Laserfiche WebLink
r77 <br /> B. SEPTIC TANK <br /> Septic tanks store accumulated sludge, scum and effluent(clear zone) volumes, which in turn <br /> affect treatment of nitrogen within the tanks. Detention time calculations demonstrate that when <br /> the maximum ADF is applied to the existing tank,there remains sufficient detention time: <br /> Detention Time Calculation: <br /> Detention Time= 1600 gal tank capacity x 0.70(30%volume lost to sludge/scum accumulation) <br /> 1.5 (Peaking factor)x 300 gals/day(ADF) <br /> Detention Time=2.5 days. The minimum acceptable detention time is 1.0 day. <br /> C. LEACHLINE/LEACHFIELD SIZING CALCULATIONS <br /> Base Tank Capacity(BTC)= 1,200 gal. Leachline Equivale equirement= 1,200 gallons BTC <br /> + 300 gpd max ADF x 0.250 clay loam Soil Factor(SFf� ineal feet of leachline(LFLL). <br /> 375 LFLL x 4 sf/ft= 1,500 sf. 3 - 60 ft LL= 180 ft x 4 sf/ft '720 sf. 3 - 2'Wx10'Lxl2'D sumps <br /> 308 sf x 3= 924 sf. 720+924= 1644 sf. Leachlines=44%, Sumps= 56%. <br /> D. 100% REPLACEMENT/RESERVE AREA <br /> When, and if, the replacement area is to be activated, it can be installed directly to the west <br /> primary disposal field, as noted on the plans. The replaceme_ nt area- r.bed_J <br /> �nnctni in, rl tr�ng�lar in chane Sizing: 375 LFLL x 4= 00 s.f. filter bed area. <br /> Filter bed dimensions: 46' E-W x 65' N-S = 1,495 s.f. <br /> IV. CONCLUSIONS AND RECOMMENDATIONS <br /> NLS§ 4.1. The nitrate loading calculations show the effluent from the proposed project will <br /> theoretically possess a nitrate-nitrogen concentration at one-third the Federal nitrate Maximum <br /> Contaminant Level (MCL) of 10 ppm nitrate as nitrogen, or 45 ppm as nitrate. A total nitrogen <br /> concentration equivalent to domestic sources, as referenced in the.scientific literature, was used in <br /> the loading calculations. <br /> SSS§ 5.4,6.8. The soils underlying the proposed leachfield area show a surprisingly slow <br /> permeability considering that the soil texture at test depth is composed of a silty loam soil. The <br /> slow permeability can be attributed to a tight and compact silt soil. Applying the effluent <br /> uniformly by capping the ends of the three standard perforated leachlme p'— ipe�s, thing the <br /> applica ion of effluerif&qq aZIy—over the entir�-eachl ne enc area wi a ow p imum a went <br /> management by the receiving soils. Sumps dve been specified at the en s 7�Va!s <br /> ach ii ne <br /> �cause�ie-project-is--in a sump area and not a seepage pit area, and the pronaccessible to <br /> a drill rig. --- - <br /> Page -8- <br /> Chesney Consulting <br />