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1 <br /> On January 3, 2019, percolation testing commenced at 1100 hrs. No standing water was observed <br /> after the 24-hr soak period. Consequently, EHD Perc Test Procedure#2 was conducted. Testing <br /> was done over a four-hour period to induce maximum soil saturation. <br /> I <br /> The test results indicate acceptable permeability at 20.8 minutes/inch. A summary of the perc test <br /> results with corresponding application rates in gallons of effluent accepted per square foot of soil per <br /> day are illustrated in Table 2: <br /> TABLE 2 <br /> PERCOLATION TEST RESULTS WITH CORRESPONDING SOIL TYPE, <br /> PERCOLATION RATES AND APPLICATION RATES IN GALLONS/FT'/DAY <br /> 36 INCH DEEP PERC TEST BORING <br /> SILT LOAM 20.8 min/inch / _0.643 gallonsdt2/day <br /> PERCOLATION RATE/APPLICATION RATE <br /> Application Rate adapted from California State Water Resources Control Board OWTS Policy and is derived from the Perc Rate. <br /> III. GROUNDWATER/DOMESTIC WATER INFORMATION <br /> Groundwater information was pres iir the.tgroged <br /> Environmental Report and was <br /> estimated by them to be eigh 18 ft below the surface. <br /> IV. NITRATE LOADING MITIGATION MEASURES <br /> Actual nitrate loading mitigation measures are discussed below in this Section of the report. <br /> Parameters that contribute to, or have some control over nitrate loading are discussed first. <br /> Wastewater Flow Volume Projections <br /> To determine nitrate-nitrogen loading from any project, wastewater flow volumes must be determined <br /> as accurately as possible. Domestic flow volume projections have been approximated from the <br /> USEPA Onsite Wastewater Treatment Systems Manual, Pg. 3-4. Residential (domestic) flow volumes <br /> average approximately 69 gallons/person/day. The EHD specifies that each bedroom has the potential <br /> for two people, for an ADF of 140 gpd, 365 dpy. The proposed house will have four bedrooms. <br /> Therefore, total flow volume projection=4 x 140= 560 gallons wastewater/day. Considering that <br /> inhabitants of any given residential structure are rarely there 24/7/365 dpy,this flow volume creates a <br /> significant safety factor in the calculations below. <br /> Septic Tank Size Calculation <br /> Properly sized septic tanks store the accumulated sludge, scum and effluent(clear zone)volumes, <br /> which in turn affect treatment of nitrogen within septic tanks by lowing�N concentrations:The ratio <br /> of peak hourly flow to average flow gives the Peaking Factor used in the cafcua-tion below. It is <br /> generally accepted to be 1.9 for single family residential units. S6 we.0 <br /> i <br /> Page 3 of 13 <br /> Chesney Consulting <br />