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LOGE 20-43: Ward-Crummey Percolation Test Page 2 September 5, 2020 Percolation Test Procedure Live Oak conducted the percolation test for the borings on September 1, 2020. Percolation test procedures conformed to San Joaquin County Environmental Health Department policy. Due to the soil types observed, a standard four-hour test was selected. Water level measurements were taken every 30 minutes during this four-hour period. Daria Afonskaia, Registered Environmental Health Specialist at the San Joaquin County Environmental Health Department, observed the percolation test. An electronic well sounder with a depth accuracy of 1/100th foot was utilized for the water level measurements. The water level was measured against a fixed reference point on the well casing. Measurements were recorded on the data sheet in decimal feet. When necessary after measuring the water level, the deep hole was refilled. Per San Joaquin County Environmental Health Department policy, the deep hole is allowed to be filled with water to a level of three feet above the most permeable soil stratum selected, (personal communication with Michael Kith, RENS, Program Coordinator, August 6, 2020). In this case, the stratum of coarse sand with silt and gravel from 8 to 16 feet bgs was selected. Percolation Test Results The completed percolation test form is attached to this letter. The form was signed by Ms. Afonskaia and indicates a percolation rate for the hole based on the least water drop observed. Per San Joaquin County Environmental Health Department's definition, a shallow percolation test hole has a depth between 36 and 42 inches; a satisfactory percolation rate for a shallow test is greater than 1 minute per inch (min/in) but less than or equal to 60 min/in drop. A deep percolation test hole has a depth between 42 inches and 25 feet; a satisfactory percolation rate for a deep test is greater than or equal to 1 minute per inch (min/in) but less than or equal to 30 min/in drop. For the Site to utilize a standard septic system, one percolation test (shallow or deep) must demonstrate a satisfactory percolation rate within the proposE�d septic system disposal field. Details and results of the percolation test are summarized in the following table. Table 1. Percolation Test Summary Test No., Percolation Test Percolation Rate Test Duration Comments Date Tested Depth (ft.) (minutes/inch) (see note) Pi-S No movement, 9/1/20 3.50 --- 4 hr. failed* Shallow Test P1-D Satisfactory perc. 9/1/20 24.92 2.5 4 hr. rate' Deep Test Note: A satisfactory percolation rate for a"shallow"test is greater than 1 min/in but less than or aqual to 60 minln. A satisfactory percolation rate for a"deep"test is greater than 1 but less than or equal to 30 minutes per inch. Only one percolation test hole(shallow or deep)is required to pass for the location to be considered acceptable for a standard septic system. 1 Per San Joaquin County Environmental Health Department,a rate between 1.0 and 5.0 min/in requires a 20-foot separation between the bottom of dispersal system and ground water,or mitigation by system design or enhancement.