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California,",agional Water Quality C,,..,,trol Board �^ � <br /> Central Valley Region <br /> Katherine Hart, Chair <br /> 11020 Sun Center Drive,#200, Rancho Cordova, California 95670-6114 <br /> Linda S.Adams (916)464-3291 • FAX(916)464-4645 Edmund G.Brown Jr. <br /> Acting Secretary for http://www.waterboards.ca.gov/centraIvaIIey Governor <br /> Environmental Protection <br /> To: Wendy Cohen '" FROM: Kristi Shelton <br /> Senior Engineer Water Resources Control Engineer <br /> Aboveground Tanks Cleanup Unit Aboveground Tanks Cleanup Unit <br /> DATE: 28 February 2011 SIGNATURE: <br /> SUBJECT: NO FURTHER ACTION REQUIRED, PG&E FRENCH CAMP GENERAL <br /> CONSTRUCTION YARD, FRENCH CAMP, SAN JOAQUIN COUNTY <br /> I reviewed the 21 December 2010 Site Closure Report and Request for No Further Action <br /> (Report) prepared by Stantec Consulting Corporation (Stantec) on behalf of Pacific Gas and <br /> Electric Company (PG&E) for the property at 401 East French Camp Road in French Camp <br /> (Site). The Report summarizes the Site history, previous investigation activities, and <br /> recommendations for-Site closure. The Site history and rationale for issuing a No Further <br /> Action Required letter are summarized below. <br /> BACKGROUND <br /> PG&E has used the Site since the late 1950s as a general construction yard and purchased <br /> the property in 1991. In June 2005, PG&E performed a Phase I environmental site <br /> assessment, which found that in 1995, PG&E removed one concrete ConVault-style <br /> aboveground tank (AGT). The ConVault tank had replaced older steel AGTs and consisted of <br /> separate vessels for storing diesel and gasoline. The French Camp Fire Department oversaw <br /> the 1995 removal of the ConVault AGT. It is unknown when the steel AGTs were removed. <br /> Figure 1 shows a Site plan. <br /> PG&E currently uses the Site for storage to support regional construction projects. PG&E <br /> personnel are not present at the Site on a daily basis. <br /> SOIL INVESTIGATIONS <br /> In December 2005, PG&E conducted a limited subsurface investigation to evaluate soils <br /> beneath the former ConVault and steel AGTs. Soil samples contained minor concentrations <br /> of total petroleum hydrocarbons as diesel (TPHd) and TPH as motor oil (TPHmo) at a depth of <br /> two feet below ground surface (bgs). Shallow soils consist of silts and clays, underlain by a <br /> hardpan layer at about 3.5 feet bgs. Table 1 contains the soil sample analytical results. <br /> Following the 2005 investigation, PG&E obtained additional information showing that the older <br /> steel AGTs were not at the ConVault location that was the subject of the 2005 investigation. <br /> The older AGTs were in a nearby structure identified historically as the heavy equipment <br /> storage shed. In May 2006, PG&E drilled seven soil borings in this area to depths of about <br /> 3.3 to 3.8 feet bgs. All seven borings were terminated at the hardpan layer. As shown in <br /> Table 1, the 1.5-foot bgs soil sample from the boring south of the former heavy equipment <br /> California Environmental Protection Agency <br /> p�a Recvcled Paper <br />