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Mr. Jeffrey Wong March 27, 2001 Page 3 Work Plan Addendum Ramage Environmental's work plan proposed that three wells be installed in the city of Stockton right-of-way, one of which was proposed for the center lane of East Charter Way. For safety reasons, the city denied the encroachment for the well in this center lane. As an alternative, Ramage Environmental approached the San Joaquin County Fairgrounds to encroach on their property to install the well. As shown on the enclosed map, Ramage Environmental recommends that two monitoring wells be installed on the fairgrounds property to better define and monitor the existing plume of impacted groundwater. Currently, the request to access the fairgrounds property is under review of the fairground's board of directors. Both of the monitoring wells proposed for the fairgrounds property would be constructed, developed, surveyed, monitored and sampled according to the same specifications outlined in Section 2.4 of Ramage Environmental's approved work plan. All four of the new wells would be incorporated into the quarterly groundwater monitoring and sampling program at the site. At your verbal request, Ramage Environmental proposes drilling a single CPT boring in the center lane of East Charter Way, in lieu of the originally proposed monitoring well. L According to the city of Stockton, an encroachment permit should be granted for this activity since it does not involve a permanent well installation. Like at CPT-1, a pair of soil borings would be advanced at the proposed CPT location to a maximum depth of approximately 125 feet bgs. Since impacts to subsurface soil have mostly been delineated by previous on-site soil borings, additional soil samples will not be collected for analysis from the proposed CPT boring. To evaluate the lateral and vertical extent of impacted groundwater, discrete groundwater samples will be collected at the groundwater table and from each sand and/or gravel sequence identified beneath the groundwater table. The depth-discrete groundwater samples will be collected using a Hydropunch. To confirm concentrations of gasoline hydrocarbons detected in the groundwater sample collected at 60 feet bgs from CPT-1, and to further evaluate the vertical extent of impacted groundwater beneath the site, another CPT boring will be advanced at CPT-1. This single boring will be drilled to collect discrete groundwater samples from the sand and/or gravel intervals previously identified at CPT-1 at approximately 60 and 105 feet bgs. These groundwater samples will also be collected using a Hydropunch. All groundwater samples will be collected into laboratory-supplied containers, which will be labeled, packaged in an iced cooler, and transported with chain-of-custody documentation to Kiff for analysis. Kiff will analyze the groundwater samples for TPH-as-gasoline, BTEX, MTBE, DIPE, ETBE, TAME, TBA, 1,2-DCA and EDB by EPA Method 8260B.