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994 GSF Eljen System 2019 1 r q fg a g s c JPs 3 x <rt 3 8 g` �a s. 4„ �=-vc, i y £ y, a> KK sm Q e f 3 r 3 Anp a b ,�.. OT k d "OF It Massachusetts 8 01 01 Desi n" '," ,� 1£nstTallatibohi Manual 3� S. 31 k \ - 4 U Q i� g't 3°r N� �, yy F^„vim a January 2019 CORPORATION ���w�w�rr Innovative Onsite Prod cts&Solutions Since 1970 yr rr .e Ij e n.v o m Table of Contents SUBJECT PAGE GLOSSARYOF TERMS..................................................................................................................3 GSF SYSTEM DESCRIPTION........................................................................................................5 1.0 SYSTEM PRECONDITIONS.....................................................................................................6 2.0 DESIGN AND INSTALLATION..................................................................................................7 3.0 TRENCH INSTALLATION SIZING AND GUIDELINES...........................................................15 4.0 BED INSTALLATION SIZING AND GUIDELINES ..................................................................18 5.0 MOUND INSTALLATION GUIDELINES..................................................................................21 6.0 DOSING DISTRIBUTION GUIDANCE....................................................................................23 7.0 PRESSURE DISTRIBUTION GUIDANCE...............................................................................23 8.0 SYSTEM VENTILATION..........................................................................................................25 GSF DRAWINGS AND TABLES DRAWINGS FIGURE 1: GSF SYSTEM OPERATION ......................................................................................5 FIGURE 2: TYPICAL A42 CROSS SECTION ..............................................................................7 FIGURE 3: TYPICAL B43 CROSS SECTION ..............................................................................7 FIGURE 4: VERTICAL SEPARATION DISTANCE.......................................................................8 FIGURE 5: SERIAL DISTRIBUTION DROP-BOX DETAIL...........................................................9 FIGURE 6: PLAN VIEW-TRENCH SYSTEM EXAMPLE ...........................................................16 FIGURE 7: SECTION VIEW-TRENCH SYSTEM EXAMPLE-LEVEL SITE............................16 FIGURE 8: SECTION VIEW-TRENCH SYSTEM-SLOPING SITE.........................................16 FIGURE 9: PLAN VIEW-BED SYSTEM EXAMPLE-LEVEL SITE ..........................................19 FIGURE 10: SECTION VIEW-BED SYSTEM EXAMPLE..........................................................19 FIGURE 11: SECTION VIEW-BED SYSTEM EXAMPLE-SLOPINGSITE.............................19 FIGURE 12: CROSS SECTION-MOUND SYSTEM..................................................................21 FIGURE 13: CROSS SECTION-SLOPED MOUND SYSTEM..................................................21 FIGURE 14: PRESSURE PIPE PLACEMENT............................................................................23 FIGURE 15: PRESSURE CLEAN OUT.......................................................................................24 FIGURE 16: CONTOURED TRENCH PRESSURE DISTRIBUTION..........................................24 FIGURE 17: VENT LAYOUTS FOR GRAVITY AND LOW PRESSURE SYSTEMS....................25 FIGURE 18: GSF WITH 4"VENT EXTENDED TO CONVENIENT LOCATION..........................25 TABLES TABLE 1: SPECIFIED SAND SIEVE REQUIREMENTS................................................................4 TABLE 2: A42 TRENCH SIZING CHART.....................................................................................11 TABLE 3: B43 TRENCH SIZING CHART.....................................................................................12 TABLE 4: A42 BED SIZING CHART............................................................................................13 TABLE 5: B43 BED SIZING CHART............................................................................................14 2019 Massachusetts Design&Installation Manual Page 2 www.eljen.com Glossary of Terms A42 Module 48"x 24"x 7"(L x W x H) B43 Module 48"x 36"x 7"(L x W x H) Cover Fabric The geotextile cover fabric (provided by manufacturer) that is placed over the GSF modules. Design Flow The estimated peak flow that is used to size a GSF system is 110 gallons per day per Bedroom for residential systems or as specified in 310 CMR 15.203. Non-residential systems shall meet effluent quality standards for residential septic effluent or include additional pretreatment to meet these water quality requirements. Distribution Box A plastic or concrete box that receives effluent from a septic tank and splits the flow to pipes placed above the GSF modules.. For equal distribution, the outlet pipe orifices are typically set at the same elevation to equalize the flow to each line. - GSF The Eljen Geotextile Sand Filter Modules and the 6-inch sand layer at the base and 6 inches along the sides of the modules. GSF Module The individual module of a GSF system. The module is comprised of a cuspated plastic core and geotextile fabric. Serial Distribution For designs commonly used on sloping sites where GSF module rows are laid on contour at varying elevations and where each successive module row receives septic tank effluent only after the preceding module row have become full to the bottom of the invert.This design supports unequal length of module rows. Sequential Distributiori A method of effluent distribution for sloping sites using drop boxes where the effluent discharges first to the lowest outlet in the upper most box and then backs up to a slightly higher overflow outlet to the next down slope row of modules. Sequential loading maximizes utilization of a row of modules and allows downstream rows to rest for use only during peak flows or stress conditions. It can also be applied to a distribution box for a level bed system by fitting the outlet pipes with dial-a-flows. This method of distribution also supports inspection and management of the system to define the percent of the system in use, maximum use, and to monitor and adjust system stress. 2019 Massachusetts Design&Installation Manual Page 3 www.eljen.com Glossary of Terms Specified Sand To ensure proper system operation, the system MUST be installed using ASTM C33 Sand. ASTM C33 sand will have less than 10% passing the#100 Sieve and less than 5% passing the # 200 sieve. Ask your material supplier for a sieve analysis to verify that your material meets the required specifications. TABLE 1: SPECIFIED SAND SIEVE REQUIREMENTS ASTM X33 qx � SAND SPECIFICATIONR , a Sieve Square Specification Sieve Size Opening Size Percent Passing (Wet Sieve) 3/8 inch 9.52 mm 100 No.4 4.76 mm 95- 100 No.8 2.38 mm 80- 100 No. 16 1.19 mm 50-85 No. 30 590 pm 25-60 No. 50 297 pm 10-30 No. 100 149 Nm < 10 No.200 75 pm < 5 2019 Massachusetts Design&Installation Manual Page 4 www.ellen.com GSF System Des 'ription Primary Treatment Zone • Perforated pip is centered above the GSF module to distribute septic effluent over and into corrugations cr aated by the cuspated core of the geotextile module. • Septic effluent s filtered through the Bio-Matt fabric.The module's unique design provides increased surface area fo r biological treatment that greatly exceeds the module's footprint. • Open air channn,els within the module support aerobic bacterial growth on the modules geotextile fabric interface,surpassing the surface area required for traditional absorption systems. • An anti-siltation geotextile fabric covers the top and sides of the GSF module and protects the Specified Sand and soil from clogging,while maintaining effluent storage within the module. Secondary Treatment Zone • Effluent drips ir to the Specified Sand layer and supports unsaturated flow into the native soil. This Specified San /soil interface maintains soil structure, thereby maximizing the available absorption interface in the native soil. The Specified Sand supports nitrification of the effluent, which reduces oxygen demand In the soil,thus minimizing soil clogging from anaerobic bacteria. • The Specified(Sand layer also protects the soil from compaction and helps maintain cracks and crevices in the soil. This preserves the soil's natural infiltration capacity, which is especially important in Iner textured soils, where these large channels are critical for long-term performance. • Native soil provides final filtration and allows for groundwater recharge. FIGURE 1: GSF SYSTEM OPERATION Foroirs`Fop of the Eljen G F Perforated.Pipe allows&apotransplr16tion'.8.nd, distributes e€tlubnt to:the oxygen exchange for bettdir F)ien GSE pipe is'secured to efltu6pt treatment: the GSF iModules with preformed s . metal clamps. • .Anti=siltation Fabric: l keeps tines out of the Ijen ASF Primary Treatment Zane fabric. • Untreated EiEffluentforms on Bio-Mattr1' ' Signiticant fabric provided s • Bio-MattTM Fabric for every ft'"of soil interface., • Cusp ated'Plastic Core Secondary Treatment Zone ,prcvldes sboaratlon h6tyv rrforms at sand,layer.Long term layers.of 01048ttr; fabric ��� i �,e; acceptance rate of this biomat Marntajns structural rntecrt of ", 5. layer is significantly increased as modules`&aids 6x,/gen tr6j isfer.,; I £ t= compgred to conventional systems. lncreases.treatment surfae arca&effluent stprage cap crty , $$ SpecifiedS hoot.aver provides-adfilit±onal filtration,: e FilteredE,ifluent Native Soil or Fitt x Treated:Effluent. provides final filtration 2019 Massachusetts Design&Installation Manual Page 5 www.eljen.com 1.0 System Preconditions 1.1 REQUIREMENTS: GSF systems must meet the local rules and regulations except as outlined in this manual. The Massachusetts Title 5 regulations and the local regulations will be referred to as the guidelines in this manual.The sizing charts apply to residential systems only. Please contact Eljen's Technical Resource Department at 1-800-444-1359 for design information on commercial systems.- 1.2 ystems.1.2 WATER SOFTENER BACKWASH: At no time should water softener backwash be disposed of in the septic system. Water softener backwash should be discharged to a separate soil absorption field. 1.3 GARBAGE DISPOSALS: Eljen discourages the use of garbage disposals with septic systems. If a GSF system is to be designed and installed with garbage disposals the following measures must be taken to prevent solids from leaving the tank and entering the GSF system: • Increase the septic tank capacity by a minimum of 50% or • Installation of a second septic tank installed in series • And a 50% larger leachfield Eljen requires the use of septic tank outlet effluent filters on all systems especially on those systems that have single compartment tanks, even if up-sized, and when the dwelling has a garbage disposal installed. 1.4 ADDITIONAL FACTORS AFFECTING RESIDENTIAL SYSTEM SIZE: Homes with expected higher than normal water usage may consider increasing the septic tank volume as well as incorporating a multiple compartment septic tank. Consideration for disposal area may be up-sized for expected higher than normal water use. For example: • Luxury homes, homes with a Jacuzzi style tubs, and other high use fixtures. • Homes with known higher than normal occupancy. 1.5 SYSTEM PROHIBITED AREAS: All vehicular traffic is prohibited over the GSF system. GSF systems shall not be installed under paved or concreted areas. If the system is to be installed in livestock areas, the system must be fenced off around the perimeter to prevent compaction of the cover material and damage to the system. 2019 Massachusetts Design&Installation Manual Page 6 www.eljen.com 2.0 Design and Installation IGURE 2: TYPICAL A42 CROSS SECTION SEED AND LOAM IN 12" GEOTEXTILE OF C LEAN FABRIC FILL 7" SPECIFIED SAND 6" 24" 6" 36" A42MODULE (LxWxH)48"x24"x7" IGURE 3: TYPICAL B43 CROSS SECTION SEED AND LOAM M N 12" GEOTEXTILE OFCLEAN FABRIC FILL 7 6" SPECIFIED SAND 6" 36" 6" 48" B43 MODULE (L x W x H)48"x 36"x 7" All systems are required to have a minimum of: • 6 inches of Specified Sand is at the edges of the GSF module. • 6 inches of Specified Sand is at the beginning and end of each GSF Row. • 6 inches of Specified Sand is directly below the GSF module. • Minimum 12 inches of cover above the module. 2019 Massachusetts Design&I istallation Manual Page 7 www.eljen.com 2.0 Design and Installation 2.2 SEPTIC TANKS: Dual compartment tanks are recommended for all systems. Eljen supports this practice as it helps to promote long system life by reducing TSS and BOD to the effluent disposal area. Effluent filters are also required. 2.2 SEPTIC TANK FILTERS: Septic tank effluent filters are REQUIRED on the outlet end of septic tank. Filter manufactures require that filters be cleaned from time to time.Ask your installer or designer for specific cleaning requirements based on the type or make of the filter installed. Eljen requires the septic tank to be pumped every three years or as needed which would be a good time to check and conduct filter maintenance. 2.3 VERTICAL SEPARATION TO LIMITING LAYER: Massachusetts remedial rules allow for a reduction in the depth of the naturally occurring pervious material or depth to groundwater to 2 feet. Consult your approving authority to approve this reduction. The Vertical Separation from bottom of the 6 inches of sand under the GSF units to the limiting layer shall not be less than 2 feet. It may be higher for percolation rates faster than 2 minutes per inch. FIGURE 4: VERTICAL SEPARATION DISTANCE SEED AND LOAM MIN 12" GEOTEXTILE OF CLEAN FABRIC FILL 7 : .,. 6" SPECIFIED SAND 24".-MIN TO GROUNDWATER-24"MIN TO BEDROCK 2.4 SPECIFIED SAND SPECIFICATION FOR GSF SYSTEMS: The sand immediately under, between rows and around the perimeter of the GSF system must meet ASTM C33 SPECIFICATIONS, WITH LESS THAN 10% PASSING A #100 SIEVE AND LESS THAN 5% PASSING A #200 SIEVE. Please place a prominent note to this effect on each design drawing. See Table 1 for more information on the sand and sieve specifications. Washed concrete sand easily meets the above specification and is a reliable choice. Suitability of bank run sand must be verified. 2.5 PLACING GSF MODULES: The"painted stripe"on the GSF modules indicates the top of the module and is not intended to indicate the location of the distribution pipe. With the painted stripe facing up, all rows of GSF modules are set level, end to end on the Specified Sand layer. Beds on level sites require a minimum spacing of 12" of Specified Sand between parallel module rows with 24" of separation required on sites with 15%to 20% slope. No mechanical connection is required between modules. 2.6 DISTRIBUTION: Gravity, pump to gravity or pressure distribution are acceptable when using the GSF System. Piping shall meet the requirements guidelines; however, Eljen strongly recommends the use of SDR 35 pipe and fittings as to prevent crushing during backfill. All systems require a perforated 4" diameter pipe centered on top of the GSF modules unless the system is curving. The distribution pipe continues along the entire length of all modules in a trench or row. Holes are set at the 4 and 8 o'clock position and secured by the Eljen provided wire clamps. When using pressure distribution, a pressure manifold is placed inside the 4-inch distribution pipe. Section 7.0 of this manual goes into details of how to construct the distribution network. All piping must meet state and local regulations. 2019 Massachusetts Design&Installation Manual Page 8 www.eljen.com 2.0 Design and In -tallation 2.7 CONNECTIONS AN0 FITTINGS: Connections of lines to tanks and distribution boxes must be made using watertight mechanical seals. Use of any grouting material is not permitted. 2.8 DISTRIBUTION BOX CONNECTION: Plastic or concrete distribution boxes are acceptable. Provide D-Box(s) installed in acco dance with 310 CMR 15.232. Distribution boxes must be installed level and on a compacted layer of said or a base of gravel to prevent movement over time. Set gravity system distribution box outlet pips 1/2"to 1/8" drop to per foot above the perforated pipe above the modules. A 2" minimum drop to the perforated pipe is required for pumped systems. Non-perforated pipes from the distribution box to the GS17 modules must be placed on a compacted surface and secured with fill material that will prevent moverner t and settling. Dial-a-Flow fittings on outlet pipes are required for demand dosed systems. 2.9 PARALLEL DISTRI .UTION: Parallel distribution is the preferred method of dosing to a gravity or pump to gravity system. t encourages equal flows to each of the lines in the system. It is recommended for most trench systems. 2.10 SEQUENTIAL DISTRIBUTION: Sequential Distribution using a distribution box will fully utilize the uppermost section of the system prior to spilling effluent into a lower row of modules. This is for use on any site with greater than 0.5% slope when not using parallel distribution. FIGURE : SEQUENTIAL DISTRIBUTION DROP-BOX DETAIL B A GSF MODULES CJ DIAL-A-FLOW UPPER MOST TRENCH i INVERTSETTING DIAL-A-FLOWFITTINGS ARE NOT INSTALLED ON THE OVER FLOW LINE B A FROM THE SEPTIC TANK OR THE DISTRIBUTION PIPE LEADING TO THE GSF MODULES GSF MODULES LOWER TRENCHES i O Or THE INVER OF DIAL-A-FLOW"B" IS SET AT THE 9:00 POSITION GSF MODULES LOWEST TRENCH DIAL-A-FLOW FITTINGS ARE NOT INSTALLED O ® ON THE OVER FLOW LINE FROM A UPPER DROP-BOX OR THE DISTRIBUTION PIPE LEADING TO THE GSF MODULES THE INVER OF DIAL-A-FLOW"B" THE LOWEST TRENCH ALONG TI iESLOPE IS SETAT THE 9:00 POSITION DOES NOT REQUIRE DROP-BOX,ALTHOUGH RECOMMENDED WITH COMMERCI DESIGNS OUTFLOW TO FOR INSPECTION AND OBSE ATION DOWNSIDE IN FLOW FROM SEPTIC TANK, DROP BOX PUMP CHAMBER OR UP SLOPE DROPBOX - OUTFLOW TO DOWNSIDE SLOPE j DROP BOX OUTFLOW TO GSF IN FLOW FROM SEPTIC TANK LATERAL LINE PUMP CHAMBE OR UP SLOPE OUTFLOW TO DROP BOX DOWNSIDE SLOPE DROP '7 110 OUTFLOW TO GSF LATERAL LINE 2019 Massachusetts Design&I istallation Manual Page 9 www.eljen.com 2.0 Design and Installation 2.11 COVER FABRIC: Geotextile cover fabric is provided by Eljen Corporation for all GSF systems. It is placed over the top and sides of the module rows to prevent long term siltation and failure. Cover fabric substitution is not allowed. Fabric should drape vertically over the pipe and must not block holes in the distribution pipe or be stretched from the top of the pipe to the outside edge of the modules. "Tenting"will cause undue stress on fabric and pipe. 2.12 SYSTEM VENTING: It is required to vent all systems that are over 18" below finished grade and systems beneath any surface condition that would not allow for surface air exchange with the system such as patios. Systems that exceed 50 feet in length require venting as well according to Title 5. See Section 8.0 for a more detailed explanation of venting GSF products. 2.13 BACKFILL & FINISH GRADING: Complete backfill with a minimum of 12 inches of clean porous fill measured from the top of modules. Fill should conform to title 5 requirements. Title 5 requirements for Backfill are in 310 CMR 15.240 (9). Where natural backfill cannot be used, Title 5 fill is required. Backfill exceeding 18 inches requires venting at the far end of the trench or bed. Use well graded native soil fill that is clean, porous and devoid of large rocks. Do not use wheeled equipment over the system. A light track machine may be used with caution, avoiding crushing or shifting of pipe assembly. Divert surface runoff from the Effluent Disposal Area. Finish grade to prevent surface ponding. Place topsoil and seed system area to protect from erosion. 2.14 SYSTEM GEOMETRY: Design systems as long and narrow as practical along site contours to minimize ground water mounding especially in poorly drained low permeability soils. If possible, design level systems with equal number of modules per row. For trench system using the A42,the edge to edge spacing is a minimum of 6 ft. For the B43 unit,the edge to edge spacing for trenches is 8 ft. 2.15 NUMBER OF GSF MODULES REQUIRED: Tables 2 — 5 indicate the minimum number of GSF modules required for various percolation rates and number of bedrooms. At a minimum,every system shall be sized at 5 B43 modules per bedroom or 6 A42 modules per bedroom. Units are scaled up for slower soils to improve distribution in the absorption area. 2.16 SIZING GSF SYSTEM FOR TRENCHES, BEDS &SAND MOUNDS: Eljen GSF products receive a 40% reduction to standard system sizing. Eljen GSF modules can be used in conjunction with an ATU at a 50% sizing reduction. Eljen's 40% reduction and an ATU's 50% reduction cannot be combined. Individual counties may have different sizing based on local regulations. Eljen GSF modules can also be used following nitrogen reduction systems. 2019 Massachusetts Design&Installation Manual Page 10 www.elien.com 2.0 Design and In tallation 2.17 SIZING CHARTS: TABLE 2: A42 TRENCH SIZING CHART Tri3nch Istatlations Effective; lea 314 ffr Module' esu ' Mrnrrnum Trench Bat#am.Area Mrmrnuill Number of Modules Modules A Applrafron Table 2 Tinah 'eraoiatron Raiz � �Fer Bach Required(ft j Required � A42 Mads e°, � � QPplf{2 Bedroarns per House Bedraarns per House Additional ; Bedroom Class 1 1 -5 0.74 216 288 360 18 24 30 6 Class II 1 -5 0.6 216 288 360 18 24 30 6 Class 6 0.7 216 288 360 18 24 30 6 Class II 6 0.6 216 288 360 18 24 30 6 Class ) 7 0.68 216 288 360 18 24 30 6 Class II 7 0.6 216 288 360 18 24 30 6 Class 8 0.66 216 288 360 18 24 30 6 Class II 8 0.6 216 288 360 18 24 30 6 Class II 10 0.6 216 288 360 18 24 30 6 Class 11 15 0.56 216 288 360 18 24 30 6 Class III 15 0.37 312 420 528 26 35 44 9 Class II 20 0.53 228 300 372 19 25 31 6 Class III 20 0.34 348 456 576 29 38 48 10 Class II 25 0.4 288 384 480 24 32 40 8 Class 111 25 0.33 360 468 588 30 39 49 10 Class II 30 0.33 360 468 588 30 39 49 10 Class III 30 0.29 408 540 672 34 45 56 11 Class III 40 0.25 468 624 768 39 52 64 13 Class III&IV 50 0.2 576 768 960 48 64 80 16 Class III&IV 60 j 0.15 1 768 1 1032 1284 64 86 107 21 RemedialdtJse.60.-.9(I Class III&IV 60 0.15 1 768 1032 1284 64 86 107 21 Pressure Dosed Systems s ` ! . . ,,., . . , Class III 40 0.29 408 540 672 34 45 56 11 Class III&IV 50 0.25 468 624 768 39 52 64 13 Class III&IV 60 0.2 576 768 960 48 64 80 16 1. The minimum nu ber of A42s per bedroom is 6 modules per bedroom at 12 sf per module (actual bottom area). 2. The calculation for minimum trench bottom area is calculated by multiplying the conventional sizing by 60% (310 CM 15.242) or calculating the actual footprint required for the minimum number of units per bedroo 3. Wastewater'flow�s based on 110 gallons per bedroom in accordance with 310 CMR 15.203. 4. A minimum effective leaching area of 400 sf is required for new construction. 5. When recorded p rcolation rates are between those listed in 310 CMR 15.242,the next slower rate shall be used for Jesign purposes. 2019 Massachusetts Design&I istallation Manual Page 11 www.eljen.com 2.0 Design and Installation TABLE 3: B43 TRENCH SIZING CHART Trench lnstal�afions EffectiArea 41 y5 Riper"fvlodute « :, ox R v Percolation Application M�n�mum Trench Bottom A," Nurr�ber of Modules �Modules�o 7able3 TTenet Requited tff�) � Requ�red Per Egch Rate Rae .. w g Additional B43 Module CPblftz Bedrooms per House Oedroorn per House77"', 4 r a .. Y Bedroom 1 5' _0 7_4 24�0� 320 400 1�5` 20 25 5 Class II 1 -5 0.6 —240' 320 400 X15" 20 25 5 Class 1 6 0.7 240 320 400 15 20 25 5 Class II 6 0.6 240 320 400 15 20 25 5 Class 1 7 0.68 240 320 400 15 20 25 5 Class II 7 0.6 240 320 400 15 20 25 5 Class 1 8 0.66 240 320 400 15 20 25 5 Class II 8 0.6 240 320 400 15 20 25 5 Class II 10 0.6 240 320 400 15 20 25 5 Class II 15 0.56 240 320 400 15 20 25 5 Class III 15 0.37 352 464 576 22 29 36 7 Class II 20 0.53 240 320 400 15 20 25 5 Class III 20 0.34 384 512 624 24 32 39 8 Class II 25 0.4 320 432 528 20 27 33 7 Class III 25 0.33 384 512 640 24 32 40 8 Class II 30 0.33 384 512 640 24 32 40 8 Class III 30 0.29 448 592 736 28 37 46 9 Class III 40 0.25 512 688 848 32 43 53 11 Class III& IV 50 0.2 1 640 1 848 1 1056 40 53 66 13 Class III& IV 60 0.15 848 1136 1408 1 53 1 71 88 18 (2emedial lJse,6Q..90 AKq, s .,. : Class III& IV 1 60 0.15 848 1136 1408 11 53 71 88 18 Pressure°posed,Sy$terns..__ _..... - e.... F Class 111 1 40 0.29 448 592 736 28 37 " 46 9 Class III& IV 50 0.25 512 688 848 1 32 1 43 53 11 Class III& IV 1 60 0.2 640 848 1056 1 40 1 53 66 13 1. The minimum number of B43s per bedroom is 5 modules per bedroom at 16 sf per module(actual bottom area). 2. The calculation for minimum trench bottom area is calculated by multiplying the conventional sizing by 60% (310 CMR 15.242) or calculating the actual footprint required for the minimum number of units per bedroom. 3. Wastewater flow is based on-110—gallonss p.er bedroom-in-accordance,with 31:0�CMR 15.203. �4. A minimurn� effective'leaching_are_a"of 4'00 sf 1s required for_rJe-c",o�astruct Eft. 5. When recorded percolation rates are between those listed in 310 CMR 15.242,the next slower rate shall be used for design purposes. 2019 Massachusetts Design&Installation Manual Page 12 www.eljen.com 2.0 Design and In tallation TABLE 4: A42 BED SIZING CHART Bed j�sat�l t�prts,�ffect�ve Areas 20 Q4 tt�yper lVjodule,,, N ,. qa R;eroltiarii aApP,6 �num:BasalAreaRegOredIvinimum Narber atiMocfulea Macules Pet Tble 4 BedeRaateRegwred 1=ach Additional A42°MQdtle tae Z edrOoS PeloUsl? F BedrearS PerlgUSe GPIJ�ft yB2tlroom . &Salf�fyper3 4 � 5INIKQ �4 � Class 1 1 -5 _ 0.74 � 268 357 446 20 24 30 6 Class II 1 -5 0.6 330 440 550 20 24 30 6 Class 1 6 0.7 283 378 472 20 24 30 6 Class II 6 0.6 330 440 550 20 24 30 6 Class 1 7 0.68 292 389 486 20 24 30 6 Class II 7 0.6 330 440 550 20 24 30 6 Class 1 8 0.66 300 400 500 20 24 30 6 Class II 8 0.6 330 440 550 20 24 30 6 . Class 11 10 0.6 330 440 550 21 28 35 7 Class 11 15 0.56 354 472 590 21 28 35 7 Class III 15 0.37 536 714 892 24 32 40 8 Class II 20 0.53 374 499 623 24 32 40 8 Class III 20 0.34 583 777 971 24 32 40 8 Class II 25 0.4 495 660 825 27 36 45 9 Class 111 25 0.33 600 800 1000 27 36 45 9 Class II 30 0.33 600 800 1000 27 36 45 9 Class 111 30 0.29 683 911 1138 30 40 50 10 Class III 400.25 792 1056 1320 33 44 55 11 Class III&IV 50 0.2 990 1320 1650 39 52 65 13 Class III&IV 60 0.15 1320 1760 2200 39 52 65 13 Remedial:Use 60 9 (?MP1 vat Class III&IV 60 0.15 1320 1760 2200 39 52 65 13 Pr`.essure,Dosed Systems.-- •',, yIP Class III 40 0.29 683 911 1138 11 30 1 40 50 10 Class III&IV 50 0.25 792 1056 1320 39 52 65 13 Class III&IV 60 0.2 990 1320 1650 39 52 65 13 1. The minimum nu ber of A42s per bedroom is 6 modules per bedroom. 2. The calculation for minimum basal area is calculated by multiplying the conventional sizing by 60% (310 CMR 15.242)or calculating the actual footprint required for the minimum number of units per bedroom. 3. Wastewater flow is based on 110 gallons per bedroom in accordance with 310 CMR 15.203. 4. A minimum effective leaching area of 400 sf is required for new construction. 5. When recorded percolation rates are between those listed in 310 CMR 15.242,the next slower rate shall be used for design purposes. 2019 Massachusetts Design&Installation Manual Page 13 www.eljen.com 2.0 Design and Installation TABLE 5: B43 BED SIZING CHART Applicat�o Mmimurri Basal A,iea Required Mm�mumNumber Qf Modulen 4 odu es p r, Table 5 Bed PeroolaY�on �{z� ` Required I �achAdditionala B43 Madge Rate z Bedrooms per}louse Bedrooms perObuse Bedroom SPD/ft z SoilTps. d 3v. 4 az= � $ 3 4 4 Class I 1 1 -5 0.74 272 357 446 17 20 25 5 Class II 1 -5 0.6 330 440 550 17 20 25 5 Class 1 6 0.7 283 378 472 17 20 25 5 Class II 6 0.6 330 440 550 17 20 25 5 Class 1 7 0.68 292 389 486 17 20 25 5 Class II 7 0.6 330 440 550 17 20 25 5 Class 1 8 0.66 300 400 500 17 20 25 5 Class II 8 0.6 330 440 550 17 20 25 5 Class II 10 0.6 330 440 550 18 24 30 6 Class II 15 0.56 354 472 590 18 24 30 6 Class III 15 0.37 536 714 892 21 28 35 7 Class II 20 0.53 374 499 623 21 28 35 7 Class III 20 0.34 583 777 971 21 28 35 7 Class II 25 0.4 495 660 825 24 32 40 8 Class III 25 0.33 600 800 1000 24 32 40 8 Class II 30 0.33 600 800 1000 24 32 40 8 Class III 30 0.29 683 911 1138 27 36 45 9 Class III 40 0.25 792 1056 1320 30 40 50 10 Class III&IV 50 0.2 990 1320 1650 33 44 55 11 Class III&IV 60 0.15 1320 1760 220033 44 55 11 Remedial Use ti0-90'M r � &.. �.. a Class III&IV 60 0.15 2200 2934 3667 11 33 44 55 1 11 POssure Dosed Systems Class III 40 0.29 1138 1518 1897 30 40 50 10 Class III&IV 50 1 0.25 1320 1760 2200 33 44 1 55 11 Class III&N 60 1 0.2 1650 2200 2750 33 44 1 55 11 1. The minimum number of B43s per bedroom is 5 modules per bedroom. 2. The calculation for minimum basal area is calculated by multiplying the conventional sizing by 60% (310 CMR 15.242)or calculating the actual footprint required for the minimum number of units per bedroom. 3. Wastewater flow is based on 110 gallons per bedroom in accordance with 310 CMR 15.203. 4. A minimum effective leaching area of 400 sf is required for new construction. 5. When recorded percolation rates are between those listed in 310 CMR 15.242,the next slower rate shall be used for design purposes. 2019 Massachusetts Design&Installation Manual Page 14 www.eljen.com 3.0 Trench Installation Sizing and Guidelines Trench Example: House size: 4 Bedrooms Soil Permeability&Class: 30 min/in, Class III Soil Absorption Field Type: Trench Unit Used: A42 Calculate Minimum.Number of Units and Bottom Area Required Lookup the information required from Table 3: A licatian Mltt�mt�l> TrenCt�Bottnrn Area Minimum Number of Mod�iles; P 3 Table 2 Trench Percolate n A a� e Ulr$ f�)$ �Re WOO Rate q ( A2iMoule Rates CFp/ftp Bedraams per House Bedrooms perHouse Solvmype � ` �._� 5 3 5 Class III 30 0.29 408 1 40 672 34 k 452 1 56 Minimum Units required 45 A42 Modules Minimum Trench Bottom required 540 ft2 Calculate Minimum Trer ch Length 45 Units x 4+ 1 ft 181 linear feet Trench Width Trench idth (ft) A42 3 B43 4 Final Dimension Layout (Note:System layout an number of rows will vary based on site constraints) Min. Product Length 180 ft. (note: 6 inches of sand r quired at each end of trench making the minimum trench length 181 ft.) Trench Width 3 ft. Minimum Number of Units 45 A42 Modules 2 Trench Rows 22.5 Modules, round up to 23 Modules per row, 93 ft. per row. 3 Trench Rows 15 A42 per row, 61 ft. per row. Min. System Area 540 ft2 2019 Massachusetts Design&Installation Manual Page 15 www.eljen.com 3.0 Trench Installation Sizing and Guidelines FIGURE 6: PLAN VIEW-TRENCH SYSTEM EXAMPLE CAP ALL ENDS SPECIFIED SAND DISTRIBUTION BOX 61011 PERFORATED ��/����NATIVE SOIL DISTRIBUTION PIPE �\//�/� ATjV s 3'0" L92' 0'6" 93' (*2 Rows of 9 B43's shown in Figure 6) FIGURE 7: SECTION VIEW-TRENCH SYSTEM EXAMPLE - LEVEL SITE SEED AND LOAM MIN 12" \ �' / �GE6TEXTILE // • • i OF CLEAN FABRIC FILL I NATIVE SOIL SAN PECIF1 IE t6- 24" 6" 36' 6' FIGURE 8: SECTION VIEW-TRENCH SYSTEM - SLOPING SITE SEED AND LOAM MIN 12" ` GEOTEXTILE OF CLFEAN ILL FABRIC 7" j NATIVE SOIL 6!' : PECIFIED SAN PECIFIED SAN :±.`: 6" 24" 6" �-24 36" 6' 36" 2019 Massachusetts Design&Installation Manual Page 16 www.eljen.com 3.0 Trench Installation Sizing and Guidelines 1. Ensure all component leading to the GSF system are installed properly. Septic tank effluent filters are required with the GSF system. 2. Determine the number of GSF Modules required using the trench sizing example. 3. Prepare the site. Do iot install a system on saturated ground or wet soils that are smeared during excavation. Keep ma hinery off infiltrative areas. u 4. Plan all drainage reqirements above (up-slope) of the system. Set soil grades to ensure that storm water drainage and ground water is diverted away from the absorption area once the system is complete. 5. Excavate the trench; repare the receiving layer to maximize the interface between the native soil and specified sand. 6. Minimize walking in the trench prior to placement of the specified sand to avoid soil compaction. 7. Place specified sand in a 6" lift and stabilize by foot, a hand held tamping tool or a portable vibrating compactor.The minimum stabilized height below the GSF module must be level at 6". 8. Place GSF modules with PAINTED STRIPE FACING UP,end to end on top of the specified sand along their 4-foot length. 9. A standard 4-inch perforated pipe, SDR 35 or equivalent, is centered along the modules 4-foot length. Orifices are set at the 4&8 o'clock position. 10. All 4-inch pipes ares cured with manufacturers supplied wire clamps, one per module. 11. (Pressure Distribution Systems) Insert a pressure pipe (size per design and code)into the standard 4- inch perforated pipe. The pressure pipe orifices are set at the 12 o'clock position as shown in Figure 14. Each pressure la eral will have a drain hole at the 6 o'clock position. Each pressure lateral shall include sweeping cleE nouts at the terminal ends and be accessible from grade. 12. Cover fabric substitution is not allowed. The installer should lay the Eljen provided geotextile cover fabric lengthwise down the trench, with the fabric fitted to the perforated pipe on top of the GSF modules. Fabric should be neither too loose, nor too tight. The correct tension of the cover fabric is set by: a. Spreadin the cover fabric over the top of the module and down both sides of the module with the cover fabric tented over the top of the perforated distribution pipe. b. Place shc velfuls of Specified Sand directly over the pipe area allowing the cover fabric to form a mc stly vertical orientation along the sides of the pipe. Repeat this step moving down the pipe. 13. Place the sand exten ions along both sides of the modules edge. A minimum of 6 inches of Specified Sand is placed at the beginning and end of each trench. 14. Complete backfill with a minimum of 12 inches of clean porous fill measured from the top of the module. Backfill exceeding 18 inches requires venting at the far end of the trench. Use well graded native soil fill that is clean, porous and devoid of large rocks. Do not use wheeled equipment over the system. A light track machine m y be used with caution, avoiding crushing or shifting of pipe assembly. 15. Divert surface runoff from the system. Finish grade to prevent surface ponding. Topsoil and seed system area to protect from erosion. 2019 Massachusetts Design&Installation Manual Page 17 www.eljen.com , ' 4.0 Bed Installation S' 'nd Guidelines Bed Example: House size: 4Badruomo Soil Permeability&Class 3Omin/in. Class III Soil Absorption Field Type: Bad Unit Used: B43 Calculate Minimum Number ofUnits and Basal Area Required Lookup the information required from Table 5: trnu erbol 77 T-7 77177 Class 111 30 0.29 683 38 9 Minimum Units noqulmyd 36=32 B43 Modules Minimum Basal Area required 911ft2 Calculate Minimum Bed Length Maintain o minimum of nomm in a bed system. (4 Rows for this example) 38Units+4Rows= QyWoda/Rmw Calculate Minimum Row Length QUnits x4ft/unit+ 1ft= 37ftper Row Bed Width (Level Installation) Bed Width = Basal Area Required Row Length 011ft2-37ft=24.6. round hu 25 ft. Determine Lateral Spacing Lateral to Lohonu| Spacing = Bed Width Number ofRows 4Rowo 25ft+4rows 6.25 ft Lateral to Edge Spacing = Labono|to Lateral Spacing+2 6.25 ft-2 3.125 ft Final Dimension Layout (\o&e:System layout and number myrows will vary based onsite constraints) 4.0 Bed Installation Sizing and Guidelines FIGURE 9: PLAN VIEW- BED SYSTEM EXAMPLE - LEVEL SITE DISTRIBUTION BOX 3' 1.5" — ll. — ___7 --- - - - - - - - - - T _ 6-3.01- NON-PERFORATED LOOP PIPE NON-PERFORATED CROSS OVER PIPE L 25'9' - - - - - - - - 3-3" /—PERFORATED PIPE 1'7.5" L °.6„ _r 36'0" 37'0" FIGURE 10: SECTION VIEW- BED SYSTEM EXAMPLE SEED AND LOAM GEOTEXTILE FABRIC AM 6" 'i� .i:, ':i' SPECIFIED SAND �.`•%: T1.5" 6 " 3-3" 1.91 25'0" FIGURE 11: S CTION VIEW- BED SYSTEM EXAMPLE - SLOPING SITE SEED AND LOAM GEOTEXTILE IC- T' ;5PECIFIEDSA[IR' 3'1.5" 6' 3.3,E 1.8" 25'0" 2019 Massachusetts Design&I stallation Manual Page 19 www.eljen.com 4.0 Bed Installation Sizing and Guidelines 1. Ensure all components leading to the GSF system are installed properly. Septic tank effluent filters are required with the GSF system. 2. Determine the number of GSF Modules required using the bed sizing example. 3. Prepare the site. Do not install a system on saturated ground or wet soils that are smeared during excavation. Keep machinery off infiltrative areas. 4. Plan all drainage requirements above (up-slope) of the system. Set soil grades to ensure that storm water drainage and ground water is diverted away from the absorption area once the system is complete. 5. Excavate the bed absorption area; prepare the receiving layer to maximize the interface between the native soil and specified sand. 6. Minimize walking in the absorption area prior to placement of the specified sand to avoid soil compaction. 7. Place specified sand in 6" lifts, stabilize by foot, a hand held tamping tool or a portable vibrating compactor.The minimum stabilized height below the GSF module must be level at 6". 8. Place GSF modules with PAINTED STRIPE FACING UP,end to end on top of the specified sand along their 4-foot length. 9. A standard 4-inch perforated pipe, SDR 35 or equivalent, is centered along the modules 4-foot length. Orifices are set at the 4 &8 o'clock position. 10. All 4-inch pipes are secured with manufacturers supplied wire clamps, one per module. 11. (Pressure Distribution Systems) Insert a pressure pipe(size per design and code)into the standard 4- inch perforated pipe. The pressure pipe orifices are set at the 12 o'clock position as shown in Figure 14. Each pressure lateral will have a drain hole at the 6 o'clock position. Each pressure lateral shall include sweeping cleanouts at the terminal ends and be accessible from grade. 12. Cover fabric substitution is not allowed. The installer should lay the Eljen provided geotextile cover fabric lengthwise down the row, with the fabric fitted to the perforated pipe on top of the GSF modules. Fabric should be neither too loose, nor too tight. The correct tension of the cover fabric is set by: a. Spreading the cover fabric over the top of the module and down both sides of the module with the cover fabric tented over the top of the perforated distribution pipe. b. Place shovelfuls of Specified Sand directly over the pipe area allowing the cover fabric to form a mostly vertical orientation along the sides of the pipe. Repeat this step moving down the pipe. 13. Place 6 inches of Specified Sand along both sides of the modules edge. A minimum of 6 inches of Specified Sand is placed at the beginning and end of each module row. Beds on level sites require a minimum spacing of 12"of Specified Sand between parallel module rows with 24"of separation required on sites with 15%to 20% slope. No mechanical connection is required between modules. 14. Complete backfill with a minimum of 12 inches of clean porous fill measured from the top of the pipe. Backfill exceeding 18 inches requires venting at the far end of the bed. Use well graded native soil fill that is clean, porous and devoid of large rocks. Do not use wheeled equipment over the system. A light track machine may be used with caution, avoiding crushing or shifting of pipe assembly. 15. Divert surface runoff from the system. Finish grade to prevent surface ponding. Topsoil and seed system area to protect from erosion. 2019 Massachusetts Design&Installation Manual Page 20 www.eljen.com 5.0 Mound Installation Guidelines 5.1 MOUND REFEREN E: The following guidelines,provide an overview for mound design and construction. Mound distribution can either be pump to gravity or pressurized. Systems with 2000 GPD or greater shall require pressure distribution in accordance with 310 CMR 15.231. FIGURE 12: CROSS SECTION - MOUND SYSTEM *Note: Design Can Utilize Either B43 or A42 Modules TOP SOIL&SEED TO PROTECT FROM EROSION 15'MIN TITLE 5 PER DESIGN 12"MIN FILL 1IN PER :CODE Y:': y! t• :.((j• :IK' ':ti{._ry'....'`i :�ti.' ��1�•V�'•ii:'. > �,:'• 2"MIN'.: SPECIFIED SAND ORIGINAL GRADE REMOVE TOP SOIL&SET SYSTEM BASE BELOW ORIGINAL GRADE FIGURE 13: CROSS SECTION - SLOPED MOUND SYSTEM *Note: Design Can Utilize Either B43 or A42 Modules TOP SOIL&SEED TO PROTECT FROM EROSION 15'MIN 12 MIN PER DESIGN 12"MIN TITLE 5 FILL PER CODE SPECIFIED SAND ORIGINAL GRADE •' — — REMOVE OP SOIL&SET SYSTEM BASE BELOW ORIGINAL GRADE 2019 Massachusetts Design&Installation Manual Page 21 www.eljen.com r 5.0 Mound Installation Guidelines 1. Ensure all components leading to the GSF system are installed properly. Septic tank effluent filters are required with the GSF system. 2. Determine the number of GSF Modules required using the sizing formula. 3. Prepare the site. Do not install a system on saturated ground or wet soils that are smeared during preparation. Keep machinery off infiltrative areas. 4. Plan all drainage requirements above (up-slope) of the system. Set soil grades to ensure that storm water drainage and ground water is diverted away from the absorption area once the system is complete. 5. Remove the organic soil layer. Prepare the receiving layer to maximize the interface between the native soil and Specified Sand. Minimize walking in the absorption area prior to placement of the Specified Sand to avoid soil compaction. 6. Place fill material meeting local requirements (or Specified Sand requirements) onto the soil interface as you move down the excavated area. Place specified sand in a 6" lift, stabilize by foot, a hand held tamping tool or a portable vibrating compactor.The stabilized height below the GSF module must shall meet the mound design requirements. 7. Place GSF modules with PAINTED STRIPE FACING UP,end to end on top of the specified sand along their 4-foot length. 8. A standard perforated 4-inch distribution pipe is centered along the modules 4-inch length. Orifices are set at the 4 &8 o'clock position. 9. All distribution pipes are secured with manufacturers supplied wire clamps, one per module. 10. (Pressure Distribution Systems) Insert a PVC Sch. 40 pressure pipe (size per design and code) into the standard perforated distribution pipe. The pressure pipe orifices are set at the 12 o'clock position as shown in Figure 14. Each pressure lateral will have a drain hole at the 6 o'clock position. Each pressure lateral shall include sweeping cleanouts at the terminal ends and be accessible from grade. 11. Cover fabric substitution is not allowed. The installer should lay the Eljen provided geotextile cover fabric lengthwise down the row, with the fabric fitted to the perforated pipe on top of the GSF modules. Fabric should be neither too loose, nor too tight. The correct tension of the cover fabric is set by: a. Spreading the cover fabric over the top of the module and down both sides of the module with the cover fabric tented over the top of the perforated distribution pipe. b. Place shovelfuls of Specified Sand directly over the pipe area allowing the cover fabric to form a mostly vertical orientation along the sides of the pipe. Repeat this step moving down the pipe. 12. Ensure there is 6 inches of specified sand surrounding the GSF modules in the mound. Slope the sand away from the mound as described on the plan. 13. Complete backfill with a minimum of 12 inches of cover material measured from the top of the module. Use well graded native soil fill that is clean, porous and devoid of large rocks. Do not use wheeled equipment over the system. A light track machine may be used with caution, avoiding crushing or shifting of pipe assembly. Divert surface runoff from the system. Finish grade to prevent surface ponding. Topsoil and seed system area to protect from erosion. 14. Divert surface runoff from the system. Finish grade to prevent surface ponding. Topsoil and seed system area to protect from erosion. 2019 Massachusetts Design&Installation Manual Page 22 www.eljen.com Y 6.0 Dosing Distribution Guidance 6.1 PUMP TO DISTRIBUTION BOX: Specify an oversized distribution box for pumped dosed systems. Provide velocity reduction in the d-box with a tee or baffle. Set d-box outlets at the same elevation to equalize flow to each line or use drop boxes at the head of each line for serial distribution. If the absorption area is installed deeper t an 18 inches, the system must be vented. See section 8.0 of this manual for detailed information on VE nting of systems. 6.2 DOSING DESIGN AND FLOW RATE: Dosing volume must be set to deliver a maximum of 4 gallons per B43 Module and 3 g [Ions per A42 Module per dosing cycle. Higher flow rates and short dose cycle push the effluent down the line and thus disperse the effluent over a larger area. A valve on the force main is recommended to sett a flow rate so that the outlet pipes are submerged but prevents the d-box from over flowing. 7.0 Pressure Distr bution Guidance 7.1 PRESSURE DISTRIBUTION: Dosing with small diameter pressurized laterals is acceptable for GSF systems. The pipe netwoi ks must be engineered and follow principles established for pressure distribution. Using pipe-in-pipe networks as shown in Figure 14,the orifice size and spacing of 3/16 inch and 4 feet is respectively recommendE d. On sloping sites, the orifices should be offset by 2 feet on each line. For example,the orifice on lin 3 one may be at 1 ft, 5 ft, 9 ft etc.with the next line at 3 ft, 7 ft, 11 ft etc. Flushing ports are required to main ain the free flow of effluent from orifices at the distal ends of each lateral.Contact Eljen's Technical Resource Department at 1-800-444-1359 for more information on pressure distribution systems Standard procedures for c esign of pressure distribution networks apply to the GSF filter. A minimum orifice size according to the regulations shall be maintained. A drain hole is required at the 6 o'clock position of each pressure lateral for drainage purposes. The lateral pipe network, constructed of PVC Sch. 40 pipe (size per design and cod ), is placed within a standard 4-inch perforated pipe. The perforation in the 4- inch outer pipe are set at the 4 and 8 o'clock position, the drilled orifices on the pressure pipe are set to spray at the 12 o'clock position directly to the top of the 4-inch perforated pipe as shown below. Pressure clean outs are required at the end of each lateral. IGURE 14: PRESSURE PIPE PLACEMENT 4"DIAMETER PRESSURE CLEAN OUT PERFORATED PIPE PRESSURE PIPE 4"END CAP WITH HOLE DRILLED 00 o PRESSURE PIPE CROSS SECTION FOR ALL APPLICATIONS 4"DIAMETER PERFORATED PIPE PRESSURE PIPE 2019 Massachusetts Design&Installation Manual Page 23 www.eljen.com 7.0 Pressure Distribution Guidance FIGURE 15: PRESSURE CLEAN OUT 6-8"DIAMETER LAWN SPRINKLER FINISHED GRADE— — — — _ — "�NSAME DIAMETER — THREADED LATERAL ENDS AT LAST 4"PERFORATED PIPE CLEANOUT PLUG ORIFICE WHERE VARIABLE 4"END LENGTH CLEANOUT BEGINS CAP LONG SWEEP 90 OR TWO 45 DEGREE BENDS AS LATERAL DISTRIBUTION LATERAL LATERAL CLEANOUT FIGURE 16: CONTOURED TRENCH PRESSURE DISTRIBUTION PRIOR TO PLACING FABRIC COVER,HAND STANDARD FITTING(S) SHOVEL SPECIFIED SAND IN THESE AREAS 4"PERFORATED PIPE DRAIN OPENING AT 6 O'CLOCK CAP END OF 4"PIPE PRESSURE PIPE (SIZE PER DESIGN/CODE) PRESSURE PIPE EXTENDS THRU END CAP,AND IS EXTENDED FOR CLEAN OUT GSF Pressure Distribution trench placed on a contour or winding trenches to maintain horizontal separation distances may also be used in Dosed or Gravity system by removing the pressure pipe and using the 4- inch diameter perforated distribution pipe. 2019 Massachusetts Design&Installation Manual Page 24 www.eljen.com 8.0 System Ventilz tion 8.1 SYSTEM VENTILATI N: Air vents are required on all absorption systems located under impervious surfaces or systems with more than 98 inches of cover material as measured from the top of the GSF module to finished grade. This will ensure proper aeration of the modules and sand filter. The GSF has aeration channels between the rows of GSF modules connecting to cuspations within the GSF modules. Under normal operating c nditions, only a fraction of the filter is in use. The unused channels remain open for intermittent peak flows and the transfer of air. 8.2 VENT PIPE FOR GR VITY AND LOW-PRESSURE SYSTEMS: Systems with over 18"of cover over the top of the modules reiluire a vent. If the system is a low-pressure distribution system, ensure that the LPP clean outs are located in the vent for easy access. FIGURE 17: VENT LAYOUTS FOR GRAVITY AND LOW-PRESSURE SYSTEMS TREADED CAP EDGE OF LAST MODULE IN = EDGE OF LAST MODULE IN ?; ABSORPTIONAREA ION AREA "X. SPECIFIED SAND SPECIFIED SAND AT END OF ROW AT END OF ROW 8.3 VENTILATION PLACEMENT: In a GSF system, the vent is usually a 4-inch diameter pipe extended to a convenient location behind shrubs, as shown in the figure below. Corrugated pipe may be used. If using corrugated pipe, en. ure that the pipe does not have any bends that will allow condensation to pond in the pipe. This may clo a off the vent line. The pipe must have an invert higher than the system so that it does not drain effluent. FIGURE 18: GSF WITH 4" VENT EXTENDED TO CONVENIENT LOCATION SHRUB MOUNDED BACKFILL OVER MODULES ZL CLEAN BACKFILL GSF MODULES COVER FABRIC NOT SHOWN OVER DISTRIBUTION PIPE AND MODULES 2019 Massachusetts Design&I'stallation Manual Page 25 www.eljen.com k , -24 . t r ' �&« s , a y ss ro 4q 6 A Qat sg a e W4� zk m : Q COMPANYHIST Off Y� aEstablfshedn X970,-Ellen Corotitin,creatdth uuorld�s first •e. pre#zbricated drainage system for�foundation drainage,at" erosion control aplrcations� �nhe rnid 1980s� eve introdgced oui'GeoteXtrle$and Filter products for the passive aduarced treatmentof cnslke wastewater m both residentialx.,ard cornmercia( ,.a < applications. `today, Ellen:is aglobal (eaderir pro�rding in&nvatrue @ 4 � ° products and`salutions for protecting our environment and \ pub(ichealth � „ .• k `? 45: COMPANY P ILOSOPHI, " s Eljen Corporation is committed to advancing"the onsite,A) dustry j� through continuous development of innovative new products, delivering high quality products and services to our customers at the best price, and building lasting partnerships with our" z employees, su suppliers, and customers. pp �•, ell- L 40 CORPORATION a: 90 Meadow Road, Windsor, CT 06095 • Tel: 800-444-1359 Fax: 860-610-0427 www.eljen.com OD Val ©copyright Elien Corporation Printed in U.S.A.on recycled paper