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w� s A S S b C 1 A T E S I fN C GROUNDWATER MONI'T'ORING AND SAMPLING ATC performed quarterly groundwater monitoring on July 15, 2004 Field work included measuring the depth-to-water in wells MW I through MW3 and purging and sampling the water from the site's domestic well The sample was analyzed for the presence of dissolved petroleum hydrocarbons Depth to water measurements were attempted and recorded on July 15, 2004 from monitoring wells NMI through MW3 The upper most groundwater table elevation has decreased over 6 0 feet in the monitoring wells since the last monitoring event in April 2004 MW1, MW2 and MM3 were dry, therefore, groundwater gradient and direction in the uppermost aquifer beneath the site on July 15, 2004, was unmeasurable MW 1 and MW2 are screened at between 71 and 91 feet below ground surface (bsg) MW3 is screened at between 715 and 91 5 feet bsg A depth to water measurement in DW was recorded for the first time as 98 99 feet below the top of the casing Historically, groundwater beneath the site generally flowed in a northeasterly direction Groundwater monitoring data are summarized in Table 1 Monitoring wells MW 1, MW2 and MW3 were dry, therefore groundwater samples were not collected from these wells Field notes are included in Attachment 1 ATC collected a water • sample from the sampling port of the on-site domestic well (DW) after measuring depth to water and purging approximately 112 gallons The groundwater sample collected was placed on ice and transported under chain-of-custody to State-certified Argon Laboratories, Inc , (DHS Certification No 2359) The sample was analyzed for BTEX by EPA method 8021B, TPHg by EPA method modified 8015, and oxygenate fuel additives, including 1,2-dichl oro ethane (1,2-DCA), and 1,2-dibromoethane (EDB) by EPA method 8260B RESULTS Laboratory analyses detected no petroleum hydrocarbon constituents in the sample collected from well DW There have been consistently no detectable petroleum hydrocarbon analytes in DW since it was first sampled in December 20, 1999 Analytical results are summarized in Table 1 Laboratory reports and chain-of-custody documentation are presented in Attachment 2 CONCLUSIONS The nondetectable concentrations of petroleum hydrocarbon constituents in DW appear to be generally consistent with historical data The upper most groundwater table elevation has decreased over six feet in the monitoring wells since the last monitoring event in April 2004 MW 1, MW2 and MW3 were dry, therefore, w 114885`reporU0q 2004 dm 3