Laserfiche WebLink
v <br /> A S S O C I A T E S I N C <br /> average increase in the water table elevation of approximately 1 12 feet since January 1999 The <br /> water level data were used to develop the groundwater elevation contour map (Figure 3) <br /> Assuming that horizontal isotropic conditions prevail, groundwater in the uppermost aquifer <br /> beneath the site flowed generally towards the east-northeast The average hydraulic gradient on <br /> April 9, 1999 was calculated to be 0 002 ft/ft or approximately 9 ft/mile A summary of <br /> groundwater monitoring data is presented in Table 1 <br /> ADDITIONAL SITE ACTIVITIES <br /> On May 27, 1999, ATC personnel supervised the transport and disposal of 900 gallons of purge <br /> water stored on site Prior to the purge water disposal, analytical data was supplied to Clearwater <br /> Environmental to profile the purge water for the appropriate disposal method Clearwater <br /> pumped the purge water into a vacuum truck and transported the purge water to Alviso, <br /> California where it was recycled by Alviso Independent Oil Copies of the non-hazardous waste <br /> manifests are included in Attachment 3 <br /> CONCLUSIONS <br /> Concentrations of petroleum hydrocarbon constituents remained approximately the same in well <br /> MW-3 and remained at nondetectable concentrations in well and MW-6 It appears as though <br /> there is residual petroleum hydrocarbon contamination remaining in the soil <br /> The direction of groundwater flow and the magnitude of hydraulic gradient are generally <br /> consistent with previous quarters <br /> RECOMMENDATIONS <br /> Based on the results of the second quarter 1999 monitoring episode, we recommend the <br /> following <br /> o Conduct the Third Quarter 1999 groundwater monitoring and sampling of wells MW-1 <br /> through MW-6 <br /> o Continue to analyze the groundwater samples from all wells for TPHg, BTEX, and MTBE <br /> by EPA Method 8015/8020 <br /> w 1626MquaAlyl2gr-1999 doe 3 <br />