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(0 IV. CPKCLUSIONS AND RECOMMENDATIONS SSS§ 5.4. The soils underlying the proposed effluent disposal area for the new Gurudwara Sahib Tracy Sikh Temple show acceptable permeability that can be considered acceptable for the short- term. For long-term effluent acceptance rate, the permeability of the soils will no doubt slow based r on the numerous factors described in this report. These include historical evidence based on repairs/ replacements/additions, biomat formation, groundwater table influences and the unknown characteristics of the wastewater. From the soil chemistry test results, it.appears that there is significant denitrification potential from I the 59-inch depth to the 77-inch depth,where saturated soils conditions were encountered. The 59- i inch depth nitrate-nitrogen concentration was found to be 22 ppm, which decreased to 9 ppm in the short distance of 18 inches. Additionally, the TKN concentrations show a continual decrease throughout the soil profile from a very high 1698 mg/kg at the soil surface to 307 mg/kg at the 77- inch depth, indicating substantial decrease in nitrate loading potential. NLS§ 4 SSS§ 6.7. -Due to the high(shallow)water-table, an engineer d moun effluent disposal—, , system must be installed for this project. The exact dimensions and size f this stern is currently unknown, and it may be that changes may have to be made to parking areas and possible structure I , footprints. The sand basal area will create a"pre-treated"effluent before it enters the native soil. As referenced above, effluent that may nitrify may theoretically denitrify at the observed soil depths (59" -77")where denitrification appears to be occurring. SSS§ 6.8. The Average Daily Flow for Phase H is calculated to be 472 gals/day from the Sikh Temple and Kitchen. The Application Rate at the native soil-efflue interface is presently 0.545 gals/ft'/day based upon the observed infiltration rate. With a preliminary disposal area as depicted on the Site Plans of approximately 52 ft N-S x 50 ft E-W =2,60 - 2 soil-effluent interface should accept the anticipated effluent flow readily. Even with a pgfierm Ac tance Rate (LTAR) of 0.2 ! gals/ft2/day still gives an ADF of: 2,600 ft' x 0.2 gals11 2 520 gpd. NLS§ 4.1. The nitrate loading potential for Phase H of the projec 'n ' ate lie per olating effluent may have a resultant nitrate-nitrogen concentration of 13.7 ppm, rhi exceeds the aximum Contaminant Level (MCL). As referenced, however, the percolati ' effluent s Id produce a dilution effect to this nitrate concentration. It is important to recogn' hen adding one concentration of a solute (i.e.,NO3-N concentration determined in the effluent recharge) to another concentration of a solute(i.e., NO3-N concentration determined in the underlying water table),where both solutes are in ppm, the result is not cumulative or the sum of the two solutes. Parts per million is amass ratio (mg per106 mg). For example, the Nr(the resultant average concentration of nitrate- .'r.:. nitrogen in effluent recharge in pprn of NO3-N), was determined to be 13.7 ppm by the Hantzsche- Finncmore Equation. This equals 13.7 milligrams of nitrate in 106 milligrams of water(one liter). If this 13.7 ppm concentration is added to the same volume of water(1 x 106 milligrams) of the concentration determined from the underlying water table where the sample was taken from,which I was 21.8 ppm NO3-N (97 ppm NO3), then the resultant concentration is now: 13.7 milligrams per n liter+ 21.8 milligrams per liter= 35.5 milligrams in 2 x 106 milligrams (2 liters, or parts per 2 C , k million) of water. r' E 16 I Chesney Consulting