ARCHIVED REPORTS_XR0002921 - Laserfiche WebLink

Home Browse Search

a fj • Mr Sam Savig Project No 880-040 1A February 21, 2002 Page 3 petroleum hydrocarbons as gasoline (TPH-g), benzene, toluene, ethylbenzene, xylenes (BTEX compounds), and for five gasoline oxygenates (methyl tert-butyl ether [MtBE], di-isopropy ether [DIPE], ethyl tert-butyl ether [ETBE], tert-amyl methyl ether [TAME] and tert-butyl alcohol [TBA]) using U S Environmental Protection Agency (EPA) Methods 8015 Modified, 8020 and 8260, respectively Field and laboratory procedures are presented as Attachment A Certified analytical reports, chain-of-custody documentation, and field data sheets are presented as Attachment B Fourth Quarter Groundwater Monitoring Results Since the previous sampling event on November 1, 2001, groundwater levels at the site increased an average of 1 52 feet Generally, groundwater flow direction continued to be to the northeast at an average gradient of 0 002 ft/ft This trend is consistent with the • previous sampling events Table 1 lists the groundwater elevation data Figure 1 is a groundwater elevation contour map for January 28, 2001 TPH-g was detected in wells MW-1 and MW-3 at concentrations of 8,700 and 560 micrograms per liter (µg/1), respectively Benzene was detected in wells MW-1 and MW-3 at concentrations of 1,100 and 5 9 µg/1, respectively MtBE was detected in wells MW-1, MW-2 and MW-3 at concentrations of 18,000, 3,300, and 590 µg/I, respectively TAME was reported in well MW-3 at a concentration of 3 8 µg/1 Elevated reported detection limits were for sample results from MW-1 and MW-2 Table 1 lists groundwater analytical data Figure 2 is TPH-g, benzene, and MtBE concentration map based on January 28, 2001 data CONCLUSIONS Since the fourth quarter 2001 sampling event, groundwater levels have increased an average of 1 52 feet Generally, groundwater results showed a decrease or stable TPH, BTEX and MtBE concentrations trend in all three wells since the previous sampling events IT CORPORATION SAC W IsacDP120021PRAPJ818801880040IA 2aa doc-0IVt 1 (01070000)