ARCHIVED REPORTS_RPT OF WASTE DISCHARGE FOR WASTEWATER DISPERSAL 2011

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REPORT OF WASTE DISCHARGE- APPENDIX D Diamond Pet Food Processors of Ripon,LLC June 30,2011 Report of Waste Discharge—Antidegradation Analysis Page 5 of 14 associated with designated beneficial use(s). This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. SUMMARY OF AVAILABLE WATER QUALITY DATA GROUNDWATER OCCURRENCE Figure 6 shows a geologic map of the Site and vicinity. Figures 7 though 9 show cross sections through the Diamond site. Geology and hydrogeology of the site and vicinity has been described in detail in previous reports.3 Briefly, the site is underlain by a sequence of Tertiary and Quaternary continental deposits (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 Lawrence &Associates 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 deep zone from 240 to greater than 300 feet bgs. Permeability in the aquifer zones has been estimated at approximately 525 gallons per day (gpd)/square foot; permeability in the confining layers has been estimated at 3.5 gpd/square foot-4 The direction of the groundwater gradient in the semiperched and upper semiconfined zones in the vicinity of Ripon is generally to the west.5 North of Ripon, the direction of the groundwater gradient is to the north. Southwest of Ripon, on the southwest side of the San Joaquin River, the groundwater gradient is to the north, towards the river. Figures 10, 11, and 12 show groundwater elevation contour maps for October 2010, for the semiperched,upper, and intermediate zones, respectively. The deep zone is not contoured, as there is only one monitoring well at the site for that zone. Based on recent data(2010), mounding within the semiperched,upper, and intermediate aquifers occurs offsite in the vicinity of the City of Ripon's WWTP ponds and their fresh water infiltration pond. The groundwater gradient is generally flat across most of the Diamond site. The direction of the groundwater gradient is away from the mounding, and then generally towards the north. 3 Lawrence&Associates,May 5, 1992,Impacts on Receiving Waters from Discharge at the Simpson Paper Company Facility,Ripon, California. 4 Ibid., p.27. 5 Ibid., Figure 3. 010070.00, Task I Lawrence&Associates w:I clients)diamond pet foods1010107.00-ripon rowdldiamondpet_rowdjune2011_draft.docx