SITE INFORMATION AND CORRESPONDENCE

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Dopaco Inc. (Case 1 Tank C) -4- 15 April 2015 800 W. Church St., Stockton San Joaquin County - Showing Area of Excavation), as required by the Court Order. The excavation removed three hundred twenty (320) cubic yards of soil containing approximately 9.3 pounds (1.5 gallons) of Toluene. An estimated 2.5 pounds (0.4 gallons) of Toluene remain in soil. Confirmation soil samples were not taken from the pit walls due to metal shoring restricting access and the wet floor of the excavation. 12)Post remediation monitoring of shallow groundwater in source area monitoring well DMW-5A show Toluene concentrations declined from a maximum of 25,000 ug/L in March 2014 to 1,600 ug/L in December 2014 over five (5) sampling events. Groundwater monitoring, down-gradient of the Site, showed Toluene pollution is limited in areal extent and has not migrated significantly from the Site. Toluene has not been detected in monitoring wells constructed across Church Street, less than 80 feet away. Reductions in concentrations of Toluene on-site are likely due to the excavation activities that removed the bulk of the mass of Toluene in the subsurface. GC did not estimate residual Toluene in groundwater. 13) In January 2015, GC submitted the Request for Closure for Toluene (Closure Report). In the Report, GC concluded that the Site is adequately characterized for the extent of Toluene. GC states WQOs will be met for Toluene by 2075 (60 years). 14)Public participation through distribution of a Fact Sheet was performed on 15 February 2015. The public participation period ran from 15 February 2015 to 15 April 2015, and no comments were received. 15)All monitoring wells installed at the Site will be utilized for investigation of petroleum hydrocarbons and chlorinated solvents impacts at the Dopaco Area Case 3. Recommendations Based on available data, we concur with GC's recommendation for case closure of the Toluene impacts at the Dopaco Area Case 1. Over-excavation removed the majority of the mass in soil and groundwater impacts are stable and decreasing in areal extent and concentrations. GC estimates 9.3 pounds of Toluene-impacted soil were removed by over-excavation. An estimated 2.5 lbs. of Toluene remain in soil. Groundwater concentrations appear to be stable to declining. Nine (9) Site monitoring well will continue to be utilized for investigation of tanks A, B, D, E, F, G and H in Case 3, Attachments: Figure 1 Site Location Map Figure 2 Site Plan Map — Underground Storage Tanks Location on Dopaco Area Figure 3 Stipulated Injuction and Consent Decree Area Figure 4 Sensitive Receptor Location Map with Destroyed Supply Well Locations Figure 5 Summary of Toluene Concentrations in Shallow (A zone) Groundwater Figure 6 Site Layout Showing Area of Toluene Above ESL Table 4 Groundwater Monitoring Results Attachment A Stipulated Injunction and Consent Decree