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C. PERCOLATION TEST RESULTS SSS§ 6.2. To assess the permeability at the 42-inch test depth, the percolation test boring was completed in the location depicted on the Site Plan map found in Appendix C. 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 September 30, 2019,percolation testing commenced at 0700 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. The test results indicate a rapid perc rate given the sandy loam soil structure at test depth, of 10.9 min/in. A perc rate of<60 min/inch,>5 min/in is considered acceptable and a rate slower or faster than this must have the system designed and certified by a CA registered civil engineer. The project site is in the"High Water Table Areas"as denoted on the Septic System Requirements Soils Map where leachlines and filter beds are permitted. Consequently, a filter bed has been stipulated for this project. 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 40 INCH DEEP PERC TEST BORING 10.9 min/inch / 0.786 gallons/ft'/day PERCOLATION RATE/APPLICATION RATE OFFICIAL PERC TEST Application Rates adapted from Waste Quality Control for Siting,Design,Operation and Maintenance of On-site Wastewater Treatment Systems,based on the Perc Rate. D. GROUNDWATER INFORMATION 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 25 and 35 ft below grade. Only in 2008 was the depth of the water table approximately 18 ft below grade. The Lines of Equal Elevation Maps illustrates the groundwater directional flow to be in a northeasterly direction. NLS§2.2,3.1, SSS§2.1,4.2. Since the subject Parcel and surrounding properties have been farmed for a number of decades,the potential for nitrate contamination to the underlying groundwater aquifers can be considered significant. Page -3- Chesney Consulting