COMPLIANCE INFO_1991-1997 - Laserfiche WebLink

Home Browse Search

EMCOR 1433 North Market Boulevard • Sacramento, California 95834-1943. • X916) 928-3300 • Fax (916) 928-3341 T' �€ p " e 3, 1996 Project 20B02-001.010 Mr. Mike Miller Department of Public Works, City Hall 425 North El Dorado Street Stockton, California 95202-1997 Re: Austin Road Landfill, First Quarter Retest Dear Mr. Miller: Enclosed are the analytical results for the retest of volatile organic compounds (VOCs) in monitoring wells MW -12, MW -13, and MW -14. The results of the first quarter sampling event (March 11, 1996) and the retest (May 9, 1996) are presented in the attached table and summarized below. During the first quarter, carbon disulfide was detected at a concentration of 3.2 micrograms per liter (µg/L) in well MW -12. Carbon disulfide was not detected in the retest performed on May 9, 1996. The following VOCs were detected during the first quarter in MW -13: 1,1-dichloroethane (1.4 µg/L), tetrachloroethylene (PCE) (14 µg/L), and trichloroethene (TCE) (2.4 µg/L). The only compound detected in the retest was a trace (2 µg/L) of PCE. During the first quarter, PCE (26.4 µg/L), TCE (5.7 µg/L), and trichlorofluoromethane (1.6 µg/L) were detected in MW -14. PCE (26 µg/L) and TCE (trace [0.5 µg/L]) were confirmed during the retest, and the following compounds were detected in trace concentrations: dichlorodifluoromethane (CFC 12) (3 µg/L), trichlorofluoromethane (CFC 11) ( µg/L), and cis-l,2-dichloroethene (0.2 µg/L). The results of the retest indicate that a release has been confirmed at MW -14, a trace of PCE was confirmed in MW -13, but no VOCs were confirmed in MW- 12. In addition to the retests performed, a private well (8106A) was sampled on May 9, 1996. The following VOCs were detected in trace concentrations: CFC 12 (5 µg/L), 1,1-dichloroethane (0.3 µg/L), TCE (2 µg/L), and PCE (7 µg/L). This well was tested three times in 1989. The results of the previous analyses are contained in the "Solid Waste Assessment Test Report" (SWAT) (EMCON, June 1989). Table 8 from the SWAT report is attached. A comparison of the most recent data from well 8106A with the previous 1989 data indicates that the constituents and the concentration levels have remained essentially unchanged. A long-term assessment of the results of the off-site wells indicates that MW -12 has not shown any signs of impact, MW -13 has shown some low-level sporadic signs of impact, and MW -14 has, for the first time this quarter, shown a confirmed impact. This information would indicate that the lateral extent of VOC impact has not reached MW -12, has reached MW -13 in low levels, and has just reached -14. However, it is interesting SAON TI"BOUB020011.OGS-96\pas:4