ERIE COUNTY WATER AUTHORITY DESIGN STANDARDS FOR WATERMAIN, PUMP STATION, AND TANK CONSTRUCTION

Transcription

1 ERIE COUNTY WATER AUTHORITY DESIGN STANDARDS FOR WATERMAIN, PUMP STATION, AND TANK CONSTRUCTION Design Manual, \\ecwa1\engineering\2006 Dsgn Standards\Cover.doc Rev.10/06

2 ERIE COUNTY WATER AUTHORITY DESIGN MANUAL TABLE OF CONTENTS SECTION PURPOSE AND GOALS PAGE 1.01 General 1-1 SECTION DESIGN ADMINISTRATION PROCEDURES 2.01 Submittals Project Schedule Design Standards ECWA File Numbers and Title 2-4 SECTION DESIGN PROCEDURES FOR WATERMAIN CONSTRUCTION 3.01 Survey Requirements Soils Investigations Drawing Layout Standard Details Standard Specifications General Notes Pipe Sizes Flow Velocities Pipe Cover Pipe Material Selection and Design Valve Requirements Hydrants Bedding Requirements Air & Vacuum Valve Requirements Thrust Restraint Requirements Pressure and Leakage Testing Procedure Disinfection Blow-off Requirements Fittings Corrosion Protection Chambers & Vaults Tapping Requirements Casing Requirements Tree Bores Easements Trenching & Backfilling 3-12 Design Manual, Table of Contents, \\ecwa1\engineering\2006 Dsgn Standards\TOC.doc i Rev.10/06

3 3.27 Utilities Interconnections Vertical & Horizontal Clearances Service Replacement Design Checklist 3-14 SECTION 4.0 DESIGN PROCEDURES FOR PUMP STATIONS AND TANKS 4.01 Tanks Pump Stations Instrumentation SCADA System Pump Control Pump Start-up Pump Shut-down Electrical Systems Lighting HVAC and Plumbing 4-8 SECTION GENERAL ADMINISTRATIVE 5.01 Permit Acquisition Engineers Estimate Bidding Procedure Addendum Procedure Pre-Bid Meetings Bid Summary Contract Execution 5-3 APPENDICES A. Review Checklist for Watermain Rehabilitation and New Watermain Projects Design Manual, Table of Contents, \\ecwa1\engineering\2006 Dsgn Standards\TOC.doc ii Rev.10/06

4 SECTION 1.0 PURPOSE AND GOALS 1.01 General A. This manual shall be used as a guide and shall not replace the traditional role of the Engineer in preparing a quality design in accordance with the standards of the engineering profession. B. The goals of this manual are to achieve the following: 1. Uniformity of approach All projects will be designed with similar characteristics, configuration and features as much as practical, considering specific project requirements. 2. All watermain improvement projects, pump station, and tank projects, whether in the Authority s Direct Service area or in a Leased Managed area, are to follow these Design Standards and utilize the Authority s Standard Specifications and Details. 3. Economy of Design and Schedule: by establishing requirements and preferences at the project outset. 4. Technical Quality Improvement. 5. Information: eliminates unnecessary inefficiencies by addressing common questions. 6. Variation from Water Authority standards will be considered on a case by case basis. 7. Exceptions will be allowed only with prior written Water Authority approval. Design Manual, Purpose and Goals, \\ecwa1\engineering\2006 Dsgn Standards\Sect1.doc 1-1 Rev.10/06

5 SECTION 2.0 DESIGN ADMINISTRATION PROCEDURE 2.01 Submittals A. The following documents shall be submitted to the ECWA: 1. Design Report and/or Engineer s Report, 2. Preliminary Plans, 3. Final Plans, 4. Specifications, 5. Cost Estimates, 6. Schedules B. All documents shall be submitted at least thirty days prior to the date on which approvals and/or comments by the ECWA are desired. The Design Report, Engineer s Report, and Preliminary Plans should be submitted for review and approval prior to the preparation of final plans. No approval for construction can be issued until final, complete, detailed plans and specifications have been submitted to and approved by the ECWA and found to be satisfactory. C. There are two basic types of watermain projects: rehabilitation or replacement projects and new projects. The administrative requirements may be met by completing the review check list identified as Appendix B. Pump Station and tank projects may follow the same check list. D. The Design and/or Engineer s Report for water system improvements shall, as a minimum present the following information: 1. An executive summary with recommendations. 2. Extent of water system improvements, including: a. Description of the nature and extent of the area to be served. b. Provisions for extending the water system to include additional areas. c. Appraisal of the future requirements for service, including existing and potential industrial, commercial, institutional, and other water supply needs. 3. Alternate Plans: where two or more solutions exist for providing water supply facilities, each of which is feasible and practicable, a complete evaluation of the alternate plans shall be made. Reasons shall be provided for selecting the recommended improvement, including financial considerations. 4. Soil, groundwater, and foundation conditions, including a description of: a. The character of the soil through which watermains are to be installed or pump station or tank is to be constructed. b. Foundation conditions prevailing at sites of proposed thrust blocks and other watermain appurtenances. Design Manual Design Administration Procedure \\ecwa1\engineering\2006 Dsgn Standards\Sect2.doc 2-1 Rev.10/06

6 c. The approximate elevation of ground water in relation to the work. d. Corrosive soils. 5. Water use data, including: a. A description of the population trends as indicated by available records, and the estimated population which will be served by the proposed water supply system. b. Present water consumption and the projected average and maximum daily demands, including fire flow demand. c. Present and/or estimated capacity of the sources of supply. d. Unusual occurrences. 6. Flow requirements, including: a. Hydraulic analyses and a schematic of the system with a hydraulic grade line based on peak flow demands and pressure requirements. This shall be accomplished by use of hydraulic modeling software consistent with ECWA Standards, b. Fire flows, when fire protection is provided, meeting the recommendations of the Insurance Services Office or other agency for the service area involved. 7. Sources of water supply. 8. Cost Estimates, evaluated to the anticipated mid-point of construction, including: a. Cost alternates based on alternate siting or routing location. b. Cost alternate based on alternate materials or methods of construction. c. Annual cost of operation, if applicable. d. Proposed methods of finance including both capital charges and operating expenses, if applicable. 9. Schedule. E. The preliminary drawings shall include as a minimum: 1. Horizontal alignment of the watermain. 2. Existing utilities and topography. 3. Vertical alignment. 4. Locations of line valves, air valves, blow-offs, hydrants, sample points, and other appurtenances. 5. Proposed easements, if required. 6. Interconnections. 7. Restraint system or details. 8. Testing and material schedule. 9. A listing of all plans that are not yet completed. 10. Outline specifications. 11. Hydraulic profile (separate from plan). Design Manual Design Administration Procedure \\ecwa1\engineering\2006 Dsgn Standards\Sect2.doc 2-2 Rev.10/06

7 F. The final drawings and specifications shall be submitted at least thirty days prior to the date of advertisement and be in conformance with the ECWA guidelines and standards. G. A final cost estimate of the construction cost and quantity take off shall be submitted with the final plans and specifications. H. The design checklist shown as Appendix A shall be submitted with the final plans and specifications. I. The procedure for submitting the above data will be as follows: 1. Engineer submits three copies of the Design and/or Engineer s Report to the ECWA Executive Engineer. 2. ECWA issues comments and/or approval of Engineer s Report within thirty calendar days. 3. Engineer submits three revised Final Reports back to ECWA. 4. ECWA issues notice to proceed with preparation of preliminary plans and specifications, when required. 5. At the 50 percent point of the Design Phase, the Engineer submits three sets of plans and specifications to the ECWA. 6. ECWA shall meet with the Engineer within two weeks of the submittal of the preliminary plans. 7. Within two weeks following the preliminary plan meeting the ECWA will issue its comments on the preliminary plans. 8. At the 80 percent point of the Design Phase, the Engineer shall submit three sets of bid ready specifications and plans for the ECWA review. 9. Within 30 days the ECWA will issue to the Engineer the final comments. 10. The Engineer shall incorporate the final comments and issue the appropriate number of sets of as advertised Contract Documents, cost estimate, and design checklist to ECWA. 11. The ECWA will then make all arrangements and place the advertisement in the official newspaper (on work in the Direct Service Area only) Project Schedule A. The Engineer shall provide the ECWA with a schedule for the project. This schedule will be submitted within two weeks of the Design notice to proceed and shall include a detailed task listing with milestones. Design Manual Design Administration Procedure \\ecwa1\engineering\2006 Dsgn Standards\Sect2.doc 2-3 Rev.10/06

8 B. Suggested milestones are as follows: Milestone Percentage Complete Preliminary Conference 5% Preliminary Design Report, Proposed Easements 20% Preliminary Plans & Specifications 50% Final Plans & Specifications 80% Final Easement(s), Documents, & Permits 80% Cost Estimates 90% Advertisement 100% C. All changes in the schedule must be requested in writing from the ECWA two weeks prior to the occurrence of a milestone deadline. This request must include an explanation of the deviation from the schedule and measures undertaken to correct the deviations. D. The contract specifications shall include a requirement for a construction schedule to be submitted by the Contractor. This schedule shall be reviewed by the Engineer and submitted to the ECWA and updated on a monthly basis Design Standards A. The Engineer shall design all water system improvements in accordance with the latest editions of the American Water Works Association (AWWA) and the Recommended Standards for Water Works Great Lakes Upper Mississippi River Board (Ten States Standards), unless as otherwise noted by ECWA standards ECWA Project Numbers and Title A. The ECWA will assign a Project Number for each project. On Direct Service work, an associated Contract Number shall be assigned. These numbers shall be used on all documents associated with the project. B. The Title for the Contract Drawings and Specifications shall follow the following format: 1. Contract Number. 2. Description a. Water System Improvements for watermain projects, b. Pump Station, or c. Tank. 3. Municipality. 4. ECWA Project Number. 5. Bid month and year. Design Manual Design Administration Procedure \\ecwa1\engineering\2006 Dsgn Standards\Sect2.doc 2-4 Rev.10/06

9 SECTION 3.0 DESIGN STANDARDS FOR WATERMAIN PROJECTS 3.01 Survey Requirements A. The following guidelines shall be used when providing survey services: 1. Perform control field work, photogrammetry or field methods to prepare and furnish a contour map of the project at 1-inch equals 40-feet scale and a contour interval of 1!foot. Other scales are subject to approval by ECWA. Include capturing topography and planimetric details digitally for output in AutoCAD version 2004 or 2006 format. Elevations shall be based on USGS datum. Survey data shall be according to NAD83 and NGVD29 standards. 2. Centerline profile is required for all pipelines. If contours were obtained by field method, include elevations within all rivers or stream. 3. All physical features such as roads, road shoulders, roadside ditches, driveways, trees, telephone poles, vents, houses, utilities (culverts, manholes, valves, hydrants, etc.), walls, fence lines, rivers, streams, lakes, ponds, sidewalks, curbs, etc are to be shown. 4. Existing buried utilities and structures with their easements, including inverts in all adjacent manholes and culverts are to be shown. 5. Indicate all adjacent property owners and their boundaries, including all property pins located in the field. 6. All road boundaries, street names and ownership (State, County, Local), as per the governing Municipality designation are to be identified. 7. For restoration purposes, the types of road and driveway (gravel, asphalt, stone) and grass areas, shall be noted. 8. Include field and office work necessary to field edit utilities and perform field topography and detail to supplement or add to digital terrain database. 9. Prepare preliminary computations, descriptions and sketches of proposed watermain easements or rights-of-way. 10. Computations of horizontal and vertical control data is necessary to provide a control survey traverse line and bench marks for construction and to establish control for existing ECWA networks. 11. Include field surveys to locate existing property corner markers, subsequent office computations and positional analysis, and preparation of a property base map in the digital database. 12. Indicate the field location of wetlands areas as determined and marked by others in field. 13. Perform stakeout and obtain elevations of all soil boring locations (not to be shown on construction drawings). 14. Identify field survey location of geotechnical test pits. 15. This stakeout of the centerline and baseline shall be established by Engineer. Construction stakeout services shall be coordinated with final construction. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-1 Rev.10/06

10 3.02 Soils Investigations 16. Perform all right-of-way, permit, and field survey work required to prepare rights-of-way drawings for each property accompanied by a written metes and bounds description, if required. 17. Land record research, computations, plottings of individual parcels, right-ofway and lots, and subsequent analysis and computations necessary to prepare CADD based composite drawing. A. The Engineer shall recommend a soils investigation to be performed as outlined below. B. Subsurface soil investigation shall be conducted to ascertain and report expected subsurface conditions. Subsurface exploration should also be made where unknown or unexpected conditions are encountered. Test borings will be placed at intervals of approximately 300-feet for watermain work, or to the extent the Engineer deems necessary and at a depth of approximately three (3) feet below the invert of the proposed pipeline sufficient to reveal subsurface conditions at these points or to a depth deemed necessary by the Engineer. 1. The groundwater elevation shall be noted. 2. A report in accordance with Section 8 of ASTM D-1586, shall be completed by the boring contractor with the following exceptions: a. The soils classifications must be performed or confirmed by a qualified soils engineer or geologist. b. The existing ground elevation (USGS) and location of each soil boring and/or test pit shall be obtained by a licensed surveyor. 3. Pavement thicknesses are to be measured to verify the requirements for pavement replacement. 4. The existing ground elevation (USGS) and location of each soil boring and/or test pit shall not be shown on the Contract Drawings. Instead, this information shall be available to all bidders as a separate document. C. Additional testing (field and/or laboratory), shall be undertaken in areas with unusual conditions that could jeopardize the integrity of the pipe; either short or long term. If the Engineer does not have the capability to design for unusual soil conditions, a soils consultant shall provide the required design. In addition to soil borings, test pits shall be dug in the areas of unusual conditions. D. Soils shall be analyzed to determine if corrosion protection systems are necessary. E. The Engineer may recommend that said analysis and borings may not be necessary. If so recommended, pavement cores shall be taken as a minimum to verify the requirements for pavement replacement. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-2 Rev.10/06

11 F. The results of the soils testing program shall be included in the engineering design report submittal Drawing Layout A. All Contract Drawings shall be prepared in the following format: 1. All Contract Drawings shall be 24x36 inches except as approved by the ECWA. 2. Information included on the drawings: a. Cover Sheet: 1) Project Title. 2) Commissioners names and titles, Executive Engineer s signature. 3) Designer s name and address. 4) Seal and signature of Engineer. 5) Location Plan. 6) Index of drawings. b. Second Sheet: 1) General notes. Repetition of information given in the specification should be avoided. Materials requirements shall be identified in the specifications. 2) Standard title block (pertains to all sheets). 3) Key plans where appropriate. 4) Project Title (all sheets). c. Plan and Profile Sheets: 1) Watermain plan at 1"=40'. 2) Watermain profile at 1"=5' vertical. 3) Other scales must be reviewed and approved by ECWA. 4) Notes particular to project area shown on drawing. 5) North arrow generally pointed up or to the right. d. Other Drawings 1) Standard details. 2) Details of all waterline interconnections at an appropriate scale. 3) Special details Standard Details A. ECWA standard details shall be incorporated in the Contract Documents. These details shall not be modified except with prior written approval of the Water Authority. When details are changed they shall be incorporated into the Contract Drawings as special details. B. Copies of the ECWA standard details are available in PDF format for download from the ECWA web site at Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-3 Rev.10/06

12 3.05 Standard Specifications A. This section describes the ECWA procedures for the preparation, submittal and review of specifications. When preparing specifications the following criteria shall be followed: 1. ECWA standard specifications shall only be used by the Engineer. Copies of the specifications are available from ECWA s web site at Leased Managed projects may not use the standard "Front End" documents, but must use the ECWA standard General Requirements and Technical Specifications. 2. Specifications are written to supplement the drawings therefore information shall not be duplicated in the drawings. 3. Special provisions of the project that may be required by the owner, ECWA or regulatory agencies must be obtained, reviewed and approved by ECWA prior to advertisement. 4. Any deviation of ECWA standard specifications and/or format must be approved by the Water Authority. B. The submittal and review of specifications and bid documents occurs in three steps, as follows: 1. Preliminary conference; 2. An intermediate review at the 50% point; 3. A final review at the 90% point. C. Following the final review, the Engineer submits to the ECWA an original of a final specifications, proofread and ready for printing General Notes A. A standardized set of general notes to be used for ECWA watermain projects are in ECWA Standard Details SD29 and SD30. The Engineer shall supplement this list only as necessary and with the approval of the Water Authority Pipe Sizes A. The minimum size of watermains shall be 8-inch diameter unless approved in writing by the ECWA. Larger size mains will be required if necessary to allow the required Insurance Service Organization fire flows while maintaining the minimum residual pressure of 20 psi at ground level at all points in the system under all conditions of flow. The normal working pressure in the system should not be less than 35 psi. B. The Engineer shall verify the design fire flow for each project from the fire underwriter for that project. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-4 Rev.10/06

13 3.08 Flow Velocities A. Maximum flow velocity shall be 10-feet per second under peak flow conditions. Recommended design velocities should be between 3 and 7 feet per second Pipe Cover A. Minimum pipe cover shall be 5 feet for watermains 12 inches in diameter and smaller. For water mains larger than 12 inches in diameter the minimum cover shall be 4 feet. Minimum cover shall be indicated on the Contract Drawings. B. A general note shall be placed on the Contract Drawings indicating that if the proposed watermain conflicts with a subsurface obstruction and when the minimum cover cannot be maintained by going above the obstruction, the contractor shall install the watermain below the obstruction, maintaining the appropriate separation. C. Cover less than the minimum must be approved in writing by the ECWA Pipe Material Selection and Design A. There are three pipe materials that are acceptable for watermains. These materials are ductile iron pipe (DIP), prestressed concrete cylinder pipe (PCCP), and polyvinyl chloride pipe (PVC). B. The following Table shows acceptable minimum for material selection. MAIN DIAMETER (INCHES) DIP PVC PCCP 6 X - Class 53 for hydrants Otherwise Class 52 8 X Class52 X minimum DR X Class 52 X minimum DR X Class X Class 51 X LCP 20 X Class 51 X LCP 24 X Class 51 X LCP 30 X Class 51 X - LCP 36 and larger X Class 51 X LCP or ECP Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-5 Rev.10/06

14 C. PVC pipe shall not be used under State, County, or locally heavily traveled roads or in casing pipes. In addition, PVC pipe shall not be installed within 5 feet adjacent to State, County, or Town Highways. D. The Engineer shall, submit all calculations necessary to support the pipe material, thickness, class, and flows. The following parameters shall be included: 1. Pipe Material. 2. External Loading (H-20, E-80, etc.) 3. Pipe Loading Calculations (Dead, Live, Impact). 4. Internal Pressure (Static, Dynamic, Surge). 5. Trench Loading Factors. 6. Pipe Thickness Calculations. 7. Internal Lining/External Coatings. 8. Design Period. 9. Pressures in proposed system and at existing connections. 10. Flow Demand Projection. 11. Corrosion protection system. 12. Thrust restraint type system. E. Recommended roughness coefficients for design progress are: Diameter Coefficient of Roughness 8-inch to 12-inch inch to 20-inch inch and above 120 F. Flexible pipe such as DIP and PVC shall be designed using the prism loads. Rigid pipe such as PCCP pipe shall be designed using the positive projecting embankment condition. G. Fire flows shall be in accordance with the latest edition of the Insurance Services Offices, AGuide for Determination of Required Fire Flows@. H. Peak daily demand flows shall be based on a multiplier of 2.0 minimum and peak hourly flow shall be based on a multiplier of 3.0 minimum. I. Total peak flow shall be the addition of fire flow and peak daily flow Valve Requirements A. Types of valves acceptable to ECWA are: 1. Resilient-Seated Gate Valves on 12-inch and smaller water mains. 2. Butterfly Valves on watermains 12-inch and larger. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-6 Rev.10/06

15 B. Resilient seat tapping valves are acceptable; however, size on size taps are not allowed. Double disc tapping valves shall not be used unless approved by ECWA. C. All valves shall open counter clockwise. D. Sufficient number of valves shall be provided on watermains so that inconvenience and sanitary hazards will be minimized during future maintenance or repairs. Valves shall be located at not more than 500-foot intervals in commercial/industrial areas and at not more than one block or 800-foot intervals (whichever is less) in other areas. Other spacing requirements are as follows: Water Main Size (Inches) Maximum Distance (Feet) and larger 2500 E. The Engineer shall obtain local fire department input and approval for residential areas for valve spacing. Fire department approval shall be forwarded to the ECWA by the Engineer. F. In general, no more than 2 hydrants shall be shut off at one time; a valve shall be placed on every hydrant line and multiple valving at connections of mains to provide minimal affect on the residents in the event of watermain repair. G. Where possible, valves shall be located adjacent to physical features such as buildings or hydrants so the valves can easily be found. H. Valves shall be placed in unpaved areas whenever feasible. I. Valves shall be the same size as the watermain Hydrants A. All hydrant installations shall be approved by the Towns or Fire Districts having jurisdiction. The following standards are to be considered as guidelines. B. Hydrants shall be provided at each street intersection and at intermediate points between intersections as recommended by the State Insurance Services Office. Generally, hydrant spacing may range from 400 to 600 feet depending on the area being served. C. Hydrants should be placed as close to the road boundary as possible and in line with property lines between adjoining property owners. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-7 Rev.10/06

16 D. The depth of bury is critical. Hydrant extensions shall be included in the Contract Documents to permit adjustment in the field. E. A hydrant shall be installed at all dead end mains. F. Ductile iron pipe, Class 53 shall be the only piping material allowed for hydrant piping from the main line tee to the hydrant base Bedding Requirements A. The design of the pipe class must correspond to the bedding condition specified. The Engineer shall correlate the bedding conditions with the load factor in the design of PCCP pipe and with the E (modulus of soil reaction) factor in the design of PVC or DI pipe Air and Vacuum Valve Requirements A. Combination air release and vacuum valves shall be installed at high points in all transmission watermains or distribution mains where air can accumulate. Automatic air relief valves shall not be used in situations where flooding of the air valve structures may occur. All efforts should be made to avoid cross connections to the air valve assembly. B. Each air and vacuum valve manhole shall have a vent pipe that extends above grade to at least three feet above grade and be provided with a screened, downward-facing elbow. The pipe must be sized correctly for air release and vacuum requirements. The vent pipe shall be the same size or larger than the air and vacuum valve sizing. C. All supporting calculations shall be submitted Thrust Restraint Requirements A. Watermains shall be restrained for the total of static, normal operating and surge (water hammer) pressures. B. Restrained joints shall be used on watermains 16-inches in diameter and larger. Restrained joints and solid concrete thrust blocking shall be used on all pipe 12 inches in diameter and smaller. C. Restrained joints for watermain shall be as specified in the specifications. Gasket with metal wedge inserts or other similar methods shall not be allowed as thrust restraint. D. Solid concrete block sizing must be supported by subsurface investigations and calculations that define the bearing capacity of the soil at the location of the proposed blocks. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-8 Rev.10/06

17 E. The determination of restrained pipe length must account for the weight of soil overburden, water table elevation, coefficient of friction between soil and pipe with and without polyethylene encasement, weight of pipe, and the weight of the contents of the pipe. A minimum safety factor of 1.5 shall be used to determine the length of restrained joints or bearing area of solid concrete blocks or anchor collars. F. Harnessed lengths shall be clearly shown on the construction plans in table form and/or noting the lengths on the watermain profiles. G. Hydrant branches shall be both restrained and blocked. H. Valves shall be considered a dead end condition and mechanical restraints shall be installed on each side accordingly. I. Where two 45Ε bends are used back to back to achieve a 90Ε bend the pipe shall be restrained as a 90Ε bend. The deflection angle for thrust restraint calculations may be reduced by 15Ε for each 20' separation between 45Ε bends. J. The Contract Documents shall consider the restraint required for testing the watermains as a dead end or bulkhead condition Pressure and Leakage Testing Procedure A. All pipelines shall be pressure and leakage tested in accordance with the methods described in ECWA=s standard specifications and AWWA standard C600. Refer to AWWA C600 for specific conditions not covered in the ECWA specification. B. In the event of a conflict between ECWA standard specification and AWWA standard C600, the more stringent of any requirement shall apply. The methods described in the ECWA standard specification applies to all pressure watermain. C. The Engineer shall consider the following when determining the test pressure: 1. Test pressure shall be 170 psi at the low point along the watermain for pipe sizes through 12 inches. Test pressure shall be 150 psi for pipe sizes 16 inches and larger. 2. The test pressure shall not exceed valve, pipe or thrust-restraint pressures. 3. The test pressure shall not vary by more than (+ -) 5 psi for the duration of the test Disinfection A. All new or repaired watermain shall be cleaned, chlorinated, flushed and bacteriologically tested in accordance with the methods described in ECWA=s Standard Specification. This specification is based on AWWA standard C651, ADisinfecting Water Mains@. Refer to AWWA C651 for specific conditions not covered. In the event of a conflict between the ECWA Standard Specification and Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-9 Rev.10/06

18 AWWA standard C651, the more stringent of any requirement shall apply. Existing mains shall be protected at all times from cross connections with watermains being chlorinated. Cross connection protection shall be achieved by use of a reduced pressure zone backflow preventer (RPZ). B. Large diameter transmission mains may require the installation of temporary components to adequately provide for proper disinfection and disposal. These requirements shall be included on the design drawings. C. Hydrants shall not be used as a source for taking samples for bacteriological testing Blow-off Requirements A. Blow-offs shall be located at selected low points in the system to allow the draining of the watermain. The location must consider discharge of the water in an environmentally acceptable manner. Where a low point is near the end of a water system the blow-off should be located at the end of the system. Hydrants shall be used as blow-offs where possible for the dead end situations. B. Blow-off sizing must allow for a minimum flushing velocity of 2.5 fps in the main line. C. All blow-offs shall be designed in accordance with ECWA standards and at locations approved by the ECWA Fittings A. Compact ductile iron fittings shall be used with either DIP or PVC watermain. B. Ductile iron fittings shall be covered with poly wrap when used with either ductile iron or PVC pipe Corrosion Protection A. The Engineer shall identify, during design, the potential causes for corrosion along the watermain alignment and recommend the proper external protection measures. The results of the soils testing and the method to be used for protecting the pipeline from corrosion shall be included in the design report submittal. B. Specifying additional thickness of pipe material is not acceptable as a corrosion protection measure Chambers and Vaults A. Chambers and vaults shall be designed in accordance with the ECWA standard details. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-10 Rev.10/06

19 B. All fittings, piping etc. inside of these structures shall be drawn to scale to insure adequate room for maintenance and removal of fittings from the structure. C. Special consideration must be given to the location of multiple access points to permit the removal of larger fittings Tapping Requirements A. Service taps, tapping sleeves/saddles and valves and all appurtenances shall be furnished and installed in accordance with ECWA=s standard specifications and with the recommendations of the manufacturer. B. Size on size taps shall not be allowed. For example, 8-inch taps on 8-inch watermains are not allowed Casing Requirements A. Casing pipes shall be used in tunneling, boring and jacking installations and shall be adequately sized to permit the installation of skids and hold down straps. Casings shall be new, uncoated steel pipe or liner plates. The steel casing pipe shall be designed in accordance with A.W.W.A. C202 with 5 / 16 inch minimum thickness for sizes up to 24-inch diameter and 9 / 16 minimum thickness over 24-inch and up to 42- inch diameter with minimum diameters as noted below: Carrier Pipe Encasing Pipe 4" 12" 6" 16" 8" 18" 10" 20" 12" 24" 16" 30" 20" 36" 24" 42" B. All carrier pipe shall be either ductile iron pipe or prestressed concrete cylinder pipe with restrained joints within the casing. PVC pipe is not allowed. C. Casing spacers, specially manufactured for this purpose, or full-length hard wood skids (exclusive of bells) shall be used Tree Bores A. Trees to be bored shall be noted on the Contract Drawings. Additional tree bores may be ordered during construction as needed. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-11 Rev.10/06

20 B. The casing or carrier pipe, installed by the boring, jacking or tunneling method, shall have a minimum length equal to the tree dripline. In order to reduce possible damage to the tree root system, the depth of the casing pipe installation shall allow for a minimum of 5 feet of cover over the top of the pipe. C. If there are major root fragments encountered in the soil borings, remedial measures must be taken to mitigate the stress resulting from the altered root/crown ratio. These measures shall involve reducing the lateral crown growth, thinning the crown and fertilizing the root area under the supervision of a certified arborist Easements A. Watermains shall be installed in public rights-of-way. In some cases, watermains may be installed in permanent easements contiguous with the public right-of-way. In other cases, temporary easements may be needed to facilitate construction. B. Temporary construction easements and permanent easements shall be obtained where needed and shall be shown on the Contract Drawings. C. A list of property owners where easements are required along the watermain route shall be submitted to the ECWA during the alignment or site selection study. D. A legal description and map shall be prepared and submitted to the authority at the 80% point in the final design process. E. A note shall be placed on the Contract Drawings that defines the work area. F. All easements, including special easement conditions, shall be included in Contract Document as an Appendix Trenching and Backfilling A. The following topics are covered in the ECWA standard specification for trenching. These topics should be reviewed for the particular project and if there are any special conditions that have to be addressed, they should be brought to the attention of the ECWA in the design phase. These topics include: 1. Alignment and depth of the trench. The tolerances and how this will be controlled. 2. The width of the trench at the top of the pipe and how it will effect the pipe material design. For example: Based on the elevation of the soil borings is it reasonable to expect that the loading on the pipe be a trench load versus an embankment load. 3. Depending upon the type of neighborhood or traveled way how much the trench should be left open at one time. 4. The use of plates or other bridging to serve business and residents. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-12 Rev.10/06

21 3.27 Utilities 5. A careful evaluation of the soil borings to determine the extent of use of the material excavated from the trench. 6. A type of subgrade that can be expected and any special treatments that are needed. 7. Storage of material along the trench, for example; because of maintaining traffic and access does it need to be removed as the work progresses. 8. Carefully assess requirements for removing of water. 9. What will be the pipe embedment requirements. 10. Special trenching techniques crossing drainage swales and water ways. 11. Temporary and permanent restoration of the trench. 12. Type of backfill material and availability in the vicinity of the project. 13. Special installation requirements of backfill; for example: paved areas versus unimprovement open fields and lawns and so forth. 14. Compaction requirements 15. Define the difference between the type of material and compaction requirements for the pipe zone versus not above the pipe. 16. Consideration of special types of backfill to prevent migration of ground water or movement of the sub-base material into the backfill material. 17. The need for permanent or temporary sheeting shall clearly be delineated in the design drawings. A. The Engineer shall obtain all available information relating to the location of existing utilities along proposed watermain alignments. The preliminary watermain alignment will be submitted to the owners of the utilities by formal transmittal with a request for their review and return to the consultant within a time frame that permits incorporation into the Contract Documents. B. The Contract Drawings shall identify the locations of test pit excavation to establish the horizontal and vertical location of utilities. All known utilities shall be clearly shown and labeled on the construction plans. C. If required, the Engineer shall design the relocation of the utilities and or coordinate the relocation design by the utility owner and incorporate this information in the Contract Documents Interconnections A. No interconnections between potable water supplies shall be made without prior ECWA approval. B. Upon receiving ECWA approval, only one connection may be made to any existing watermain prior to disinfection and Completed Works Approval is issued by the Water Authority Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-13 Rev.10/06

22 C. All other interconnections will be made after disinfection and Completed Works Approval is issued by the Water Authority Vertical & Horizontal Clearances A. Vertical and horizontal clearance requirements shall conform to the ECWA Standard Specifications and the latest edition of the Recommended Standards for Water Works (Ten State Standards) Service Replacement A. The Engineer shall include in the Contract Documents a bid item for the furnishing and installing of copper services on all water distribution projects. B. All water services shall be replaced from the new watermain to the right-of-way line with connection to the existing service with a new curb stop and box. The cover shall be 5 feet and adjustment of grades shall be made after the new stop Design Checklist A. The design, plans, and specifications for each project shall be verified by the Engineer and ECWA completing the checklist. All information called for on the check list must be included either on the plans in the design information submitted or in the specifications. Two copies of the completed checklist shall be submitted with the final plans and specifications. The checklist is shown as Appendix A. Design Manual, Design Procedures, \\ecwa1\engineering\2006 Dsgn Standards\Sect3.doc 3-14 Rev.10/06

23 SECTION 4.0 DESIGN STANDARDS FOR STORAGE TANK AND PUMP STATION PROJECTS 4.01 General A. Pump stations and storage tanks shall be sized to address future demand and expansion. B. Conform to all pertinent safety laws and regulations as outlined by OSHA and New York State. C. Sampling locations shall be provided to facilitate collection of water samples for bacteriological and chemical analysis. D. Pump stations and tanks shall be provided with SCADA antenna, and connection to an Authority supplied SCADA RTU to transmit information to the Authority=s SCADA system. Radio path study and FCC approval are required. E. A radio path study for site communication via the Authority s SCADA protocol to the Windom Tank site is required. A communication path study shall be performed early in the project design, since the quality of the communication path could affect site location. F. Door locks shall be as manufactured by Best Lock with 110 Volt power at head end. G. Intrusion alarm on the man door shall be wired to the RTU. H. Sites shall be fenced with a locking gate. I. sites shall be provided with paved access road and a parking area. J. Tank site shall have a fire hydrant located near tank. K. Tank foundations shall be designed following applicable sections of AWWA D100, local building codes, and ECWA requirements. L. All foundations shall be reinforced concrete in accordance with ACI codes, prevailing design standards for water works structures, prevailing seismic conditions and local codes. M. Doors shall be reinforced steel with heavy duty hardware capable of using Best Lock system. Design Manual Tanks and Pump Stations \\ecwa1\engineering\2006 Dsgn Standards\Sect4.doc 4-1 Rev.10/06

24 4.02 Storage Tanks A. All pressure zones shall have a minimum of one storage tank. B. Tank construction shall be welded steel ( AWWA Standard D100), composite, or pre-stressed concrete (AWWA Standard D110). C. Tank sizing shall take into account pumping rate equalization, peak hourly flows, fire flows, and emergency storage. D. Minimum usable tank capacity shall be the larger of either maximum day demand or average day demand plus fire flow. Tanks shall be designed to provide ISO requirements for fire flows of a minimum 20 psi residual pressure for a minimum duration of two hours. E. Minimum tank level shall be based on all usable tank capacity being delivered to all customers at a minimum pressure of 35 psi. F. All tanks shall have watertight roofs that exclude birds, animals, insects and dust. G. Tank drains shall discharge to atmosphere. Connections to sewers or storm drains are not allowed. H. Separate inlet and outlet piping shall be provided to facilitate the circulation and turnover of water in the tank. Inlet and outlet piping shall have bends, diffusers, and silt-stops as required. I. Over flow piping shall discharge to atmosphere and be of sufficient size to permit the wasting of water in excess of the filling rate. Over flow piping shall be equipped with a screened flap gate. Connections to sewers or storm drains are not allowed. J. Tank vents shall be sized such that the designed air exchange capacity of the vent is greater than the design water fill/discharge rate. Vents shall be designed to prevent entrance of rainwater, birds, animals, insects and dust. Vents shall also be designed to function in freezing weather without reduction in capacity. Vents shall be clog resistant, vacuum break/pressure relief design. K. Tanks shall be designed with access manholes. All tanks shall meet regulatory confined space requirements. 1. Elevated steel tanks. a. 30-inch diameter drywell access hatch on roof. b. 30-inch diameter roof hatch, adjacent to drywell hatch. c. Two 24-inch minimum diameter tank access hatches located at the balcony level. Design Manual Tanks and Pump Stations \\ecwa1\engineering\2006 Dsgn Standards\Sect4.doc 4-2 Rev.10/06

25 2. Elevated composite tanks. a. 30-inch diameter drywell access hatch. b. 30-inch diameter roof hatch, adjacent to drywall hatch. c. 30-inch diameter painter s access hatch located near rim. d. All hatches located on the roof. 3. Ground storage tanks. a. 30-inch diameter roof hatch. b. Two 30-inch diameter wall hatches accessible at grade. L. Interior paint systems shall meet NSF Standard 61. After curing, the coating system shall not transfer any substance to the water to make it toxic or cause taste or odor problems. Prior to placing the tank in service, an analysis for volatile organic compounds shall be completed to demonstrate compliance with New York Sanitary Code Part 5. M. Interior paint systems shall be 3-coat epoxy, color white. Exterior paint systems shall be 2-coat epoxy, 1-coat urethane, color light blue preferred. N. Tanks shall be disinfected in accordance with current AWWA Standard C652, method 2. Two or more successive sets of samples, taken at 24-hour intervals, shall be completed to demonstrate compliance with New York Sanitary Code Part 5, before the tank is placed into service. Samples shall be taken at least from the bottom of the tank and at the pump. One sample shall be analyzed for volatile organic compounds. O. All tank ladders shall be provided with safe-t-climb device and a locking ladder gate climb prevention shield. P. Tank level indicator/transmitter shall be provided. Q. Drain sump and drain for cleaning shall be provided. R. Tanks shall comply with FAA requirements for obstruction marking and/or lighting. FAA approval if required. S. Altitude valves, when required shall be controlled through SCADA system. T. Spider rods are to be removed after tank construction and prior to painting. U. Ground storage tanks shall have a small building for RTU, tank level transmitter, and radio. Design Manual Tanks and Pump Stations \\ecwa1\engineering\2006 Dsgn Standards\Sect4.doc 4-3 Rev.10/06

26 4.03 Pump Stations A. The roof shall be a steel frame or steel truss design. B. The exterior shall be compatible with surrounding areas: brick and block or architectural block walls and shingled roof. C. The exterior walls shall be brick/block with an insulated double door or overhead door facing the street. D. Pump Station basements and/or pipe chases shall have sump pumps. E. The firm pumping capacity (largest pump out of service) of the pump station shall be sized for maximum day demand as a minimum. The pump station sizing in conjunction with the storage tank shall address peak hour flow and fire flow. F. Pumps shall be either horizontal centrifugal, split case style or vertical turbine lineshaft pumps. G. Horizontal centrifugal pumps shall be as manufactured by Worthington, Gould, or Allis Chalmers. Vertical turbine pumps shall be as manufactured by Layne and Bowler, Peerless, Floserv, and Floway. H. Pump impellers shall not exceed 90% of the maximum allowable impeller diameter for the particular pump. I. Pump curves shall be approved by ECWA, where practical, hours of pump operations shall be during off peak power use periods. Pump(s) must be capable of refilling storage during the off peak window and during peak day demand. J. Variable frequency drives shall be used in locations where warranted. They shall include sites that require continuous flow or also wide variations of demand. K. Variable frequency drives shall be equipped with an autotransformer bypass starter. Acceptable manufacturers include Cutler Hammer, Siemens Energy and Automation (Robicon). L. Motors shall be premium efficiency and include General Electric, Westinghouse, and U.S. Motors. Pumps with variable frequency drives shall have inverter duty motors. M. Motors shall be equipped with space heaters, which energize when the motor is off. N. Pump control valves shall be globe bodied with stop check pistons. All pump check valves shall include a back pressure or differential pressure control pilot to ensure Design Manual Tanks and Pump Stations \\ecwa1\engineering\2006 Dsgn Standards\Sect4.doc 4-4 Rev.10/06

27 pumps do not operate off their curves and be provided with power failure emergency solenoids. O. Pressure relief and surge valves shall be connected from the discharge and suction sides. P. Acceptable valve manufacturers include: Valve Type Butterfly Valves Pump Check Control Valves Air Release Valves Pressure Relief/Surge Control Valves Manufacturer Pratt, DeZurik Ross Crispin or Val-Matic Ross Q. Suction pressure, discharge pressure, and flow indicators/transmitters shall be provided R. Flow meters shall be ASME certified venturi type, differential pressure type and be sufficient pipe diameters downstream of pumps and fittings to accurately measure flow. Flow straightening vanes shall be provided upstream of venturis, if necessary. S. Pump stations shall have satellite disinfection systems such as AccuTab, as required. T. Monorail/trolley system shall be provided with adequate capacity to lift the heaviest piece of equipment in the station. It shall extend over all pump units with travel to the access doors. U. Pump stations shall have satellite disinfection systems, such as AccuTab, as required Instrumentation A. An instrumentation system shall be provided that includes transmitters, indicators, switches, gauges and alarms in the station; RTU, radio, and antenna equipment for connection to the Authority=s SCADA system. B. Pressure transmitters shall be installed on suction and discharge piping and shall be manufactured by Rosemont. Flow transmitters shall be as manufactured by Rosemont. Flow transmitters from venturi shall be mounted below the pipe Design Manual Tanks and Pump Stations \\ecwa1\engineering\2006 Dsgn Standards\Sect4.doc 4-5 Rev.10/06