ARCHIVED REPORTS_XR0004882 - Laserfiche WebLink

Home Browse Search

�1 �y Quik Stop Market No 121 CCI Project No 12118-2 Page 2 in well RW-1 Each well was purged of stagnant water prior to the collection of a sample It should be noted that the water table was found to be very low In five of the eight wells sampled, five wells were found to have 1 5 to 2 feet of water Normal field measurements, including pH, conductivity, and water temperature, were periodically recorded during the purging process A sample was collected when these parameters stabilized to within 10% of each other After the groundwater was purged from each well, the groundwater samples were (a) collected with a clean disposable bailer, (b) transferred to appropriate laboratory-supplied bottles, ( c) labeled, (d) logged on a chain-of-custody form, and (e) placed in a chilled ice chest for transportation to a state-certified laboratory Monitoring well purge data is summarized in data Table 1 Laboratory Analysis The groundwater samples were submitted to Entech Analytical, Inc (Entech), a state-certified laboratory located in Santa Clara, California, for chemical analysis The laboratory employed methods approved by the California Regional Water Quality Control Board (CRWQCB) and the EPA The groundwater samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg) and benzene, toluene, ethylbenzene and total xylenes (BTEX) and fuel oxygenates • including methyl tertiary butyl ether (MTBE), using EPA Test Method 8260 Summary of Laboratory Results Six of the eight groundwater monitoring wells (screened from approximately 9 to 24 feet) were sampled and found to be impacted with petroleum hydrocarbons or MTBE Monitoring well MW-1, located on the northwest side of the site (Figure 2), near the intersection of Union Road and West Louise Avenue, was reported to contain TPHg at a concentration of 210 micrograms per liter (ug/1), no detectable BTEX compounds and MTBE at 760 ug/l Monitoring well MW-2, also located on the north side of the site, was reported to have MTBE at 8 5 ug/l and was reported to be free of detectable TPHg and BTEX compounds Monitoring well MW-3, located on the southeast side of the property, was reported to contain 1,000 ug/l TPHg and benzene at 6 7 ug/l This well was reported to have MTBE at a concentration of 110,000 ug/l Recovery well RW-1, located near the east side of the fuel tanks, was also reported to contain 5,300 ug/l TPHg, 17 ug/1 benzene and 120,000 ug/l MTBE Monitoring well MW-4, screened from 33 to 43 feet, was reported to contain 760 ug/1 TPHg and 70,000 ug/l MTBE Monitoring well MW-5, located on the southwest side of the site was reported to contain 80 ug/l TPHg and 120 ug/1 MTBE Monitoring MW-7, located on the east side of the site was reported to be free of detectable petroleum hydrocarbons this quarter Deep well MW-6, screened from 65 to 75 feet, was reported to be free of detectable TPHg and . BTEX compounds MW-6 was however, reported to have 30 ug/l MTBE The results of the groundwater analysis are summarized in Table 2 The analytical reports from Entech and chain-