Laserfiche WebLink
08/28/2006 13:48 FAX fM008%027 <br /> n <br /> H ; <br /> We do not know of any existing and/or potential groundwater contamination issues in <br /> the project vicinity. There are no existing gas stations or dairies adjacent to the <br /> property. Seasonal fertilization of the off-site agricultural land, if performed, and other <br /> septic tank/leach field systems in the project area are probably the largest contributor <br /> of nitrogen to groundwater in the project vicinity. <br /> i <br /> 7. SOIL PROFILE <br /> The subsurface soil encountered in our soil profile boring consisted of brown, fine <br /> grained silty sand to a depth of approximately 6 feet below site grade, Rollawed by tine <br /> grained relatively "clean" sand to a depth of about 121/2 feet. The sand was underlain <br /> by sandy silt to a depth of about 13'/2 feet, followed by a strata of silty clay to the depth <br /> explored. <br /> The Soil Survey of San Joaquin County, California published by the U.S. Department <br /> of Agriculture, Soil Conservation Service (1992) refers to the near-surface sail wiftn <br /> the western area of the project as belonging to the Bisgani Loamy Coarse Sand soil <br /> series (Map Symbol 109) and the soil within the eastern area of the project as <br /> belonging to the Tinnily Loamy Coarse Sand soil series (Map Symbol 255). This sail is <br /> described as having "moderate" percolation characteristics for septic tank absorption, <br /> Other attributes are given in the table below: <br /> Map <br /> Available Water Organic Content, <br /> SSoil Name Capacit , PH percent <br /> ymbc1 j <br /> -- -.... BI5 +3nE LO... <br /> Incheslinch <br /> - ...... .......... _-w.W.......-. ...--.._..................- ....... ..... <br /> Loamy e Sand 0.06-0.08 7.4-8.4 1-3 <br /> 205 Tinnin lwoarr Coags ,,.._._ ;_...___ .__.-.."" ._........ <br /> -5 e Sand 0-05-0.0? i.. <br /> 8. PERCOLATION TESTING <br /> The result of our percolation test is presented below. A copy of our field percolation <br /> test result is attached. <br /> TestNumber1 Soil Description Test Hale .' perces ate � SJCE HD Approved <br /> depth <br /> P-1 j Silty Sand 3.2 i 1.7 i Yes <br /> 9.. NITRATE LOADING CALCULATIONS <br /> Per SJCEHD requirements, the following summarizes our nitrate loading Calculations <br /> for the proposed leach field. The state drinking water standard for nitrate is 45 <br /> milligrams per liter (NO3) and 10 reg/1 as Nitrogen (N) in groundwater. In our a <br /> evaluation of nitrate loading, we have used the Hantzsche mass balance equation <br /> 7 3?.h.Cpir�;f(yGFtO�t June 29 2000 <br /> Coppicght 2000 Kfninfoidaf, Ine. P,3go 4 of 8 <br />