ARCHIVED REPORTS_XR0012721 - Laserfiche WebLink

Home Browse Search

-- -� �— :a -- ff i _ 15 ,,n Em --- SG County of San Joaquin Public Health Services 4 D April 4, 1990 (881680) Ground water samples were collected from four locations: 1) House Well No. 10; 2) Well No. 5338; 3) Well No. 5298; and 4) Well No. 5272. Locations are illustrated on Plate I - Site Map. The chilled ground water samples were hand-delivered accompanied by chain-of-custody documentation to Coast to Coast Analytical Services, Inc, in Goleta, California, where they were analyzed for STEX and TPH by EPA method 524.2 and for total lead by EPA method 7426 following digestion by EPA method 3050. The laboratory analytical results are presented in Table 2 - Analytical Results of Ground Water Sampling. - j All four wells contained trace amounts of benzene and three contained trace amounts of tolt!ene. Both constituents were present in concentrations well below the applicable State of California Drinking Water Standards. 4 It is our opinion the ground water contamination has been caused by a source other than the LIST. This was based on the fact that benzene was found in the ground water samples, but not in the confirmatory soil samples collected from the excavation and because several of the wells containing benzene are t located upgradient of the removed UST. Prior to field activities of .January. 9, 1990, SCD conducted a restricted survey of the properties surrounding the site which may contain USTs. SGD learned that two sites which reportedly use UST9 exist north of the Color c Spot site. Reportedly seven USTs exist at 5401 East Harney Lane, Bailey's l Nursery and one UST is located at the cemetery located at the northeast corner Jof Highway 99 and East Harney Lane. It should be noted that each of these surrounding properties are apparently located hydrologically upgradient of the u site. -) The believed upgradient UST site located at 5401 East Harney Lane, z which reportedly contains as many as seven USTs, may be a source of the benzene i y contamination. Given the fact that diesel fuel typically contains less than 0.20 { h L1 percent benzene and that not even trace concentrations of benzene have been found ) T in any soil samples collected at the site, we believe that benzene contamination ss _ of the ground water wells caused by the Color Spot facility is highly improbable. } ax . For the above reasons, SGD strongly believes that Color Spot, Inc., t should not be required to implement a ground water investigation and that PHS-EHD ; 1 should investigate other possible sources of the benzene contamination. SGD also x d r_, recommends that the previously suggested quarterly well monitoring program (Soil Vapor Study, Color Spot, Lodi, California, October 1989) to be conducted by Color i r; Spot be discontinued. jG t1 � ti. � � r CLOSURE 5 '-- We believe that all the requirements imposed on Color Spot, Inc. in the letter from PHS-MID, dated January 17, 1990, have been satisfied or responded E f to in a reasonable manner. If you wish to discuss any of the responses curtained j