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I Mr Ron Rowe Page 2 of 5 GROUNDWATER ACTIVITIES ' Groundwater Monitoring and Sampling ' Groundwater monitoring was conducted on November 18, 1999 The depth to groundwater was measured in each well and subtracted from the wellhead elevation to determine groundwater elevation Water levels fell an average of 167 feet since last monitored on August 3, 1999 Groundwater flow was generally northeasterly with a gradient averaging approximately 0 004 feet per foot A groundwater gradient map generated using the November 18, 1999 monitoring data is shown on Figure 2 Recent groundwater monitoring data are summanzed in Table 1 ' Monitoring logs and well construction information are Included in Attachment A On November 17 and 18, 1999 Ground Zero collected groundwater samples from groundwater ' monitoring wells MW 1 through MW 13 At least three well casing volumes were purged from each groundwater monitoring well prior to sampling Physical parameters (pH, conductivity, ' temperature) were monitored during purging and allowed to stabilize prior to sampling Samples were collected after groundwater recharged to 100% of the original level Purged water was contained in 55-gallon drums approved by the Department of Transportation and stored onsite in a locked enclosure Purge logs are included in Attachment A Samples were placed on ice and transported under chain of custody to Argon Laboratories (DHS #2359) Samples were analyzed for TPHg using modified EPA method 8015 and BTEX using EPA method 8020 Additional sample matrix collected from monitoring wells MW1 through MW 13 was analyzed for oxygenates using modified EPA method 8260 Analytical results for ' TPHg, BTEX and MTBE are summarized in Table 2, oxygenate results are summarized in Table 3 Attachment B contains laboratory reports and chain of custody documentation ' Groundwater Analytical Results The groundwater surface was above the top of the screened intervals in wells MW3 through ' MW12 Petroleum hydrocarbons were detected in groundwater samples collected from all monitoring wells, except MW6, MW11, and MW12 The highest concentrations of TPHg and BTEX were detected in samples collected from wells MW4 and MW 13 Concentrations of TPHg ' and BTEX in the sample collected from well MW5 were within the middle historical range Concentrations of TPHg and BTEX in MW 13 continue to decline, benzene is more than an order ' of magnitude lower than detected in 1995 Hydrocarbon concentrations in wells MW2 and MW8 continue to decrease substantially ' Hydrocarbon concentrations in MW4 surpassed those in MW5 for the fifth consecutive sampling event An overall increase in hydrocarbon concentrations in MW3 was also observed for the second consecutive sampling event Moderate levels of TPHg and BTEX were present in well roek\gtwAgm 1999