NS On-site Sewage Disposal Systems Technical Guidelines: Summary of Changes January 2013

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1 NS On-site Sewage Disposal Systems Technical Guidelines: Summary of Changes January 2013 PRIMARY CONTACT: Leah Boutilier, P. Eng, PhD Acting On-site Services Program Coordinator (902) Terminal Road P.O. Box 442 Halifax, NS B3J 2P8 All proposed changes to the Nova Scotia On-site Sewage Disposal Systems Technical Guidelines are summarized below and changes are highlighted within this document for clarity. This summary document has been developed to simplify the consultation process and an updated version of the Technical Guidelines will be available to industry, the public and EMC staff once the consultation period has ended, comments have been addressed and approved by NSE. Targeted consultations with EMC staff and industry will occur throughout January and February 2013, and a final version of the Technical Guidelines is anticipated to be complete by April A grace period may be permitted for changes that will affect product manufacturers and distributors (e.g. septic tank increase in minimum size requirement). Stakeholders that will be impacted by this change are asked to provide comment or recommendation on the details (length and conditions) of this grace period. PLEASE NOTE All comments received, including any personal information which you provide, may be made available for public review. Any personal information is subject to the provisions of the Nova Scotia Freedom of Information and Protection of Privacy (FOIPOP) Act and will only be disclosed in keeping with the privacy provisions of that Act. Should you wish any of the information provided on this form to be held in confidence, please clearly indicate this. 1

2 1. Subject: Replacement of a malfunctioning system with a sloping sand filter, irrelevant bullet points removed or modified During the last revision of the guidelines in 2009, the sloping sand filter was permitted for use on any lot, not just for a malfunction replacement. Bullet points discussing sand filter application as a replacement for a malfunction were removed from section 2.9 based on a recommendation from EMC staff as these points were missed during the last revision of the guidelines. 2.9 REPLACING A MALFUNCTIONING SYSTEM First bullet removed. Second bullet was edited to remove the specific reference to a sloping sand filter design. Bullet 2 (previously) now bullet 1 reads: If a Qualified Person level II cannot select a system to fit on the lot, then a Qualified Person Level I may be able to design a system for the lot. Bullet 4 (previously) was edited, now bullet 3 reads: When a sloping sand filter or innovative system is utilized as the replacement system and results in a surface discharge, the replacement system can only be designed or selected for the existing sewage loading from the structure. Surface discharge will only be permitted where subsurface distribution of effluent is not possible and risk to public health is minimal. Last bullet removed: If the replacement system being proposed is to include an increase in sewage loading than a sloping sand filter or innovative system cannot be utilized. In these cases an on-site system as described elsewhere in these guidelines, excluding a holding tank or privy, must be employed and will be considered providing the system is designed or selected for the proposed loading and the meets the requirements of the Regulations Respecting Onsite Sewage Disposal Systems. REMOVED 2. Subject: Septic tank size requirements increased to accommodate peak flows (tank to be sized based on 4 day retention time at average flows) based on a recommendation from a consultant report Septic Tanks Any septic tank is required to meet the following specifications: (Figure 3A) 2

3 1. All tanks must conform to the latest edition of Standard CAN/CSA-B66-00 or the latest revision, published by the Canadian Standards Association. 2. It must include a watertight access for purposes of maintenance, inspection, and pump-out. 3. Septic tanks for dwellings must have a capacity not less than that stated in Table 3.1. For larger systems the minimum capacity should be: For average daily flows up to 9000 l/day: Vtank(1) = 4Q Where: Q - average daily flow in litres Vtank - tank volume in litres For average daily flows 9000 l/day or more: Vtank(2) = Q Where: Q - average daily flow in litres Vtank - tank volume in litres The minimum required septic tank size is 4000 L. Septic tank sizes larger than the required minimum may reduce problems and extend the life of an on-site system. TABLE 3.1 MINIMUM CAPACITY OF SEPTIC TANKS FOR DWELLINGS Number of Bedrooms Up to3 4 5 Minimum Liquid Capacity (litres) Subject: Required septic tank effluent filter based on recommendation from a consultant report. All residential septic tanks will be required to have a septic tank effluent filter that meets NSF Standard 46 (components of wastewater treatment systems) and has easy access at the outlet of the septic tank for filter maintenance. Changed wording in bullet # 12 in section Septic Tanks 12. All residential septic tanks are required to have a septic tank effluent filter that meets NSF Standard 46 (components of wastewater treatment systems) and has easy access at the outlet of the septic tank for filter maintenance. A properly fitted effluent filter will decrease the risk of solids entering the disposal field and prolong life of the system. 3

4 4. Subject: Use of recycled crushed glass as a replacement for imported or filter sand Marketing of recycled products has become more prevalent with increasing incentives and awareness around re-using and recycling. NSE has been approached in the past to approve individual manufacturer s recycled crushed glass product for use as sand in an on-site sewage disposal system. Moving forward, crushed glass may be used as a replacement for imported or filter sand provided it meets the same permeability specifications as outlined in the technical guidelines for its intended purpose. Recycled crushed glass added to sections & New section added to address safety considerations for use of crushed glass, Barrier Material bumped to section Imported Sand Fill The following requirements apply to: the buffer in a distribution system ie: C2 and raised C2 the construction of all above ground systems, ie: a C3 and a mound This material shall: if it is a naturally occurring sand or sandy gravel or a washed sand or recycled crushed glass, have a permeability, as placed on site, between and m/sec, as determined by the falling head permeability test (Appendix B) and have a maximum particle size of 25 mm. when designing a system with a specified fill permeability within the above acceptable range of and m/sec; the Qualified Person 1 shall ensure that fill with the specified permeability range required by the design is available Filter Sand and Sloping Sand Filter Material The following requirements apply to: The layer of sand (filter sand) installed under the crushed rock in all systems The sand used to construct a sloping sand filter This material shall: be a washed concrete sand that meets the current ASTM-33 or CSA A23.1 specifications or be a naturally occurring or washed sand or recycled crushed glass having a permeability, as placed on site, between and m/second as 4

5 determined by the falling head permeability test (Appendix B) and have a maximum particle size of 25 mm Safety Considerations for use of Recycled Crushed Glass When using recycled crushed glass as a replacement for imported or filter sand in an on-site sewage disposal system, the QP must ensure its permeability meets the requirements outlined in Sections & for its intended purpose. Please note the following safety considerations: Unused crushed glass shall be removed from the site when the installation has been completed. Qualified persons and installers intending on using the crushed glass in on-site sewage disposal systems in Nova Scotia shall be knowledgeable of the material safety information provided by the manufacturer. 5. Subject: Clarification Table 3.3: Siphons and Pumps Dosing and Chamber Capacity Table 3.3 is now Table 3.2 and heading Minimum Siphon Chamber Capacity has been changed to Minimum Gravity Dosing Chamber Capacity. Clarification recommended by EMC staff. TABLE 3.2 SIPHONS AND PUMPS - DOSING AND CHAMBER CAPACITY Flow Dosing Amount per Discharge Event in Litres Minimum Pump Chamber Capacity* Minimum Gravity Dosing Chamber Capacity 1000 L 500 L 1000 L 500 L 1350 L 675 L 1350 L 675 L 1500 L 750 L 1500 L 750 L * below any horizontal seam 6. Subject: Alternative/Innovative On-site Wastewater Treatment Technologies New Section (3.10) after 3.9 Approved Products (slight changes to wording in Section 3.9) based on a recommendation from a consultant report. 5

6 3.9 APPROVED PRODUCTS Products for use in on-site sewage disposal must be approved by Nova Scotia Environment, unless the product meets the requirements outlined in Section Manufacturers or suppliers who wish to market their product in NS that meets the criteria outlined in Section 3.10 are asked to submit a product summary and manual to the On-site Services Program Coordinator. The Onsite Coordinator will confirm the product meets requirements, and classify the product before adding it to the Province s list of approved products. Keep second paragraph in this section as is ALTERNATIVE/INNOVATIVE ON-SITE SEWAGE TREATMENT TECHNOLOGIES Alternative wastewater treatment technologies must satisfy all of the following requirements to be marketed in Nova Scotia for the purpose of on-site sewage treatment and disposal: A proven on-site wastewater treatment technology that has undergone third party testing and is recognized by at least one of the following certifications: o BNQ Standard NQ Stand-alone Wastewater Treatment Systems CLASS II Secondary treatment minimum requirement. o NSF 40 Residential Wastewater Treatment System Class I o Alternatively, third party testing may be completed (e.g. NS On-site Wastewater Research Centre, Truro, NS) for a minimum of 12 consecutive months. The manufacturer or supplier is responsible for the cost of testing and shall submit a report to Nova Scotia Environment summarizing treatment performance. Treated effluent must meet or exceed the BNQ and NSF effluent quality requirements. Flow equalization is provided to ensure peak and intermittent flows do not disrupt treatment performance. Application for on-site approval must be submitted by a Professional Engineer licensed to practice in Nova Scotia. System must be installed by an installer certified by the Province of Nova Scotia. Complies with the Nova Scotia On-site Sewage Disposal System Regulations. Meets Nova Scotia Environment s On-Site Sewage Disposal Systems: Technical Guidelines. 6

7 Provides the department and on-site industry with an installation manual that includes operation and maintenance instructions. Manual must contain sufficient information for the installer to construct the system properly and according to the manufacturer s specifications. Active systems (systems including any mechanical/moving components: e.g. pumps, aeration) must include an Operation and Maintenance (O&M) contract between the homeowner and a qualified person to ensure proper function of the proposed system for the life of the system. The requirement of an O&M contract must be outlined under the terms and conditions of all On-site Sewage Approvals for Alternative/Innovative technologies including active components. No surface discharge of treated effluent will be permitted; treated effluent must be discharged subsurface following the requirements outlined in the manufacturer s engineering/design manual or as described in Table 3.3. Surface discharge may be considered when replacing a malfunction only if the proposed lot can not accommodate subsurface disposal. NOTE Table 3.3 Max Vertical Hydraulic Loading of Treated Sewage Effluent is for design of vertical flow systems only. Lateral flow contour systems must be designed based on soil permeability and Darcy s law, as described in Chapter 5 of this Guideline. Unless effluent is of disinfection quality (E. coli = 0 CFU/100mL), dispersal trenches receiving treated effluent from an alternative/innovative technology as described in this section, must maintain vertical and horizontal regulatory separation distances (Table 2.5A). Any exceptions will be reviewed by the On-site Services Program Coordinator on a case by case basis specific to the technology (e.g. peat modules allowed 600 mm separation to bedrock, water table or too permeable soil) 7

8 Soil Type TABLE 3.3 MAXIMUM VERTICAL HYDRAULIC LOADING OF TREATED SEWAGE EFFLUENT Permeability range m/s x Treated Effluent MAC 2 30 mg/l TSS & BOD5 L/d/m 2 Rock or gravel > Medium to coarse sand Fine sandy gravel Silty Sand Sandy Silt Clayey Silt Clay*if deemed permeable < NSF 40 Residential Wastewater Treatment System Class I or BNQ Standard NQ Stand-alone Wastewater Treatment Systems Class II (minimum) Certification 2 Effluent must be treated to meet the following Maximum Acceptable Concentrations (MAC); TSS: BOD 5 (MAC) = 30:30 (mg/l) 7. Subject: Design depth of saturation for lateral flow system design increased from 100 mm to 150 mm. Changed D sat from 100 mm (0.10 m) to 150 mm (0.15 m) for raised C2, sloping sand filter and mound system design based on recommendation from a consultant report. 5.5 DESIGN OF C2 SYSTEMS Generally it is not recommended to exceed a linear loading rate of 60 L/day per m for both a standard and raised C2, even if calculations indicate that shorter system is feasible. A saturation depth in imported sand fill should be kept around 0.05 m and generally not exceed 0.15 m. There should be approximately 0.3 m of fill above maximum saturation level in fill. 3. Calculate required system length: C2 DESIGN SUMMARY: Note: For a Standard C2 design; D sat is normally 0 m For a raised C2 design; D sat is not to exceed 0.15 m. 8

9 5.7 DESIGN OF MOUND SYSTEMS There shall be approximately 300 mm of fill above maximum saturation level in the downslope buffer of the imported sand fill. Saturation depth in fill should not exceed 150 mm. There should be a minimum of 600 mm of imported sand fill below the distribution trench. The depth of the buffer should be a minimum of 300 mm at a distance of 5 m. 5.9 SLOPING SAND FILTER.after equation 13: The maximum linear loading rate varies based on the intended usage of the system as outlined in subsequent sections (5.9.2, and 5.9.4) of the Guideline. Where : Q - sewage flow in ( liters) L - length of the sand filter across the slope (m) K fill - permeability of the imported sand fill (m/sec) D sat - saturation of the sand (should not exceed 0.15 m) (m) I - slope of the filter bottom (this is not necessarily the same as the surface slope at the filter location) (m/m). After equation 13: SLOPING SAND FILTER DESIGN SUMMARY D sat is not to exceed 0.15 m. 8. Subject: Hydraulic loading rate for sloping sand filter mantle design Table 5.3 was updated to be consistent with the loading rates permitted for treated effluent (outlined in Table 3.3) since effluent will be treated to at least 30/30: BOD/TSS after passing through the sand in a sloping sand filter. 9

10 TABLE 5.3 MAXIMUM HYDRAULIC LOADING RATES FOR SLOPING SAND FILTER BASAL AREA Permeable Soil Type Maximum Hydraulic Loading Rate (L/day) /m 2 Med. to coarse sand 45 Fine Sandy Gravel 45 Silty Sand 22 Sandy Silt 15 Clayey Silt 11 Silty Clay 8 Clay*If deemed permeable 8 Refer to Section 6.11 for the construction details. 9. Subject: Cluster System section revisions intended to remove barriers for in-law suite development, recommendations from consultant report, Municipalities and EMC staff. i. Changed lot size requirements to lot requirements as not all of the requirements are actually regarding lot size. Replaced section (2) with: 2) The minimum lot requirements shall be as stated in Section of the Guidelines. This change was also made under the following sections: (3)i, (2), (3) ii. Removed the 15% increase for all cluster systems and replaces it with what should be a standard design consideration for collection systems. Replaced section (6) with: 6) For cluster systems which include a sewage collection system that serves multiple buildings and may have components susceptible to future infiltration and inflow, consideration should be given to increasing the design flow appropriately. iii. Added section (8) 8) In the case of a cluster system being proposed to immediately address any adverse effects, the system shall be considered a malfunctioning system under the On-Site Sewage Disposal Systems Regulations and these Guidelines provided the design does not incorporate any increase in flow over what was legally in place at the time of the malfunction. 10

11 iv. New title and section (2) breaks down creation of lot into its own subsection. Applies lot size requirements only to those lots created after the subdivision regulations came into effect. This is consistent with the holding tank section of the regulations in terms of the concept Minimum Lot Requirements for Cluster Systems 1) The minimum requirements for the creation of a lot to be serviced by a cluster system are as follows: (i) (ii) (iii) (iv) for the first 1500 liters per day of design flow, lot size requirements shall satisfy Section 7 of the On-Site Sewage Disposal Systems Regulations ; for every design flow increase of 1500 liters per day, or part thereof, the lot area shall be increased a minimum of one-half the lot size requirement found in Section 7 of the On-Site Sewage Disposal Systems Regulations ; notwithstanding (i) and (ii), the lot must have sufficient area and width to accommodate the proposed cluster system, a location for a replacement system, roadways, structures, and water supply(s) all other requirements of sections 5, 6, and 7 of the On-Site Sewage Disposal Systems Regulations are to be met 2) The minimum requirements for an on-site system approval including a cluster system to service an existing lot created August 6, 1984 or later are as follows: (i) (ii) (iii) (iv) for the first 1500 liters per day of design flow, lot requirements shall satisfy Section 7 of the On-Site Sewage Disposal Systems Regulations; for every design flow increase of 1500 liters per day, or part thereof, the lot area shall be increased a minimum of one-half the lot size requirement found in Section 7 of the On-Site Sewage Disposal Systems Regulations; notwithstanding (i) and (ii), the lot must have sufficient area and width to accommodate the proposed cluster system, a location for a replacement system, roadways, structures, and water supply(s) all minimum clearance distances as prescribed in Section 13 of the On-Site Sewage Disposal Systems Regulations are to be met. A variation shall not be considered. 11

12 10. Subject: A number of minor changes were made to various forms and appendices within the Guideline to clarify areas of concern raised by EMC staff and improve consistency across the Province. i. Figure 7A On-site Sewage Disposal System Malfunctioning Inspection Form Changed Lot Category to Lot Area ii. Appendix F minor clarifications (F-11 Industrial/Office) & edits (F-4 Medical/Personal Care; F-6 Food Service) F-4 duplicate flow rate for Hospital (bed) no laundry removed (550 L) F-6 changes Food Service Facility Unit of measure Minimum design flow Litres Bar/Longue customer 8 Comments Bar/longue seat 125 Restaurant Not 24 hr Restaurant Not 24 hr Restaurant (Not 24 hr) Auto dishwasher - Add Restaurant (Not 24 hr) dishwasher and/or food waste disposer meal 9 seat 31 seat 12 seat 43 12

13 F-11 changes Industrial/Office Facility Unit of measure Minimum design flow Litres Comments Industrial buildings Excluding industrial waste, cafeteria and showers Industrial buildings (NO cafeteria) Excluding industrial waste, Including showers Industrial buildings Excluding industrial waste, Including cafeteria & shower employee 45 employee 75 employee 132 iii. Appendix H Submission Standard On Application for Approval FORM changed APENS# to Engineers NS # Changed wording on Site Evaluation of Lot/Proposed System FORM regarding location of test pit in relation to on-site system, on-site system changed to disposal field to reflect the intent of the statement. Now reads: The test pit location is shown in reference to two fixed points on the property and is within 6 meters of the disposal field location. Application for Variance Checklist added and changed to be consistent with all other check lists in the Guideline (boxes are intended to be checked): Application for a Request of Variance to the Regulations Respecting On-site Sewage Disposal Systems Owner: PID: Community: Subdivision: Lot #: 13

14 This checklist and application is to be included with every variance request. By completing this checklist the Qualified Person certifies that the variance request and supporting documents conforms with the Environment Act, the On-Site Sewage Disposal Systems Regulations, and the On-Site Sewage Disposal Systems Technical Guidelines. PLEASE NOTE: If an item is NOT checked off in Section A, the variance request will NOT be approved without suitable justification. Any item not checked off in Section B may result in delays in the processing of the application. Section A The lot was created prior to August 6, 1984; The minimum lot size requirements, clearance distances and specifications of the On-site Sewage Disposal Systems Regulations and Guidelines can NOT be met; The lot was never deemed unsuitable for the installation of an on-site sewage disposal system, or it was never stipulated by the Municipality or proponent the intended use for the lot did not require the installation of an on-site sewage disposal system. The separation distance to a dug or drilled well, cistern or contained water system on a neighbouring property as specified under Section 13 of the OSSDS Regulations can be maintained. The 1 m separation distance to bedrock, groundwater or soil with permeability greater than 500 x 10-6 metres per second as specified under Section 13 of the Regulations can be achieved. Section B (the following documentation MUST be included with variance request): Documentation that the minimum clearance distances, as per Section 13 of the Regulations were maintained where possible or otherwise maximized. Report completed by the Qualified Person Level 1 that outlines reasons why failure to meet the regulations will not result in the increased possibility of an adverse effect. Documentation that dimensions of any imported sand fill will meet the requirements the Guidelines and are to be contained within the lot boundary. A report from a hydrogeologist licensed to practice in the Province of Nova Scotia if the request includes a variance of the separation distance from the on-site sewage disposal system to a dug or drilled well. This report is to confirm that if the variance were granted, it would not result in an increased possibility of an adverse effect. Documentation that indicates that the separation distance to a dug or drilled well, cistern or contained water system on a neighbouring property are no less than the separation distances specified under Section 13 of the Regulations. All documentation / information on the creation of the lot. Name (print): Name (sign): Engineers NS #: Date: On-site Sewage Disposal System Completion Three Day Notification FORM updated to include QP and Installer contact information, also wording in the NOTE was changed to clarify some inconsistent interpretations of the 3 day notice. NOTE now reads: 3 day notification is given by the Qualified Person 3 business days prior to covering the system (ie. at the end of the 3 days the field is complete but still open for inspection). For 14

15 example; if the system installation is to be ready to cover on Thursday, the three day notification would be given on Monday. After the notice has been submitted to NSE, the system may be at any stage of completion within the 3 days. Contact QP for site specific information. iv. Figure labels updated for clarification based on recommendation from EMC staff. Pipe label for distribution trench changed from perforated pipe to distribution pipe in Figures; 1C; 4A; 4C; 4D; 4E; 4F; 4G; 4H; 4I; 5A; 5B; All Schedule Cs. This is consistent with wording used throughout the Guideline. Pipe label for interceptor trench changed from perforated pipe to optional perforated pipe as installing perforated pipe in an interceptor is not required. Updated in Figures; 1B; 4B; 4C; All Schedule Cs. Figure 3A Septic Tank updated optional effluent filter to required effluent filter. 15