SU0003868 SSNL - Laserfiche WebLink

Home Browse Search

bw February 6,2006 NOA Project Number: E05173A Page 5 4.0 GROUND WATER INFORMATION 6. 4.1 Ground Water Depth and Gradient The San Joaquin County Flood Control and Water Conservation District (1998 and 1999) ground ` water depth and elevation maps were reviewed to determine the ground water levels near the Site. The Fall 1998 and Spring 1999 maps are the most current maps available from the County. ` Examination of these maps indicates that no water level da i-":i, ble for the Tracy/Banta area, which includes the Site,and no definite comments as to depth or gx dient flow direction can be made. The depth to water in this area is typically ab 't't 8�ee The depth to ground water below the site is not known. 4.2 Potential Ground Water Contamination Issues Identifying potential ground-water contamination sources was not part of the scope of work for the sod suitability study. L Potential ground-water contamination can occur from a number of sources which often include leaky underground storage tanks, agricultural activities, dairies, septic systems,and stottn water inSltration.,---� Any past agricultural activities and the present use of septic systems in the area should be considered potential ground-water contamination sources. Please see section 4.3 for additional water quality details. 6o 4.3 Water Sample Location (Three water w_ 'st on the subject property. A nitrate and DBCP well water s was collected otn dmesttc water w head located at 33510 S. Koster Road,propose The water sample was anal6. yzed for nitrate d DBCP. Nitrate was found a 19.9 m NO3,az . below the taminant le (MCL�et by the US EPA of 45 mg/L 03. DBCP was not etected in the water sample. The an c reports prepared by Precision Enviro-Tech can be found in appendix of this report The presence of nitrates is not uncommon in shallow ground water aquifers in San Joaquin County / and other parts of the Central Valley. Nitrate in ground water occurs as a result of the application of fertilizers,livestock waste, and untreated septic tank waste. Nitrate is mobile and often accumulates in the shallow ground water zones. In the early 1900s,natural levels of nitrate in ground water were measured in forty- ee (43) ells throughout the Sacramento Valley by Bryan (1923). It was thought that ground water tlhat . e was close to "natural' conditions. Based on the work by Bryan,it is estimated that under"natural' r 5 r