ARCHIVED REPORTS_XR0006497 - Laserfiche WebLink

Home Browse Search

n CLEARWATER G R O U P • Enorron men ta7 Srrb iris GROUNDWATER MONITORING RESULTS Depth to water 12 91 (MW-7) to 14 47 (MW-3) feet below top of well casing Flow direction/gradient NW at 0 001 ft/ft TPHg concentration < 50 gg/L (MW-2, MW-3, MW-4, MW-6, MW-7, and MW-8) to 6,200 gg/L (MW-5) Benzene concentration <0 5 gg/L (MW-2, MW-3, MW-4, MW-6, MW-7, and MW-8) to 7 1 gg/L (MW-1) MTBE Concentration < 0 5 gg/L (MW-3, MW-4,MW-7,MW-8) to 2 2 gg/L (MW-5) Other oxygenates TBA = 15 ug/l (MW-1) and ethanol= 7300 (MW-3) Remarks • The groundwater flow direction and gradient are generally consistent with previous results, • Contaminant concentrations were very low or non-detect for all wells sampled except for MW-1 and MW-5, • The fuel oxygenate MTBE was detected at a maximum concentration of 2 2µg/L(MW-5), • Ethanol was detected in MW-3 at 7300 ug/l This was from antifreeze accidentally released during • car maintenance operations into the well box According the station operator this was a one-time event and measures have been taken to avoid a recurrence PROJECT STATUS Per the decision of the RWQCB and the County to continue quarterly sampling, Clearwater will perform an additional 3-4 rounds of quarterly sampling which will be used to develop a more recent profile of contaminant concentrations in the groundwater if trends continue to show low to non- detectable concentrations of contaminants in the groundwater than it is anticipated that Clearwater will again petition the County and the RWQCB for case closure ATTACHMENTS Groundwater Elevations and Sample Analytical Results (Table 1) Site Location Map (Figure 1) Site Pian (Figure 2) Groundwater Contour Map-2/05/01 (Figure 3) Hydrocarbon'Distribution Map-2/05/01 (Figure 4) Well Gauging,Data field notes Laboratory Report and Chain-of-Custody Form Clearwater Groundwater Morutoring and Sampling Protocols I 1 I t I I I ZB878C 1Q01 QMR I� 2 I MaIrch 30,2001 ! II III I I ' I i li