WIXLIB

April 2013399. It is recommended that the holding tank be tested on site after assembly, for watertightness (see Section 6.4 for a recommended testing procedure).3.1.3Pump and Siphon ChambersThe pump or siphon chamber discharge capacity must be sized to distribute effluent over theentire disposal field during each dose. This allows utilization of the entire field andminimizes the possibility of breakout of effluent in a localized area. Periodic dosing alsoallows the infiltrative surface to drain between doses. These cycles of alterative dosing andresting may maintain higher infiltration rates in the clogging mat and thus extend the life ofthe system.The normal dosing frequency should be a minimum of two times per day for a system that isselected. More frequent lower volume doses are recommended. The discharge volume mustbe large enough to flood the entire distribution pipe. Unless the level 1 or 2 qualified personspecifically selects the pump to be used, it is the installers responsibility to ensure that thepump has the proper capacity of achieving equal distribution throughout the field.A typical pump chamber is shown in Figure 3.C and shall conform to Canadian StandardsAssociation specification CAN/CSA-B66-00 or the latest revision.Requirements for a pump chamber include:1. The liquid capacity of the chamber shall provide storage equal to one days flow.2. The chamber shall be equipped with an audible and visible high level alarm, levelcontrols, and other accessories required to assure its effective and reliable operation.3. If the top of the tank is more than 150 mm below finished grade, a riser must beprovided to extend to within 150 mm of finished grade. Extending the riser to groundsurface is recommended and must include a cover and locking mechanism.4. The dimension of any opening shall meet CSA requirements.5. The elevation of the tank shall be such that any horizontal seam is located above thehighest seasonal groundwater table6. The high water alarm level must be below the level of the horizontal seam.7. It is recommended that the pump chamber be tested on site after assembly, for watertightness (see Section 6.4 for a recommended testing procedure).A siphon chamber shall conform to Canadian Standards Association specificationCAN/CSA-B66-00 or the latest revision. A sample of a siphon chamber is detailed inFigure 3.E and 3.F.Requirements for a siphon chamber include:1. If the top of the tank is more than 150 mm below finished grade, a riser must beprovided to extend to within 150 mm of finished grade. Extending the riser to groundsurface is recommended and must include a cover and locking mechanism.2. The dimension of any opening shall meet CSA requirements.3. It is recommended that the pump chamber be tested on site after assembly, for watertightness (see Section 6.4 for a recommended testing procedure)

FIGURE 3.BBell for audible alarm may be switched offALARM DEVICEAlarm should sound whenholding tank is 75% full.Light to give a visualalarm remains on afterbell is switched off anduntil tank is emptiedCover with lock toprevent unauthorizedaccessExtension with watertight connection to tankAll connections must be made water tightWatertight if below watertableNOTE:If effluent is pumped totank, an appropriate ventshould be installed.Alarm float controlFasten both sides of the holdingtank to prevent frost uplifting.If riser is provided it also must befastened to prevent frost upliftingPlug all openingsMake a watertightconnectionNOTE:Tank must be made watertight and it isrecommended that the tank be tested for leaksbefore it is placed in operation. See section6.4 for a recommended testing procedure.Dimensions shown on this drawingare for illustration only. Design ofthe tank must follow latest edition ofstandard CAN/CSA - B66-00HOLDINGTANK

FIGURE 3.CPump installationSiphon Breaker is required on allpump systems with pump chamber atlower elevation than finished gradeover disposal field.The siphon breaker does not protectagainst backflow into the pumpchamber, septic tank and possibly thehome, should surface or ground waterflood the system to a level above thebottom of the “breaker”. Lot gradingand interceptor ditches will reduce thepossibility of this occuring. A checkvalve can also be installed on the linebetween the tank and the pumpchamberAlarm inside homeRelay in water-proof enclosure orhouseCover must be secured toprevent unathorized accessSeal if below watertableHanger pipe forpump removalReserve capacity afteralarm soundsQuick disconnectslider couplerFromseptic tankTYPICAL DETAIL OF FORCEMAINCONNECTION TO DISPOSAL FIELD“SIPHON BREAKER”Minimum 300 mm ofsoil cover3 mm air hole top ofpipe450 mm minimumMust be protectedfrom freezingFinished grade300 to 450 mm150mm75 mm crushed rock andgeotextile over entire pipePerforated distributionpipeTo disposal fieldPressure pipe frompump chamberAll joints must be watertightApproved pump chamberPump alarm levelNOTES:1. The pump chamber must be watertight and surface water must be diverted away from the pump chamber.2. The pump intake should be kept above the floor at the distance recommended by manufacturer .(Frequently 150 mm or more).3. The start level control should be set to deliver the required dosage plus an allowance for backflow fromthe discharge line (if backflow is used for frost protection).4. The alarm system and the pump must be on separate circuits.5. All electrical connection are to be made outside the pump chamber and must comply with appropriateelectrical code and safety regulations.6. Pump must be suitable for submerged sewage operation.7. Level control floats to be non clogging.8. All pipe joints must be pressure resistant.9. The pump stop level should be at leastVolume of 1m pipe section100 mm above the impeller of the pumpDiameter (mm) Volume(l/m)Dosing volumePump on levelStartPump off levelStopLevel control float(switch)FROST PROTECTION:Following may be employed to protect pressure pipe from freezing:PIPE INSULATION1. Allowing the effluent to drain back through the pump and into the pumpchamber by removing the check valve. This can only be done if design of thepump allows it. Check with manufacturer prior to removing check valve.2. Installation of check valve at the pump with a bleeder hole just ahead of it. Thiswould prevent effluent from flowing back through the pump and still allow theline to drain.3. Installation of check valve and pipe protection such as:a. Sufficient soil cover over the line. (Usually 1.5 m)b. Insulation of the line.c. The use of heater tapePipe must be installed to prevent any sagging.SurfaceUsually 1.5 m300150600Insulation. Usually 25 mm foreach 300 mm of soil cover lessthan 1.5 m.HI-60 Styrofoam .706.207.128.20

June 2013423.2BUILDING SEWERS AND EFFLUENT LINESA building sewer for a single unit dwelling, which is defined as the part of the buildingdrainage system carrying sewage that extends from the septic tank or public sewer to a pointone metre out from the foundation wall, shall be a 100 mm diameter pipe, conforming toCanadian Standards Association specification CAN/CSA B-182.1. Cleanouts shall beprovided at intervals of not more than 30 m, if the length of the building sewer exceeds 60 m.A building sewer shall be laid at a slope of not less than 2 percent.An effluent pipe for a single unit dwelling, which is defined in the Regulations as a nonperforated pipe used in a system to transfer effluent from a septic tank, pump or siphonchamber to a disposal field shall be a 75 or 100 mm diameter pipe for gravity flow systemsand must conform to Canadian Standards Association specification CAN/CSA B-182.1.An effluent pipe for a gravity flow system shall be laid at a slope of not less than 1 percent.3.3DISTRIBUTION SYSTEM3.3.1Crushed Rock or GravelCrushed rock shall be: cleaned, washed, and screened, free of soft or friable material, 98% (by weight) of rock or gravel shall pass a 35 mm screen and 98% (by weight) of the rock or gravel shall be retained on a 12 mm screen.3.3.2Imported Sand FillThe following requirements apply to: the buffer in a distribution system, i.e., C2 and raised C2 the construction of all above ground systems, i.e., a C3 and a moundThis material shall: if it is a naturally occurring or manufactured sand or recycled crushed glass, have apermeability, as placed on site, between 0.00003 and 0.0005 m/sec, as determined bythe falling head permeability test (Appendix B) and have a maximum particle sizecorresponding to the appropriate ASTM-33 or CSA A23.1 specification for fineaggregate. when designing or selecting a system with a specified fill permeability within theacceptable range of 0.00003 and 0.0005 m/sec; the Qualified Person shall ensure thatfill with the specified permeability range required by the selection or design is used insystem construction.3.3.3 Filter Sand and Sloping Sand Filter MaterialThe 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

June 201343This material shall: be a manufactured sand that meets the current ASTM-33 or CSA A23.1specifications; or be a naturally occurring or manufactured sand or recycled crushed glass having apermeability, as placed on site, between 0.0001 and 0.0005 m/second as determinedby the falling head permeability test (Appendix B) and have a maximum particle sizecorresponding to the appropriate ASTM-33 or CSA A23.1 specification for fineaggregate.3.3.4 Safety Considerations for use of Recycled Crushed GlassWhen using recycled crushed glass as a replacement for imported or filter sand in an on-sitesewage disposal system, the QP must ensure its permeability meets the requirements outlinedin Sections 3.3.2 & 3.3.3 for its intended use.Qualified persons and installers intending on using the crushed glass in on-site sewagedisposal systems in Nova Scotia shall be knowledgeable of the material safety informationprovided by the manufacturer.3.3.5Barrier Material (Geotextile)Barrier material is required in disposal fields to prevent silt in the covering soil from washingor falling into the crushed rock distribution trench.The barrier material shall: be a non-degradable man-made fibre such as polyester or polypropylene;have an opening size less than 700 microns; andhave a permeability greater than 0.001 m/sec.This specification will normally be met with a light weight (50 g/sq. m or more) non-woven(i.e. felted, needle punched or heat bonded fibre) fabric or proprietary geotextile. The abilityto stretch and deform is perhaps of more importance than tensile strength. It should be notedthat typical woven geotextiles of ribboned film have insufficient permeability and porosityfor adequate aeration of the disposal field and for upward permeation of effluent in highwater table conditions.3.4EFFLUENT DISTRIBUTION PIPE3.4.1GeneralUniform distribution of septic tank effluent over the entire area of the disposal field is criticalfor the performance and the long life of the system: uneven distribution can result inprogressive clogging of the soil interface, or inadequate treatment in very permeable soils.Periodic dosing of the effluent, with resting periods between doses, also improves theperformance of a system.Effluent distribution can be accomplished by one of two basic methods:

April 201344 a gravity distribution system, in which effluent flows from a septic tank to a disposalfield because the water level in the tank is higher than the level of the field, or a pressure system, in which a pump or siphon is used to create pressure that will forceeffluent throughout the distribution systemPipe and pipe joint fittings used in a disposal system must be selected to provide: 3.4.2durabilityresistance to crushing due to surface loadingresistance to differential settlement of soils and system components.Gravity Distribution PipesGravity pipes in an on-site system shall:1. be watertight, except for pipes in a disposal field;2. have an internal diameter not less than 75 mm; and3. have a slope of 50 to 100 mm / 30 m.Distribution pipes shall conform with Canadian Standards Association standard CSA B182.1with a hole spacing as described and shown in diagram 3.D. The pipe shall be of PVC orABS plastic, unless an alternative material with equal or better properties is approved NovaScotia Environment.The pipe shall be perforated with 13 mm holes: in the invert, at intervals of 3 to 4 m; andat 60 degrees to the invert, at intervals of 1 m or less.The invert holes are intended to disperse smaller flows; the side holes will disperse largerflows.3.4.3Pipe Used In a Pressurized SystemA pressurized system is more effective than a gravity system as it provides both uniformdistribution and periodic dosing of the disposal field. The disadvantage of a pressurizedsystem is the higher capital cost and the extra maintenance requirements associated with thepump or siphon. Pressurizing using a pump or siphon is required: where an end fed field is longer than 30 m or a center fed field is longer than 60m;where the natural ground slope is not uniform and a gravity system might concentrateeffluent at one on more weak spots in the field;for all C3 and Mound fields; orfor any system where the disposal field is at a higher elevation than the septic tank.Where a pump or siphon is required, the solid pipe from the pump or siphon chamber to thedisposal field must have a minimum diameter as specified by the pump or siphonmanufacturer but shall not be less than 30 mm. For a pump system this line shall beequivalent to the Canadian Plumbing Code requirements for water pipe (CSA B137 Series)

April 201345so that it can withstand the pressure exerted by the pump. Lower pressures are generated by asiphon and solid pipe meeting CSA B182.1 with glued joints should be acceptable. Allpumped systems should be connected to the disposal field using a “siphon breaker” as shownin Figure 3.C.For any system selected to serve a single family home using a Mound or C3 field, solid 75 or100 mm pipe with holes drilled as outlined in Subsections 4.7.4 and 4.8.4 must be used.For any other system selected to serve a single family home using a pump or siphon, theperforated pipe in the distribution field can be similar to gravity distribution pipe (Subsection3.4.2) only all joints must be glued and a 13 mm hole drilled in the top of the pipe 150 mmfrom the end cap(s). In addition the distribution piping must be placed such that there isno slope on the piping in the distribution trench.For systems serving more than 1500 l/day (designed by a QP1), the pipe diameter, and holespacing must be calculated, based on the system hydraulics, in an effort to provide uniformdistribution throughout the disposal field. In a designed system the minimum acceptable pipediameter is 35 mm.Freezing of the pressure line is a potential problem if it does not empty after every dischargeand it is not insulated. Figure 3.C. lists several steps that can be taken to protect the pressureline from freezing.3.5PUMPS AND SIPHONS3.5.1GeneralA pressure distribution system may be fed by a pump or a siphon.selection of these devices include: Considerations inSiphons do not require a power source or involve moving partsA siphon will operate more effectively if the available elevation difference betweenthe siphon discharge point and the disposal field distribution pipe is 1 m or more. Fora normal siphon installation this is equivalent to 2m in total from the tank outlet to thedisposal field.Siphons can be selected for distances up to 30 m and no less than 0.5m drop from thedischarge to the disposal field unless indicated otherwise in the manufacturer'sinformation; in which case, the syphon shall be installed in accordance with themanufacturer's instruction.Siphons can be designed for distances greater than 30 m.When a pressure distribution system is required, the siphon or pump should be designed toflood the disposal field a minimum of twice per day. More frequent lower volume doses arerecommended - ensure the entire pipe is completely filled and under pressure.Where a siphon is required, the siphon must follow a standard design established, approvedor adopted by the Department, or shall be designed by a Level I Qualified Person.

April 20133.5.1.a Hydraulic Characteristics46When choosing a pump, consideration should be given to the following: The difference in elevation between the pump and the distribution pipe. The friction loss in the discharge line between the pump and the far end of thedistribution pipe. A residual head of 600 mm at the end of the distribution pipe.

FIGURE 3.DGRAVITY FED DISTRIBUTION PIPERemove all burrs to leavea clean bore pipeCROSS - SECTION13 mm holes at intervals of 1 meter or less13 milimeters holes at intervals of 3 m to 4 m at invertGRAVITY FED DISTRIBUTION SYSTEMPipe diameter 75mm minimumMaximum length - 60 metres if center fedMaximum length - 30 metres if end fedSlope 50 to 100 mm per 30 m (0.16% to 0.32%)Hole diameter 13 mmHole interval at 30 degrees to invert 1 metre or lessPipe shall conform to CSA B182.1PRESSURE FED DISTRIBUTION PIPE13 mm vent hole on each side150mm13 mm holesPRESSURE FED DISTRIBUTION SYSTEMNOTE: for large systems that are designed holeintervals must be calculatedPipe diameter 38 mm minimum (designed system) ,75 or 100 mm (selected system)No slope requiredHole diameter 13 mmHole interval at invert 1.25 metres or less (selected system)Pipe shall conform to CSA B182.1 or CSA 137For larger systems a hydraulic calculations should be used to determine best holespacingRemove burrs to leave a cleanbore pipeSee Table 4.9 for hole spacing details

FIGURE 3.ESECTIONAL VIEWSIPHONOverflowVent pipeFRONT VIEWCapHTop water levelPCDOverflow/vent pipeSiphon long legDischargevolumeBADischarge to disposal bedGQBottom water levelAlternative position of pipeEFMinimum 10 degrees offverticalPLAN VIEWSIPHON BREAK DELAYTANKCAVent/inspection holeD100 mm pipe with end caps. Across full widthof the tankBEF; G; HFlat plastic disc with 8 mmhole off centreSiphon break delay tank (alternative locations)100 x 100 mm Tee

FIGURE 3.FSIPHON INSTALLATIONSECTIONAL VIEWOverflowCapTop water levelAvoid sharp bends in discharge pipe to preventair locking.DischargevolumeBottom waterlevelInsulate or cover withsoil for frost protectionAlternativeposition of pipeInstall discharge pipe with uniform slopeSIPHON TESTING:1. Test for watertightness, if required, as outlined on figure 3A forseptic tanks. Siphon chamber should be filled with water to thelevel just before the discharge level.2. After completing water tightness test, if required, slowly fill up thechamber to trigger siphon discharge. Repeat this test to see ifsiphon discharges a second time.VERTICAL DROP:Distance up to 30 meters - 500 mm ormanufacturer’s requirements.Distance over 30 meters must bedesigned by QP1

April 201350The actual design of a pressure distribution system is based upon hydraulic principles and isbeyond the scope of these Guidelines. In an attempt to simplify selection and standardizeequipment requirements for single family homes, the required dosing capacity for siphonsand pumps is as shown in Table 3.2.TABLE 3.2MAXIMUM DOSING VOLUMES AND PUMP CHAMBER CAPACITYFlow*MAX Dosing Amount perDischarge Event in Litres*1000 L500 L1350 L675 L1500 L750 LMore frequent, lower volume doses are recommendedMinimum PumpChamber Capacity1000 L1350 L1500 LWhen pumping a considerable distance, the dosing amount may have to be increased tocompensate for effluent in the pump line returning to the pump chamber after the pump shutsoff.3.5.2Pumps and ControlsThis section specifically addresses pressurized systems for delivery of septic tank effluent toa distribution system in a disposal field. However, the component specifications in thissection, and the design principals, apply also to pump systems that may be used to transfersewage from a dwelling to a septic tank,

SEPTIC TANK GENERAL: 1. A septic tank for a single family will generally require pumping every 3 to 5 years, but should be inspected yearly. 2. Septic tank for commercial applications should be inspected every 6 months. 3. Septic tank should be pumped when the sludge accumulates to a level approximately 450 mm