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Bird Road Facility Page 7 of 13 <br /> Project Number: E07183A <br /> November 30, 2007 <br /> of water above the bottom level of the percolation test hole. The readings were taken every 30 <br /> minutes for a period of four hours. <br /> I.6.6 Percolation Test Forms and Results <br /> The completed percolation test form is included in the appendix of this report. <br /> A shallow percolation test is defined by the EHD as being between 36 and 42 inches in depth; a <br /> satisfactory percolation rate for a shallow test is less than or equal to 60 minutes per inch drop. <br /> A deep percolation test is defined as being between 3.5 and 25 feet in depth; a satisfactory <br /> percolation rate for a deep test is 30 min/in or less. One percolation test must demonstrate a <br /> satisfactory percolation rate within the proposed septic system disposal field of each parcel to <br /> utilize a standard septic system. Details of the percolation tests are summarized in the table <br /> below. <br /> Table 3 <br /> Sum ary of Percolation Tests. <br /> Test No., Percolation Test Percolation Rate Test Duration Comments <br /> Date Tested Depth (ft.) (minutes/inch) (see notes) <br /> 11-20-07 3.3 9.61 4 hr. Satisfactory Perc Rate <br /> Note: A satisfactory percolation rate for a"shallow"test is less than or equal to 60 minutes per inch. <br /> +.. A satisfactory percolation rate for a"deep"test is less than or equal to 30 minutes per inch. <br /> I.6.7 Discussion of Percolation Test Results <br /> The soils within the sewage disposal areas of the site have demonstrated a satisfactory <br /> percolation rate in accordance with the requirements of the EHD for the use of a standard <br /> septic system. <br /> I.6.8 Discussion of Septic System Sizing <br /> ` Septic system construction should follow the San Joaquin County On-Site Wastewater Disposal <br /> Standards where applicable. <br /> II. NITRATE LOADING STUDY <br /> Because of concern regarding nitrate leaching into ground water from septic systems, a nitrate <br /> loading analysis was required by the EHD for the proposed development to measure the <br /> potential concentration of percolating effluent and rain fall over the long term. Where <br /> percolating effluent leaches into the ground, ground water quality may be impacted to some <br /> degree should the effluent reach ground water. <br /> The method utilized for the nitrate loading analysis is based on a simple mass balance formula, <br /> discussed in a published article by Hantzsche and Finnemore (1992), which provides a <br /> convenient and simplified method to estimate long-term ground-water nitrate impacts on an <br /> area-wide basis. <br /> 902 Industrial Way•Lodi,CA 95240•209.367.3701 •Fax 209.369.4228 ©2007 Neil 0,Anderson&Associates,Inc <br />