ARCHIVED REPORTS_SECOND QUARTER 2013 GW MONITORING RPT

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Diamond Pet Food&Ripon Cogeneration July 12,2013 Second-Quarter 2013 Groundwater Monitoring Report Page 4 of 5 HYDROGEOLOGIC SETTING Geology and hydrogeology of the site and vicinity have been described in detail in previous reports.2 Briefly, the DP/Cogen 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/ft2.3 Groundwater movement in the semiperched and upper semiconfined zones in the vicinity of Ripon is generally to the west.4 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). PURGING PROCEDURES Wells were purged and sampled with a 12-volt PVC submersible pump. Groundwater was purged from each well until three well volumes of water had been removed from the wells or until the field parameters of conductivity and pH had stabilized. Purge water was discharged directly to the ground and allowed to infiltrate or evaporate. SAMPLE COLLECTION Each groundwater sample was collected in appropriate sample bottles provided by the analytical laboratory,placed on ice in a cooler with a chain-of-custody form, and shipped under chain-of- custody to BC Laboratories, Inc. in Bakersfield, California for analyses. FIELD ANALYSES L&A performed field analyses for temperature, conductivity, and pH on groundwater samples using a Hanna Combo pH/conductivity meter and a LaMotte 2020 turbidity meter. All meters were field calibrated with standardized solutions before use. 2 L&A,May 5, 1992,Impacts on Receiving Waters from Discharge at the Simpson Paper Company Facility, Ripon, California. 'Ibid., P.27. 'Ibid., Fig. 3. 10107.04 Task 2 Lawrence&Associates W.ICLIENTSIDiamond Pet Foods1010107.01-Groundwater MonitoringlGroundwater Monitoring1201312Q201312nd quarter 2013.docx