SU0011793_SSNL - Laserfiche WebLink

Home Browse Search

Soil Suitability/Nitrate Loading Study 1rerracon Proposed Global Carrier Inc. ■ Manteca, California August 8, 2018■ Terracon Project No. NA187034 In the early 1900s, natural levels of nitrate in groundwater were measured in forty-three (43)wells throughout the Sacramento Valley by Kirk Bryan (1923). It was thought that groundwater at that time was close to "natural" conditions. Based on the work by Bryan, it is estimated that under "natural" conditions, groundwater concentration containing nitrate is no more than about 13.5 mg/L-NO3 (3 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). DBCP (dibromochloropropane) is a nematocide and soil fumigant for vegetables and grapes. It is thought to cause health problems consisting of kidney damage, liver damage, and cancer. The use of DBCP was discontinued in 1979. EDB (ethylene dibromide) was used in gasoline to prevent lead deposits and build up. It was also used in pesticides and fumigants. Exposure to EDB is linked to many adverse health effects stemming from organ damage to cancer. Agricultural activities, industrial activities, and the use of septic systems in the area should be considered potential groundwater contamination sources. The concerns for groundwater contamination in this area are deemed moderate to high due to the depth to groundwater of 30 to 50 feet bgs and sandy soils in the area. 1.4.3 Water Sample Location On June 25, 2018, two groundwater samples (GW1 and GW2) were collected from a faucet located on the north side of the residence. The domestic groundwater well is located south of the residence garage. Refer to Appendix A, Exhibit 2 for groundwater sample and well locations. 1.4.4 Groundwater Sample Analysis Groundwater sample GW1 was collected into a 125 milliliter(mL) plastic bottle and groundwater samples GW2 were collected into four clean glass VOAs containing ascorbic and meleic acid. The groundwater samples were sealed, labeled, and immediately placed on ice along with a trip blank for same day transportation to McCampbell Analytical Inc., Pittsburg, California. Groundwater sample GW1 was analyzed for Nitrate as N and Nitrate as NO3- by EPA Method 300.1 with laboratory results reported in milligrams per liter(mg/L). Groundwater sample GW2 (1 of 4) and GW 2 (2 of 4) were analyzed for 1,2-dibromo-3-chloropropane (DBCP) and 1,2- dibromoethane(EDB)by EPA Method E524.3 with results reported in micrograms per liter(ug/L). The following table summarizes the laboratory results: Responsive■ Resourceful ■ Reliable 8