the System is installed; identifying the location of the installed System and components in relation to structures on the property. The As-Built Drawing is completed after the System is installed or repaired. Authorized Representative: Person or Persons authorized by the property Owner to act on the property Owner s behalf on matters pertaining to application for Permits and services, or holder of an easement sufficient to authorize the work on the land on which the System is to be installed, in order to represent the Owner s or easement holder s interests. Bedrock: Unweathered solid rock that is impermeable or has less than 15% porosity. If present, fractures are tight, dry, and cemented. Beneficial use: Those qualities of waters of the state that may be protected against quality degradation that include, but are not necessarily limited to, domestic, municipal, agricultural and industrial supply; power generation, recreation; esthetic enjoyment; navigation; and preservation and enhancement of fish, wildlife and other aquatic resources or preserves. Biological Oxygen Demand (BOD): The amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. Blackwater: See Wastewater Building Permit: An official document or certificate issued by the authority having jurisdiction which authorizes performance of a specified activity. Building Division: A local building agency of a city or county which has the jurisdiction to issue Building Permit to construct, alter, Repair or destroy structure.

156 CHAPTER 15 DEFINITION OF TERMS Building Sewer: The part of the System or drainage piping which conveys sewage from a building to the Septic Tank or public sewer. Cesspool: An excavation in the ground receiving Wastewater, designed to retain the organic matter and solids, while allowing the liquids to seep into the Soil. Cesspools differ from Seepage Pits because a Cesspool does not have a Septic Tank. Chemical Toilet Facility: See Portable Toilet Clay: See Soil Texture Cleanout: A fitting inserted into a piping system, with a removable plug whereby access to the pipe is obtained for the purpose of cleaning or unstopping. Cluster System: An Onsite Wastewater Treatment System serving at least two (2) but not more than four (4) Dwellings or other buildings that are sources of Wastewater discharge on the same Lot and under the same ownership. Color: See Soil Color. Commercial Facility: Any structure or building, (excluding single-family residential units), or any portion thereof, intended for commercial or industrial use. Community System: A System that accepts Wastewater discharges from two or more Lots or a System shared by Dwellings under separate ownership whether or not they are on the same Lot. A Community System is not a Public Sewer System. Composting Toilet: A type of dry toilet that uses a predominantly aerobic processing system to treat human excreta, by composting or managed aerobic decomposition. Conditions Associated with Saturation: The following are Conditions Associated with saturation: a. Reddish brown or brown oxidized Soil Horizons with dull gray zones of redox depletions (chromas of 2 or less), and red or yellowish red zones of redox concentrations; or b. Reduced, or iron-depleted Horizons of gray, blue, or olive colors (chromas of 2 or less) with dull red, yellowish red, or brown zones of redox concentrations; or c. Organic Soils and dark-colored Soils very high in organic matter. 1 Consistence: See Soil Consistence. Contamination: Impairment to the quality of the waters of the State from Wastewater to a degree which creates a hazard to public health through toxicity or through the spread of disease. Contamination shall include any equivalent effect resulting from the disposal of Wastewater, whether or not waters of the state are affected. Contractor: A Person who possesses an active license as a General Engineering Contractor (Class A), a General Building Contractor (Class B), a Sanitation System Contractor (Class C-42) or a Class C-36 Plumbing Contractor (Class C-36) license in accordance with the provisions of the California Business and Professions Code. Contractors shall be approved by the Department

157 CHAPTER 15 DEFINITION OF TERMS and shall possess knowledge, and skills of Systems siting, design using given design parameters, and installation. Cumulative Impacts: The persistent and/or increasing effect resulting from the density of System(s) discharges in relation to the assimilative capacity of the local environment. Examples include, but not limited to: a. Nitrate, salt additions, or other indicator of human excreta to ground water or surface water; or b. Rise in Groundwater levels that interfere with the performance of the System, causing drainage problems or results in other adverse hydrological or Soil conditions affecting public health, water quality or public safety; or c. Coliform Contamination from animal and human waste in surface water, Groundwater, and drinking water wells. Cut or Embankment: Any altered area of land surface having distinctly greater Slope than the adjacent natural ground surface, over 24 inches in vertical height, and any part of which is lower in elevation than the ground surface at the nearest point of the System. Cuts supported by retaining walls or similar structures shall be included in this definition as shall steep natural ground surfaces where a sharp break in the ground Slope is discernible. Curtain Drain: An Artificial Drain installed up Slope from a disposal field to intercept and divert ground water. Deep Trench System: A system with disposal trenches greater than thirty (36) inches deep. Department: See Department of Environmental Health. Design Daily Sewage Flow: The quantity of daily sewage flow assigned to a building or structure. It may be referred as Design Flow. Design Flow: See Design Daily Sewage Flow. Director of Environmental Health: The Director of the Alameda County Department of Environmental Health and his/her designated employee(s). Dispersal Field: The area occupied by the Dispersal System. It may also be referred to as leach field. Dispersal System: A subsurface Wastewater distribution System and its components which conveys Wastewater from the Septic Tank, Pump Tank and or Supplemental Treatment Unit to the Soil for subsurface discharge and final Wastewater treatment. Dispersal Trench: A ditch or trench with vertical sides and substantially flat bottom designed to receive Wastewater Effluent. Distribution Box: A structure which receives Effluent and distributes it to the Dispersal Field. Distribution Pipe or Lateral Pipe: A perforated pipe used in the dispersion of Effluent into disposal trenches.

158 CHAPTER 15 DEFINITION OF TERMS Distribution Unit: A Distribution Box, crossover unit, Dosing Tank, Diversion Valve or box, Header Pipe, Effluent lift pump or other means of transmitting Effluent from the Effluent Sewer to the Distribution Pipes. Diversion Valve: A device that receives Wastewater through one inlet and distribute it to two (2) or more outlets, only one of which is used at a given time. Department of Environmental Health: The Alameda County Department of Environmental Health, the Director of Environmental Health, and designated employees. Also called the Department in this Manual. Domestic Wastewater: Wastewater with a measured strength less than high-strength Wastewater and is the type of Wastewater normally discharged from, or similar to, that discharged from plumbing fixtures, appliances and other household devices including, but not limited to toilets, bathtubs, showers, laundry facilities, dishwashing facilities, and garbage disposals. Domestic Wastewater may include Wastewater from commercial buildings such as office buildings, retail stores, and some restaurants or from industrial facilities where the Domestic Wastewater is segregated from the Industrial Wastewater. Domestic Wastewater may include incidental RV Holding Tank dumping but does not include Wastewater consisting of a significant portion of RV Holding Tank Wastewater such as at RV dump stations. Domestic Wastewater does not include Wastewater from industrial processes. Dosing Tank: A watertight receptacle constructed of approved materials designed to receive and store clarified Effluent and convey it to a secondary Treatment device or a Dispersal field under positive pressure. The Dosing Tank is equipped with a pump(s), Effluent screen, and level control and alarm floats. Drain Rock: Clean, sound gravel or crushed rock ranging in size from 3/4 to I 1/2inch diameter, with <5% outside this range. Drainage Swale: Any course of concentrated drainage water that has formed over time by either natural or man-made forces or where flow of water is either at or near ground surface. Drainage Swale may also be referred to as Swale. Drainage Way: An unlined channel, with definite bed or banks, which conveys storm water runoff and provides surface hydraulic continuity with either seasonal or Perennial Streams or water bodies. This also includes facilities used for dispersal of roof runoff or other Site drainage, such as vegetated swales and infiltration/ percolation trenches or basins. Dwelling: Any structure or building or any portion thereof which is used, intended, or designed to be occupied for human living purposes including, but not limited to, houses, houseboats, boathouses, mobile homes, travel trailers, hotels, motels, and apartments. Effective Infiltrative Area: The surface area measured in square feet per one lineal foot of trench length that is allowed to be considered for receiving the Wastewater effluent dispersal in the Dispersal Field. Effective Soil: Permeable, unsaturated Soil providing sufficient aeration and retention for optimal filtration Treatment of Sewage Effluent. Effective Soil excludes Soil layers that meet the criteria for "Soil with rapid Permeability, Conditions Associated with Saturation", and "Limiting Layers". Effective Soil Depth: The depth of Soil material from ground surface that effectively provides filtration of Effluent.

159 CHAPTER 15 DEFINITION OF TERMS Effluent: Sewage, water, or other liquid, partially or completely treated or in its natural state, flowing out of a Septic Tank, aerobic Treatment unit, Dispersal System, or other System component. Effluent Lift Pump: A pump used to lift Effluent to a higher elevation. Effluent Sewer: That part of the system of drainage piping that conveys sewage Effluent from a Septic Tank or other Treatment facility into a Distribution Unit or a disposal area. Ephemeral Stream (Intermittent Stream or Seasonal Stream): A natural stream that does not flow continuously throughout the year, but that has a well-defined channel of stream gravel or Bedrock control. Evapotranspiration System: A type of System using a method of dispersing Effluent through evaporation (the change of liquid into vapor that passes into the atmosphere) or transpiration (the passage of water through a plant from the Roots through the vascular system to the atmosphere). It is typical constructed as an evapotranspiration pond or bed. Existing Lot: A Lot or parcel legally created prior to the effective date of this Manual. Existing System: Any installed System constructed in conformance with the rules, laws and local ordinances in effect at the time of construction. Expansion: The increase in the size of the Dispersal Field, usually as a result of a planned or potential increase in the estimated Wastewater flow to the Dispersal Field. Expansive Clay Soil: Mineral Soil that swells and shears when wet, and shrinks and develops cracks when dry, forming slickened sides and wedge-shaped structures. Expansive Clay Soil is very hard or extremely hard when dry, very firm when moist, and very sticky and very plastic when wet. When wet, Expansive Clay Soil is massive and cracks and structure are not evident. Final Approval: The document, issued by the Department that certifies the System was installed in compliance with the provisions of this Manual and all Permit conditions of approval have been met, including issuance of an Operating Permit. Flow Equalization: The process of mitigating changes in flow rate through a portion of a System by providing storage to hold water when it is arriving too rapidly, and to supply additional water when it is arriving less rapidly than desired. Fractured Bedrock: Moderately to slightly weathered Bedrock that usually is hard and fractured, but not impermeable to water. Geotechnical Report: A written document prepared by a California Registered Geotechnical Engineer and used to communicate Soil and geologic site conditions, interpretations, analysis and recommendations pertinent to the design, installation and operation of a System in or near areas of steeply sloping terrain, flood control levees, or Unstable Land Masses. Graywater: Pursuant to Health and Safety Code Section , Graywater means untreated wastewater that has not been contaminated by any toilet discharge, and has not been affected by infectious, contaminated, or unhealthy bodily wastes, and does not present a threat from contamination by unhealthful processing, manufacturing, or operating wastes. Graywater includes but is not limited to wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs, but does not include wastewater from kitchen sinks or dishwashers.

160 CHAPTER 15 DEFINITION OF TERMS Graywater System: A Graywater System that is designed to collect graywater and transport it out of the structure for distribution in an Irrigation Field. A Graywater System may include tanks, valves, filter, pumps, or other appurtenances along with piping and receiving landscape. Groundwater: Water below the ground surface that is at or above atmospheric pressure. For purposes of this Manual, Groundwater may also refer to evidence of the high seasonal groundwater as determined through a Site Evaluation. Groundwater Mounding: A rise in the Water Table which may occur beneath or down-gradient of System as a result of the concentrated or high volume of hydraulic loading from one or more Systems in a limited area. Hardpan: An irreversibly hardened layer caused by the cementation of Soil particles. The cementing agent may be silica, calcium carbonate, iron, or organic matter. Header Pipe: The tight jointed part of the sewage drainage conduit which receives Septic Tank Effluent from the Distribution Box, crossover unit or Effluent Sewer and conveys it to and within the disposal area. High Strength Wastewater: Wastewater has a 30-day average concentration of Biochemical Oxygen Demand (BOD) greater than 300 milligrams-per-liter (mg/l) or of total solid suspended solids (TSS) greater than 330 mg/l or of fats, oil, and grease (FOG) greater than 100 mg/l prior to the Septic Tank or other System Treatment component. High Seasonal Groundwater: The highest level of saturation in the soil in a year with normal rainfall. Holding Tank: A watertight receptacle designed to receive and store sewage to facilitate disposal at another location. A Holding Tank is a Non-Discharging Wastewater Disposal Unit. Horizon: See Soil Horizon Hydrometer: An instrument for measuring the density of liquid. Impermeable Soil: Soil that has a Percolation Rate slower than 120 mpi. Incineration Toilet: A type of dry toilet that burns human feces instead of flushing them away with water. Individual System: A System that is not a Cluster or Community System and serves only one Dwelling or building on one Lot or parcel. Industrial Wastewater: Any Wastewater generated from any manufacturing, processing institution, commercial, or agricultural operation, or any operation that discharges other than Domestic Wastewater. Installation Permit: A document issued by the Department that conveys approval of and sets forth applicable conditions for construction, the installation, replacement, enlargement, repair, modification or abandonment, or modification of a System, or of System components. The Installation Permit may also be referred to as the construction permit. Installer: A Person meeting the definition of Contractor, as defined herein, or where approved by the Department.

161 CHAPTER 15 DEFINITION OF TERMS Invert: The lowest portion of the internal cross section of a pipe or fitting. Land Use Project: A development project requiring a land use entitlement, including, but not limited to, tentative maps, Use Permits, variances, site plan review, and Lot line adjustments, which is implemented through the local building or planning department authority. Land Use Projects requiring conditions from this Manual shall be regulated by the Department. Other County requirements have separate processes and requirements. Large System: A Large System is a System with a Design Flow greater than 1,500 gallons per day. Leach Pit: See Seepage Pit. Limiting Layer: A layer that inhibits the movement of water, air, or the growth of plant Roots. Includes hardpan, claypan, fragipan, bedrock, and expansive clay soil. Lot: A legally recognized and defined piece of land that can be sold individually, as described on an instrument or map recorded or filed with the County Recorder. A Lot may also be referred to as parcel. Public road easements on Lots should be excluded from the Lot for the purpose of locating a System Major Repair: Major Repair includes replacement of or addition to the Dispersal Field, Treatment unit, or any part thereof. Manual: See Onsite Wastewater Treatment System Manual. Minor Repair: Minor Repair includes replacement of the Septic Tank, replacement of a broken pipe, Distribution Unit, or any part of the System external to the Septic Tank or Treatment facility, except the Wastewater Dispersal System. Unless classified as a Major Repair or major maintenance, any replacement of a part of a System with a part that meets the original design specifications is a Minor Repair. Modification: As in System Modification, Modification includes the increase to the projected or actual Wastewater flow, including addition(s) of Bedroom(s) increases in restaurant seating capacity or changes to a business use or occupancy Monitoring Port: Any artificial excavation by any method for the purpose of monitoring fluctuations in ground water levels, quality of underground water, or the concentration of contaminants in underground water. Mound System: An above-ground system that consists of a Pressure Distribution network that evenly distributes sewage Effluent to a "mounded" bed of filter material over sand media. Nitrogen Loading: The total amount of nitrogen entering the Groundwater during a given time. Non-Discharging Wastewater Disposal Unit: A self-contained, watertight container designed to hold Wastewater until it is pumped and/or cleaned. A Non-Discharging Wastewater Disposal Unit includes but is not limited to a Holding Tank, Vault Privy, Portable Toilet, and Waterless Toilet. Non-Expansive Clay: Clay Soil that does not demonstrate expansion when wetted. Properties of Plasticity, cohesion, shrinkage, and swelling are negligible.

162 CHAPTER 15 DEFINITION OF TERMS Occupant: Any Person living, or sleeping in a Dwelling or Person using or occupying a structure served by a System. Onsite Wastewater Treatment System (System): A Wastewater disposal facility that includes tanks, piping, Treatment devices or other facilities that convey, store, treat or dispose of Wastewater located on the property where it originates or an adjacent or nearby property under the control of the user which is not connected to a Public Sewer System. This definition includes the designated Replacement Area necessary for System Repairs. Onsite Wastewater Treatment System does not include Graywater Systems pursuant to Health and Safety Code Section , and also does not include Public Sewer System(s) or Non-Discharging Wastewater Disposal Unit(s). An Onsite Wastewater Treatment System may be referred to as System in this Manual. It may also be referred to as a Septic System, Wastewater System or OWTS in references, supporting documents and Manuals. Onsite Wastewater Treatment System Manual (Manual): The document developed, maintained, and amended by the Department, containing policy, procedural and technical details for implementation of Chapter of the County Ordinance, as approved by the San Francisco Bay Regional Water Board and adopted by resolution of the Board of Supervisors of Alameda County. It is referred to as this Manual. Onsite Wastewater Treatment System Policy (OWTS Policy): The Water Quality Control Policy for Siting, Design, Operation and Maintenance of Onsite Wastewater Treatment Systems (OWTS Policy), adopted by the State Water Resources Control Board, took effective on May 13, The OWTS Policy establishes a statewide, risk-based, tiered approach for regulation and management of System installations and replacements. The purpose of the Policy is to allow the continued use of Systems while protecting water quality and public health. Operating Permit: The administrative document issued by the Department that authorizes the initial and/or continued use of an Alternative System in conformance with the provisions of the Ordinance and Manual, intended to aid in verification of the adequacy of Alternative System performance and that may contain both general and specific conditions of use. An Operating Permit may also be required for circumstances other than an Alternative System as provided in this Manual or where, in the opinion of the Director of Environmental Health, the type, size, location, strength of Effluent or other details of a particular System and/or Wastewater activity warrant the additional level of oversight provided by an Operating Permit. Operation, Maintenance and Monitoring (OM&M) Program: A program that encourages or requires regular inspections, monitoring, and/or service to Systems, Non-Discharging Wastewater Disposal Units, and Graywater Systems as delineated in the Manual to ensure long-term performance, and Groundwater and public health protection. Owner: Any Person who alone, or with others: a. Has legal title to any single Lot, Dwelling, Dwelling unit, or Commercial Facility, or an easement, sufficiently to allow installation and maintenance of the System; or b. Has care, charge, or control of any real property as Applicant, executor, executrix, administrator, trustee or guardian of the estate of the holder of legal title. Parallel Distribution: The distribution of effluent to the Dispersal Field by gravity flow, loading all sections of the Dispersal Field equally at the same time. Parcel: See Lot.

163 CHAPTER 15 DEFINITION OF TERMS Percolation Test: A measurement of the ability of the Soil to absorb liquid. The test is conducted with clean water and test results can be used to establish the Dispersal System design. Percolation Tests shall be conducted as provided in this Manual or as specified by the Department. Perennial Stream: A natural stream where water is present nine (9) months or more of the year, including all irrigation ditches and other public water conveyances. Permit: See Installation Permit or Operating Permit. Person: Any individual, firm, association, organization, partnership, corporation, business trust, company, state agency or department, or unit of local government who is, or that is, subject to the requirements of Chapter of the Alameda County General Code, this Manual and all the Permit conditions of approval. Plasticity: See Soil Consistence. Plot Plan: A scaled map of the Lot and relevant features on surrounding Lots that detail the features of the Site according to the requirements of this Manual to aid the Site Evaluation. Pollution: The undesirable change in the physical, chemical, or biological characteristics of air, land, and water that may or will harmfully affect human life or that of other desirable species, industrial processes, living conditions, and cultural assets; or that may or will waste or deteriorate raw material resources. Pores: See Soil Pores. Portable Toilet: Any self-contained Chemical Toilet Facility that is housed within a Portable Toilet Shelter. The Portable Toilet has no direct water connection and is a Non-Discharging Wastewater Disposal Unit. Portable Toilet Shelter: Any easily moved structure built to house a Portable Toilet. Pressure Distribution: A method of Effluent distribution designed to distribute Wastewater equally and evenly throughout the Dispersal Field by placing the liquid Effluent under pressure in the pipe. It may be referred as Pressure Dosing. Pressure Distribution Lateral: Piping and fittings in Pressure Distribution systems which distribute Effluent to filter material through small diameter orifices. Pressure Distribution Manifold: Piping and fittings in a Pressure Distribution System which supply Effluent from Pressure Transport Piping to Pressure Distribution Laterals. Pressure Distribution System: Any System designed to uniformly distribute Effluent under pressure in a disposal area. Pressure Dosing: See Pressure Distribution. Pressure Transport Piping: Piping which conveys Effluent to a Pressure Distribution Manifold. Public Entity: A local agency, as defined in the State of California Government Code Section et. seq., which is empowered to plan, design, finance, construct, operate, maintain, and to abandon, if necessary, any sewerage system or the Expansion of any sewerage system and sewage Treatment facilities serving a land development.

164 CHAPTER 15 DEFINITION OF TERMS Public Health Hazard: A condition created by a discharge of biological, chemical, physical, and/or radiological agents which are likely to cause human illness, disorders or disability. Public Nuisance: Public Nuisance shall include but not be limited to, anything which: a. Is injurious to public health or is indecent or offensive to the senses or any obstruction to the free use of property so as to interfere with the comfortable enjoyment of life or property; and b. Affects at the same time an entire community or neighborhood or any considerable number of Persons, although the extent of the annoyance or damage inflicted upon individuals may be unequal; and c. Is an attractive nuisance which may prove detrimental to children or others, whether in a building, on the premises of a building, or upon an unoccupied Lot. This includes any Abandoned Wells or shafts, Failing System, Abandoned System, Cesspool, seepage Pit, System installed without an Installation Permit; and d. Is dangerous to human life or is detrimental to health, as determined by the Director of Environmental Health; and e. Inadequate or unsanitary or unapproved sewage or plumbing facilities. Public Water System: A system for the provision to the public of water for human consumption through pipes or other constructed conveyances, if such system has at least fifteen service connections or regularly serves at least twenty-five individuals, as defined in Part 12, Chapter 4, Section of the California Health and Safety Code. Public Sewer System: Any sewer system constructed, installed, maintained, operated and owned by or for a municipality or Public Entity established for sewage dispersal purposes. Pump Tank: A sewage tank or separate compartment within a sewage tank, which receives Septic Tank Effluent that serves as a reservoir for a pump. Qualified Professional: An individual licensed or certified by the State of California and who has been approved by the Department to design Systems using design parameters provided in the Manual and practice as an expert for other associated services, as allowed under their license or registration and as demonstrated by their possession of knowledge, and skills of Systems siting, design and installation. Depending on the work to be performed and various licensing and registration requirements within the provisions of the California Business and Professions code, this shall include an individual with one or more of the following credentials: a. California Certified Engineering Geologist c. California Registered Civil Engineer d. California Registered Environmental Health Specialist e. California Registered Geologist For the purpose of performing site evaluations, Soil Scientists certified by the Soil Science Society of America are considered as Qualified Professionals.

165 CHAPTER 15 DEFINITION OF TERMS Redoximorphic Features: features formed by the processes of reduction, translocation, and oxidation of Iron and Manganese oxides in seasonally saturated Soils. Redoximorphic Features are described in Soil Horizons by various types of redox concentrations, redox depletions, and reduced matrices. Regional Water Quality Control Board: The California Regional Water Quality Control Boards (Regional Water Board) designated by Water Code Section 13200, which have authority for adopting, implementing and enforcing water quality control plans (also called basin plans) which set forth the State s water quality standards and the objectives or criteria necessary to protect those Beneficial Uses. The San Francisco Bay and Central Valley Regional Water Boards have jurisdiction over Alameda County. Repair (System Repair): Installation, replacement and/or connection of the portion(s) of a System necessary to eliminate a Public Health Hazard or Pollution of public waters created by a Failing System. Replacement Area: An area of land dedicated for replacement of an entire System upon its failure. Restrictive Layer: See Limiting Layer Sand Filter System: A System combining a Septic Tank or other Treatment unit, Dosing System with Effluent pump(s) and controls, piping and fittings, sand filter and disposal area. Types of Sand Filter Systems includes, but not limited to the following: a. Intermittent sand filter bed system b. Recirculated sand filter bed system c. Raised sand filter bed system Rock Fragment: See Soil Rock Fragment. Roots: See Soil Roots. Scum: A mass of organic or inorganic materials floating on the surface of sewage. Seepage Pit: A drilled or dug excavation, three to six feet in diameter, and typically fifteen (15) to thirty-five (35) feet in depth either lined or gravel filled, that receives the Effluent discharge from a Septic Tank or other system Treatment unit for disposal of Effluent. Serial Distribution: The distribution of effluent to the Dispersal Field by gravity flow that progressively loads one section of the Dispersal Field to a predetermined level before overflowing to the succeeding section(s) and does not place a dynamic head on the lower section of the soil dispersal system. Septage: Materials accumulated in Septic Tanks, Cesspools, Vault Privies, Portable Toilets, Holding Tanks, or any other sewage holding apparatus that receives wastewater from plumbing fixtures. Septage does not include sewage sludge from Public Sewer Systems. Septage Hauler: See Septage Pumper Septage Pumper: A Person with an active approved Septage Pumper Permit issued by the Director of Environmental Health pursuant to California Health and Safety Code Section et seq., who is qualified to pump and haul waste from Septic Tanks, Chemical Toilets, Cesspools, Seepage Pits, Chemical Toilets, or other sewage containments.

166 CHAPTER 15 DEFINITION OF TERMS Septic Tank: A watertight receptacle which receives sewage from a building or structure, that functions to separate solids from liquids, retains and digests organic matter and discharges the resulting Effluent to a second Treatment unit or to a Soil disposal area. Service Provider: An individual approved by the Department to perform or conduct oversight of inspections, maintenance and monitoring of Systems operating under the Operation, Monitoring and Maintenance (OM&M) Program. Service Providers shall be approved by the Department and possess knowledge, and skills of Systems and possess one or more of the credentials required of a Qualified Professional, or Contractor as defined in this Manual. Site (Building Site): An area of a Lot designated for a specific purpose including an approved Usable Area for sewage disposal, building, etc. Site Assessment: A preliminary review of the physical surface features of the Site that may limit the available dispersal area for the proposed System; and/or limit the available area for proposed work associated with a Building Permit that may interfere with an existing or proposed System. Site Evaluation: An assessment of the characteristics of a lot sufficient to determine its suitability for the installation and sustainability of a System meeting the requirements of this Manual. The Site Evaluation shall be in accordance with procedure and criteria contained in this Manual. The Site Evaluation shall take into consideration the public and environmental health aspects relating to the installation and operation of a System including but not limited to anticipated Wastewater flow, anticipated Wastewater strength, soil texture, soil percolation rate (if a Percolation Test is performed), depth to groundwater, distance from natural land features and structures, site topography, and Usable Space for the installation and repair of the System. Site Evaluation Report: A report prepared by a Qualified Professional that includes all information obtained from a Site Evaluation including detailed information regarding the design parameters of the System. The report will be used by the Department to ensure that a parcel is capable of sustaining a System compliant with this Manual. Single Family Residences: A Dwelling designed for and commonly occupied exclusively by one family. Slope: The rise or fall in feet per one hundred (100) feet of horizontal distance. Slope is expressed as a percent of grade. For example: a land surface at a 45 degree angle has a Slope of 100%. Soil: The naturally occurring body of porous mineral and organic materials on the land surface, which is composed of unconsolidated materials, including sand-sized, silt-sized, and Clay-sized particles mixed with varying amounts of larger fragments and organic material. The various combinations of particles differentiate specific Soil Textures identified in the Soil Textural triangle developed by the United States Department of Agricultural (USDA). For the purposes of this Manual, Soil shall contain earthen material of particles small than 0.08 inches (2 mm) in size. Soil Color: Color of moist Soil in terms of hue, value, and chroma based on Munsell soil color system. It may be referred as Color. Soil Consistence: The attributes of the Soil materials as expressed in its degree of cohesion and adhesion or in its resistance to deformation or rupture. Terms used in describing Consistence are: wet Soil-non sticky, slightly sticky, sticky, and very sticky; Plasticity-non-plastic, slightly plastic, plastic, and very plastic; moist Soil-loose, very friable, firm, very firm, and extremely firm; dry Soilloose, soft, slightly hard, hard, very hard, and extremely hard; cementation-weakly cemented, cemented, strongly cemented, and indurate. It may be referred as Consistence.

167 CHAPTER 15 DEFINITION OF TERMS Soil Description: A notation of Soil properties during the Soil Profile Study including Slope, rock fracturing, Effective Soil Depth, and depth to Groundwater, if observed; and, for each Horizon observed, a notation of depth, texture, Rock Fragment content, Color, Redoximorphic Features, structure, Pores, Clay films, Consistence, Plasticity, Stickiness, Roots, Horizon boundary, and moisture content. Soil Horizon: A layer of Soil that is distinguishable from adjacent layers by characteristic physical properties such as structure, Color, or texture, or by chemical composition, including content of organic matter or degree of acidity or alkalinity. It may be referred as Horizon. Soil Horizon Boundary: The topography and distinctness of the change between two Soil Horizons. In Soil Descriptions, the Soil Horizon Boundary is noted as smooth, wavy, irregular or broken. Distinctness of the changes between Horizons is noted as abrupt, clear, gradual, or diffuse. Soil Moisture: The moisture content of the Soil at the time the Soil Description was made. Described as dry, damp, moist, saturated, or seepage. Soil Mottling: Soils irregularly marked with spots that vary in Color, number and size. Soil Pores: Generally tubular voids o the Soil material formed by Roots, animals, and other agents. In Soil Descriptions Pores are noted as few, common, or many in quantity, and as fine, medium or coarse in size. It may be referred as Pores. Soil Profile Study: An evaluation of the Soil Horizons in an area proposed for Wastewater disposal and for the Replacement Area to ascertain its ability for that purpose. Characteristics of Soil examined in a Soil Profile may include Soil Structure, Soil Texture, Color, impervious layers, or evidence of Groundwater as determined by direct observation or presence of Soil mottles. Soil Rock Fragment: Rock and mineral particles in the Soil greater than 2.0 mm in diameter. Includes gravel, cobbles, and stones. In Soil Descriptions noted as percent by volume. It may be referred as Rock Fragment. Soil Roots: The abundance and size of Roots in a Soil Horizon. In Soil Descriptions abundance is noted as none, few, common, or many. Where present, Root size is noted as very fine, fine, medium, or coarse. It may be referred as Roots. Soil Separate: The groups of mineral particles separated on the basis of range of size. The principal separates are sand, silt, and Clay. Soil Stickiness: See Soil Consistence. It may be referred as Stickiness. Soil Structure: The combination or aggregation of primary Soil particles into aggregates or clusters (peds), which are separated from adjoining peds by surface of weakness. Soil Structure is classified on the basis of size, shape, and distinctness into classes, types, and grades. Soil Test Pit: An Excavation dug for the purposes of the Soil Profile Study of sufficient size and depth to allow thorough examination of the Soil to evaluate its suitability for sewage disposal. Soil Texture: The relative proportion of Soil Separates in a Soil as described by the twelve (12) classes of Soil Texture as defined by the United States Department of Agriculture. The major textural classifications are defined as follows:

168 CHAPTER 15 DEFINITION OF TERMS a. Sand: Soil material that contains 85% or more of sand; percentage of silt, plus 1.5 times the percentage of Clay shall not exceed 15. b. Loamy Sand: Soil material that contains at the upper limit 85% to 900~? sand, and the percentage of silt plus 1.5 times the percentage of Clay in not less than 15; at the lower limit it contains not less than 70% to 85 % sand, and the percentage of silt plus twice the percentage of Clay does not exceed 30%. c. Sandy Loam: Soil material that contains either 20% Clay or less, and the percentage of silt plus twice the percentage of Clay exceeds 30%, and 52% or more sand; or, less that 7% Clay, less than 50% silt and between 43% and 52% sand. d. Loam: Soil material that contains 7% to 27% Clay, 28% to 50% silt, and less than 52% sand. e. Silt Loam: Soil material that contains either at least 50% silt and 12% to 27% Clay; or 50% to 80% silt and less than 12% Clay. f. Silt: Soil material that contains 80% or more silt and less than 12% Clay. g. Sandy Clay Loam: Soil Material that contains 20% to 35% Clay, less than 28% silt, and 45% or more sand. h. Clay Loam: Soil material that contains 27% to 40% Clay and 20% to 45% sand. i. Silty Clay Loam: Soil material that contains 27% to 40% Clay and less than 20% sand. j. Sandy Clay: Soil material that contains 35% or more Clay and 45% or more sand. k. Silty Clay: Soil material that contains 40% or more Clay and 40% or more silt. l. Clay: Soil material that contains 40% or more Clay, less than 45% sand, and less than 40% silt. Soil With Rapid Permeability: Soil with the following properties. a. Percolation Rates of five (5) minutes per inch or faster, or b. Soil Texture classes of sand or loamy sand as defined in the Soil Texture, or c. Soils containing more than 50% coarse fragments greater than 2 mm. in diameter. Stickiness: See Soil Stickiness. Swale: See Drainage Swale. Standard System: A System comprised of a Septic Tank and a gravity-fed Dispersal System which includes Trenches installed in approved undisturbed native Soil. Effluent will flow to the trenches by gravity, or may be pumped to the first distribution box of the Dispersal Field. Subdivision: Subdivision as defined by the Subdivision Map Act of the State (Government Code Section et seq).

169 CHAPTER 15 DEFINITION OF TERMS Substandard Tank: Any tank constructed of wood or brick, or any tank which is deteriorated to an extent that it cannot effectively hold and or treat Wastewater, or because of its condition poses a threat to health or safety. Supplemental Treatment: A Supplemental Unit or engineered System used to perform additional Wastewater Treatment functions, beyond that provided by a Standard System, and capable of reliably producing Wastewater Effluent of secondary quality or better, prior to discharge to the Dispersal System. Secondary quality is defined as Effluent meeting 30-day average concentration limits of 30 mg/l for biochemical oxygen demand and 30 mg/l for Total Suspended Solids. If the Supplemental Treatment is for the purpose of nitrogen reduction, the quality is defined as meeting a 50 percent reduction in total nitrogen when comparing the 30-day average influent to the 30- day average Effluent. Supplemental Treatment Unit: Alternative System listed by National Sanitation Foundation (NSF) and certified by NSF as meeting NSF Standard 40 or NSF Standard 245 or equivalent, and is designed to provide enhanced Treatment over that which would be provided by a Standard System, and that produces Effluent meeting a predetermined performance requirement as specified in this Manual, prior to dispersal into the Dispersal Field. An independent third party testing and listing agency which provides equivalent services as compared to NSF for testing and continuous quality control and consumer complaint response may be used in lieu of NSF upon the approval of the Director of Environmental Health. System: See Onsite Wastewater Treatment Systems. System Design: A System installation/construction plan prepared by a Qualified Professional or Contractor based on the Site Evaluation Report. Test Pit: See Soil Test Pit Texture: See Soil Texture. Total Suspended Solids (TSS): Solids in water that can be trapped by a filter. TSS can include a wide variety of material, such as silt, decaying plant and animal matter, industrial wastes, and sewage. Treatment: Any process or action that accomplishes a measureable reduction in wastewater strength or separation of liquid from solids, such as the reduction of solids or organics, dewatering, coagulation, settling, filtration or aeration. Unstable Land Mass: Land prone to subsidence, erosion, or mass land movement as indicated by historical landslide events, published maps or reports, or evidence of characteristics such as surface rupture, scarps, creep or other irregularities in ground Slope conditions Usable Space: A dedicated area of land on a Lot capable of sustaining the installation and operation of a System compliant with this Manual. Use Permit: A discretionary entitlement granted by the local Planning Division or Planning Department allowing use of a property for a specific purpose. Vault Privy: A Vault Privy is a structure used for disposal of human waste without the aid of water. It consists of a shelter built above a subsurface vault into which human waste falls. The Vault Privy has no water connection. A Vault Privy is a Non-Discharging Wastewater Disposal Unit.

170 CHAPTER 15 DEFINITION OF TERMS Vertical Separation: The depth of Effective Soil for Effluent filtration that exists between the bottom of a Dispersal Field and the restrictive or Limiting Layer, Groundwater or other feature including, but not limited to: a. Permanent or seasonal Groundwater level; or b. Consolidated Soil with insufficient permeability or porosity to provide Wastewater Treatment; or c. Fractured rock with excessive permeability that would not provide effective Wastewater Treatment; or d. Soils determined to be limiting as defined in this Manual. Wastewater: Wastewater includes Blackwater or Graywater a. Blackwater means Wastewater contaminated with human or kitchen wastes, generally originating from toilets and kitchen sinks. It includes, but is not limited to, Wastewater discharges from kitchen sinks, garbage grinders, water closets, toilets, urinals or similar fixtures alone or in combination with other Wastewater. b. Pursuant to Health and Safety Code Section , Graywater means untreated wastewater that has not been contaminated by any toilet discharge, and has not been affected by infectious, contaminated, or unhealthy bodily wastes, and does not present a threat from contamination by unhealthful processing, manufacturing, or operating wastes. Graywater includes but is not limited to wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs, but does not include wastewater from kitchen sinks or dishwashers. Watercourse: A definite channel with bed and banks within which water flows either perennially, ephemerally or intermittently, including overflow channels contiguous to the main channel. A Watercourse may be either a natural or man-made channel. For purposes of this Manual, Watercourse also includes water bodies such as ponds, lakes, marshes, seasonal wetlands and tidal waters. Waterless Toilet: A composting toilet, incinerating toilet or similar device for the holding and processing of Wastewater from a toilet. A Waterless Toilet is a Non-Discharging Wastewater Disposal Unit. Water Table: That level of Groundwater where the hydraulic pressure is zero. Wet Weather: Wet Weather conditions are defined as when seventy-five (75) percent of the average annual rainfall has occurred for the elevation where the property is being tested.

171 Appendix A: Tables

172 Table 2-1 Qualified Professionals Designation Professional Licensing/Registration/Certification Entity PE GE CEG PG CHG LLS REHS CPSS Professional Civil Engineer Professional Geotechnical Engineer Certified Engineering Geologist Professional Geologist Certified Hydrogeologist Professional Land Surveyor Registered Environmental Health Specialist Certified Professional Soil Scientist Licensed by the California Board for Professional Engineers, Land Surveyors, and Geologists 1 Registration by California Department of Public Health ( Certified by the Soil Science Society of America Licensed Contractor Class A (General Engineering Contractor) Class C-36 (Plumbing Contractor) Class C-42 (Sanitation System Contractor) Class C-57 (Well Drilling Contractor) ---- Registered Septage Pumper Licensed by the California Contractors State License Board ( Registered with Alameda County in accordance with California Health and Safety Code et seq Onsite Wastewater System Maintenance Provider Class C-36 (Plumbing Contractor) Class C-42 (Sanitation System Contractor) Registered with Alameda County. Completion of an onsite wastewater certification training course by a third-party entity, such as the California Onsite Wastewater Association (COWA), National Association of Waste Transporters (NAWT), National Sanitation Foundation (NSF), or other acceptable training program as determined by the Department Refer to the following guides for more information: Consumer Guide to Professional Engineering and Professional Land Surveying Guide to Engineering & Land Surveying for City and County Officials (

173 Table 2-2 Qualified Professionals Scope of Work Allowed by Registration, Certification, or License Activity Required Work Chapter Minimum Qualifications Site Evaluation Topographic Surveying Cumulative Impact Assessment Geotechnical Assessment Performance Evaluation System Design Conduct field studies and evaluate geology, soil and groundwater for System siting and design. Perform site surveys, property line determinations, and generate topographic maps for System siting and design. Assess nitrate loading, groundwater mounding or other cumulative impacts of Systems for flows as required by the Manual Assess slope stability, drainage and other geotechnical issues for Systems located on slopes over 30 percent. Conduct performance evaluations of Existing Systems in connection with building permits, land use project, business license, biennial registration, annual operating permit, and failure investigation. Prepare plans and supporting design analysis required for permitting and installation of Systems Chapter 3 Chapter 3 Chapter 3 Chapter 15 Chapters 4-12 PE, PG, REHS, CPSS, or CHG as allowed by their registration, certification, or registration and provisions in this Manual. PE or LLS as allowed by their license PE, PG, or CHG as allowed by their license and provisions in this Manual. PE, GE, CEG PE, PG, REHS, or Contractor depending on the scope of work and provisions in the Manual. PE, PG, or REHS as allowed by their registration or license and provisions in this Manual System Installation, Repair or Abandonment Install, repair or abandon Systems in accordance with approved plans and permit conditions issued by the Department Chapter 13 Licensed Contractor License (Class A, C-42, or C-36) Inspection and Monitoring of Systems with an Operating Permit Inspection and Monitoring of Standard Systems Well Installation or Abandonment Perform inspection, monitoring and annual reporting of System in accordance with conditions of operating permit issued by the Department Perform inspection, monitoring, or functionality testing and biennial reporting to the Department confirming proper functioning Install or abandon a well under permit by the well permitting agency Chapter 14 Chapter 14 Chapter 1, 3, 4, 13, 14 RCE, REHS, Onsite Wastewater Maintenance Provider, or Licensed Contractor depending on the system type and as allowed by their registration or license. Property owner, RCE, REHS, PG, or Licensed Contractor depending Licensed Contractor License (Class C-57)

174 Table 2-3 Alameda County Department of Environmental Health Onsite Wastewater Treatment System Service Providers Company Name: Mailing Address: Services Provided: Phone No: Website URL: Certified Engineering Geologist Civil Engineer (PE) Contractor (Class A: General Engineering) Contractor (Class C-36: Plumbing) Contractor (Class C-42: Sanitation System) Contractor (Class C-57: Well Drilling Geologist (PG/RG) Geotechnical Engineer (GE) Hydrogeologist (CHG) Land Suveryor (LLS) OM&M Service Provider Registered Env. Health Specialist (REHS) Septage Tank Pumper Soil Scientist Performance Evaluation Site Evaluation OWTS Design OWTS Installation OWTS Operations & Maintenance Septic Tank Pumping Topographic Surverying Property Line Determination Slope Stability Evaluation Drainage System Design Hydrogeologic Evaluation Well Installation & Abandonment Groundwater Well Sampling Other: Qualified Professional Name: Liscences, Registrations, Certifications:

175 Table 3-1 Soil Profile and Percolation Test Requirements by System Type Standard Systems (Primary Treatment with Gravity Fed Trench Dispersal) System Configuration Required Level of Treatment Dispersal System Effective Soil & Vertical Separation to Groundwater Requirements (from the Bottom Infiltrative Surface of the Dispersal System) No. Primary and/or Supplemental Treatment Gravity Fed or Pressure Dosed Dispersal System Type Bottom Infiltrative Surface Depth (feet bgs) Minimum Effective Soil Minimum Separation to Groundwater Minimum Soil Profile Depth (feet bgs) Percolation Test Hole Depth (feet bgs) N/A (> 120 mpi) N/A N/A 5 feet (31 to 120 mpi) 7.5 to 10 1 Primary Treatment Gravity Fed Conventional Trench 2.5 to 5 5 feet 8 feet (6 to 30 mpi) 10.5 to to feet (1 to 5 mpi) 22.5 to 25 N/A (< 1 mpi) N/A N/A N/A (> 120 mpi) N/A N/A 2 Primary Treatment Gravity Fed Shallow In- Ground Trench with Cover Fill 1.5 to < feet 5 feet (31 to 120 mpi) 6.5 to feet (6 to 30 mpi) 9.5 to feet (1 to 5 mpi) 21.5 to to N/A (< 1 mpi) N/A N/A Page 1 of 7

176 Table 3-1 Soil Profile and Percolation Test Requirements by System Type Alternative Systems (Primary Treatment with Pressure Dosed Trench Dispersal) System Configuration No. Required Level of Treatment Primary and/or Supplemental Treatment Gravity Fed or Pressure Dosed Dispersal System Dispersal System Type Bottom Infiltrative Surface Depth (feet bgs) Effective Soil & Vertical Separation to Groundwater Requirements (from the Bottom Infiltrative Surface of the Dispersal System) Minimum Effective Soil Minimum Separation to Groundwater Minimum Soil Profile Depth (feet bgs) Percolation Test Hole Depth (feet bgs) N/A (> 120 mpi) N/A N/A 3 Primary Treatment Pressure Dosed Conventional Trench 2.5 to 5 3 feet 3 feet (60 to 120 mpi) 5.5 to 8 5 feet (1 to 5 mpi) 7.5 to to 5 1 N/A (< 1 mpi) N/A N/A N/A (> 120 mpi) N/A N/A 4 Primary Treatment Pressure Dosed Shallow In- Ground Trench with Cover Fill 1.5 to < feet 3 feet (60 to 120 mpi) 4.5 to feet (1 to 5 mpi) 6.5 to to N/A (< 1 mpi) N/A N/A 5 Primary Treatment Pressure Dosed Pressure Dosed Sand Trench (Conventional or Shallow Trench Depths) N/A N/A N/A (> 120 mpi) N/A N/A 1.75 to 6 2 feet 2 feet 2 (6 to 120 mpi) 3.75 to to to 6 2 feet 3 feet 3 (1 to 5 mpi) 4.75 to to 6 1 N/A N/A N/A (< 1 mpi) N/A N/A Page 2 of 7

177 Table 3-1 Soil Profile and Percolation Test Requirements by System Type Alternative Systems (Primary & Supplemental Treatment with Gravity Fed Trench Dispersal) System Configuration No. Required Level of Treatment Primary and/or Supplemental Treatment Gravity Fed or Pressure Dosed Dispersal System Dispersal System Type Bottom Infiltrative Surface Depth (feet bgs) Effective Soil & Vertical Separation to Groundwater Requirements (from the Bottom Infiltrative Surface of the Dispersal System) Minimum Effective Soil Minimum Separation to Groundwater Minimum Soil Profile Depth (feet bgs) Percolation Test Hole Depth (feet bgs) N/A (> 120 mpi) N/A N/A 6 Primary & Supplemental Treatment Gravity Fed Conventional Trench 2.5 to 5 3 feet 3 feet (31 to 120 mpi) 5.5 to 8 5 feet (6 to 30 mpi) 7.5 to 10 8 feet (1 to 5 mpi) 10.5 to to 5 1 N/A (< 1 mpi) N/A N/A N/A (> 120 mpi) N/A N/A 7 Primary & Supplemental Treatment Gravity Fed Shallow In- Ground Trench with Cover Fill 1.5 to < feet 3 feet (31 to 120 mpi) 4.5 to feet (6 to 30 mpi) 6.5 to feet (1 to 5 mpi) 9.5 to to N/A (< 1 mpi) N/A N/A N/A (> 120 mpi) N/A N/A 8 Primary & Supplemental Treatment 6 Gravity Fed Deep Trench > 5 to 8 3 feet 3 feet (31 to 120 mpi) 8 to 11 5 feet (6 to 30 mpi) 10 to 13 8 feet (1 to 5 mpi) 13 to 16 5 to 8 1 N/A (< 1 mpi) N/A N/A Page 3 of 7

178 Table 3-1 Soil Profile and Percolation Test Requirements by System Type Alternative Systems (Primary & Supplemental Treatment with Pressure Dosed Trench Dispersal) System Configuration No. Required Level of Treatment Primary and/or Supplemental Treatment Gravity Fed or Pressure Dosed Dispersal System Dispersal System Type Bottom Infiltrative Surface Depth (feet bgs) Effective Soil & Vertical Separation to Groundwater Requirements (from the Bottom Infiltrative Surface of the Dispersal System) Minimum Effective Soil Minimum Separation to Groundwater Minimum Soil Profile Depth (feet bgs) Percolation Test Hole Depth (feet bgs) N/A (> 120 mpi) N/A N/A 9 Primary & Supplemental Treatment Pressure Dosed Conventional Trench 2.5 to 5 2 feet 2 feet (6 to 120 mpi) 4.5 to 7 3 feet (1 to 5 mpi) 5.5 to to 5 1 N/A (< 1 mpi) N/A N/A 10 Primary & Supplemental Treatment Pressure Dosed Shallow In- Ground Trench with Cover Fill 1.5 to < feet N/A (> 120 mpi) N/A N/A 2 feet (6 to 120 mpi) 3.5 to to feet (1 to 5 mpi) 4.5 to 5.5 N/A (< 1 mpi) N/A N/A N/A (> 120 mpi) N/A N/A 11 Primary & Supplemental Treatment 4 Pressure Dosed Deep Trench > 5 to 8 2 feet 2 feet (6 to 120 mpi) 7 to 10 3 feet (1 to 5 mpi) 8 to 11 5 to 8 1 N/A (< 1 mpi) N/A N/A 12 Primary & Supplemental Treatment Pressure Dosed Pressure Dosed Sand Trench (Conventional, Shallow or Deep Trench Depths) N/A N/A N/A (> 120 mpi) N/A N/A 1.25 to 8 2 feet 2 feet 5 (6 to 120 mpi) 3.25 to to to 8 2 feet 2 feet 2 (1 to 5 mpi) 3.75 to to 8 1 N/A N/A N/A (< 1 mpi) N/A N/A Page 4 of 7

179 Table 3-1 Soil Profile and Percolation Test Requirements by System Type Alternative Systems (Primary and/or Supplemental Treatment with Dispersal Systems other than Trenches) System Configuration No. Required Level of Treatment Primary and/or Supplemental Treatment Gravity Fed or Pressure Dosed Dispersal System Dispersal System Type Bottom Infiltrative Surface Depth (feet bgs) Effective Soil & Vertical Separation to Groundwater Requirements (from the Bottom Infiltrative Surface of the Dispersal System) Minimum Effective Soil Minimum Separation to Groundwater Minimum Soil Profile Depth (feet bgs) Percolation Test Hole Depth (feet bgs) N/A (> 120 mpi) N/A N/A 13 Primary and Supplemental Treatment Pressure Dosed Subsurface Drip 0.67 to 1 2 feet 2 feet (6 to 120 mpi) 3 3 feet (1 to 5 mpi) 4 1 N/A (< 1 mpi) N/A N/A N/A (> 61 mpi) N/A N/A 14 Primary Treatment Pressure Dosed At-Grade 0 3 feet 6 2 to 3 2 to 3 5 feet (1 to 5 mpi) N/A (< 1 mpi) N/A N/A 15 Primary and Supplemental Treatment Pressure Dosed At-Grade 0 2 feet 6 N/A (> 120 mpi) N/A N/A 2 feet (6 to 120 mpi) 2 to 3 2 to 3 3 feet (1 to 5 mpi) 2 to 3 2 to 3 N/A (> 120 mpi) N/A N/A 16 Primary Treatment Pressure Dosed Mound 0 2 feet 7 2 feet (6 to 120 mpi) 1 to 2 1 to 2 3 feet (1 to 5 mpi) N/A (< 1 mpi) N/A N/A Page 5 of 7

180 Table 3-1 Soil Profile and Percolation Test Requirements by System Type Additional Options for Repair and Replacement of Existing Individual Residential Systems on Severely Constrained Sites Only System Configuration No Required Level of Treatment Primary and/or Supplemental Treatment Primary & Supplemental Treatment 4 Primary and Supplemental Treatment 4 Primary Treatment 9 Primary and Supplemental Treatment 10 Primary and Supplemental Treatment Gravity Fed or Pressure Dosed Gravity Fed Pressure Dosed Pressure Dosed Pressure Dosed Pressure Dosed Dispersal System Dispersal System Type Deep Trench Bottom Infiltrative Surface Depth (feet bgs) Effective Soil & Vertical Separation to Groundwater Requirements (from the Bottom Infiltrative Surface of the Dispersal System) Minimum Effective Soil > 5 to 8 3 feet Deep Trench 5 5 to 8 2 feet Raised Sand Filter Bed 0 2 feet 7 Raised Sand Filter Bed Engineered 5 Fill with Drip Dispersal System 0 2 feet feet 11 Minimum Separation to Groundwater Minimum Soil Profile Depth (feet bgs) Percolation Test Hole Depth (feet bgs) N/A (> 120 mpi) N/A N/A 3 feet (31 to 120 mpi) 8 to 11 5 feet (6 to 30 mpi) 10 to 13 8 feet (1 to 5 mpi) 13 to 16 5 to 8 8 N/A (< 1 mpi) N/A N/A N/A (> 120 mpi) N/A N/A 2 feet (6 to 120 mpi) 7 to 9 3 feet (1 to 5 mpi) 8 to 11 5 to 8 8 N/A (< 1 mpi) N/A N/A N/A (> 60 mpi) N/A N/A 2 feet (6 to 60 mpi) 2 3 feet (1 to 5 mpi) 3 2 to 3 N/A (< 1 mpi) N/A N/A NA (>120 mpi) N/A N/A 2 feet (1 to 120 mpi) 2 to 3 2 to 3 N/A (< 1 mpi) N/A N/A N/A (> 120 mpi) N/A N/A 2 feet (6 to 120 mpi) feet (1 to 5 mpi) N/A (< 1 mpi) N/A N/A Page 6 of 7

181 Table 3-1 Soil Profile and Percolation Test Requirements by System Type Notes: 1 Minimum of three (3) tests shall be collected at the proposed trench bottom; other tests shall be conducted within the sidewall effective infiltration zone. 2 Trench sand thickness of twelve (12) inches. 3 Trench sand thickness of twenty-four (24) inches. 4 Nitrogen reducing Supplemental Treatment required. 5 Trench sand thickness of six (6) inches. 6 Minimum effective soil depth and percolation rate requirements shall apply within the dispersal area and in the adjacent area extending a minimum horizontal distance of twenty-five (25) feet down slope from the edge of the perimeter of the gravel bed on sloping sites, and fifteen (15) feet on all sides on level sites. 7 Minimum effective soil depth and percolation rate requirements shall apply within the dispersal area and in the adjacent area extending a minimum horizontal distance of twenty-five (25) feet down slope from the edge of the perimeter of the sand bed on sloping sites, and fifteen (15) feet on all sides on level sites. 8 Effective infiltrative surface may be increased up to a maximum of eight (8) square feet per lineal foot. 9 Sand fill depth of twenty-four (24) inches. 10 Sand fill depth of twelve (12) inches. 11 Minimum effective soil depth consisting of one (1) foot of native soil plus one (1) foot of engineered fill. 12 Percolation rate in native soil. Consolidated fill shall have a percolation rate between 5 and 60 mpi. 13 Percolation test hole depth in native soil. bgs = Below native ground surface mpi = Minutes per inch N/A = Not allowed Page 7 of 7

182 Table 3-2 Projects Requiring Cumulative Impact Assessment 1 Type of Project Geographic Location Lot Size (acres) Design Wastewater Flow (gpd) Groundwater Mounding Analysis Nitrogen Loading Analysis Individual Residence Residence with Second Unit Countywide Impaired Areas No criteria 1,000+ (more than 6 bedrooms) Countywide < 1 1,000+ (more than 6 bedrooms Impaired Areas No Per Area of Concern Criteria No Per Area of Concern Criteria No Yes Multiunit and Non- Residential Subdivisions Countywide Impaired Areas Countywide Impaired Areas < 1 1,000+ No Yes No criteria 1,500+ Yes No No criteria 2,500+ Yes Yes Per Area of Concern Criteria > No criteria No No < No criteria No Yes Per Area of Concern Criteria Any System < 200 feet from a Countywide No criteria No criteria Yes Yes Wetland or Vernal Pool 3 Notes: 1 Additionally, the Department reserves the right to require the completion of a Cumulative Impact Assessment in any case where special circumstances related to the size, type, or location of the System warrant such analysis. 2 This is an average lot size for a subdivision. 3 The hydrological and water quality analysis requirements may be modified depending on site specific conditions and the extent to which the System discharge contributes flow to any catchment area. Page 1 of 1

183 Table 4-1 Wastewater Design Flows for Single Family Residences and Secondary Units No. of Bedrooms Design Flow (gal/day) > per bedroom Page 1 of 1

184 Table 4-2 Wastewater Design Flow Guidelines Multiunit and Non-Residential Facilities Type of Business or Facility Design Flow (gallons per day) Assisted living/ residential care home - per resident bed space, ambulatory residents - per resident bed space, non-ambulatory residents - live-in caregiver - per employee (day use) Camps (per person) - day use - overnight use, with flush toilets, no showers - overnight use, with flush toilet and showers Churches and assembly halls (per seat) - without kitchen - with kitchen 5 15 Country clubs - per resident member or caretaker - per guest - per employee Day care (per patron, employee) 15 Detention center - per resident bed space - per employee Factories and industrial buildings (toilet wastes only) - without showers (per employee) - with showers (per employee) Hotels or motels - per guest - per employee - additional for restaurant, spa or other facilities Laundromat, with self-service washing machines - per machine, or - per customer case-by-case Mobile home parks (per space) 250 Multiunit residential housing - apartments, per bedroom - boarding house and farm labor housing, per bed Page 1 of 2

185 Table 4-2 Wastewater Design Flow Guidelines Multiunit and Non-Residential Facilities Type of Business or Facility Design Flow (gallons per day) Parks with picnic areas (per person) - with flush toilets - with flush toilets and showers Offices and stores (per employee) 15 Recreational vehicle parks without individual sewer hook-ups (per space) - with individual sewer hook-ups (per space) Restaurants and Food Service - toilet and kitchen wastes (per patron) - kitchen wastes only (per meal served) - additional for bars (per patron) - per employee Service Station - per vehicle served - per employee Schools, boarding Schools, day - student and live-in staff (per person) - daily staff (per person) - without cafeteria or showers (per student) - with cafeteria (per student) - with cafeteria and showers (per student) - staff (per person) Swimming pools Theaters - per patron - per employee - per seat - per employee Wineries (sanitary waste only) - tasting room, per visitor - per employee - special events case-by-case Note: The Qualified Professional may propose differing design flow based on adequate evidence and justification Page 2 of 2

186 Table 4-3 Wastewater Strength Characteristics Constituent Domestic Strength Wastewater Concentration (mg/l) High Strength Wastewater Concentration (mg/l) TSS 330 > 330 BOD 300 > 300 TN 75 > 75 FOG 100 > 100 Notes: TSS = Total Suspended Solids (30-Day Average) BOD = Biological Oxygen Demand (30-Day Average) TN = Total Nitrogen FOG = Fats, Oil and Grease mg/l = milligrams per liter Page 1 of 1

187 Table 4-4 High Strength Commercial Facility Wastewater Characteristics Wastewater Type Type of Business of Facility Wastewater Types Primary-treated Effluent Concentrations 1 1 Apartments Condominiums Mobile Home Parks Residential Subdivisions Work Camps Domestic Wastewater (Blend of Black and Grey Water Waste) BOD5: 140 to 250 mg/l TSS: 40 to 140 mg/l TKN 2 : 50 to 80 mg/l 2 Airport Campgrounds Fire Departments Golf Courses Manufacturing Facilities Offices Parks Public Toilets/Rest Areas RV Parks Visitor Centers Primarily Black Wastewater BOD 5: 300 to 500 mg/l TSS: 80 to 250 mg/l TKN 2 : 90 to 200 mg/l 3 Churches Schools Primarily Black Wastewater with Surge Flows BOD 5: 300 to 500 mg/l TSS: 80 to 250 mg/l TKN 2 : 90 to 150 mg/l 4 5 Hospitals Retirement Facilities Veterinary Clinics Bars Casinos Delis Gas Stations Hotels/Motels Restaurants Resorts Shopping Centers Strip malls Primarily Black Wastewater with Pharmaceuticals or Toxic Inhibitors Black Water with Restaurant Waste BOD 5: 300 to 700 mg/l TSS: 100 to 350 mg/l TKN 2 : 70 to 120 mg/l BOD 5: 300 to mg/l TSS: 80 to 300 mg/l TKN 2 : 90 to 200+ mg/l Notes: Bold Text indicates high strength wastewater characteristics. 1 The System Designer is responsible for ensuring that wastewater in each project is properly characterized and, whenever possible, waste streams should be sampled and actual values used in the design. 2 Nitrogen is usually introduced into the System as Organic Nitrogen (Organic-N) and Ammonium Nitrogen (NH4-N). Organic-N (including feces, urea, and other animal and vegetable matter) in wastewater is converted into NH4-N by the process of ammonification. In ammonification, proteins, amino acids, and other nitrogen-containing compounds are biochemically degraded by heterotrophic bacteria. Ammonification typically occurs in primary tankage (septic tank) and transport lines, as well as in the secondary treatment process. Because of this, a raw wastewater ammonia measurement may be significantly lower than the true value. Thus TKN is a better measure of overall nitrogen content and should be used when determining the waste load to System components downstream of the primary tankage. Page 1 of 1

188 Table 4- WASTEWATER APPLICATION RATES FOR S AND PRESSURE DOSED SYSTEMS Percolation Rate (MPI) Application Rate (gpd/ft 2 ) Percolation Rate (MPI) 1 to UTILIZING PRIMARY ( ) TREATMENT ONLY Application Rate (gpd/ft 2 ) Note: Pressure distribution recommended for soil with percolations rates slower than 60 mpi Page 1 of 1

189 Percolation Rate (MPI) Application Rate (gpd/ft 2 ) Percolation Rate (MPI) 1 to Table 4-6 WASTEWATER APPLICATION RATES: AT-GRADE SYSTEMS PRIMARY TREATMENT (1 to 60 MPI), SUPPLEMENTAL TREATMENT (61 to 120 MPI) Application Rate (gpd/ft 2 ) Note: Rates for MPI only applicable where Supplemental Treatment provided. Page 1 of 1

190 Table 4-7 Enhanced Wastewater Application Rates for use with Advanced Systems with Supplemental Treatment Application Rate (gpd/ft 2 ) Percolation Rate (MPI) Percolation Rate (MPI) & Pressure Distribution Trenches, Pressure-Dosed Sand Trenches, Mounds, or Raised Sand Filter Beds Application Rate (gpd/ft 2 ) Note: High Strength Wastewater. Reduction in the above wastewater loading rates to insure the long-term integrity and performance of Dispersal Systems may be required for high strength waste flows. Page 1 of 1

191 Table 4-8 Enhanced Wastewater Application Rates Advanced Systems with Supplemental Treatment & Subsurface Drip Dispersal Soil Type 1 Soil Percolation Rate (mpi) Wastewater Application Rate (gpd/ft 2 ) Coarse Sand 1 to Fine Sand 5 to Sandy Loam 11 to Loam 21 to Clay Loam 31 to Silt-Clay Loam 46 to Clay, non-swell 61 to Clay, swell 91 to Notes: 1 Soil types listed for reference information only; design shall be based on site-specific percolation data. Page 1 of 1

192 Table 4-9 Soil Types and Associated Percolation Rates Soil Type 1 Soil Percolation Rate (mpi) Coarse Sand 1 to 4 Fine Sand 5 to 10 Sandy Loam 11 to 20 Loam 21 to 30 Clay Loam 31 to 45 Silt-Clay Loam 46 to 60 Clay, non-swell 61 to 90 Clay, swell 91 to 120 Notes: 1 Soil types listed for reference information only; design shall be based on site-specific percolation data. Page 1 of 1

193 Table 4-10 Minimum Horizontal Setback Distances Site Feature Minimum Horizontal Setback Distance 1 (Feet) To Tight Line (Sewer Line, Effluent Line) To Dispersal Field To Tanks, Supplemental Treatment Units Private water supply wells and springs Public water supply wells Flowing surface water bodies including streams, creeks, and other watercourses 2 (from top of bank): General Between 1,200 to 2,500 feet from a state small water or public water system intake 4 Within 1,200 feet of a state small water or public water system intake 4 Drinking water reservoir or lake (from highwater mark): General Within 1,200 feet of a state small water or public water system intake 4 Non-drinking water pond, spring or lake Ephemeral creek, drainage way, drainage swale (from edge of flow path) Edge of 100-year flood plain Impervious lined (concrete, asphalt or equal) drainage ditch Unlined earthen channel or V-ditch, for site drainage only Closed drain pipe or watertight culverts or conduits Curtain drains: 5 Uphill of the dispersal field Lateral to the dispersal field (along slope contour) Downhill of the dispersal field N/A N/A N/A N/A N/A N/A Energy dissipaters: 6 Downslope Lateral of the System components N/A N/A Cut banks, fill banks, or steep embankments (from top of cut) 10 4 X h 7,8 10 Unstable land mass Steep slopes (from break of Slope) 9 4 X h 7,8 10 Property line Structures and foundations, including footings 10 N/A 10 5 Ground Mounted Solar Panels N/A Swimming pool, lined pond or basin Page 1 of 2

194 Table 4-10 Minimum Horizontal Setback Distances Site Feature Minimum Horizontal Setback Distance 1 (Feet) To Tanks, Tight Line To Dispersal Supplemental (Sewer Line, Field Treatment Effluent Line) Units Edge of road easement, right of ways, pavement, driveway, or 0 areas subjected to vehicular traffic 5 5 Edge of utility easements Refer to CCR Refer to CCR Title 22 Water Title 22 Water Water line - Public Works Works Standards Standards Refer to CCR Title 22 Water Works Standards Water line - Private Underground irrigation or drainage systems (water tight piping) Underground irrigation or drainage system (non-water tight piping) Trees N/A Notes: 1 Repairs and replacement systems shall comply with horizontal setback distances to the maximum extent practicable. 2 Flowing water bodies identified as any type of blue line on the United States Geological Survey (USGS) map. 3 Sewer pipes crossing creeks, streams or other watercourses may require a permit from the California Department of Fish and Wildlife, United States Army Corp of Engineers or other agency. 4 For areas tributary to and upstream of water supply intake; setback distance measured from high water mark. Exceptions allowed as follows: (a) for replacement Systems, comply to the maximum extent practicable and incorporate supplemental treatment unless there is evidence that there is no impact or significant threat to water source; (b) for new Systems on pre-existing lot of record, comply to maximum extent practicable and incorporate supplemental treatment for pathogens in accordance with the requirements in Chapter 6. 5 Measured from edge of dispersal trench to edge of curtain drain trench (perforated pipe section) 6 Measured from edge of nearest dispersal trench to the daylight end of outlet pipe 7 Where h equals the height of cut or embankment, in feet. The required setback distance shall not be less than twenty five (25) feet nor more than one hundred (100) feet. 8 Setback distance may be reduced in accordance with recommendations provided in a geotechnical report prepared by a registered Civil Engineer or Certified Engineering Geologist consistent with Chapter 3 of this Manual. 9 Steep slope is considered to be land with a slope of greater than fifty (50) percent and distinctly steeper (at least twenty [20] percent steeper) than the slope of the adjacent tank or dispersal field area. 10 Including porches, steps, breezeways, roof patios, carports, covered walkways, covered driveways, fences, retaining walls and other similar structures and appurtenances. 11 This distance may be reduced to four (4) feet when installed over and between dispersal trenches and design is stamped by a Registered Civil Engineer. Layout and design of solar system shall conform to the requirements set forth in Chapter 14 of this Manual. 12 If sewer tight line is properly bedded or sleeved. 13 Unless easement is specifically for an onsite wastewater treatment system. 14 These distances can be reduced to ten (10) feet if the underground irrigation or drainage system is located upslope of the dispersal system. N/A = Not Applicable CCR = California Code of Regulations Page 2 of 2

195 Table 4-11 Alternative Systems with Subsurface Dispersal - Configurations & Siting Criteria System Configuration No. Primary and/or Supplemental Treatment Gravity Fed or Pressure Dosed Dispersal System Dispersal System Type Maximum Dispersal System Slopes Dual System Requirement Constraints Addressed Standard Systems (Primary Treatment with Gravity Fed Trench Dispersal) 1 Primary Treatment Gravity Fed Conventional Trench 30% Primary Installed and Reserve Identified N/A 2 Primary Treatment Gravity Fed Shallow In-Ground Trench with Cover Fill 20% Primary Installed and Reserve Identified N/A Alternative Systems (Primary Treatment with Pressure Dosed Trench Dispersal) 3 Primary Treatment Pressure Dosed Conventional Trench 40% 1 Primary Installed and Reserve Identified A, B, C, D, E 4 Primary Treatment Pressure Dosed Shallow In-Ground Trench with Cover Fill 20% Primary Installed and Reserve Identified A, B, C, D 5 Primary Treatment Pressure Dosed Pressure Dosed Sand Trench (Conventional Trench Depth) Pressure Dosed Sand Trench (Shallow Trench Depth with Cover Fill) 40% 1 Primary Installed and Reserve Identified 20% Primary Installed and Reserve Identified Alternative Systems (Primary & Supplemental Treatment with Gravity Fed Trench Dispersal) A, H A, B, C, D 6 Primary and Supplemental Treatment Gravity Fed Conventional Trench 30% Primary Installed and Reserve Identified A, B, C, D, E 7 Primary and Supplemental Treatment Gravity Fed Shallow In-Ground Trench with Cover Fill 25% Primary Installed and Reserve Identified A, B, C, D, E 8 Primary and Supplemental Treatment Gravity Fed Deep Trench 6 20% Primary Installed and Reserve Identified D Page 1 of 4

196 Table 4-11 Alternative Systems with Subsurface Dispersal - Configurations & Siting Criteria System Configuration No. Primary and/or Supplemental Treatment Gravity Fed or Pressure Dosed Dispersal System Dispersal System Type Maximum Dispersal System Slopes Dual System Requirement Alternative Systems (Primary & Supplemental Treatment with Pressure Dosed Trench Dispersal) Constraints Addressed 9 Primary and Supplemental Treatment Pressure Dosed Conventional Trench 40% 1 Primary Installed and Reserve Identified A, B, C, D, E 10 Primary and Supplemental Treatment Pressure Dosed Shallow In-Ground Trench with Cover Fill 20% Primary Installed and Reserve Identified A, B, C, D, E 11 Primary and Supplemental Treatment Pressure Dosed Deep Trench 5 20% Primary Installed and Reserve Identified D, F Pressure Dosed Sand Trench (Conventional Trench Depths) 40% 1 Primary Installed and Reserve Identified D, F 12 Primary and Supplemental Treatment Pressure Dosed Pressure Dosed Sand Trench (Shallow Trench Depths with Cover Fill) 20% Primary Installed and Reserve Identified D, F Pressure Dosed Sand Trench (Deep Trench Depths) 30% Primary Installed and Reserve Identified Page 2 of 4

197 Table 4-11 Alternative Systems with Subsurface Dispersal - Configurations & Siting Criteria System Configuration No. Primary and/or Supplemental Treatment Gravity Fed or Pressure Dosed Dispersal System Dispersal System Type Maximum Dispersal System Slopes Dual System Requirement Constraints Addressed Alternative Systems (Primary and/or Supplemental Treatment with Dispersal Systems other than Trenches) 13 Primary and Supplemental Treatment Pressure Dosed Subsurface Drip 50% 1 Subsurface Drip with Cover Fill 20% Primary Installed and Reserve Identified A, B, C, D, E, F, G 14 Primary Treatment Pressure Dosed At-Grade (soil with 61 to 120 mpi) 15% At-Grade (soil with 1 to 60 mpi) 20% Primary Installed and Reserve Identified A, B, C, F 15 Primary and Supplemental Treatment Pressure Dosed At-Grade (soil with 61 to 120 mpi) 15% At-Grade (soil with 1 to 60 mpi) 20% Primary Installed and Reserve Identified A, B, C, F 16 Primary Treatment Pressure Dosed Mound (soil with 61 to 120 mpi) 15% Primary Installed and Reserve Identified A, B, C, D, F Mound (soil with 1 to 60 mpi) 20% Page 3 of 4

198 Table 4-11 Alternative Systems with Subsurface Dispersal - Configurations & Siting Criteria System Configuration No. Primary and/or Supplemental Treatment Gravity Fed or Pressure Dosed Dispersal System Dispersal System Type Maximum Dispersal System Slopes Dual System Requirement Constraints Addressed Additional Options for Repair and Replacement of Existing Individual Residential Systems on Severely Constrained Sites Only 17 Primary and Supplemental Treatment Gravity Fed Deep Trench 20% Primary Installed and Reserve Identified F 18 Primary and Supplemental Treatment Pressure Dosed Deep Trench 20% Primary Installed and Reserve Identified F 19 Primary Treatment Pressure Dosed Raised Sand Filter Bed 30% Primary Installed and Reserve Identified A, B, C, D, E, F 20 Primary and Supplemental Pressure Dosed Raised Sand Filter Bed Treatment 30% Primary Installed and Reserve Identified A, B, C, D, E, F 21 Primary and Supplemental Treatment Pressure Dosed Engineered Fill with Drip Dispersal System 10% Primary Installed and Reserve Identified A, B, C, D, F 22 Primary Gravity Conventional Trench (Grid Design) 5% Primary Installed and Secondary Installed F Notes: A = High groundwater E = Steep terrain B = Shallow soil over impermeable soil or bedrock F = Limited dispersal area C = Shallow soil over fractured rock or coarse alluvium G = Large and/or dense tree cover D = Slow percolation at shallow dispersal trench depths H = Rapid percolation rates 1 Slopes greater than 30 percent require a geotechnical evaluation Page 4 of 4

199 Table 5-1 Grease Interceptor Tanks and Primary Tanks Sizing Chart Guidelines Based on Hydraulic Residence Time (HRT) Facility Minimum Preferred Office/Manufacturing/Light Industrial Grease Tankage 1 Primary Tankage 2 Grease Tankage 1 Primary Tankage 2 HRT (days) HRT (days) HRT (days) HRT (days) a) restrooms only n/a 3 n/a 4 Restaurant/Deli a) restrooms and kitchen Convenience Store/Gas Station a) restrooms only n/a 3 n/a 4 b) restrooms and kitchen/deli Hotel/Motel/Multiple Dwelling Units Church School a) restrooms only n/a 3 n/a 4 b) restrooms and restaurant/kitchen a) restrooms only n/a Surge n/a 4 + Surge b) restrooms and kitchen Surge Surge a) restrooms only n/a 3 + Surge n/a 4 + Surge b) restrooms and kitchen Surge Surge Dog Kennel/Veterinary Clinic RV Park Casino a) restrooms only n/a 3 n/a 4 b) restrooms and floor drains n/a 3 + Surge n/a 4 + Surge a) RV spaces n/a 3 n/a 4 b) dump station n/a 8 n/a 10 a) gaming floor n/a 3 n/a 4 b) hotel/motel n/a 3 n/a 4 c) restaurant/deli Resort/Camp a) bunk houses n/a 3 n/a 4 b) main houses n/a 3 n/a 4 c) kitchen Notes: 1. Grease tankage HRT is based on a separate kitchen peak flow, which is integrated into the main flow prior to introduction to the primary septic tanks. 2. Primary tankage HRT is based on total peak flow. Tankages are based on long-term performance satisfaction (with respect to septage removal) and nominal (minimum) to high-quality (preferred) effluent. If effluent strength is higher than the expected level or if a higher level of treatment is required, greater tankage will be necessary. Source: Orenco Systems Inc.

200 Table 5-2

201 Table 5-3

202 TABLE 6-1 INTERMITTENT & RECIRCULATING SAND FILTER INSPECTION WELLS Inspection wells shall be constructed of two (2) inch to four (4) inch diameter pipe, equipped with a wrench-tight cap or pipe plug and a bottom cap. All wells shall be perforated beginning at a depth of eighteen (18) inches below grade and extending to the bottom of the pipe. Perforations shall consist of hacksaw slots at nominal one (1) inch spacing, or equivalent commercially-slotted pipe. To prevent surface water infiltration, inspection wells shall be sealed with a bentonite or concrete annular seal (or equivalent), extending from the ground surface to depth of twelve (12) inches, minimum. (See Figure 6-4) System Type Recirculating & Intermittent Sand Filters Figure 6-1 Figure 6-2 Figure 6-3 Location An inspection well shall be installed in the gravel distribution bed of each sand filter compartment. The inspection well shall extend from finished grade to the pea gravel-sand interface of the distribution bed and shall be perforated in the pea gravel zone only. For intermittent sand filters, inspection wells shall be sealed against surface infiltration with a bentonite or concrete annular seal through the soil backfill zone. For Intermittent Sand Filters, inspection wells shall be sealed against surface infiltration with a bentonite or concrete annular seal through the soil backfill zone.

203 TABLE 7-1 STANDARD & PRESSURE DISTRIBUTION TRENCH DISPERSAL SYSTEMS EFFECTIVE INFILTRATIVE AREA AND TRENCH SIZING CRITERIA (SHALLOW AND DEEP) CALCULATION Trench Infiltrative Area (square feet) 1 Trench Length (feet) FORMULA Q/ A Q / (R*A) Notes: 1 The Effective Infiltrative Area for trench dispersal systems shall be limited to four (4) square feet per lineal foot of trench length, which may include any combination of trench bottom area and trench sidewall area below the invert of the perforated distribution pipe. Q = Design wastewater flow, gallons per day (gpd) A = Total infiltrative area per lineal foot of trench, in square feet (ft 2 ) R = Wastewater application rate, in gallons per square foot per day (gall/ft 2 /day)

204 TABLE 7-2 CONVENTIONAL TRENCH SPECIFICATIONS Parameter Minimum Maximum Leach Lines per Field 1 No Limit Trench Length 25 feet 100 feet Trench Bottom Width 18 inches 36 inches Trench Depth 30 inches, measured on the upslope side of the trench 60 inches Soil Cover over Rock 12 inches 18 inches Depth of Drain Rock Under Pipe 12 inches 35 inches Depth of Drain Rock over Pipe 2 inches 3 inches Size of Rock ¾ inches 2 ½ inches

205 TABLE 7-3 SHALLOW IN-GROUND TRENCH SPECIFICATIONS Parameter Minimum Maximum Leach Lines per Field 1 No Limit Trench Length 25 feet 100 feet Trench Bottom Width 24 inches 36 inches Trench Depth 18 inches, measured on the upslope side of the trench <30 inches Soil Fill Cover over Rock 12 inches, after settling 18 inches Depth of Drain Rock Under Pipe 12 inches 35 inches Depth of Drain Rock over Pipe 2 inches 3 inches Size of Rock ¾ inches 2 ½ inches

206 TABLE 7-4 TRENCH DISPERSAL SYSTEMS TRENCH SPACING CRITERIA Parameter Minimum Maximum 5 feet minimum Trench Spacing One (1) foot additional spacing for every five (5) percent increase in dispersal area ground slope above twenty (20) percent No limit Minimum of two (2) times the depth of rock below the pipe allowed for repairs on constrained sites

207 TABLE 7-5 SUBSURFACE DISPERSAL SYSTEM GROUNDWATER MONITORING INSPECTION WELLS Inspection wells shall be constructed of two (2) inch to four (4) inch diameter pipe, equipped with a wrench-tight cap or pipe plug and a bottom cap. All wells shall be perforated beginning at a depth of eighteen (18) inches below grade and extending to the bottom of the pipe. Perforations shall consist of hacksaw slots at nominal one (1) inch spacing, or equivalent commercially-slotted pipe. To prevent surface water infiltration, inspection wells shall be sealed with a bentonite or concrete annular seal (or equivalent), extending from the ground surface to depth of twelve (12) inches, minimum (see Figure 6-4). System Type Pressure Distribution Trench Location Upslope Within Dispersal Field Downslope One (1) well shall be located upslope of the dispersal field, typically 10 to 15 away, to serve as a background or control well, extending from the ground surface to a depth of three (3) feet below the bottom of the dispersal trenches or to contact with impermeable materials, whichever is less. One (1) well shall be located within the dispersal field, typically between trenches near the center of the field. The well shall extend from the ground surface to a depth of three (3) feet below the bottom of the dispersal trenches or to contact with impermeable materials, whichever is less One (1) well shall be located down-slope of the dispersal field, typically ten (10) to twenty-five (25) feet horizontally from the lowest trench(es), and positioned to provide a representative point for monitoring the area estimated to be in the probable flow path of percolating wastewater. The well shall extend from the ground surface to a depth of three (3) feet below the bottom of the dispersal trenches or to contact with impermeable materials, whichever is less. Pressure Dosed Sand Trench One (1) well shall be located upslope of the dispersal field, typically ten (10) to fifteen (15) away, to serve as a background or control well. One (1) well shall be located within the dispersal field, typically between trenches near the center of the field. One (1) well shall be located down-slope of the dispersal field, typically ten (10) to twenty-five (25) feet horizontally from the lowest trench(es), and positioned to provide a representative point for monitoring the area estimated to be in the probable flow path of percolating wastewater. Page 1 of 2

208 TABLE 7-5 SUBSURFACE DISPERSAL SYSTEM GROUNDWATER MONITORING INSPECTION WELLS System Type Drip At-Grade Figure 7-10 Figure 7-11 Mound Figure 7-13 Figure 7-14 Figure 7-15 Figure 7-16 Raised Sand Filter Bed Figure 7-19 Location Upslope Within Dispersal Field Downslope One (1) well shall be located ten (10) to fifteen (15) feet up-gradient of the dripfield, extending to a depth of a minimum of three (3) feet or to contact with impermeable materials, whichever is less. One (1) well shall be located five (5) to ten (10) feet upslope of the At-grade system, midway along the length of the At-grade, extending from the ground surface to a depth of five (5) feet or to contact with an impermeable substratum, whichever is less. One (1) well shall be located near the center of the mound, extending from the mound surface to the bottom of the gravel distribution bed. One (1) well shall be located five (5) to ten (10) feet upslope of the raised bed system, midway along the length of the at-grade, extending from the ground surface to a depth of five (5) feet or to contact with impermeable materials, whichever is less. One (1) well shall be located within the dripfield area, extending to a depth of a minimum of three (3) feet or to contact with impermeable materials, whichever is less. One (1) well shall be located near the center of the At-grade system, extending from the fill surface to the bottom of the gravel distribution bed. One (1) well shall be located within the effective basal area (outside of the distribution bed), extending from the mound surface to six (6) inches into the native soil. One (1) well shall be located near the center of the raised bed, extending from the fill surface to the bottom of the gravel distribution bed. One (1) well shall be located near the center of the raised bed, extending from the fill surface to the sand-soil interface. One (1) well shall be located ten (10) to fifteen (15) feet down-gradient of the dripfield, extending to a depth of a minimum of three (3) feet or to contact with impermeable materials, whichever is less. One (1) well shall be located midway along the down-slope length of the At-grade, within five (5) to ten (10) feet from the toe of the fill slope, extending from ground surface to a depth of five (5) feet or to contact with an impermeable substratum, whichever is less. Four (4) wells shall be located, respectively, midway along each of the four sides of the mound, near the toe of the slope, extending from ground surface to a depth of five (5) feet or to the depth of impermeable materials, whichever is less. One (1) well shall be located midway along the downslope length of the raised bed, within ten (10) to fifteen (15) feet from the edge of the bed, extending from ground surface to a depth of five (5) feet or to the depth of impermeable materials, whichever is less. Page 2 of 2

209 TABLE 7-6 PRESSURE DOSED SAND TRENCH DISPERSAL SYSTEM EFFECTIVE INFILTRATIVE AREA AND TRENCH SIZING CRITERIA CALCULATION Trench Infiltrative Area (square feet) 1 Trench Length (feet) FORMULA Q/ A Q / (R*A) Notes: 1 The Effective Infiltrative Area for PDST Dispersal Systems shall be limited to three (3) square feet per lineal foot of trench length based on trench bottom area only. Q = Design wastewater flow, gallons per day (gpd) A = Total infiltrative area per lineal foot of trench, in square feet (ft 2 ) R = Wastewater application rate, in gallons per square foot per day (gall/ft 2 /day)

210 TABLE 7-7 PRESSURE DOSED SAND TRENCH DISPERSAL SYSTEM CONVENTIONAL TRENCH SPECIFICATIONS Parameter Minimum Maximum Leach Lines per Field 1 No Limit Trench Length 25 feet 100 feet Trench Depth 30 inches 96 inches (measured on the upslope side of the trench) Depth of Soil Cover over Rock 12 inches 18 inches Depth of Rock 1 over Pipe 2 inches 3 inches Depth of Pea Gravel 1 Under Pipe 6 inches 60 inches Trench Width Primary Treatment Effluent 18 inches 36 inches Supplemental Treatment Effluent 12 inches 36 inches Primary Treatment Effluent Supplemental Treatment Effluent Depth of Medium Sand 1 Fill Under Pea Gravel 12 inches (6 to 60 mpi) 24 inches (1 to 5 mpi) 6 inches (6 to 120 mpi) 12 inches (1 to 5 mpi) No Limit No Limit Notes: 1 See Chapter 9 for material specifications

211 GRAVEL BED BASAL AREA: TABLE 7-8 AT-GRADE DISPERSAL SYSTEM GRAVEL DISTRIBUTION BED SIZING (Refer to Figure 7-10 and 7-11) The minimum basal area of the gravel distribution bed shall be sized to meet the maximum wastewater application rates and linear loading requirements as follows: GGGGGGGGGGGG BBBBBB BBBBBBBBBB AAAAAAAA (ffff22) = WWWWWWWWWWWWWWWWWWWW FFFFFFFF RRRRRRRR (gggggg) WWWWWWWWWWWWWWWWWWWW AAAAAAAAAAAAAAAAAAAAAA RRRRRRRR (gggggg/ffffff) Where: Wastewater Flow Rate. The wastewater flow used for sizing the gravel bed area shall be the design wastewater flow rate for the System (Chapter 4). Wastewater Application Rate (or Soil Loading Rate). The wastewater application rates used for sizing the gravel distribution bed area shall be in accordance with the criteria in Table Reduction in the above wastewater loading rates or other provisions to insure the long-term integrity and performance of the At-Grade system may be required for high strength waste flows. GRAVEL BED BASAL WIDTH (A): The maximum width (A) of the basal area of the gravel distribution bed shall as follows: A = 10 feet (maximum) GRAVEL BED BASAL LENGTH (B): The effective length (B) of the basal area of the gravel distribution bed shall be determined by dividing the design wastewater flow by the Linear Loading rate. BB = EEEEEEEEEEEEEEEEEE LLLLLLLLLLLL (ffff) = WWWWWWWWWWWWWWWWWWWW FFFFFFFF RRRRRRRR (gggggg) LLLLLLLLLLLL LLLLLLLLLLLLLL RRRRRRRR (gggggg/llllllllllll ffffffff) (continued on next page)

212 Where TABLE 7-8 AT-GRADE DISPERSAL SYSTEM GRAVEL DISTRIBUTION BED SIZING Wastewater Flow Rate. The wastewater flow rate used for determining the effective length shall be as follows: System Type Q (gpd) Residential Systems 100 gpd/bedroom 1 Commercial, Institutional, Industrial and Multiresidential Systems Design wastewater flow rate Linear Loading Rate. Maximum linear loading rates for At-Grade systems vary according to ground slope, effective soil depth and percolation rate as indicated in the table below. If a variance from these criteria is proposed, it must be supported by detailed groundwater mounding analysis carried out in accordance with accepted methodology and/or scientific references dealing with water movement in soils and utilizing site specific hydraulic conductivity data. Maximum Linear Loading Rates (gpd/lineal foot) Effective Soil Depth (feet) Ground Slope (%) Percolation Rate (MPI) to NA to NA to NA > NA

213 TABLE 7-9 MOUND DISPERSAL SYSTEM GRAVEL DISTRIBUTION BED SIZING (Refer to Figure 7-12 through 7-18) GRAVEL BED AREA: The minimum area of the gravel distribution bed shall be sized to meet the maximum wastewater application rates and linear loading requirements as follows: GGGGGGGGGGGG BBBBBB AAAAAAAA (ffff22) = WWWWWWWWWWWWWWWWWWWW FFFFFFFF RRRRRRRR (gggggg) WWWWWWWWWWWWWWWWWWWW AAAAAAAAAAAAAAAAAAAAAA RRRRRRRR (gggggg/ffffff) Where: Wastewater Flow Rate. The wastewater flow used for sizing the gravel bed area shall be the design wastewater flow rate for the System (Chapter 4). Wastewater Application Rate (or Sand Loading Rate). The wastewater application rates used for sizing the gravel distribution bed area shall be as follows: Facility Type Wastewater Application Rate (gpd/ft 2 ) Individual Residential 1.2 Commercial, Industrial, Institutional and Multi-residential 1.0 Reduction in the above wastewater loading rates or other provisions to insure the long-term integrity and performance of the mound distribution bed may be required for high strength waste flows. GRAVEL BED WIDTH (A): The maximum width (A) of the distribution bed shall as follows: A = 10 feet (maximum) (continued on next page)

214 GRAVEL BED LENGTH (B): TABLE 7-9 MOUND DISPERSAL SYSTEM GRAVEL DISTRIBUTION BED SIZING The effective length (B) of the gravel distribution bed shall be determined by dividing the design wastewater flow by the Linear Loading rate. BB = EEEEEEEEEEEEEEEEEE LLLLLLLLLLLL (ffff) = WWWWWWWWWWWWWWWWWWWW FFFFFFFF RRRRRRRR (gggggg) LLLLLLLLLLLL LLLLLLLLLLLLLL RRRRRRRR (gggggg/llllllllllll ffffffff) Where Wastewater Flow Rate. The wastewater flow rate used for determining the effective length shall be as follows: System Type Q (gpd) Residential Systems 100 gpd/bedroom 1 Commercial, Institutional, Industrial and Multiresidential Systems Design wastewater flow rate Linear Loading Rate. Maximum linear loading rates for Mound systems vary according to ground slope, effective soil depth and percolation rate as indicated in the table below. If a variance from these criteria is proposed, it must be supported by detailed groundwater mounding analysis carried out in accordance with accepted methodology and/or scientific references dealing with water movement in soils and utilizing site specific hydraulic conductivity data. Maximum Linear Loading Rates (gpd/lineal foot) Effective Soil Depth (feet) 2.0 to to to 4.0 >4.0 Ground Slope (%) Percolation Rate (MPI) NA NA NA NA

215 TABLE 7-10 MOUND DISPERSAL SYSTEM SAND FILL SIZING (Refer to Figures 7-12 through 7-18) SAND FILL AREA: The minimum basal area of the sand fill (i.e., sand/soil interface area) shall be sized to meet the maximum basal wastewater application rates and linear loading requirements as follows: SSSSSSSS FFFFFFFF BBBBBBBBBB AAAAAAAA (ffff22) = WWWWWWWWWWWWWWWWWWWW FFFFFFFF RRRRRRRR (gggggg) WWWWWWWWWWWWWWWWWWWW AAAAAAAAAAAAAAAAAAAAAA RRRRRRRR (gggggg/ffffff) Where: Wastewater Flow Rate. The wastewater flow used for sizing the sand fill basal area shall be the design wastewater flow for the System (see Chapter 4). Wastewater Application Rate (Sand/Soil Interface). Wastewater application rates used for sizing the basal area of the sand fill shall be based on the soil percolation rate in the upper (12) to twenty-four (24) inches of soil depth in accordance with Table 4-5 (Standard Wastewater Application Rates) for systems utilizing primary treatment only and Table 4-7 (Enhanced Wastewater Application Rates0 for systems using Supplemental Treatment. SAND FILL WIDTH (W): The width (W) of the sand bed in plan view shall be determined as follows: W = A + I + J SAND FILL LENGTH (L): The horizontal length (L) of the sand bed in plan view shall be determined as follows: L = B + 2K (continued next page)

216 TABLE 7-10 MOUND DISPERSAL SYSTEM SAND FILL SIZING Variable Name Dimension (Value/Formula) A Gravel Bed Width 1 See Table B Gravel Bed Length 1 See Table D Thickness of the sand at the upslope edge of the gravel bed 2 12 inches (6 to 120 mpi) 24 inches (1 to 5 mpi) E Thickness of the sand at the downslope edge of the gravel bed 2 Level Sites 2%: E = D Sloping Sites >2%: E = D + (% of natural slope * A) F Gravel bed thickness 2 (2 inches above and 6 inches below 9 inches (0.75 feet) distribution piping) I Downslope width of the sand fill 1 I = 2 + [3 * (E + F) * Slope Correction Factor] Note: All dimensions in formula must be in feet J Upslope width of the sand fill 1 Level Sites 2%: J = I Sloping Sites >2%: J = 1 + [3 * (D + F) * Slope Correction Factor] Note: All dimensions in formula must be in feet K = 2 + 3[(D+E)/2 + F] K Sand end slope length 1 Note: All dimensions in formula must be in feet Notes: 1 Dimension represents horizontal dimension in plan view 2 Dimension represents vertical dimension in cross section

217 Slope (%) TABLE 7-10 MOUND DISPERSAL SYSTEM SAND FILL SIZING See next page for slope correction factors Slope Correction Factors Down Slope Correction Factor Up Slope Correction Factor

218 Table 7-11 Raised Sand Filter Bed Maximum Linear Loading Rates (gpd/lineal foot) Effective Soil Depth (feet) Ground Slope (%) Percolation Rate (MPI) to to to >

219

220

221

222 TABLE 9-1 SAND FILTER MEDIA SPECIFICATIONS Sieve Size Raised Sand Filter Beds & Intermittent Sand Filters Percent Passing Sieve 1 Pressure Dosed Sand Trench Systems, Mound Systems, & Recirculating Sand Filters 2 3/ #4 90 to to 100 #10 62 to to 100 #16 45 to to 82 #30 25 to to 55 #50 5 to 20 5 to 20 #60 0 to 10 0 to 10 #100 0 to 4 0 to 4 #200 0 to 2 0 to 2 Notes: 1 Documentation of laboratory sieve analysis results for the proposed sand filter media material shall be supplied to the Department to verify conformance with the above specifications. 2 Additional sand specifications for RSF: a. Effective size of sand/gravel, D10: 1.5 to 2.0 millimeters (mm) b. Uniformity coefficient, Uc < 2.5

223 Table System Inspection Requirements Element Site Inspection Wastewater Plumbing Inspection Drainage Inspection Dispersal System Inspection Tanks and Risers Inspection Supplemental Treatment System Inspection Pumps, Control Panels, Telemetry Other System Components Inspections Description of Work Inspect site to assess current site development (buildings, structures, decks, fences, ponds, pools, spas, ground-mounted solar panels, driveways, retaining walls, animal pens, etc.) against conditons on permitted System plans or approved As-built System plans. Inspect site topography in the vicinity of System components includingcut/fill areas, steep slopes, and graded areas for signs of instability or effluent seepage. Verify horizontal setbacks to site development structures for compliance with the plans and requirements in Chapter 4. Inpect site in the vicinity of System components for cave-in or exposed System components and sewage odors. Inspect site to ensure that all grey and balck water plumbing is rounted to the System. Inspect plumbing fixtures for leakage. Verify if garbage disposal is routed to the System. Verity if a water treatment appliance backflushes to the System. Inspect site in vicinity of System components for drainage issues including location and integrity of stormwater diversion structures (swales, inlets, dissipation devices, etc), sump pumps, foundation drains, roof runoff and other drainage related features that could impact or be impacted by the System. Inspect surface conditions in Dispersal System area (including downslope and surrounding areas) for odors, effluent leakage, wet areas, soil erosion, burnt out grass or ground staining, gopher holes, abnormal vegetation, trees, landscaping, irrigation, signs of heavy objects or vehicular traffic (impressions or tracks), etc. Inspect area around tank(s) for odors, effluent leakage, wet areas, soil erosion, drainage/infiltration, abnormal vegetation, signs of vehicular traffic, landscaping, irrigation, etc. Inspect conditon of risers for integrity, accessibiltiy, secure covers, etc.) and compliance with permitted System plans or approved As-built plans. Inspect conditon of tanks, baffles, inlet and outlet tees, effluent filters etc. for integrity, material/component type, tank size, and liquid/scum/sludge levels for compliance with permitted System plans or approved As-built plans. Inspect proprietary supplemental treatment train components in accordance with Manufacturer s specifications. Inspect surface conditions in Sand Filter System area (including downslope and surrounding areas) for effluent leakage, wet areas, soil erosion, gopher holes, abnormal vegetation, trees, landscaping, irrigation, signs of vehicular traffic, etc. Inspect pumps, float switches, control panels, alarms, electrical wiring and other appurtenances (per O&M Manual, Manufacturer s recommendations, and Guidelines in this Manual). Inspect pipes, valves, headworks, valve boxes, distribution boxes, monitoring ports, groundwater monitoring wells, etc. for integrity, functionality and compliance with permitted System plans or approved As-built plans.

224 Table System Maintenance, Monitoring & Reporting Requirements Element Routine Maintenance Activities (Permit from the Department of Environmental Health not Required) Description of Work Perform all maintenance work as recommended by System Designer or equipment Manufacturer. Replace all components as necessary with equivalent materials and/or equipment. Purge and balance laterals. Clean and check operation of valves to ensure functionality and repair and/or replace as necessary. Perform all maintenance work on pumps, float switches, hose and valve assemblies, and other pump related components. Check functionality of alarms, flow meters, and control boxes and replace and/or repair as necessary. Record flow, dose counter, and/or elapsed time meter readings. Remove and clean and/or replace filters Measure liquid, scum and sludge levels in tanks and have tanks pumped by a licensed Septage Pumper as required. Uncover and/or replace damaged valve boxes and tank riser covers. Repairs and Corrective Action (Permit from the Department of Environmental Health Required) Water Monitoring & Sampling Repair irrigation and storm water diversion structure problems in the vicinity of System components creating storm water run-on or run-off problems, infiltration, erosion or other deleterious effects to System components. Control rodents causing damage to System components. Maintain fill area landscape vegetation and erosion control measures. Report findings to the Department of Environmental Health and perform System repairs or corrective action work after obtaining requisite approvals and/or permits from the Department. In the case of emergency or System failure conditions, immediately perform corrective actions necessary to abate human health, water quality, or other environmental impacts and immediately report to the Department of Environmental Health. Measure and record water levels in observation ports located in and around Dispersal System and Sand Filter areas. Obtain and analyze water samples from monitoring ports, as applicable, per permit requirements. Measure and record water levels in groundwater monitoring wells and obtain and analyze water samples per permit requirements. Obtain water samples from surfacing liquid in the vicinity of System components and analyze for bacteria indicator parameters (total coliform, fecal coliform and e. coli). Reporting Submit a report with findings to the Department of Environmental Health per Biennial Registration or Annual Operating Permit requirements. Reports shall include completed forms supplied by the Department or other approved forms, documenting the inspection, maintenance, monitoring and corrective action work performed.

225 Appendix B: Figures

226

227

228 Figure 3-3 USDA Soil Textural Traingle

229 Figure 4-1. Treatment System Selection Preliminary Design Steps and Considerations Source: Onsite Wastewater Treatment Systems Manual (USEPA, 2002)

230 Figure 4-2. Treatment System Selection Development of the Onsite Wastewater System Design Concept Source: Onsite Wastewater Treatment Systems Manual (USEPA, 2002)

231 3 TYPICAL SITING CONSIDERATION FOR ONSITE WASTEWATER TREATMENT SYSTEMS ALAMEDA COUNTY FIGURE 4-3

232 FIGURE 4-4 System Requirements within Zone 7 Water Agency Jurisdictional Boundaries Total Allowble Nitrate Loading from All Systems on Parcel (lbs N/yr) Limit Outside Areas of Concern Limit Inside Areas of Concern 1 RRE/parcel 0.7 RRE/parcel RRE = Rural Residential Equivalent Parcel Size (Acres) Page 1 of 1

233 TYPICAL SEPTIC TANK FIGURE 5-1

234

235 PVC GATE VALVE (TYP.) CLEANOUT WITH THREADED CAP (TYP.) 30 MIL PVC LINER, SECURE TOP EDGE BY FASTENING TO BOARD STANDARD ORIFICE SHIELD OR CHAMBER OVER EACH LATERAL (TYP.) 12" TO 18" (TYP.) INSPECTION RISER (TYP.) TO GRADE INSPECTION WELL (TYP.) UTILITY BOX (TYP.) 24" TO 36" (TYP.) 2" PVC END MANIFOLD CLEAN OUT WITH THREADED CAP (TYP.) 4" SCH.40, PVC SLOTTED COLLECTION PIPE 2" PRESSURE LINE FROM PUMP CHAMBER #1 PLAN VIEW INTERMITTENT SAND FILTER PLAN VIEW FIGURE 6-1

236 PRESSURE LINE FROM DOSING PUMP LATERAL SHUT-OFF VALVE DISTRIBUTION LATERAL PEA GRAVEL DISTRIBUTION BED; 6" MIN. BELOW PIPE, 2" MIN. ABOVE PIPE UTILITY BOX (TYP.) MANIFOLD FILTER FABRIC SILT BARRIER TOPSOIL 6" MIN. MEDIUIM SAND 24" MIN. DEPTH 12" (TYP.) DOUBLE WASHED PEA GRAVEL DISCHARGE HOLES W/ SHIELD, OR EQUAL (TYP.)* INSPECTION WELL INTERNAL PUMP BASIN, 30" DIA. PVC (TYP.) TO DISPOSAL FIELD END RISER & FLUSH PORT 4" UNDERDRAIN CLEANOUT PERIMETER RETAINING STRUCTURE (TYP.) 30 MIL PVC LINER OR EQUAL PERFORATED PVC AIR INJECTION MANIFOLD; W/ CONNECTION PORT AT SAND FILTER SURFACE FOR PORTABLE BLOWER SLOTTED UNDERDRAIN SLOPE =.02 SAND BEDDING (TYP.) * NOTE: DISCHARGE HOLES MAY BE SHIELDED WITHIN A CONTINUOUS PLASTIC CHAMBER, OR THEY MAY BE ORIENTED DOWN WITHOUT THE NEED FOR ANY SHIELD. INTERMITTENT SAND FILTER WITH INTERNAL PUMP BASIN FIGURE 6-2

237 PEA GRAVEL DISTRIBUTION BED; 6" MIN. BELOW PIPE, 2" MIN. ABOVE PIPE UTILITY BOX (TYP.) DISCHARGE HOLES W/ SHIELD, OR EQUAL (TYP.)* INSPECTION WELL END RISER & FLUSH PORT 4" UNDERDRAIN CLEANOUT MANIFOLD 12" (TYP.) RIVER RUN ROCK PERIMETER RETAINING STRUCTURE (TYP.) PRESSURE LINE FROM DOSING PUMP LATERAL SHUT-OFF VALVE DISTRIBUTION LATERAL 6" MIN. COURSE SAND 24" MIN. DEPTH DOUBLE WASHED PEA GRAVEL 30 MIL PVC LINER OR EQUAL PERFORATED PVC AIR INJECTION MANIFOLD; W/ CONNECTION PORT AT SAND FILTER SURFACE FOR PORTABLE BLOWER SLOPE =.02 SLOTTED UNDERDRAIN SAND BEDDING (TYP.) RETURN LINE TO RECIRCULATION TANK * NOTE: DISCHARGE HOLES MAY BE SHIELDED WITHIN A CONTINUOUS PLASTIC CHAMBER, OR THEY MAY BE ORIENTED DOWN WITHOUT THE NEED FOR ANY SHIELD. RECIRCULATING SAND FILTER FIGURE 6-3

238 FIGURE 6-4

239 INSPECTION WELL RISER CAP FILTER FABRIC NATIVE TOPSOIL BACK FILL DRAIN PIPE SANITARY TEE DRAIN ROCK SIDE VIEW NATIVE TOPSOIL BACK FILL UTILITY BOX FINISHED GRADE SANITARY TEE DRAIN PIPE END VIEW ALTERNATE END DETAIL TYPICAL STANDARD DISPERSALTRENCH FIGURE 7-1

240 REVEGETATE SOIL FILL W/ GRASSES OR OTHER GROUND COVER FOLLOWING PLACEMENT AND COMPACTION ' MIN. (UPSLOPE AND SIDESLOPE DIRECTIONS) SOIL COVER FILL; SIMILAR TO NATIVE SOIL TEXTURE; PLACE AND COMPACT IN LIFTS OF 6" OR LESS; COMPACT BY TRACK-ROLLING, TWO (2) PASSES MIN. 12" MIN. 15' MIN. (DOWNSLOPE DIRECTION) ORIGINAL GRADE; STRIP VEGETATION AND PLOUGH OR RIP, 8" TO 12" DEEP, PRIOR TO PLACEMENT OF SOIL COVER FILL 3 1 DISPOSAL TRENCHES; INSTALL FOLLOWING FILL PLACEMENT NATIVE GROUND SLOPE, 20% MAX. APPLY EROSION CONTROL MEASURES, SUCH AS STRAW WATTLES, AS NEEDED COVER FILL SYSTEM CROSS-SECTION FIGURE 7-2

241 FIGURE 7-3 STANDARD DISPERSAL FIELD

242 FIGURE 7-4: STANDARD DISPERSAL FIELD - SLOPING SITE Septic Tank Diversion Valve Perforated Pipe Varies; 5 min o.c. Popover Varies; 5 min o.c. 12 min native backfill over rock Overflow pipe at least 4 lower than septic tank outlet 2 min rock over pipe 12 rock beneath pipe End View Varies; 5 min o.c, Add 1 foot for each 5% over 20% slope

243 LATERAL SHUT-OFF/ADJUSTMENT VALVE (TYP.) PRESSURE DISTRIBUTION TRENCHES & LATERALS SUPPLEMENTAL TREATMENT (OPTION) DIVERSION VALVE PRIMARY DISPOSAL FIELD P SECONDARY DISPOSAL FIELD SEPTIC TANK PUMP CHAMBER PVC PRESSURE LINE END RISER & FLUSH PORT (TYP.) DISTRIBUTION MANIFOLD (TYP.) SHALLOW PRESSURE DISTRIBUTION SYSTEM SCHEMATIC FIGURE 7-5

244 FILTER FABRIC SILT BARRIER 12" MIN. TRENCH BACKFILL (NATIVE SOILS) 2" DRAIN ROCK ABOVE PIPE PRESSURE DISTRIBUTION PIPE TRENCH INSPECTION WELL W/ END CAP INSPECTION RISER, W/ THREADED END CAP 3/4" TO 1 1/2" DRAIN ROCK SIDE VIEW UTILITY BOX FINISHED GRADE FILTER FABRIC SILT BARRIER 3/4" TO 1 1/2" DRAIN ROCK *12" WIDTH OK WITH SUPPLEMENTAL TREATMENT 18" TO 36"* END VIEW SHALLOW PRESSURE-DISTRIBUTION SYSTEM FIGURE 7-6

245 INSPECTION RISER W/ THREADED CAP FILTER FABRIC SILT BARRIER TRENCH BACKFILL (NATIVE SOIL) PRESSURE DISTRIBUTION PIPE MEDIUM SAND 6" MIN. 6" TO 12", SEE BELOW DOUBLE WASHED PEA GRAVEL SIDE VIEW INSPECTION WELLS UTILITY BOX INSPECTION WELL FILTER FABRIC SILT BARRIER EXISTING GRADE DOUBLE WASHED PEA GRAVEL MEDIUM SAND FILL 6" MIN. 12" TO 24" MIN. FOR SEPTIC TANK EFFLUENT, 6" TO 12" MIN. FOR SUPPLEMENTAL TREATMENT END VIEW 12" TO 36" (EFFECTIVE APPLICATION AREA) PRESSURE DOSED SAND TRENCH FIGURE 7-7

246 AIR/VACUUM RELIEF VALVE AT HIGH POINTS (TYP.) POLYETHYLENE DRIP TUBING; 24" DRIPLINE SPACING; 24" O.C; 8-12" DEEP (TYP.) DISPERSAL AREA PERIMETER PUMP CHAMBER PVC SUPPLY MANIFOLD SUPPLEMENTAL TREATMENT SEPTIC TANK P PVC FLUSH RETURN MANIFOLD PVC FLUSH RETURN LINE FLUSH VALVE, SOLENOID OR MANUAL, NORMALLY CLOSED HEADWORKS, WITH FILTER, VALVES & PRESSURE REGULATION DRIP DISPERSAL SYSTEM SCHEMATIC FIGURE 7-8

247 1/2" SCH. 80 PVC NIPPLE (LENGTH PVC PIPING AND FITTING 1/2" PVC COUPLING GEOFLOW ARV 05 AIR/VACUUM RELIEF VALVE BRICK SUPPORTS 6" ROUND VALVE BOX PEA GRAVEL SUMP BLANK DRIPLINE (TYP.) GEOFLOW DRIPLINE PVC TEE (TYP.) PVC HEADER SUPPLY MANIFOLD A 1.5' SEPARATION IS REQUIRED BETWEENT THE SUPPLY MANIFOLD AND 1ST DRIP EMMITER PVC ELL TO COMPRESSION ADAPTER (TYP.) TO SUBSURFACE DRIP DISPOSAL FIELD VORTEX FILTER PRESSURE GUAGE AIR VENT PRESSURE REGULATOR FROM PUMP CHAMBER FROM SUBSURFACE DRIP DISPOSAL FIELD AUTOMATIC HEADWORKS SOLENOID FIELD FLUSH VALVE TO SEPTIC TANK 18" FINISHED GRADE END FEED/ FLUSH MANIFOLD AS REQUIRED) THREE 1" AIR / VACUUM RELIEF (PUMPED TO PVC) 8" TO 12" DRIP DISPERSAL DETAILS FIGURE 7-9

248 SUPPLEMENTAL TREATMENT (OPTION) PEA GRAVEL DISTRIBUTION BED SLOPE SOIL COVER FILL P SEPTIC TANK DOSING PUMP PVC PRESSURE LINE INSPECTION WELL (TYP.) AT-GRADE SYSTEM SCHEMATIC FIGURE 7-10

249 UTILITY BOX (TYP.) INSPECTION RISER W/ THREADED END CAP TYP. FILTER FABRIC SILT BARRIER DISTRIBUTION BED; DOUBLE WASHED PEA GRAVEL INSPECTION WELL (TYP.) MULCHED OR PLANTED WITH NATIVE GRASSES FOLLOWING CONSTRUCTION TOPSOIL COVER; COMPACT BY TRACK-ROLLING EXISTING GRADE 12" TO 18" 4' TO 20' BASED ON GROUND SLOPE 10'TYP. DISTRIBUTION MANIFOLD AND LATERALS BASAL AREA FOR SYSTEM SIZING PRESSURE LINE FROM DOSING PUMP NATIVE SURFACE SOIL; STRIP VEGETATION AND PLOUGH OR RIP, 8" TO 12" DEEP, PRIOR TO GRAVEL AND SOIL PLACEMENT AT-GRADE SYSTEM CROSS-SECTION FIGURE 7-11

250 MOUND DISPERSAL FIELD GRAVEL BED GROUNDWATER TABLE FLOW LINE FILTER INLET COMPARTMENT 2/3 SEPTIC TANK OUTLET COMPARTMENT 1/3 SEPTIC TANK SEPTIC TANK PUMP CHAMBER DIAGRAM OF A MOUND SYSTEM FIGURE 7-12

251 GRAVEL DISTRIBUTION BED SOIL COVER PRESSURE DISTRIBUTION LATERALS (TYP.) SAND FILL; ENTIRE SAND BASAL AREA USED FOR SYSTEM SIZING SHUT-OFF VALVE INSPECTION/ CLEANOUT RISER (TYP.) PVC PRESSURE LINE FROM DOSING PUMP INSPECTION WELL (TYP.) 4' MIN. MOUND SYSTEM SCHEMATIC ~ LEVEL SITE ~ FIGURE 7-13

252 TOPSOIL COVER, COMPACT BY TRACK-ROLLING MULCHED OR PLANTED TO NATIVE GRASSES FOLLOWING CONSTRUCTION GRAVEL DISTRIBUTION BED FILTER FABRIC 18" UTILITY BOX (TYP.) INSPECTION/ CLEANOUT RISER (TYP.) INSPECTION WELL (TYP.) 10' (TYP.) MEDIUM SAND FILL ' 12" MIN. 2' 12" (TYP.) 10' (TYP.) 4' MIN. (TYP.) PLOUGH OR RIP NATIVE SURFACE SOILS, 8" TO 12" DEEP PRIOR TO SAND PLACEMENT PRESSURE DISTRIBUTION PIPING PRESSURE LINE FROM DOSING PUMP MOUND SYSTEM CROSS-SECTION ~ LEVEL SITE ~ FIGURE 7-14

253 GRAVEL DISTRIBUTION BED PRESSURE DISTRIBUTION LATERALS (TYP.) SLOPE SOIL COVER SHUT-OFF VALVE (TYP.) SAND FILL INSPECTION/ CLEANOUT RISER (TYP.) PVC PRESSURE LINE FROM DOSING PUMP BASAL AREA FOR SYSTEM SIZING INSPECTION WELL (TYP.) 4' MIN. MOUND SYSTEM SCHEMATIC ~ SLOPING SITE ~ FIGURE 7-15

254 GRAVEL DISTRIBUTION BED TOPSOIL COVER, COMPACT BY TRACK-ROLLING; MULCHED OR PLANTED TO NATIVE GRASSES FOLLOWING CONSTRUCTION FILTER FABRIC UTILITY BOX (TYP.) INSPECTION/ CLEANOUT RISER (TYP.) 10' (TYP.) ' 12" MIN. 2' MEDIUM SAND FILL INSPECTION WELL (TYP.) ' (TYP.) PRESSURE LINE FROM DOSING PUMP PRESSURE DISTRIBUTION PIPING PLOUGH OR RIP NATIVE SURFACE SOILS, 8" TO 12" DEEP, PRIOR TO SAND PLACEMENT 4' MIN. (TYP.) MOUND SYSTEM CROSS-SECTION ~ SLOPING SITE ~ FIGURE 7-16

255 FIGURE 7-17 MONITORING WELL

256 FIGURE 7-18

257 EXISTING GRADE INSPECTION WELL (TYP.) STRIP VEGETATION AND PLOUGH OR RIP, 8" TO 12" DEEP, PRIOR TO PLACEMENT OF SOIL COVER FILL INSPECTION RISER WITH THREADED END CAP (TYP.) 12" MIN. SOIL FILL PEA GRAVEL DISTRIBUTION BED; 6" MIN. BELOW PIPE, 2" MIN. ABOVE PIPE FILTER FABRIC SILT BARRIER MEDIUM SAND FILL; 12" MIN. RETAINING STRUCTURE WITH INTERIOR LINER SECURED TO INSIDE SURFACE (TYP.) PRESSURE DISTRIBUTION PIPING EXTEND LINER BELOW GRADE, 12" MIN. PVC PRESSURE LINE FROM DOSING PUMP END CROSS-SECTION RAISED SAND FILTER BED FIGURE 7-19

258 GRANULAR SLOP PROTECTION; 4" RIPRAP SURFACE DIVERSION DITCH NATIVE TOP SOIL BACKFILL; MOUND 6" TO 8" TO FORM CONTINUOUS DRAINAGE BERM NON-PERFORATED DRAINPIPE CROSS SECTION OUTLET DETAIL FILTER FABRIC; MIRADRAIN OR APPROVED EQUAL 12" DRAINFIELD TRENCH 3 4 " " DRAIN ROCK 3' 6" MIN. 3" OR 4" PERFORATED PLASTIC DRAINPIPE; LAY INVERT ON DRAIN ROCK; 2" ABOVE TRENCH BOTTOM 12" 15' MIN. CROSS SECTION IMPERMEABLE LAYER FIGURE 10-1

259 Appendix C: Forms

260 FORM 3-1 SOIL PROFILE OBSERVATIONS Soil profile observations shall be recorded on the attached Soil Profile Results form and plotted on the attached Soil Texture Triangle. To classify a soil sample using the USDA Soil Textural Triangle, you find the intersection of the three lines that correspond to the proportions of clay, sand and silt. The percentages of the three components must add up to one-hundred (100) percent. Example: Classify a soil sample that is 30% clay, 15% silt, and 55% sand. First locate 30% on the clay axis, and draw a line horizontally from left to right. Next, locate 15% on the silt axis, and draw a line going down diagonally to the left. Finally, locate 55% on the sand axis, and draw a line going up diagonally to the left. The intersection is in a region called Sandy Clay Loam. See figure below. Page 1 of 3

261 APN: FORM 3-1 SOIL PROFILE RESULTS Site Address: Street City State Zip Qualified Professional: Date of Analysis: Test Hole Designation: Depth Texture Color Structure Consistency Moisture Roots % Gravel Depth to Mottling: Depth to Limiting Layer: Comments: None Observed Groundwater Restrictive Layer Mottling Excessively Drained Please use the abbreviations below Texture Color Structure Consistency Moisture Roots "S" = Sand "Br" = Brown "Gr" = Granular "L" = Loose "Dr" = Dry "vf" = Very Fine "Si" = Silt "R" = Red "Bk" = Blocky "Fr" = Friable "M" = Moist "F" = Fine "C" = Clay "Y" = Yellow "P" = Platey "F" = Firm "S" = Saturated "M" = Medium "L" = Loam "O" = Olive "Mass" = Massive "VF" = Very Firm "Se" = Seepage "C" = Course "Dr" = Decomposed rock (specify) "G" = Grey "S" = Solid (refusal) Page 2 of 3

262 FORM 3-2 PERCOLATION TEST INSTRUCTIONS A. Percolation tests shall be conducted in accordance with the instructions below and results recorded on the attached Soil Percolation Test Recorded Measurements form. B. Clean water shall be added to bring depth of water in the test hole to approximately six (6) inches above the bottom of the hole after the minimum four (4) hour presoaking period. 1) The water level in the pipe shall be measured and recorded as WATER LEVEL START and record the time as TIME START 2) After thirty (30) minutes have passed the water level in the pipe shall be measured and recorded as WATER LEVEL FINISH and record the time as TIME FINISH 3) The water level drop shall be determined by calculating the difference in inches between WATER LEVEL START and FINISH measurements and record as Δ INCH. 4) The amount of time between START and FINISH readings shall be determined and recorded as Δ MIN 5) Calculate the rate in minutes per inch as the product of Δ MIN divided by Δ INCH and record as MPI C. Each hole shall be refilled to six (6) inches of water above the bottom of the hole and the procedures in Step 1 repeated. D. Water refill and water level drop measurement procedures shall be continued for a period of at least two (2) hours until: 1) The water level drop stabilizes from a fixed reference point; and 2) Three (3) consecutive water level drop readings do not vary by more than 10% or 1/8- inch of each other. E. If after one (1) hour the water level is dropping so rapidly to make thirty (30) minute readings infeasible, the time interval between readings shall be decreased to ten (10) minutes. 1) Hole shall be refilled to six (6) inches above the bottom and the water level drop measurement procedures in Step 1 repeated using ten (10) minute intervals instead of thirty (30) minutes. 2) The 10-minute tests shall be continued for at least one (1) hour and until the water level drop stabilizes in accordance with the requirements listed above 3) If the water drains so rapidly that 10-minute readings are infeasible: a. The interval shall be further reduced (e.g., to five (5) minutes), or b. The time it takes for the water to drop exactly one (1) inch shall be measured and recorded as the resultant rate (in MPI) Page 1 of 2

263 FORM 3-2 SOIL PERCOLATION TEST RECORDED MEASUREMENTS OWNER / APPLICANT: QUALIFIED PROFESSIONAL: LOCATION: CONTACT PERSON: PHONE: DATE: HOLE # 1 DEPTH HOLE # 2 DEPTH TIME WATER LEVEL TIME WATER LEVEL START FINISH START FINISH MIN INCH MPI START FINISH START FINISH MIN INCH MPI HOLE # 3 DEPTH HOLE # 4 DEPTH TIME WATER LEVEL TIME WATER LEVEL START FINISH START FINISH MIN INCH MPI START FINISH START FINISH MIN INCH MPI HOLE # 5 DEPTH HOLE # 6 DEPTH TIME WATER LEVEL TIME WATER LEVEL START FINISH START FINISH MIN INCH MPI START FINISH START FINISH MIN INCH MPI HOLE Stabilized MPI R Adjusted Stabilized MPI R 1 =R x 1.4 Average Adjusted Stabilized MPI R 2 =(Σ R 1 )/ # Holes # Bedrooms: FOR OFFICE USE ONLY Tank Size (Gal) Leach line (Ft) Page 2 of 2

264 Alameda County Department of Environmental Health Land Use Program 1131 Harbor Bay Pkwy, Alameda, CA Phone: Fax: Web: FORM 3-3 SITE DEVELOPMENT INFORMATION SITE INFORMATION (EXISTING CONDITIONS) N/A EXISTING RESIDENTIAL USES N/A Single Family Residential ( Primary Secondary) Multi-Unit Residential Agricultural Caretaker Unit EXISTING COMMERCIAL USES N/A Wine Tasting Wine Processing Vineyards Restaurant Event Center Bar Bed & Breakfast Dog Kennel Equestrian Center Cemetery Energy Facility Office Resort Park Facility School Grocery Store Fire Station Agriculture Other: EXISTING LOT SIZE Lot Size: Lot of Record Office Use Only: Lot 40,000 sf Lot 60,000 sf Lot 5 acres - Zone 7 EXISTING WATER SUPPLY SOURCE (ON SITE) Public Water Well Spring Community Water System Water Treatment Required Other: PUBLIC WATER SUPPLY SOURCES (WITHIN 500 FEET OF SITE) N/A Public Water Supply Well Public Water Supply System Reservoir EXISTING NATURAL SITE FEATURES (ON OR WITHIN 200 FEET OF SITE) N/A Steep Slopes Streams Creeks Lakes Ponds Swales Wetlands Other: EASEMENTS AND RIGHT-OF-WAYS Underground Utility Easements Above-ground Utility Easements Public Right-of-Ways Other: WASTEWATER TREATMENT SYSTEMS N/A Standard OWTS Total No: Advanced OWTS Total No: Wastewater Holding Tanks Wastewater Ponds ( Water Softener Industrial Process water) Total No: Total No: Page 1 of 5

265 Alameda County Department of Environmental Health Land Use Program 1131 Harbor Bay Pkwy, Alameda, CA Phone: Fax: Web: FORM 3-3 SITE DEVELOPMENT INFORMATION EXISTING ACCESSORY STRUCTURES & SITE IMPROVEMENTS INVENTORY (NOT CONNECTED TO OWTS S) N/A TYPE EXISTING PROPOSED Patios/Decks Y N Y N Bridges Y N Y N Decorative Ponds Y N Y N Graywater Systems Y N Y N Solar Y N Y N Wind Turbines Y N Y N Landscaped/Irrigated Areas Y N Y N Animal Pens/Corrals Y N Y N Potable Water Holding Tanks Y N Y N Storm Water Infiltration Trenches Y N Y N Storm Water Detention Ponds Y N Y N Storm Water Holding Tanks Y N Y N Storm Water Outfalls Y N Y N Other Storm Water Diversion Structures Y N Y N Retaining Walls Y N Y N Graded/Fill Areas (building pads, cut banks, berms, etc.) Y N Y N Other: Y N Y N Other: Y N Y N Other: Y N Y N Page 2 of 5

266 Alameda County Department of Environmental Health Land Use Program 1131 Harbor Bay Pkwy, Alameda, CA Phone: Fax: Web: FORM 3-3 SITE DEVELOPMENT INFORMATION EXISTING BUILDINGS & ACCESSORY STRUCTURES INVENTORY N/A STRUCTURE NUMBER PRIMARY USE R C R C R C R C R C R C R C R C R C R C Primary Residence Secondary Residence Ag Caretaker Unit Office Winery Processing Wine Tasting Event Center Clubhouse Restaurant Bar/ Snack Bar Warehouse Garage Barn Restroom Garbage Enclosure Crush Pad Animal Washing Other (Describe): PLUMBING FIXTURES Y N Y N Y N Y N Y N Y N Y N Y N Y N Y N Domestic Wastewater Industrial Process Wastewater Standard OWTS Advanced OWTS Holding Tanks Cesspool/Seepage Pit OWTS CORRECTIVE ACTION REQUIRED N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Needs Performance Evaluation Existing OWTS Repair Existing OWTS Replacement OWTS Abandonment Holding Tank Abandonment Note: Attach additional sheets if site has more than 10 existing building and accessory structures C= Commercial R = Residential N/A = Not Applicable Page 3 of 5

267 Alameda County Department of Environmental Health Land Use Program 1131 Harbor Bay Pkwy, Alameda, CA Phone: Fax: Web: FORM 3-3 SITE DEVELOPMENT INFORMATION PROPOSED ADDITIONS (SQUARE FOOTAGE INCREASE) AND/OR REMODELS (NO INCREASE IN SQUARE FOOTAGE) TO EXISTING SITE STRUCTURES N/A STRUCTURE NUMBER ADDITION OR REMODEL A R A R A R A R A R A R A R A R A R A R PRIMARY USE CHANGE Y N Y N Y N Y N Y N Y N Y N Y N Y N Y N Primary Residence Secondary Residence Ag Caretaker Unit Office Winery Processing Wine Tasting Event Center Clubhouse Restaurant Bar/ Snack Bar Warehouse Garage Barn Restroom Garbage Enclosure Crush Pad Animal Washing Other (Describe): PLUMBING FIXTURES Y N Y N Y N Y N Y N Y N Y N Y N Y N Y N Domestic Wastewater Industrial Process Wastewater Standard OWTS Advanced OWTS Holding Tanks Cesspool/Seepage Pit OWTS CORRECTIVE ACTION REQUIRED N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Needs Performance Evaluation Existing OWTS Repair Existing OWTS Modification Existing OWTS Replacement OWTS Abandonment Holding Tank Abandonment Note: Attach additional sheets if site has more than 10 existing building and accessory structures A = Addition R = Remodel N/A = Not Applicable Page 4 of 5

268 Alameda County Department of Environmental Health Land Use Program 1131 Harbor Bay Pkwy, Alameda, CA Phone: Fax: Web: FORM 3-3 SITE DEVELOPMENT INFORMATION PROPOSED NEW BUILDING STRUCTURES (INCLUDING ACCESSORY STRUCTURES WITH DRAINS CONNECTED TO OWTS S) Note: Attach additional sheets if site has more than 10 existing building and accessory structures C= Commercial R = Residential N/A = Not Applicable N/A STRUCTURE NUMBER PRIMARY USE R C R C R C R C R C R C R C R C R C R C Primary Residence Secondary Residence Ag Caretaker Unit Office Winery Processing Wine Tasting Event Center Clubhouse Restaurant Bar/ Snack Bar Warehouse Garage Barn Restroom Garbage Enclosure Crush Pad Animal Washing Other (Describe): PLUMBING FIXTURES Y N Y N Y N Y N Y N Y N Y N Y N Y N Y N Domestic Wastewater Industrial Process Wastewater Standard OWTS Advanced OWTS Holding Tanks OWTS CONNECTION N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Existing OWTS Modification New OWTS Page 5 of 5

269 Form 5-1 High Water Alarm: Float set two (2) inches above pump on to alert user of pump failure, both audio and visual alarms. Pump Off: Float set to turn pump off - lowest level in pump tank

270 Form 5-2