SITE HISTORY - Laserfiche WebLink

Home Browse Search

w,. Ms. Laurie Cotulla V July 25, 1989 Page 10 Groundwater. Following installation, each well was developed using a stainless steel bailer to surge and bail the well until the water was relatively sediment free. Between 60 and 75 gallons of water were purged from each well. Following the development of each well, at least three additional well volumes of water were evacuated. The pH and electrical conductivity were measured periodically during the evacuation of water and were relatively stable before samples were collected. The groundwater samples were collected in four 40-milliliter glass volatile organic analysis (VOA) bottles. The VOA bottles were filled directly from disposable polyurethane bailers which were dedicated to each well. The VOA bottles were capped with a Teflon-lined septa and checked to ensure that no air bubbles remained within. All groundwater samples were labeled and stored in the same manor in which the soil samples were stored. A chain-of-custody form was used to record possession of the samples from the time of collection to delivery to the laboratory. The groundwater samples were analyzed for petroleum hydrocarbons and BETX using EPA Methods 8015, modified and 802, respectively. The groundwater samples were analyzed at Eureka in Sacramento, California. IL Field and Analytical Results �. This section describes the field and analytical results. Laboratory reports are presented in Appendix C. i.. Soil Results. Table 3 summarizes the analytical results for the three soil samples analyzed from the boreholes during this investigation. Petroleum hydrocarbons (EPA 8015, modified) were not identified in any of the three soil samples with a laboratory detection limit of Lo 10 ppm. None of the EPA Method 8020 constituents were identified in sample ATR-6-10-10.5, with a detection limit of 1.0 parts per billion (ppb). Benzene, ethylbenzene, and xylene were identified in sample ATR-5-9-9.5 at concentrations of 7 ppb, 18 ppb, and r,,, 11 ppb, respectively. BETX was identified in sample ATR-7-9.5-10 at concentrations of 93 ppb, 182 ppb, 31 ppb, and 177 ppb, respectively. La Groundwater Results. Table 2 summarizes the laboratory results of the groundwater samples collected from the three wells. Petroleum hydrocarbons were not identified using EPA Method 8015, modified in the groundwater from ATR-6 or ATR-7 based on a detection limit of 0.2 ppm. A concentration of 6.6 ppm of petroleum hydrocarbons in the gasoline range was identified in well ATR-5- None of the EPA Method 602 constituents were identified in groundwater from ATR-6. Xylene was identified in sample ATR-7 at a concentration of 1.7 ppb, which is well below the DHS action level of 1,750 ppb. No other tested constituents were identified in sample ATR-7. Benzene, ethylbenzene, and xylene were identified in sample ATR-5 at concentrations of 693 ppb, 327 ppb, and 7.0 ppb, respectively. The DHS action levels for benzene and ethyl- La BROWN AND CALDWELL Ld 723 5 STREET SACRAMENTO,CALIFORNIA 95814-7092•(916)444-0123