ARCHIVED REPORTS_XR0009598 - Laserfiche WebLink

Home Browse Search

KEI-P89-1104 .QR3 October 31, 1991 Page 4 Analytical results of the water sample collected from the on-site domestic well indicated 160 ppb of TPH as gasoline, with non- detectable concentrations of all other analytes. The analytical results for the old and new fuel tank pit, product pipe trench, and vapor pipe trench soil samples are summarized in Table 4 . The analytical results for the waste oil tank bottom and the remote fill piping soil samples are summarized in Table 5. Analytical results for the water sample are summarized in Table 6. To comply with the requirements of the regulatory agencies and based on the analytical results, REI proposed the installation of four monitoring wells. Results of the soil samples from the tank excavation are summarized in KEI 's report (KEI-P89-1104 .R1) dated January 8 , 1990. Mr. Knoll of the SJCPHS, per telephone conversations on February 7 and March 8 , 1990, required that the water well be properly destroyed due to the levels of TPH as gasoline indicated in the laboratory analyses results. Mr. Knoll also required that one additional water sample be collected after all piping and the pump were removed from the well, and also that the well be purged of at least three to four well volumes prior to sampling. A site inspection conducted on March 15, 1990, by Mr. Don Braun of KEI and Mr. Knoll, indicated that the vicinity of the existing well had been paved with asphaltic concrete and that an old concrete Christy box was placed around the well and remaining piping. The well seal appeared intact. The well casing was locally exposed and appeared to be steel and about six-inches in diameter. The service station was connected to the municipal water system and disconnect- ed from the on-site water well prior to April, 1990. Details of the existing water well at the site were researched at the California Department of Water Resources (DWR) in Sacramento. Mrs. Betty Swatsenbarg of the DWR reviewed the State records on March 14 , 1990, and reported that no records were available for this well at the DWR. Based on Mrs. Swatsenbarg' s extensive experience at the DWR, the subject water well was probably drilled and installed prior to 1951 . At that time, steel casings were driven into the subsurface and the remainder of the wells were generally open below the casing. On April 23 , 1990, an attempt was made to destroy the existing six- inch diameter water well by West Hazmat of Rancho Cordova, California. The proposed plan involved (1) drilling out the well casing, using 12-inch O.D. (6-1/4-inch I.D. ) hollow-stem augers, to the total depth of the casing, (2) pulling out the old casing, (3) redrilling the well to the full depth, (4) and pressure grouting the well using a tremae pipe and a neat cement grout.