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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, Satisfactory perc. <br /> 6/5/2026 2.08 6.94 1 hr. <br /> rate' <br /> Shallow Test <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. <br /> 1 Per San Joaquin County Environmental Health Department, a rate between 5.0 and 30.0 min/in requires an <br /> 8-foot separation between the bottom of dispersal system and ground water, or mitigation by system design <br /> or enhancement. <br /> Discussion of Percolation Test Results <br /> The soils near the proposed septic leach field for the new ADU have demonstrated <br /> satisfactory percolation rates for the use of a septic system in accordance with the <br /> requirements of the San Joaquin County Environmental Health Department. The <br /> percolation test is considered representative of soils within a 100-foot radius of the test <br /> location. <br /> Because of the percolation rates between 5.0 and 30.0 min/in encountered in the test <br /> holes, the San Joaquin County Environmental Health Department will require an 8-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 15 to 20 feet, no <br /> modification to shallow leach line or filter bed septic systems should be necessary to <br /> comply with this requirement. <br /> Discussion of Septic System Sizing <br /> Future septic system construction should follow the San Joaquin County On-Site <br /> Wastewater Treatment Systems Standards (2017) where applicable. In this area, only <br /> shallow septic systems are allowed. Additional considerations related to nitrate loading <br /> are discussed in the following section. <br /> LOGE 2637 Page 7 <br />