Laserfiche WebLink
1 <br />3.0 Treatment Objective <br />Results of investigations performed to date indicate that the onsite contaminants of primary <br />concern (COPC) in groundwater are gasoline -based petroleum hydrocarbons and BTEX. Most <br />of the COPCs appear to be in and around the former UST location along the eastern perimeter of <br />the site property — the likely source of the groundwater contaminant plume. Because the extent <br />of the contaminant plume has not yet been fully established, the primary treatment objective will <br />be to remove the bulk of the COPCs in this area, to the extent technically and economically <br />feasible, so as to minimize further adverse impact of the groundwater. <br />According to the Water Quality Control Plan (CVRWQCB, 2007b) and the Groundwater <br />Management Plan for Eastern San Joaquin, published by Northeastern San Joaquin County <br />Groundwater Banking Authority (2004), groundwater within the city of Stockton has a current <br />beneficial use for municipal drinking water supply, although the depth of groundwater intake for <br />the supply is not readily known. Therefore, the California maximum contaminant levels (MCL) <br />will be considered as the initial target treatment goals for the COPCs in the groundwater at the <br />site. Of the COPCs, benzene has the lowest MCL; therefore, the area of treatment will be based <br />on the October 2007 benzene levels that are above the MCL (Shaw, 2007). The anticipated <br />treatment area is also shown on Figure 4. <br />FS_ Onsite Petroleum Hydrocarbon Remediation.doc 3-1 Shaw Environmental, Inc. <br />