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u c. h n A i I' 1! ic- o 6 ft i• , J 4 i i. ^ o i> i '< 0 . u u o r . _ 'GERAGHTY IJSP MILLER, INC. £/> vironm en tat Services Ground VAtter Engineering fytlructtrbM Reinediaii&i Education September 6, J994 Geoff Seibel de maximis, Inc. 186 Center Street Suite 290 Clinton, Nvw Jersey 0880D Re: Analytical Results for July 27, 1994 Croundwater Sampling of the Delegarde Supply Well, Tutu Wells Site, St. Thomas, U.S. Virgin Islands. Dear Mi. Seibel! Geraghty & Miller, Inc. has received the results for the second round of sampling of the Delegarde Supply Well. These results are summarized in Table 1, As agreed during a June 27, 1994 telephone conference with representatives of the U.S. Environmental Protection Agency (USEPA) and the Virgin Islands Department of Planning and Natural Resources (DPNR), sampling and analysis of groundwater collected at this supply well was performed for a second time to confirm the. results of the initial sampling on May 26, 1994, The May 1994 sampling event indicated the presence of tetrachloroethene (PCE) at a ctwcenuation of 14 parts per billion (ppb), which is above the USEPA diinking water standard of 5 ppb. Both the May 26 and July 27 samples were analyzed by Enseco-Bast J-aboratory for volatile organic compounds (VOCs) by USEPA Method 524.2. In addition to VOCs, the May 26, 1994 sample was analyzed for base neutral/acid extractable compounds, metals, and various water quality indicator parameters; none of these parameters were detected at elevated concentrations or above natural background levels. Therefore, the July 27, 1994 sample was analyzed only for VOCs. The results of the July 27, 1994 sampling are consistent with and confirm the results of the first sampling on May 26, 1994. The July 27, 1994 sample from the Delegarde Supply Well had a reported PCE concentration of 16 ppb. The USEPA drinking-water standard maximum TUT OO6 IOCS 201 West Pwsaic Street, 3rd Floor • RocheUe Park, New Jersey OW62 • (201) 909-0700 • ROC (201) 909-0567/0568 l\ *64663* 64663 DC., I'in/i 1 fvi i o ocp i i 3^4 j. _ - - 4 U MU . k,"jo r . i GERAGHTY # MILLER, INC 2 contaminant level (MCL) for PCE (5 ppb) was exceeded in concentration samples. The groundwater sample collecled on May 26, 1994 had a total chlorinated VOC of 24.2 ppb, The groundwater sample collecled on July 27, 1994 had a reported total chlorinated VOC valve of 28.96 ppb. The same suite of chlorinated VOC« were detected in both samples, including PCE, 1,2-dichloroethene (total) (DCE), and trichloroethene (TCE). A very low estimated chloroform concentration of 0.16 ppb was reported in the sample from July 27, 1994. The sample collected on July 27, 1994 also contained an estimated concentration of tert-Butyl Methyl ether (MTBE)(7 ppb) below the USEPA guidance value of 50 ppb. MTBE was not analyzed for in the sample collected on May 26, 1994 due to laboratory error. Due to the confirmed concentration of PCE above the MCL in these two sampling events for the Delegarde Supply Well, TEIC should forward these results to the well owner (Mr. Horace Turnbull), the USEPA, and the DPNR, If you have any questions or require additional information, please contact one of us. Sincerely, GERAGHTY & MILLER, INC. .(CfcXX' MuCCX/^ foHn C. Potenza Project Scientist/Geologist Thomas V, Danahy Senior Scientist/Project Daniel A. Nachman Vice President/Project Officer Attachment c: Paul Ryan - Texaco JCM» PR0013 03* TUT OO6 1OO9