SU0000060 SSNL - Laserfiche WebLink

Home Browse Search

1991, the predominate land use to the south-southwest (upgradient from the subject site) is agricultural production. There is medium density housing in the area of South Avenue and Cottage Avenue, also upgradient from the subject property. The following Table summarizes the analyses of the wells tested to complete the nitrate impact investigation. The Laboratory test results can be found in the Appendix: Well Location Approximate I owl Nitrate Chloride DBCP/EDB Age of Well Dissolved Solids 9330 E.Lathrop Rd. Approx.30 376 ppm 41 ppm 12 ppm Not Detected Kamper Domestic Well yrs. (ND) Kamper Irrigation Approx.40 240 ppm 30 ppm 9 ppm Not Tested Well yrs. 9351 E.Lathrop Rd. Approx. 15 288 ppm 26 ppm 21 ppm Not Tested yrs. 14972 S.Austin Rd. Approx 40 320 ppm 45 ppm 18 ppm Not Tested yrs. Well Logs for each of these wells were not available either from the Environmental Health Department or the owners. The test results indicate nitrate impact approaching and equal to, the Maximum Contaminant Level(MCL)of 45 ppm for the two older,shallow wells(Kamper Domestic Well and the Austin Road Well). Being a deeper well,and probably drawing water from the end of the casing,the Kamper Irrigation Well shows a lower nitrate level. The well at 93 51 E.Lathrop Road was probably installed to a deeper depth and grouted 100 feet, and therefore reveals a lower nitrate concentration. Because nitrate in groundwater originates from primarily sewage and agricultural inputs,its presence in groundwater can infer contamination from either or both of these sources. However, septic systems also contribute chloride to the groundwater. Chloride travels as readily as nitrate in the vadose and saturated zones and can be the first indicator of septic contamination. Therefore, high nitrate concentrations together with high chloride is a more positive indicator of septic influence than nitrate alone. A normal human eliminates an average of 6 grams of chloride per day. The chloride concentrations in most groundwater formations averages 6 mg/l. The typical concentration of chlorides in untreated domestic wastewater is 50 mg/1, with the range being 30-100 mg/1. vaffq Ag Re-search