SU0004610 SSNL - Laserfiche WebLink

Home Browse Search

L February 4,2005 NOA Project Number: E040142A 4 No ground water was encountered by the staff of Neil O. Anderson&Associates,Inc. during the Ldrilling of the percolation test holes to a depth of three feet on December 2,2004. 4.2 Potential Ground Water Contamination Issues Identifying potential ground-water contamination sources was not part of the scope of work for the soil suitability study. However, the Site is a former dairy and other dairies are located near the L subject property. Dairies are known to be potential sources of nitrate contamination in the groundwater. Other potential ground-water contamination can occur from a number of sources which often ` include leaky underground storage tanks,agricultural activities, dairies, septic systems,and storm water infiltration. Any past agricultural activities and the present use of septic systems in the area should be considered potential ground-water contamination sources. L 4.3 Water Sample Location LNo permits were found for the subject property address of 279 Homestead Road during review on December 7, 2004. A water sample was taken from the pipe manifold near the well head near the house and bam L structures on Kasson Road (Plate 1) on December IG,2004. L4.4 Water Sample Constituents The water sample was analyzed for nitrate and DBCP. Nitrate was found at 38.9 mg/L-NO3,below Lthe maximum contaminant level (MCL) set by the US EPA of 45 mg/L-NO3. DBCP was not detected in the water sample. The analytical reports prepared by Precision Enviro-Tech can be found in the 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 Lof fertilizers,livestock waste,and untreated septic tank waste. Nitrate is mobile and often accumulates in the shallow ground water zones. L In the early 1900s, natural levels of nitrate in ground water were measured in forty-three (43) wells throughout the Sacramento Valley by Bryan (1923). It was thought that ground water at that time was close to"natural' conditions. Based on the work by Bryan,it is estimated that under"natural' f conditions ground water concentration containing nitrate is no more then about 13.5 mg/L-NO3 (3 6. mg/L-N). Areas having 24.75 mg/L-NO3 (5.5 mg/L-N) or more are those in which nitrate concentrations may be increasing (Hull, 1984). M L L 5 .,44 L