Laserfiche WebLink
California Regional Water Quality Clol Board <br /> Central Valley Region „ °I <br /> Karl E.Longley,SeD,P.E.,Chairtif <br /> Linda S,Adams 11020 Sun Center Drive#200,Rancho Cordova,California 956706114 Arnold <br /> Secretaryfor Phone(916)464-3291•FAX(916)464-4645 Sehwarzenegger <br /> Environmental http://w»vro.waterboards.ca.gov/centralvalley Governor <br /> Protection <br /> 30 April 2009 <br /> Thomas DeArth <br /> Genesis Engineering & Redevelopment <br /> 351 Ruess Road <br /> Ripon, Ca 95366 <br /> REVIEW OF SITE INVESTIGATION REPORT FOR THE DEPAOLI/ARCADY OIL <br /> PROPERTY, SAN JOAQUIN COUNTY <br /> From 1979 to 1984, the Arcady Oil Company disposed of used drilling mud on two connecting <br /> parcels of land adjacent to the Whiskey Slough levee, near Holt. The northern parcel is now <br /> owned by Ronald Barber of Manteca, and the southern parcel is owned by the DePaoli Family <br /> from Stockton. The DePaoli's allowed Arcady Oil to discharge mud on their property under a <br /> lease agreement. On 26 December 1990, the Central Valley Water Board issued Cleanup and <br /> Abatement Order (CAO) 90-029 which requires site closure of the DePaoli /Arcady Oil site. As <br /> part of the closure process, the waste must first be characterized. On 28 October 2008, to <br /> comply with Item 1 of the CAO, the DePaoli's submitted their Site Investigation Report.. The <br /> DePaoli report presents the results from the drilling mud waste characterization as well as <br /> seven recommendations for site closure for their property. Staff has prepared this letter.to <br /> summarize the conditions onsite; the apparent environmental impacts caused by the drilling <br /> mud; and the closure options allowed by CCR Title 27 for the site, <br /> Covering 3.5 acres of the DePaoli property are windrows of used drilling mud. Boring logs <br /> show the thickness of the drilling mud ranges between 5 and 8 feet. The approximate volume <br /> of material disposed onsite is 45,000 cubic yards.. No interim cover has been placed over the <br /> waste. The drilling mud is lying directly on native soil. Groundwater flows from the slough, <br /> directly under the waste and then toward the center of the island. <br /> Variations of chloride concentrations in groundwater beneath this site suggests that <br /> groundwater-has been impacted by the presence of the drilling mud. Whiskey Slough, <br /> monitoring well MW2 and drilling mud sample location DM-9 are all directly upgradient of <br /> MW5. Results from the recent fourth quarter 2008 monitoring event mimic those collected <br /> during the site investigation (June 2008). Chloride concentrations in Whisky Slough and MW2 <br /> were at 111 and 173 mg/I, respectively. At 996 mg/I, chloride is highest in drilling mud sample <br /> DM-9. In monitoring well MW5, the concentration was 656 mg/l. This is 6 times the applicable <br /> water quality limit of 106 mg/I. Anthropogenic compounds like Cis -1,2 DCE have also been <br /> detected in MW5 as well as the drilling mud. The highest concentration reported was 0.7 ug/I, <br /> which is below the Department of Health Services.MCL of 6 ug/I. Additional comparisons of <br /> water quality data are impossible at this time because the laboratory reporting limits exceeded . <br /> the water quality limits. <br /> Califon-nia Eitnironmental Protection Agency <br /> 0a Recycled Paper <br />