ARCHIVED REPORTS_THIRD QUARTER 2017 GROUNDWATER MONITORING REPORT

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Diamond Pet Food&Ripon Energy October 25,2017 Third-Quarter 2017 Groundwater-Monitoring Report Page 4 of 5 NESTLES Nestl6s USA formerly operated an instant coffee and tea processing plant, located approximately 2,000 feet north of the DP/Ripon Energy site, from 1948 through 1986. Solvents used in the decaffeination process, and their daughter products (trichloroethene, dichloroethene, and vinyl chloride)have impacted soils at the site and groundwater in the upper and intermediate aquifers along the northern and western portions of the DP/Ripon Energy site, and have impacted wells south of the Stanislaus River. Nestl6s' consultant, Environmental Cost Management, historically operated two groundwater-treatment systems in the area to remediate the contaminant plumes, one on South Stockton Avenue and one on Industrial Avenue. The Stockton Avenue treatment systems effectively reduced the mass of contaminants in groundwater to the point where ECM was able to take the Stockton Avenue system offline on October 1, 2010. The Industrial Avenue system still is in operation. Based on the distance of the system's extraction well from the DP/Ripon Energy site and the volume of water treated by the system (<500 gpm), and the relatively high permeability of the aquifer, it is unlikely that the extraction system influences the hydraulic gradient in DP/Ripon Energy wells. HYDROGEOLOGIC SETTING Geology and hydrogeology of the site and vicinity have been described in detail in previous reports.4 Briefly, the DP/Ripon Energy site is located in the East San Joaquin Groundwater Basin and is underlain by a sequence of Tertiary- and Quaternary-aged continental deposits of the Tulare Formation. These deposits consist of interbedded sands/gravels and silts/clays or mixtures thereof. Four distinct aquifers or zones have been identified beneath the site and have been designated by L&A as the semiperched,upper, intermediate, and lower zones. The semiperched zone is unconfined and occurs from approximately 35 to 60 feet below ground surface (bgs). All other zones are semiconfined to confined. The upper zone occurs from approximately 85 to 110 feet bgs, the intermediate zone from 140 to 225 feet bgs, and the lower zone from 240 to greater than 300 feet bgs. Permeability in the aquifer zones has been estimated at approximately 525 gpd/ft2; permeability in the confining layers has been estimated at 3.5 gpd/ft2.5 Groundwater movement in the semiperched and upper semiconfined zones in the vicinity of Ripon is generally to the west.6 North of Ripon, groundwater moves to the north. Southwest of Ripon, on the southwest side of the San Joaquin River, groundwater also moves to the north, towards the river. GROUNDWATER MONITORING DEPTH TO GROUNDWATER The depth to groundwater was measured in all wells prior to purging and sampling using an Actat Model 300 electric well probe. The depth to groundwater was recorded to the nearest 0.01 foot(Table 2; Figure 2). 4 L&A,May 5, 1992,Impacts on Receiving Waters from Discharge at the Simpson Paper Company Facility, Ripon, California. 5Ibid. P.27. 6Ibid., Fig. 3. 010107.09 Task 3 Lawrence&Associates W.-I CLIENTSIDiamond Pet Foods 1010107.01-Groundwater Monitoring)Groundwater Monitoring1201 713Q201 713Q quarter 2017 report.docx