SU0002188_SSNL - Laserfiche WebLink

Home Browse Search

Omega Vineyard,Prase I 5 - , Page No.13, Table 2; Computed Effluent Application Factors for Percolation Rates of Figure 3,Manual of Septic Tank Practice r Percolation, Computed Clear Water Rate,(Equ. Ft'of Absorption Area. Effluent Application Factor, Rate,min/in . 1-1),gal/day/ft2 of absorption area Req'd Per Bedroom„Fig. 3 [100/(col. 1 x col.2)] i 10. 40.8 167 1.5% 20- 20.4 2 14 2.3% 30. 13.6 250. 2.90/6 40 1.0.2 284 3.5% .50 : 8.2 . 31.1 - 3.96/o .60 6.$ 329 4.5% It is assumed,that the increasing rate.of the application factor.as the percolation increases' is due to.the increased time that the effluent will be exp -t the soil. Consequently, an application factor of 5.0%.was selected for the design percolation rate of 100 min/in...Although Figure 3 is limited to 60 min./in percolation rate, the main reason for this is the problem of soil smeaning which occurs on the bottom and sides of the leach.lines during construction in increasingly clay soils. .Ifthe trenchesare excavated when the subgrade soil is not saturated(ie. winter or spring) and/or the sides and bottom are"racked" or scarified prior to gravel installation, then higher percolation rates can be designed for: For the design percolation rate of 100 min/in, the capacity for lineal foot of leach-line was computed'using equation(1-1): A(6.23) (78:5)(6.33) R = — — = 4.1 gal/day/ftz absorption area rAS (100)(1.20) ' Assuming a 2.0 foot wide shallow leach line has 3.0 ft' of absorption area per lineal-foot z of trench and a application factor of 5.0%, then the allowable capacity of the proposed shallow leach Iines.per foot of length(Cl) is as follows: ' Cr =R(3.0)(0.05) _ (4.1)(3.0)(0.05) — 0.6 gal/day/ft of length The design daily effluent flow rate, as computed in Table 1, is 350 gal/day. Itis proposed to utilize two (2);50 foot long leach lines with a dry well on the end of each. Based on the above computed leach line capacity(Ct),the total daily disposal capacity-of the two'leach lines (C,t) is as follows. Ct = C,(#and length fof leach lines) =0.6(2 x 50)'= 60 gal/day ' s r