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1 Ile 3 0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS Since the three on-site monitoring wells were last monitored and sampled in April 2001, the groundwater surface has dropped an average of 1 42 feet, and the groundwater flow 1 direction and gradient have remained relatively constant Since the wells were last sampled, the concentrations of gasoline hydrocarbons in the three wells have remained relatively consistent The results of the groundwater sample analyses indicate that the lateral extent of impacted groundwater remains undefined to the north (upgradient), west and south (downgradient) of the former UST excavation However, the lateral extent is defined to the northeast of the former USTs by MW-1 Vertically, the extent of impacted ' groundwater also remains undefined On December 13, 1999, Ramage Environmental submitted Work Plan, Environmental Site Investigation to PHSIEHD and RWQCB Tasks outlined in the work plan included a geophysical survey to further delineate metal debris in the former UST excavation, sensitive receptor survey, installation of three additional groundwater monitoring wells to further define the lateral extent of impacted groundwater, continued quarterly monitoring and sampling of the monitoring well network, and cone penetration testing to delineate the vertical extent of impacted groundwater ' On March 27, 2001, Ramage Environmental submitted to PHSIEHD, Status Report and Work Plan Addendum, which documented the results of the single on-site CPT boring and outlined an expanded scope of work The additional tasks included re-positioning two monitonng wells onto the San Joaquin County Fairgrounds property south of the site, and additional CPT borings on-site and in the center lane of Charter Way On April 30, 2001, PHSIEHD approved the work plan addendum Currently, the project permits are being obtained from the city of Stockton and PHSIEHD The city of Stockton has delayed issuance of their encroachment permit due to the resurfacing of East Charter Way As such, it may be necessary to proceed with the proposed monitoring well installations within the Sierra Nevada Street right-of-way and on the San Joaquin County Fairgrounds property, prior to gaining access to East Charter 1 Way In addition to these approved corrective action tasks, Ramage Environmental recommends that the well network continue to be monitored and sampled on a quarterly basis The next monitoring and sampling event will be in October 2001 8