SITE INFORMATION AND CORRESPONDENCE

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c_ r Mr. William H- Crooks -" 'November 12, 1996 Page 3 II. CITY OF LODI LETTER The City cif Lodi states that a tentative settlement has been reached regarding the solvent plume situaition which DMhas been investigating since 1989. Ibe City objects to the closure of the Togo's;site,_saying the closure would cause the City to.reevaluate its> position in settling*1 solvent plume situation. The City's letter is premised:on the mistaken beliefthat the petroleum hydrocarbon contamination under the Togo's site and the regional solvent prime situation are related. Fttr instance,the City complains about the Lead Agency's willingness to close the site given.MTBE and DCA.levels detected in the groundwater beneath the site: The City also i )) assents i as a fact))that these contatrinants are coaling from an"on-site souree g o a's site. The City. Tbases its assertions in part on an October 1A.1906 letter;from pW to the lead agency: Both the City and DTSC are wrong. These issues were discussed extensively during the TRC hearing, and were evaluated by the TRC during its post-hearing deliberations. The foots are I as follows. First, the gasoline station operations and associated underground tanks at the Togo's site cannon be a source of MTBE. The U.S. Environmental Protection Agency did not authorize the use of MTBE as a gasoline additive until 1979,and it was not used as an additive in California until after.1980. As noted previously, all gasoline operations at the Togo's site ceased in 1977, and the remaining underground tanks were removed in 1979, prior to the use of MTBE. Second, there is no evidence that the site is a source of DCA. Contrary to DTSC's assertion at the TRC hearing, there is no evidence of any DCA in sails at the Togo's site. Also,the petroleum;hydrocarbon contamination at the Togo's site has consistently been separated from underlying groundwater by-a vertical distance of between 8.5 and 14.5 feet during the 5 years that the site has been monitored. Accordingly,there is no indication that the Togo's site, or the prior operations on the Togo's site, are the cause of the MTBE and DCA levels in groundwater beneath the site. The source appears to be offsite, based on the data. As explained during the TRC hearing, a gasolinei station..currently operates directly across West Lodi Avenue from the TOO}s site - it has operated for many years since MTBE came into use as a gasoline additive Also,the We Lodi site is directly upgradient from the Togo's site in terms of groundwater flout: Finally, the fluctuations in MTBE;and DCA values beneath both the West Lodi site anti the Togo's site river time are closely correlated, indicating that the two: contatniaants may be coming from.the same source. As indicated above, the XTBE could :not have come from the Togo's site and therefore must have originated:off site.