Laserfiche WebLink
1.0 INTRODUCTION <br /> 1.1 SITE LOCATION, DESCRIPTION, AND HISTORY <br /> Marley Cooling Tower Company's (MCTC' s) Stockton, California facility is <br /> a manufacturing facility that primarily mills and treats wood for use in <br /> cooling towers. MCTC's 30 acre facility in Stockton is located at 150 <br /> North Sinclair Avenue and consists of a North and South Yard as shown on <br /> Figure 1-1. MCTC's wood treatment facilities are located on the North <br /> Yard and include a wood treatment building, retorts (pressure vessels used <br /> for wood treatment) , a retort pit beneath the retorts, and associated <br /> chemical storage tanks, valves, and appurtenant piping. <br /> MCTC began treating wood at the Stockton facility in 1966. In the wood <br /> treatment process, wood is loaded into the retorts where an inorganic wood <br /> preservative solution is forced into the wood under pressure. Chromium, <br /> copper, and arsenic have been used as components of the wood preservative <br /> solution. In 1982, arsenic was eliminated from the preservative solution <br /> and only copper and chromium are now used. <br /> Based on extensive soil and ground water assessment programs at the site, <br /> subsurface soils and ground water beneath the retort area are known to <br /> have been affected by wood treating activities conducted at the site. The <br /> characterization of the site, an evaluation of remediation alternatives, <br /> and a discussion of the approved remediation activities are presented in <br /> MCTC's Remedial Investigation / Feasibility Study (RI/FS) dated May 1990 <br /> and MCTC' s June 29, 1990 Remedial Action Plan (RAP) , respectively. <br /> As presented in the RI/FS, subsurface soil contamination is different in <br /> the two soil regimes beneath the retort pit. Shallow soils, less than 20 <br /> feet below the surface, are contaminated with copper, arsenic, and total <br /> chromium. Since copper, arsenic, and trivalent chromium are strongly <br /> adsorbed to soil particles, their mobility has been restricted to shallow <br /> soil depths. The deeper unsaturated soils are contaminated with <br /> hexavalent chromium. Hexavalent chromium is anionic, exists as chromate <br /> or dichromate, and is extremely mobile. The mobility of the hexavalent <br /> chromium is evidenced by vadose zone and ground water contamination <br /> directly below the retort pit area. <br /> The California Department of Health Services (DHS) issued the RAP that <br /> designated the selected remediation alternative for the subsurface soils <br /> 11654.652 1-1 <br />