ARCHIVED REPORTS XR0003283 - Laserfiche WebLink

Home Browse Search

M A S S O C I A T E S I N C historical parameters, which have indicated the predominant groundwater gradient direction is to the east with variation between northeast and south-southeast Figure 3 depicts groundwater elevation contours for July 13, 2004 The groundwater monitoring data are summarized in Table I Monitoring data and purge logs are provided in Attachment I LABORATORY ANALYSES The groundwater samples collected on July 13, 2004 were submitted to Excelchem Environmental Labs (FLAP #2119) in Roseville, California for analyses of hexavalent chromium (Cr +6) using EPA Method 7199, total chromium, aluminum, potassium, sodium, and calcium using EPA Method 60108, chloride and sulfate by EPA Method 300 0, phosphorus by EPA Method 365 3, Trichloroethene (TCE) and Tetrachloroethene (PCE) by EPA Method 826013, and total hardness as CaCO3 by method SM2340C Additional analyses for PCE, TCE, and Aluminum were requested by the RWQCB in an e-mail correspondence dated July 12, 2004 Cr +6 was not present above laboratory detection limits in the sample collected from the facility well Cr+6 was detected in the groundwater samples collected from monitoring wells MW-3 and MW-6 at concentrations above the California Primary Maximum Contaminant Level (MCL) for total chromium in drinking water of 0 05 milligrams per liter (mg/1) The reported Cr +6 . concentration in the groundwater sample collected from MW-3 was 3 4 mg/l The reported Cr +6 concentration in the groundwater sample collected from MW-6 was 0 058 mg/l Cr +6 was also detected in water samples collected from wells MW-1, MW-2, MW-4, MW-5, MW-7, MW-8, and MW-9, but at concentrations below the MCL for total chromium The distribution of Cr +6 in groundwater is shown on Figure 4 Total chromium was detected in the groundwater samples collected from MW-3 and MW-6 above the California Primary MCL for total chromium in drinking water of 0 05 mg/l The reported total chromium concentration in the groundwater sample collected from MW-3 was 3 3 mg/l The reported total chromium concentration in the groundwater sample collected from MW-6 was 0 064 mg/l Total chromium was also detected in water samples from wells MW-2, MW-4, MW-5, MW-7, MW-8, and MW-9 but at concentrations below the respective MCL for total chromium Total chromium was not present above laboratory detection limits in the water samples collected from MW-1, the municipal well, or the facility well Tetrachloroethene, also known as Perchloroethene (PCE) was not present above laboratory detection limits in the sample collected from the facility well PCE was detected in the groundwater sample collected from monitoring well MW-9 at a concentration above the California Primary Maximum Contaminant Level (MCL) for PCE in drinking water of 0 005 milligrams per liter (mg/L) The reported PCE concentration in the groundwater sample collected from MW9 was 0 051 mg/L PCE was also detected in water samples from wells MW 1, MW3, MW7, MW8, and WP-1, but at concentrations below the respective MCL for PCE The reported PCE concentration in the groundwater samples collected from MW1, MW3, MW7, MW8, and WP-1, were 0 0013 mg/l, 0 0006 mg/L, 0 0021 ing/L, 0 0018 mg/L, and 0 0014 mg/L, respectively PCE was not present above laboratory detection limits in the water samples slenvironmental1625831quarterlyl3gr-2004 doe 2