SITE INFORMATION AND CORRESPONDENCE

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Coale y Godward-LLP Mr. Michael. Harper January .6, 1997 Page 3. b. Autotronteisnot aware of any correlation between NITBEgontamination and benzene.contain oat on intbe groundwater at,the former Texaco site, Ms. LagoriW&letter states that;FDIC's consultants have contended,that benzene toWentration& in the groundwater have shown a.correlated pattern with MTBE:Cotitaniination and are thus relatedto contamination from,theBokides site. Agto"pi; is aw. of nq::.such:contention:9n,the part of the FDIC7s consultants.. Even l*fsuch a contention was made, it simply is not trate, Benzene concentrations in. 1AM-51 thewell immediately dowtigradient of the.Bokidessite, are significantly. lower than those detected t7i the three� monitor i.ng wells located on,the Jormer Texaco site, reasMTBE,concentrations. in MW�5. ::are:Uirly:high,. C. The former Texaco site is a possible source of groundwater ..onturAnation itself. In its Case Closure Report, Texaco's consultant., points out that since 1992, the depth to the top of the water table at the former Texaco site has varied from about 51feetbelow ground surface to about 57 feet below ground surface. Texaco's consultant also points out that the maximum depth of significant petroleum hydrocarbon concentrations in soils remaining at the former Texaco site range from approximately 25 feet below ground surface in the northern portion of the site and 42.5 feet below ground surface in the southern portion. Although there currently may be a gap between fuel hydrocarbon-contamination in soil and the top of the water table, historic water table information reveals that this was not always the case. According to the U.S. Geological Survey, the water table in the general area was at approximately 1& feet below ground surface in. 1928 and 1929. The water table decreased to approximately 33 feet below ground surface in 1963, according to data available from the City of Lodi relating to its water supply well. Since that time, the water table has decreased further to Itscurrent level. Thus,:the contaminants remaining in the soil at the,f0rmer'T re. exaco sitea...... at that have historically camne, into contact with the water table, and soil contamination at ft- former Texaco site is:itself:a,Iikely source of the groundwater containihatibit.there. 4.1 c OndusloW As discussed.above, Autotronic agrees with PHS-EHD's analysis that=therisks presented bythe remaining in 'I at the former Texaco facility aft.mindr. oilcpm. contamination rernai the soils closure Is4p.propria on that basis.