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r7 1 October 4,2001. Job Number:LG00=287 Page 8 r Table 5: t Summary of SJC-County observed pereolation tests,July 1.0=1.1,2001. (See Plate No. 1 for Locations) r Test No., Percolation Percolation Rate Comment Date Tested Test Depth(ft) (m:inuteslinch) 2a,July 11,2001 2.5,. . 8i min/inch Failed to achieve satisfactory percolation rate. ^- Passing rate for shallow test is<60 min/in 2b,July 11,2001' .5 62.5 min/inch Failed to achieve satisfactory percolation rate. Passing rate for deep testis<30 min/.in. { 2c,July.l 1,2001 5 250 minhnch Failed to achieve satisfactory percolation rate. Passing rate for deep test is<30 min/in. 3b,July 11,2001 5 no movement Failed to achieve satisfactory percolation rate. Passing rate for deep testis<30 min/in. Note: Shallow test is 0-to 42 inches,deep test is 42 inches to 25 feet. Considering the disappointing percolation test results, it was decided to pursue an engineered septic system that will mitigate the existence of clayey soils..Two locations for an engineered system were considered; first location was selected was at the existing septic system at the milk barn building, second location.was at the northeast cornet of property:. Percolation tests.were- erformed:at these locations. The existing 25-foot boring was retested at the milk barn utilizing an alternative 'Method for percolation testing. A 3.5-foot boring at the milk barn was also evaluated with a method similar to the SJC PHS-EHD percolation test. The northeast comer was evaluated with one 25- foot boring and two 3.5-foot borings. The 25-foot boring also utilized an alternative method for ,percolation testing. Both 3.5 foot borings utilized a method similar to the SJC PHS=EHD percolation test. The alternative method:mentioned previously consists of filling the deep boring to'about 3 or 4 feet below the ground surface with water and measuring the percolation rate of the entire tom_. boring. The testis run until the rate stabilizes to within l0 percent. The percolation rate is extrapolated to estimate:the capacity of a fully functioning seepage pit. Under a cons ellation permit, Ted Nor and of ob ed ercolation test. Only the percolation rate is presented in this.report,.the extrapolation will be presented with the engineered septic system ' design. Ted Norgard indicated that the milk barn location may be unsuitable for a septic system if the water well is to be considered a future public water supply due to well setback, ` requirements. Copies of the percolation tests.for engineered septic system are attached'to this. x R o F ,