SITE INFORMATION AND CORRESPONDENCE FILE 2

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IWSAII smuum# PALISADES GAS AND WASH CORPORATION July 28, 2004 30101 Agoura Pho e: (818)865-9200 200, Agoura FaHills, x(18)865-009211 Mr. Terry Brazell. Underground Storage Tank Program State Water Resources Control Board Division of Water Quality 1001 I Street Sacramento, California 95814 SUBJECT: ADDITIONAL INFORMATION LOCAL OVERSIGHT PROGRAM, SITE NO. 1072 EXXON#73708, COUNTRY CLUB BOULEVARD STOCKTON, CALIFORNIA, SAN JOAQUIN COUNTY FILE NO. P03-215 Dear Mr. Brazell: Palisades Gas and Wash(Palisades)recently conducted an inspection of the condition of the on- site groundwater monitoring wells at the above referenced facility. The inspection report documents numerous deficiencies regarding the condition the of wells installed and maintained by ExxonMobil Corporation(ExxonMobil), including well VEW-3 identified by the SJCEHD as the reason for filing the URR. On March 5, 2004 Stratus Environmental, Inc. (Stratus) visited the facility to inspect and document the condition of the onsite wells. Stratus noted that five of the eight wells inspected were.not properly maintained (please refer to the attached inspection report). Upon closer inspection,the well vaults were found to be flooded, indicating a faulty watertight seal. The report documents mud staining along the casing inner wall in well MW-3, indicating that the protective well plug had failed. It was also noted that the well vault for VEW-3 was flooded. As see in photos#14 and x'15,the water level appears to coincide with the level of well casing. These water levels and the evidence of plug failure noted at well MW-3 suggest that the expanding plug in VEW-3 could also have failed, and that surface water entered into the subsurface. The report also notes that well VEW-1 did not have an expanding plug but used a slip cap for protection. If any gasoline residue exists on the surface from the customary operation of the station,the unsecured wells (MW-3, VEW-1, and VEW-3) could act as vertical conduits to the subsurface. As long as these well conditions persist,the presence of dissolved petroleum hydrocarbons in the groundwater does not automatically suggest continued impact from pre-existing sources. Until the well vaults are repaired, they pose a threat to groundwater quality. It is the responsibility of the well owner (ExxonMobil)to properly maintain the wells and any release into the subsurface from improperly maintained wells is the responsibility of the well owner to cleanup.