Laserfiche WebLink
s <br /> CA �/IBRDA <br /> i <br /> ® Cambria evaluated water-level measurement data and prepared a groundwater contour <br /> map (Figure 2). Groundwater flow direction ranges from northerly to southeasterly <br /> with an approximate hydraulic gradient of 0.01. <br /> n TPHg and benzene were not detected in any of the groundwater samples. MTBE was <br /> detected in wells MW-1, MW-2, MW-3, MW-5, RW-2, VEW-1, VEW-2, and VEW-4 <br /> at concentrations ranging from 5.69 to 1,360 ppb. A chemical concentration map is <br /> presented on Figure 2. <br /> Quarterly Sampling <br /> Groundwater samples were analyzed for total purgeable hydrocarbons as gasoline (TPHg) <br /> according to EPA Method 8015 (Modified) and benzene, toluene, ethylbenzene, xylenes <br /> (BTEX), and methyl tertiary butyl ether (MTBE) according to EPA Method 8020. Well <br /> VEW-3 was also sampled and analyzed for halogenated volatile organics by EPA Method <br /> 8010B (Table 1). <br /> . Field monitoring data and chemical analytical data are presented in a summary table in <br /> Blaine's groundwater monitoring report (Appendix A). Additional groundwater analytical <br /> data is summarized on Table 1. <br /> Conclusions and Recommendations <br /> TPHg and benzene concentrations have been at low or non-detect levels at this site for <br /> several quarters. MTBE detected at this site is suspected to be from a nearby ARCO site. <br /> Cambria recommends pursuing closure at this site. Cambria also recommends groundwater <br /> monitoring and sampling be discontinued as there is no benefit to collecting additional data at <br /> this site. Monitoring and sampling will not be performed at this site beginning the first <br /> quarter of 2000 unless we hear otherwise from SJCPHS. <br /> 241-0821 2 <br />