ARCHIVED REPORTS_XR0003203 - Laserfiche WebLink

Home Browse Search

t A S S O C I A T E S i N C QUARTERLY GROUNDWATER MONITORING ACTIVITIES On December 18, 2003, ATC personnel collected groundwater samples from monitoring wells MW 1 through MW 10 and CW The locations of the monitoring wells are shown on Figure 2 ' Prior to collection of groundwater samples, the depth to water, pH, electrical conductivity, and temperature were measured in the monitoring wells and recorded A minimum of three well casing volumes was purged from each well prior to sampling The wells were allowed to recover and samples were collected from each well using dedicated disposable bailers Groundwater well purge and sample logs are contained in Attachment 1 The groundwater samples collected from each well were submitted to State-certified Argon Laboratories, Inc (ELAP Cert No 2359) for chemical analyses of TPHg by EPA method 8015B, benzene, toluene, ethylbenzene, xylenes (BTEX) by EPA method 802113, and methyl tertiary ' butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), tertiary butyl alcohol (TBA), tertiary amyl ether (TAME), di-isopropyl ether (DIPE), 1,2-dichloroethane (1,2-DCA), and ethyl dibromide (EDB) by EPA method 8260B ' Groundwater Analytical Results TPHg and/or BTEX constituents were detected at or above laboratory reported detection limits in the samples collected from wells MW1, MW6, and MW7 The groundwater samples collected from wells MW2, MW4, MW5, MW6, MW7, MW9, and CW contained low concentrations of MTBE ranging from 1 1 parts per billion (ppb) to 10 ppb The groundwater sample collected from MW 1 did not contain detectable concentrations of MTBE, but the detection limits in the sample were elevated due to dilution factors None of the groundwater samples collected ' contained detectable concentrations of ETBE, TBA, TAME, DIPE, 1,2-DCA, or EDB The samples collected from MW2, MW4, MW5, MW9 and CW contained no detectable concentrations of petroleum hydrocarbons other than low concentrations of MTBE The samples collected from MW3, MW8 and MW10 contained no detectable concentrations of petroleum hydrocarbons The groundwater sample collected in December 2003 from MW2, located near the vapor extraction wells, contained a slightly lower concentration of MTBE than the sample collected in September 2003 Groundwater samples collected from MW4 and MW9 contained slightly ' increased concentrations of MTBE with respect to the samples collected from these wells in September 2003, but are all below the Maximum Contamination Limit (MCL) and within historical ranges Concentrations in the remaining wells generally were slightly lower than those detected in September 2003 A summary of analytical results is presented in Table 1 Groundwater laboratory data sheets and chain-of-custody documentation are contained in Attachment 2 s lcnviro1625961quart1yl4gr-2003 doc 3 t