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Per San Joaquin County Environmental Health Department's definition, a shallow <br /> percolation test hole has a depth between 18 and 42 inches; a satisfactory percolation <br /> rate for a shallow test is greater than or equal to 1 minute per inch (min/in) but less than <br /> or equal to 60 min/in drop. A deep percolation test hole has a depth between 3.5 and <br /> 25 feet; a satisfactory percolation rate for a deep test is greater than or equal to 1 min/in <br /> but less than or equal to 30 min/in drop. For the Site to utilize a standard septic system, <br /> one percolation test must demonstrate a satisfactory percolation rate within the <br /> proposed septic system disposal field. <br /> Details and results of the percolation testing are summarized in the following table. <br /> Table 2. Percolation Test Summary <br /> Test No., Percolation Test Percolation Rate Test Duration Comments <br /> Date Tested Depth (ft.) (minutes/inch) (see notes) <br /> P1-S, Satisfactory perc. <br /> 7/13/23 1.81 3.79 1 hr. <br /> rate' <br /> Shallow Test <br /> P1-D, <br /> 7/13/23 4.48 62.5 4 hr. Insufficient perc. <br /> Deep Test rate <br /> Note: A satisfactory percolation rate for a "shallow"test is greater than 1 but less than or equal to 60 minutes per <br /> inch. A satisfactory percolation rate for a "deep"test is greater than 1 but less than or equal to 30 minutes <br /> per inch. <br /> 1 Per San Joaquin County Environmental Health Department, a rate between 1.0 and 5.0 min/in requires a <br /> 20-foot separation between the bottom of dispersal system and ground water, or mitigation by system <br /> design or enhancement. <br /> Discussion of Percolation Test Results <br /> The shallow soils near the proposed septic disposal area for the new house on the Site <br /> have demonstrated a satisfactory percolation rate for the use of a standard septic <br /> system in accordance with the requirements of the San Joaquin County Environmental <br /> Health Department. The percolation test is considered representative of soils within a <br /> 100-foot radius of the test location. <br /> Because of the percolation rate between 1.0 and 5.0 min/in encountered in the test <br /> hole, the San Joaquin County Environmental Health Department will require a 20-foot <br /> separation from the bottom of the dispersal system to ground water, unless mitigated by <br /> system design or enhancement. Given the estimated depth to water of 50 to 63 feet, no <br /> modification to standard systems should be necessary to meet this requirement. <br /> LOGE 2325 Page 7 <br />