The Eljen GSF® is primarily used for leach fields where advanced treatment is needed to meet environmental needs. It is used in bed and trench designs.
The Eljen GSF® A42 (4-feet long by 2-feet wide by 7-inches high) requires a longer, thinner trench, which can be a benefit where site restraints and hydraulic needs are a prime consideration.
Made from lightweight recycled material, the GSF® leach field is engineered for superior strength. The Eljen in-drain, with its pre-fabricated modular units comprised of geotextile fabric and cuspated spacer cores, provides an alternative to conventional stone and pipe or chamber leaching systems.
Substantial effluent pre-treatment occurs within the biomat which develops on the 100-square feet of geotextile fabric and the 400-square feet of cuspated core surface area in each 12-square foot type B in-drain unit.
This internal passive pre-treatment protects both the soil long-term acceptance rate (LTAR) and groundwater quality while providing reduced system trench length or leach bed footprint. At 7" thick, in-drains provide the lowest product profile, thus reducing system finished grade.
Laboratory analysis of treated effluent extracted from below the in-drains has confirmed Eljen's claims of substantial effluent pre-treatment (over 50% BOD reduction) provided by the biomat at the geotextile fabric and cuspated core surfaces.
In-drains installed in a 6-inch layer of washed concrete sand can provide secondary treatment for typical septic tank effluent.