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• or equal to 60 min/in drop. A deep percolation test hole has a depth between 3.5 and 25 feet; a satisfactory percolation rate for a deep test is greater than or equal to 1 min/in but less than 30 min/in drop. For the Site to utilize a standard septic system, one percolation test must demonstrate a satisfactory percolation rate within the proposed septic system disposal field. Details and results of the percolation testing are summarized in the following table. Table 2. Percolation Test Summary Test No., Percolation Test Percolation Rate Test Duration Comments Date Tested Depth (ft.) (minutes/inch) (see notes) P1-S, 1/16/2019 3.18 83.3 4 hr. Failed` Shallow Test P1-S (b) Satisfactory perc. 1/29/2019 3.15 35.7 4 hr. rate Shallow Test P1-D, Satisfactor;r perc. 1/29/2019 6.79 3.5 4 hr. rate Deep Test Note: A satisfactory percolation rate for a "shallow" test is greater than 1 but less than or equal to 60 minutes per inch. A satisfactory percolation rate for a "deep"test is greater than 1 but less than or equal to 30 minutes per inch. Only one test (shallow or deep) is required to pass within the proposed septic disposal area for the development to be approved for a standard septic system. 1 Per San Joaquin County Environmental Health Department, a rate less than 5 min/in requires 20' separation between the bottom of dispersal system and ground water, or mitigation by system design or enhancement. Discussion of Percolation Test Results The soils within the proposed sewage disposal area of the Site have demonstrated satisfactory percolation rates for the use of a standard septic system in accordance with the requirements of the San Joaquin County Environmental Health Department. The shallow test conducted on January 16, 2019 appears to have failed due to a problem with the hole; rainfall during the test and standing water nearby may have contributed to the problem. To ensure an accurate result, the test was repeated with a new test hole on January 29, 2019. On that date, both shallow and deep test holes demonstrated satisfactory percolation rates. Because of the rapid percolation rate encountered in the deep test hole, the San Joaquin County Environmental Health Department will require a 20-foot separation from the bottom of the dispersal system to ground water (see Table 2). Ground water is anticipated to be encountered from 74 to 90 feet below ground surface at the Site; consequently, no modifications to standard septic systems should be required. LOGE 1901 Page 6