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C. PERCOLATION TEST RESULTS i SSS§ 6.2. To assess the permeability at the 36-inch test depth, the percolation test boring was completed in the location depicted on the Site Plan map found in Appendix C. j i SSS§ 6.3. After drilling,two inches of pea gravel was placed at the bottom and a three-inch perforated PVC pipe was inserted in the test boring. After these procedures,the boring was pre- saturated with 12 inches of water approximately 24 hrs prior to the start of testing. SSS§ 6.4, 6.5. On May 25, 2022,percolation testing commenced at 0600 hrs. No standing water was observed after the 24-hr soak period. Consequently, EHD Perc Test Procedure#2 was conducted. Testing was done over a four-hour period to induce maximum soil saturation. I The test results indicate a relatively rapid perc rate of 17.9 min/in considering the clay loam soil structure. A perc rate of<60 min/inch,>5 min/in is considered acceptable. A rate slower or faster than this must have the system designed and certified by a registered civil engineer. Although the project is in the".High Water Table Areas"as denoted on the Septic System Requirements Soils Map,the standing water level (SWL) in the onsite well was measured at 77.2 ft from the well's top of casing(TOC). Leachlines and filter beds are permitted in this area, consequently, a filter bed has been designed for this project which will provide the most environmentally beneficial system. A summary of the perc test results with corresponding application rates in gallons of effluent accepted per square foot of soil per day are illustrated below in Table 2: TABLE 2 PERCOLATION TEST RESULTS WITH CORRESPONDING APPLICATION RATES IN GALLONS!FTS/DAY 36 INCH DEEP PERC TEST BORING 17.9 min/inch / 0.686 gallons/ft2/day PERCOLATION RATE/APPLICATION RATE OFFICIAL PERC TEST Application Rates adapted from Waste Quality Controlfor Siting,Design,Operation and Maintenance of On-site Wastewater Treatment Systems,based on the Perc Rate. D. GROUNDWATER INFORMATION I NLS§2.1,SSS§4.1. Groundwater depths throughout San Joaquin County are illustrated on maps published by the County Flood Control and Water Conservation District. The 2000 through 2008 and 2012, 2015, and 2016 Lines of Equal Depth Map indicate the groundwater under the property to fluctuate between 20 and 35 ft below grade. The Lines of Equal Elevation Maps illustrates the groundwater directional flow to be in a westerly and northeasterly direction. These maps are found in Appendix D. NLS§2.2,3.1,SSS§2.1,4.2,4.4,4.5,4.6. Since the surrounding upgradient properties have been farmed for a number of decades,the potential for nitrate contamination to the underlying groundwater aquifers can be considered significant. This was confirmed by the water well analysis. Chesney Consulting