SU0002188_SSNL - Laserfiche WebLink

Home Browse Search

Omega Vineyard,Phase I Page No:2 It is.-Pro"posed to utilize.shallow leach lines with dry wells on'the-ends•for on-site disposal of sewage effluent. The number and length of Ieach,lines and the-humber of dry wells has been determined based on the design flow and the results of thepercolation testing and calculations. - Following are the calculations supporting the proposed design. II'. Design Calculations Shallow Leach Lines: Initial'disposal of•effluent will be in hallow leach lines. The,four shallow percolation tests performed throughoutthe site had•rates.of 62.5;.83, 83 min/in, and no drop in the.last 30• min.,of test...The two testsperformed in the area of the proposed leach lines' had rates-of 83 min/in. and no drop.. Based on the results of the shallow tests; a design percolation rate of 100 min/i.n:was selected. .The-purpose of the following calculations is to determine an effluentapplication,rate for shallow leach lines (expressed in units of gal/day/ft. of leach:line} for a given percolation rate. Figure 3 in the Manual of Septic Tank Practice gives recommended square feet of absorption area required per bedroom for percolation•rates,varying from 0 to`60 min/in. By making the �followinassumptionsp -and calculation g ; percolation rates can be converted into clear water rates with units of.gai/day/ft? of absorption area: f _Assumptions: . ; Percolation�test hole diameter 10 in: Ave: depth of water in test hole = 3 : Calculations: To_corivertpercolation,rate with units of min/in to gal/day/W of absorption area,., the following-formula was used: A(6.23) R = Equation(1`-1 { rAS R = . . Converted rate,.gal/daylftz of absorption area " test percoIatiori rate,min/in. . A - Cross section area-of test hole, int As -, Average total sidewall and bottom.area in contact with water,.int, By assuming an.ef#lueni application"-rate of 100 gal/day/bedroom for the values in the = Figure 3 chart, fhe following Table 2 was produced which gives various clear water application rates and-the back calculated sewage_application factors'for different percolation.`rates. .