SITE INFORMATION AND CORRESPONDENCE_1987-1992

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MEMORANDUM CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD - CENTRAL VALLEY REGION 3443 Routier Road Phone: (916) 361-5600 Sacramento, CA 95827-3098 ATSS: 8-495-5600 TO: Antonia Vorster FROM: Robert Niblack DATE: 21 July 1987 SIGNATURE: + SUBJECT: LINCOLN VILLAGE WELL CONTAMINATION, STOCKTON Contamination of Lincoln Village Maintenance District's (LVMD) well number one in Stockton was reported in November of 1984 . Water sampling had been conducted as part of the AB 1803 program. Tetrachloroethene (PCE) was found at 120. 0 ppb, trichloroethene (TCE) was found at 14 . 3 ppb, and trans-l, 2-Dichloroethene (DCE) was found at 20. 0 ppb. State action levels are 4 ppb for PCE, 5 ppb for TCE, and 16 ppb for DCE. Well no. 1 was subsequently removed from the water supply system. Robert Grimshaw of the Department of Health Services wrote to Henry Hirata, Director of the San Joaquin Public Works Department, saying that well number one must remain off-line until the contaminant source was identified, and contaminant levels reduced. Well no. l . was inspected by the San Joaquin County Public Works Department using a video camera, and a major casing separation was found at 42 feet below ground surface. This well had no surface seal. The well was renovated by emplacement of a grout seal down to the 80 foot depth. On 1 May 1986 well no. 1 was placed on-line after subsequent sampling showed non-detectable levels of volatile organic compounds. Records show that the highest screened interval in well no. 1 occurs at 160 feet. San Joaquin County sampled sewer lines in the area, and found significant levels of PCE in sludge samples taken from sewer manholes in Lincoln Shopping Center. A letter from Eugene Delucchi, Deputy Director of the San Joaquin Department of Public Works to Robert Grimshaw (dated 6/13/85) states that all three dry cleaning operations located in the shopping center had discharged solvents to the sewer system. Results of the sampling program on which he based this conclusion have been forwarded to the Regional Board. In a telephone conversation on 2 June 1987, Ron Rall, of the San Joaquin Utilities Maintenance District, told me he collected these samples. He described them as a mixture of sludge and water. The San Joaquin Local Health District transmitted the results of one sample to the Regional Board when this case was referred here on 1 May 1985. The analysis by California Water Labs was labeled "Manhole Lincoln Center" . Using EPA Method 601 they found PCE in the sample at a concentration of 160, 000 ppb.