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File No 2070 2 30 November 1993 Pdge i ' 10 Status of Site Activities A Problem Assessment Report (PAR) for the site was issucd on 19 December 1991 by Anderson ' Consulting Group (ACG) The PAR summarized activities conducted at the site since the discovery in December 1986 of the release of petroleum hydrocarbons from several underground storage tanks Included in the PAR was a summary of investigations, conducted by Environmental Sciences and tEngineering (ESE) and ACG, to dctermme the extent of soil and groundwater contamination Additionally, a summary of soil remediation activities conducted in 1987 by remediation contractors Telford and Hall was also included ' Remediation of petroleum-impacted groundwater at the site has not been conducted,but is proposed Until a groundwater treatment sytitcm is on-line, the San Joaquin County Health Department has ' requested that quarterly groundwater monitoring he conducted in accordance with the State of California Regional Water Quality Control Board'% Underground Storage Tank Regulations ' 2 0 Groundwater Monitorin f The groundwater elevations for monitoring wells MW-1, MW-2, MW-3, MW-6 and MW-8 were measured and recorded on 21 October 1993 Monitoring well~ MW-4, MW-5 and MW-7 were dry at the time of our monitor ing The elevations weic used to calculate the ideal gloundwatLI flow direction and gradient for the third quarter 1993 Table 1 pre%cnts the gioundwatc,r cic.vatum mr a%urLments The groundwater flow direction and gradient is discutiticd iii Section 4 0 ' 3 0 Groundwater Samplin�� Sampling of the groundwater monitoring wclh was wriducted on 21 October 1993 Due to low ' groundwater levels, only wells MW-1, MW-6 and MW-8 contained Buff Lient water to allow samples to be collected Prior to sampling, the monitoring wells were pulgcd of well casing water For monitoring well MW-1, the temperature conductivity and pH of the groundwater was measured and recorded in five gallon intervals during purging This data was u,,cd as an aid in determining when an adequate volume of water had been removed from the well do that the true formational groundwater could be sampled A total of 25 gallons of groundwater were purged from monitoring well MW-1 Due to the limited quantity of groundwater in monitoring wells MW-6 and MW-8, temperature, conductivity and pH readings were not obtained for these wells Monitoring well MW-6 was purged of approximately 1 0 gallon of groundwater while monitoring well MW-8 was purged of approximately ' 3 5 gallons of groundwater The purged groundwater was containerized in a 55-gallon drum and stored on the site ANDERSON C , CONSULTING V GROUP