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Eljen GSF Installation Manual

Geotextile sand filter
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Download this manual See also: Owner's Manual, Installation Manual
Geotextile Sand Filter
New York
Design & Installation Manual
May 2017
www.eljen.com
CORPORATION
Innovative Environmental Products & Solutions Since 1970

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  • Page 1 Geotextile Sand Filter New York Design & Installation Manual May 2017 www.eljen.com CORPORATION Innovative Environmental Products & Solutions Since 1970...

  • Page 2: Table Of Contents

    Table 1: B43 GSF Residential Trench Sizing Table – Linear Feet Per System Table 2: B43 GSF Residential Trench Sizing Table – Modules Per System Table 3: B43 GSF Residential Bed Sizing Table – Square Feet Absorption Area Per System Table 4: B43 GSF Residential Bed Sizing Table – Modules Per System Table 5: B43 GSF Repair &...

  • Page 3: Terms And Definitions

    The area to which wastewater is distributed over the GSF modules for infiltration into the soil. The GSF module model which measures 36” W x 48” L x 7” H in size. Bio-Matt™ Fabric Special filter fabric within the Geotextile Sand Filter Modules upon which the primary biomat layer forms as shown in Figure 1.
  • Page 4 Terms and Definitions Serial Distribution Designs common to sloping sites where GSF lines that are laid on contour and receive effluent from a series of drop boxes at different elevations. Effluent floods up-slope lines and then spills excess effluent to down-slope lines. Non-perforated pipe placed on undisturbed soil connects successive down-slope trenches.
  • Page 5 University of Connecticut. Eljen Corporation has over 30 years of success in the onsite wastewater industry, with tens of thousands of systems currently in use. The GSF is recognized by industry leaders as one of the most reliable treatment technology in the marketplace today. The system specifications in this manual are founded on this research and history of installations of the GSF worldwide.

  • Page 6: Gsf System Description

     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.

  • Page 7: Basic System Design

    Specified Sand is place in the trenches in contact with the native soils. The total depth of fill is determined by the elevation of the base of the GSF Specified Sand layer and should not exceed 24 inches above the ground surface Additional fill is placed between the trenches to an elevation of 12 inches above the module by using a light weight track machine.
  • Page 8 Refer to Sections 2.0 and 3.0 for level and serial piping details respectively. Secure pipe to GSF modules with provided wire clamps, one clamp per Eljen module with both legs of the clamp against the sides of the pipe.
  • Page 9 Septic Tanks: Many designers are now specifying dual compartment septic tanks or dual tanks installed in series for all their systems. Eljen supports this practice as it helps to assure long system life by reducing suspended solids and BOD to the absorption field area. Gas baffles or effluent filters are also recommended.

  • Page 10: Trench Configuration Sizing

    Table 2 has been adjusted to provide an Eljen required minimum of 5 modules per bedroom and has been rounded up to the next full module in systems that had partial modules as calculated to meet NYDOH sizing requirements.
  • Page 11 Estimate the number of GSF modules and define the row and trench length:  Use Table 2, on Page 10, of this manual and identify the number of GSF modules required for the system. Find the value where the percolation rate of the site intersects the number of bedrooms and the associated design flow of the dwelling.
  • Page 12 Figure 2: Example Sizing of a Trench System 3 bedrooms – 110 gpd/br – Percolation rate of 13 mpi ASTM C33 48" SAND 48" 36" SEPTIC NATIVE SOIL 4' MINIMUM 6" TANK ASTM C33 SAND 6" 2014 New York GSF Design & Installation Manual www.eljen.com...

  • Page 13: Bed Configuration Sizing

    This lower density of modules disperses the effluent from each row over a larger area and thereby reduces the application of effluent onto the soil. For very large beds call Eljen for more information on how the effluent can be managed to improve dispersion using gravity or dosed d-box designs.
  • Page 14 Absorption Bed Basal Area Required. 2. Use Table 4, on Page 13, of this manual and identify the total number of GSF modules for the system by finding the value where the percolation rate of the site intersects the number of bedrooms for the specified design flow of the dwelling.
  • Page 15 7.5 ÷ 2 = 3.75’ spacing between the center of the outside module rows and the side of the bed. Figure 3: Example Sizing of a Bed System 4 bedrooms – 110 gpd/br – Percolation rate of 15 mpi 12" 3.75' SEPTIC 7.5' ASTM C33 SAND TANK 3.75' 50.0' 2014 New York GSF Design & Installation Manual www.eljen.com...

  • Page 16: Repair And Replacement System Sizing

    Tables 5 & 6 are based on a minimum design flow of 150 gpd/bedroom. For lower flows, please contact Eljen Corporation for technical support.  Eljen recommends that Repair and Replacement bed systems are installed as “long and thin” as possible when site conditions allow. ...
  • Page 17 44  61‐80  0.50  25  100  38  152  50  200  13  52  81‐100  0.42  30  120  45  180  60  240  15  60  101‐120  0.33  38  152  57  228  76  304  19  76  2014 New York GSF Design & Installation Manual www.eljen.com...
  • Page 18 Absorption Bed Basal Area Required. 2. Use Table 6, on Page 17 of this manual and identify the total number of GSF modules for the system by finding the value where the percolation rate of the site intersects the number of bedrooms for the...
  • Page 19 Figure 4: Example Sizing of a Repair and Replacement Bed System 4 bedrooms – 150 gpd/br – Percolation rate of 20 mpi 12" 2.8' SEPTIC ASTM C33 SAND 5.625' TANK 11.25' 58.0' 2014 New York GSF Design & Installation Manual www.eljen.com...

  • Page 20: Gsf Sand Filter Design

    Contact Eljen if you have any questions on the design hydraulic splitting device. For dosed filter designs use 1 gallon per foot of media per dose. Contact Eljen if you have any questions on the source and design for these tanks.
  • Page 21 5.0 GSF Sand Filter Design Figure 5: Example GSF Sand Filter Cross Section GRADE FOR PROPER DRAINAGE VEGETATIVE COVER TOPSOIL 12" CLEAN BACKFILL 12" 12" ASTM C33 SAND 3" GRAVEL >= 4" >= 2" 4" COLLECTION PIPE >= 24" HIGH GROUND WATER...

  • Page 22: Systems Designed For Level Sites

    The pipe delivers effluent into the module rows and the transfer of effluent between full corrugations within the GSF module. In beds, the ends of the pipe are looped with solid wall SDR 35 or equivalent pipe at the distal (far) end of the bed as shown in Figure 15 of this manual.

  • Page 23: Systems Designed For Sloped Sites

    Module Placement and Spacing in Shallow Trench Configurations: Shallow trench designs use fill above the ground surface to protect and cover the GSF modules. Trenches are excavated after placement and stabilization of the fill material. In a sloped shallow trench configuration with Specified Sand on the soil surface, use a minimum of 48-inch spacing between adjacent module rows.

  • Page 24: Dosed Or Pumped Systems

    Examples are shown in Figures 17 and 18. Dosing Design Criteria: Eljen requires the dosing volume be set to deliver a maximum of 4 gallons per B43 module per dosing cycle with low head high volume pumps preferred. Lines longer than 60 feet are required to be dosed with a maximum row length of 100 feet as per the requirements of Appendix 75-A.7...

  • Page 25: System Venting

    As hot air rises and exits the home, it pulls fresh air into the GSF. To maintain this air flow, it is important that air vents are located only on the distal end of the GSF pipe network.

  • Page 26: Required Notes On Design Plans

    Eljen provided geotextile cover fabric shall provide proper tension and orientation of the fabric around the sides of 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: ...

  • Page 27: System Installation Guidelines

    You must use the Specified Sand as listed on Page 4 of this manual to ensure proper system operation.  Specified sand placed along both sides and across the top of the GSF module ensures aeration of the modules. Additional sand placed above the module is recommended to maintain oxygen transfer to the system.
  • Page 28 The compacted Specified Sand height below the GSF module must be 6 inches minimum. 7. A hand tamper is sufficient to stabilize the sand below the GSF modules. Set a level surface for each row of modules on the surface of the Specified Sand using a 2-inch x 4-inch board and carpenter’s level or a laser before placing the modules.
  • Page 29 16. Complete backfill with loam to 12 inches minimum over the GSF modules. Backfill exceeding 18 inches requires venting at the distal (far) end of the module row. Fill should be clean, porous, and devoid of large rocks.
  • Page 30 The compacted height below the GSF module must be 6 inches minimum. 8. A hand tamper is sufficient to stabilize the sand below the GSF modules. Set a level surface for each row of modules on the surface of the Specified Sand using a 2-inch x 4-inch board and carpenter’s level or a laser before placing the modules.
  • Page 31 14. Install the manufacturer supplied cover fabric. Cover fabric placement requires setting the tension and orientation of the fabric around the sides of the perforated pipe on top of the GSF modules. If the fabric is too loose, it blocks the effluent from draining into the modules. If the fabric is too tight, it could tear if punctured by a sharp object and allow soil and sand to fall into the open corrugations of the modules.
  • Page 32 The compacted height below the GSF module must be 6 inches minimum. 7. A hand tamper is sufficient to stabilize the sand below the GSF modules. Check the zero grade of the top of the sand using a flat piece of lumber and a carpenter’s level and/or a laser before placing the modules.
  • Page 33 13. Install the manufacturer supplied cover fabric. Cover fabric placement requires setting the tension and orientation of the fabric around the sides of the perforated pipe on top of the GSF modules. If the fabric is too loose, it blocks the effluent from draining into the modules. If the fabric is too tight, it could tear if punctured by a sharp object and allow soil and sand to fall into the open corrugations of the modules.

  • Page 34: Design For Replacement Systems

     High groundwater with infiltration into the septic tank or pump chamber.  Specified Sand that does not meet the requirements as outlined in the Eljen Design Manual.  Pump settings that overload the GSF or does not account for drain-back between doses.

  • Page 35: Trouble Shooting Gsf Installation

    Pump Systems:  Incorrect float settings discharge a high a volume or pumping rate to d-box and GSF system.  Too low float settings do not account for drain-back and results in repeat pumping of effluent.
  • Page 36 System Drawings Note: The details found within this manual are just a small example of potential system layouts. If you do not see a specific drawing (contoured system, mound, etc.) please contact Eljen Corporations Technical Services Department at 1-800-444-1359 for assistance.
  • Page 37 6' MINIMUM 6" TOP SOIL ORIGINAL GRADE USEABLE FILL ASTM C33 SAND 4' MINIMUM 24" MINIMUM TO LIMITING UNDERLYING ORIGINAL SOIL CONDITIONS OR RESTRICTIVE SOILS 1 - 60 MPI PERCOLATION RATE 2014 New York GSF Design & Installation Manual www.eljen.com...
  • Page 38 FIGURE 12: Trench Configuration for a Sloping Site / Avoiding Rock Outcrops and Trees SLOPE NOTE: D-BOX ON LAST ROW OPTIONAL. Note: Sum of trench length shall meet or exceed minimum trench length required in Appendix 75-A. 2014 New York GSF Design & Installation Manual www.eljen.com...
  • Page 39 LATERAL LINE DOWNSIDE SLOPE DROP BOX IN FLOW FROM SEPTIC TANK, OUTFLOW TO PUMP CHAMBE OR UP SLOPE DOWNSLOPE DROP BOX DROP BOX OR LAST GSF ROW OUTFLOW TO GSF LATERAL LINE 2014 New York GSF Design & Installation Manual www.eljen.com...
  • Page 40 (For Equal Length Hillside Trenches Only) 4" NON-PERFORATED SWEEP "T" FITTING VELOCITY REDUCTION PIPE DISTRIBUTION BOX WATER LEVEL 1.5" TO 3.0" DIAMETER LOW PRESSURE PIPE GSF MODULE SPEED LEVELER MINIMUM 2" DROP TO MODULES 2014 New York GSF Design & Installation Manual www.eljen.com...
  • Page 41 SPACING BETWEEN MODULE ROWS - 12" MIN SPACING BETWEEN BED SIDEWALL AND PERIMETER OF 12" MINIMUM MODULES VARIES WITH 12" MINIMUM SEPARATION BED LENGTH VARIES WITH EQUAL NUMBER OF MODULES PER ROW 2014 New York GSF Design & Installation Manual www.eljen.com...
  • Page 42 OUTLET PIPE TO GSF MODULE ROW DISTRIBUTION FORCE MAIN INLET PIPE FROM SEPTIC TANK NOTE: THE BY-PASS AIR LINE CAN BE PLUMBED INTO THE PUMP CHAMBER RISER OR SEPTIC TANK RISER. 2014 New York GSF Design & Installation Manual www.eljen.com...
  • Page 43 ASTM C33 ASTM C33 SHRUB MOUNDED BACKFILL OVER MODULES 22.5 DEGREE FITTING 90 DEGREE ELBOW OR TEE FITING GSF MODULES ASTM C33 SAND COVER FABRIC NOT SHOWN OVER DISTRIBUTION PIPE AND MODULES 2014 New York GSF Design & Installation Manual www.eljen.com...
  • Page 44 ASTM C33 specification; or any other event not caused by Eljen Corporation. System owners shall consider the modules as single use, and re-use of modules that were previously installed in an activated on-site system shall void this Limited Warranty.
  • Page 46 In the mid-1980s, we introduced our Geotextile Sand Filter products for the passive advanced treatment of onsite wastewater in both residential and commercial applications. Today, Eljen is a global leader in providing innovative products and solutions for protecting our environment and public health.

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