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r�� PERCOLATION TEST RESULTS SSS§ 6.2. To assess the permeability of the effluent receiving soils, a perc test depth of 36" was drilled in the location of the proposed primary filter bed as depicted on the Site Plans. SSS§6.3. After drilling, the sidewall of the boring was scored with a pry-bar to open potentially smeared soil surfaces. 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 January 24, 2019,percolation testing commenced at 0900 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 relatively rapid perc rate of 13.6 min/in,which was to be expected given the sandy soil type at test depth. 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 SOIL TYPE, PERCOLATION RATE AND APPLICATION RATE IN GALLONS /FT'/DAY 36 INCH DEEP PERC TEST BORING 13.6 mionch / 0.743 gallons/ft'/&N LOAMY SAND GROUNDWATER INFORMATION ��,,r`� NLS§2.1, SSS§ 4.1. Groundwater depths and elevations throughout San Joaquin County are '' 1 illustrated on maps published by the County Flood Control and Water Conservation District. he Fall 2016 Lines of Equal Depth Maps and the Lines of Equal Elevation Maps indicate groundwater depth and directional flow. Depth to groundwater is approximately 38 ft belo grade and the groundwater directional flow appears to be in a northwesterly direction. ��o NLS§2.2,3.1, SSS§ 4.2. Surrounding agricultural properties are currently farmed and h ve been for decades, and surrounding properties have been on septic systems so the potential for ni ate contamination of the underlying groundwater can be considered significant. NLS§2.3, SSS§ 4.3,4.4,4.5. The domestic well on the property was sampled at the well head and t alkalinity and nitrate. The alkalinity is low at 106 mg/L and the nitrate concentration is 4.57 mg/L. e Well Log for this well is found in the Appendix C and illustrate clay stratum from -with continuing intermittent sand, clay and shale strata down to 210 ft. This clay stratum offers some protection from the downward migration of nitrate by preventing nitrification and promoting denitrification. Page -3- Chesney Consulting