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LOGE 2155: Cox Percolation Testing Page 2 November 9, 2021 Registered Environmental Health Specialist at the San Joaquin County Environmental Health Department, observed the final 30 minutes of 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 hole was refilled with water to a level of approximately six inches above the bottom of the hole. Percolation Test Results The completed percolation test form is attached to this letter. The form was signed by Mr. Gooderham and indicates a percolation rate for the hole based on the final water drop observed. Per San Joaquin County Environmental Health Department's definition, a shallow percolation test hole has a depth between 1.5 and 3.5 feet; 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. For the Site to utilize a standard septic system, one percolation test hole must demonstrate a satisfactory percolation rate within approximately 100 feet of the proposed septic system disposal field. Details and results of the percolation testing are summarized in the following table. Table 1. Percolation Test Summary Test No., Percolation Percolation Test Duration Comments Date Tested Test Rate (see note) Depth (ft.) (minutes/inch) P1-S, Satisfactory 11/4/21 2.66 3.09 1 hr. perc. rate' Shallow Test Note: A satisfactory percolation rate for a"shallow"test is greater than 1 min/in but less than or equal to 60 min/in. 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. The soils on the Site have demonstrated a satisfactory percolation rate for the use of standard septic systems in accordance with the requirements of the San Joaquin County Environmental Health Department. The percolation test is considered representative of soils within an approximate 100-foot radius of the test location. Because of the percolation rate between 1.0 and 5.0 min/in encountered in the 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. Based on local ground water elevation and topography maps, ground water is anticipated to be encountered approximately 60 feet below ground surface at the Site; consequently, no modification to standard systems should be required.