SU0006798 SSNL - Laserfiche WebLink

Home Browse Search

r� LEACHLINE REQUIREMENT CALCULATIONS BASED ON SAN JOAQUIN COUNTY i SEWAGE STADARDS FOR COMMERCIAL SEPTIC SYSTEMS: N Base Tank Capacity= 1,200 gal. ADF =450 gpd achline Equivalent Requirement— 1,200 gallons BTC +450 ADF x 0.250 clay Soil Factor(SF) 413 lineal feet of leachline (LFLL) required. Existing and Proposed Seepage Pits (Excludes a possible leachline since it cannot be discerned): There are two known 48 inch diameter seepage pits. It is assumed that the other three pits are 33 inches in diameter. Mr. Mike Huggins, Program Coordinator for Unit 11 of EHD will require the installation of two additional 33 inch diameter seepage pits. Therefore the seepage pit equivalents are (from SJCEHD Sewage Standards): 2 new 33 inch diameter seepage pits — 2 x 60 ft of leachline= I.20 feet 2 existing 33 inch diameter seepage pits — 2 x 60 ft of leachline— 120 feet 2 existing 48 inch diameter seOpage pits = 2 x 90 ft of leachline = 180 feet 120 ft+ 120 ft+ 180 ft 4210 equivalent lineal feet of leachline, which exceeds the required LFLL calculated above. 100% Reserve Replacement Area: The 100% replacement area can easily be accommodated to the south of the primary leachfield area, into the vineyard. IV. CONCLUSIONS AND RECOMMENDATIONS SSS§ 5.4. The soils underlying the existing disposal area to serve the phased Hamey Lane Winery show poor permeability at a shallow leachline depth of 36 inches, but excellent permeability at a slightly deeper depth of 42 inches. The deeper subsurface soils contain a high moisture content down to 25 feet, and it is assumed the high moisture content extends below this 25 foot depth. NLS§ 4.2, SSS§ 6.7. From the soil chemistry test results, it appears that the denitrification potential of the soil is significant based upon the decrease in nitrate-nitrogen content through the soil profile. Denitrification potential maybe attributed to: l.) The heavy clay content of the subsurface soils and 2.) Directly observed high soil water content. The well water chemistry results obtained from the existing on-site domestic/irrigation well indicates the nitrate impact to the underlying aquifers is relatively low at 12 ppm nitrate. This low impact may be due to the fact that the well may be deep, and this aquifer water may be protected from intervening clay strata as observed on nearby well logs. SSS§ 6.7, 6.8. The information and data obtained from these Studies has revealed that the existing septic system, with the addition of two additional 3?inch diameter seepage pits, can be used for the for the Harney Lane Winery for all three proposed Phases. The Average Daily Flow is calculated to be 450 gals/day from the entire Harney Lane Winery project after phased build-out, which is very conservative. It is my opinion there is no need for an engineered system unless there are continual ( 7 failures. 10 Chesney Consulting