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} 07/13/2005 08:23 FAX - la 0111028 <br /> K1. I-IN17r3. €'. 1: <br /> R W Average recharge rate of rainfall = 9.2 inches per year (representing 30 <br /> percent of the average annual rainfall of approximately 11.5 inches. The <br /> remaining 20 percent of rainfall is assumed to drain off-site into natural or <br /> manmade drainages or be lost to evapotranspiration_) <br /> Nb = Background nitrate nitrogen concentration of rainfall recharge at the water <br /> table = 0.5 mg/l (per Technical Memorandum, Hydrologic and Soil <br /> Investigation for the Chico Urban Area, page 6, Dames and Moore, April <br /> 1996) <br /> f <br /> A Number of dwelling units per acres on septic tanks within a square mile <br /> around the proposed Sikh Temple (unittacre) = 0.17 (estimated based an 54 <br /> lots, assuming 2 homes per lot (108 homes total), divided by (640 acres -- <br /> 5.83 acres)} <br /> W = Annual wastewater loading per dwelling unit per acre (inches) = 0.68 inches <br /> (based on 300 gpd/residence) <br /> Our calculation that includes both the proposed temple, the existing home, and <br /> considering a square mile around the site is as follows= <br /> i <br /> N, = 2.76(15)(9-0.2) + 9.2(D.$)__ ............( _1,7)(0. _(1-0,2)...+ 9.64.z _ . 4 r�, r. 5 l <br /> (2.76 X9.2) (0.17)(0.68) + 9.2 <br /> Given the above fa;tors, we estimate that the proposed Sikh Temple would require an <br /> .average wastefsewage flow of 8850 gal./week in order to exceed the state drinking <br /> water standard for nitrogen (N)of 10 mg/1 in groundwater. <br /> 10, CONCLUSIONS <br /> The results of our percolation tests indicate that a suitable soil percolation stratum <br /> does exist at the percolation test location at the SJCEHD approved depth tested of <br /> about 3 feet below existing site grade, A test was not performed in a deeper stratum <br /> due to the presence of groundwater at approximately 7 feet and the 10-'foot separation <br /> requirement between groundwater and the bottom of percolation tests greater than 42 i <br /> inches, A suitable soil condition is defined as a stratum capable of percolating water <br /> at a rate of 60 min/inch or faster at shallow depths and 30 min/inch for deep tests. <br /> As previously mentioned, there was not a concentration of DBCP found in .the <br /> groundwater in detectable amounts. <br /> The concentration of nitrate-nitrogen (N) in the groundwater was above the state <br /> standard of 10 mgll. Based on these results and the results of our nitrate loading <br /> 71UOL.0°}1IST05R75D July 13,2006 <br /> Copyright 2006 Klcintotdor,Inc, Pogo 7 of 9 <br />