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Lineal Feet of Leachline(LFLL)= 1,200 BTC+84 ADF x 0.200 Soil Factor based on the perc test results indicating a sandy loam soil at 24 inches below grade where the soil-effluent interface will occur=260 LFLL Filter Bed Are� 260 z 3(S dy Loam Soil Factor)_ 780 square ft(28 ft sqr rectangle totaling 780 sq ft),or 3-90 it Leachlines can be installed. The leachfield/filter sposal area has sufficient area for both the primary disposal areas and the 100% replacement areas. Total area(including separation distances between the primary filter bed and the 100% replacement filter bed)must be 66 ft wide x 30 ft long= 1,980 sq. ft. Since the adjacent stormwater retention basin is less than six feet deep,the disposal areas can encroach within 10 feet of this basin. V. CONCLUSIONS AND RECOMMENDATIONS S §5. 6.8. The soils underlying the area proposed for wastewater effluent disposal show acceptable peeability at the shallow depths of 24 to 36 inches below gra rom the soil chemistry test results, it app there is some denitrification potential from the soils,b t not significant as has been observed in other areas of San Joaquin County. Diminished denitrification ten al can mostly be attributed to a lack of substantial clay content within the soil environment,which would cause anaerobic microsites where denitrification can occur. NLS§4.2, SSS�6.7 Since the water table is shallow in this locale at approximate)Q675ft elow grade,a filter bed efflue isposal system is recommended and will allow the greatest distanwe the soil- effluent interface and the depth to the water table. The minimum distance is generally regar ed to be five feet. Consequently, filter beds are the best option for the septic system disposal structure to be installed for / this project. Additionally,by installing the filter bed as high in elevation as possible,evapotranspiration may be expedited and downward migration of nitrate may be impeded. Additionally,a filter bed reduces the footprint of the disposal area in comparison to conventional Leachlines. The new modular building should be installed as high in elevation as practical and/or have the influent wastewater lines plumbed through the foundation of the building. This is to ensure that the septic tank is high in elevation so there is sufficient fall between the tank outlet and the furthest disposal point without exceeding the maximum allowable filter bed depth(24 in.)and allowing for gravity flow. The general contractor,plumber and septic system contractor must coordinate on these construction details. The filter bed sizing requirement calculations demonstrate there is ample area as denoted on the 4 Creeks Engineering Site Plans for the primary disposal and the 100%replacement areas. The exact dimensions of the filter bed systems may be orientated prior to construction to conform with the setbacks from parking areas, fence lines,and the nearby stormwater retention basin. NL §4.1. he nitrate loading calculations demonstrate that if the men's and women's toilets in the mo ular ilding were flushed a combined 48x per day(1.5 gals/flush x 48 flushes+0.25 gals for hand wash =84 gpd ADF),the nitrate loading remains well below the Maximum Contaminant Level(MCL). Considering there is currently 314 ppm nitrate in the water table,the amount of nitrate emanating from the disposal area of the new building will contribute a negligible amount of nitrate in comparison to the current water table nitrate concentration. It is imperative that any food and food by-product wastes from the modular building are handled as solid wastes and not be disposed of into the septic system. This will prevent concentrated organic loading, prolong the lifespan of the wastewater disposal system and reduce nitrate loading potential. 9