Laserfiche WebLink
c7ealdgical rec/ztics kc. <br />' 1101 7"Street <br /> Modesto,California 95354 <br /> (209)522-4119/Fax(209)522-4227 <br />' REPORT <br /> Groundwater Monitoring <br />' 40' Quarter 2004 <br />' Morita Brothers <br /> 814 E. Charter Way <br /> Stockton, CA <br />' Project No 724 2 <br /> February 7, 2005 <br /> 1 <br /> MEXECUTIVE SUMMARY <br /> This report summarizes the 4`h Quarter 2004 round of groundwater monitoring and testing <br /> that occurred on November 5, 2004 The laboratory analyses indicate that five of the <br />' nineteen monitoring wells on this site remain impacted by gasoline range petroleum <br /> hydrocarbons The groundwater contamination plume appears to have migrated off site <br />' This can be seen in Figure 6 <br /> The average elevation of groundwater in the water table wells at the site was —24 13 feet <br />' MSL (below mean sea level) or approximately 39 feet below grade surface (Table 1) This <br /> project's historic low groundwater levels in the early 1990's were 20 feet lower than the <br /> current level This is part of the problem with trapped residual hydrocarbons below <br />' groundwater that act as a continuing source of groundwater contamination <br /> Groundwater gradient calculations demonstrate that groundwater flow in the three-aquifer <br />' horizons investigated, water table, intermediate and deep wells, flowed in an easterly <br /> direction The historical groundwater gradients at this site consistently trend to the east The <br /> vertical flow component of shallow groundwater gradient was mixed for this quarter Well <br />' pair MW-4/104 exhibited a downward flow that is consistent with past events <br /> The data from the wells that were installed at the site in December 2003 continues to indicate <br />' that the plume appears to extend to the east of the site It is not known whether or not <br /> contaminated properties to the northwest of the site may be contributing to the groundwater <br /> plume <br /> 1 <br />