SITE INFORMATION AND CORRESPONDENCE

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San Joaquin/ARCO Meeting Minutes, March 30,was Working 7o Restore Nature o Mike noted that a line replacement vas performed at the site last week and wanted to know if it was permitted. (ARCO stated that permitting was likely performed by the contractor conducting the work. ARCO would follow up on this matter. o Mike expressed concern on the future use of the site, saying that the site is extremely busy. He has witnessed at least one overfill. Mike also inquired about the possible future use of new and larger tanks. o ARCO stated that the site is a priority. ARCO SS No. 2168, West Charter Way, St ckton o Mike has not received the first quarter monitoring report showing the results of the ground-water sampling of two monitoring wells (downgradient MW-4 and upgradient MW-S) installed in January 1993. o RESNA presented the ground-water results from the first quarter sampling event. Date show both newly installed wells contain high levels of hydrocarbons. Both upgradient monitoring wells (MW-3 and MW-5) located on the west boundary of the property contain high concentrations of hydrocarbons, suggesting that hydrocarbons are possibly from one or multiple offsite sources. o RESNA stated that the majority of residual hydrocarbons beneath the site are concentrated within the current and historic capillary fringe. Investigations conducted at the site to date have not verified a source that could have caused the levels observed beneath the site. It strongly appears that hydrocarbons in ground water are from offsite sources. o SJ was reminded that one known so rce is the Texaco site (south of ARCO) which has a large ground-water problem. It has likely impacted a portion of the ARCO site but based on the ground-water flow direction observed over the past five quarters, it is unlikely that their release has caused all of the observed impact. Possible upgradient sources are the Chevron site (southwest of ARCO) and a muffler shop (west of ARCO). 4