ARCHIVED REPORTS_XR0004432 - Laserfiche WebLink

Home Browse Search

� r First Quarter Crroundwater Monitoring Report March 2003 Boyett Petroleum,419 S.Main,Manteca,CA Page 2 Table 1 Sumniag of March 2003 Quarter! Groundwater Monitoring Results Field Activity Number of groundwater wells 9 Number of groundwater wells sampled 7 Number of groundwater wells g Datc(s)monitored and sampled 3/21/2003 monitored Site Hydrology Average depth to groundwater Average increase(+)/decrease(—)in -1.34 feet below monitoring well measuring 17.97 feet depths to groundwater since last sampling (Shallower) Dints Approximate flow direction and 0.0008 ll/fl West/Southwest as calculated using groundwater gradient monitor wells MW-2, MW-6, and MW-8. Groundwater Contamination Monitor wells containing free None Monitor wells with detected odors 0 product MTBE Maximum concentrations detected in the Nature of contamination: Gasoline monitor wells: Oxygenates/ MTBE(gg(L) 6,400 Additives TAME(µglL) 1 33 s` Monitor wells MW-4 and MW-5 were not sampled,sediment load in MW-4 was too high and MW-5 was dry FIELD OBSERVATIONS On March 21, 2003, a Condor representative was on site to measure water levels and collect groundwater samples from monitoring wells MW-1 through MW-9. Groundwater samples were collected from monitoring wells MW-1, MW-2, MW-3, MW-6, MW-7, MW-8, and MW-9. Monitoring well MW-4 contained significant sediment and MW-5 was dry; thus, groundwater samples were not collected. The • ' locations of the monitoring wells are shown in Figure 2, attached. Field observations included water level measurement (Table 2, below), appearance of samples (color, clarity, and presence of petroleum product sheen or phase in samples), and collection of water quality field parameters. Field observations are included on the Groundwater Monitoring Field Forms, attached. No floating product, sheen, or odors associated with petroleum hydrocarbons were observed in the groundwater purged from the monitoring wells during the collection of groundwater samples. Clarity was good in all of the field inspection samples, with the exception of MW-1 that had moderate clarity. The purged groundwater from MW-1, MW-2, MW-3, MW-6, MW-7, and MW-8 tamed brown with poor clarity. The purged groundwater from MW-9 turned brown with moderate clarity. GROUNDWATER ELEVATIONS AND GRADIENT Groundwater elevations fluctuated relative to the previous quarterly monitoring event (December 2002). The average groundwater elevation increased with respect to the previous quarterly monitoring event by 1.34 feet. Groundwater elevation data is presented in Table 2, on the next page, and historic groundwater elevation data is attached. 1 i� CONDOR