ARCHIVED REPORTS_RPT OF WASTE DISCHARGE FOR WASTEWATER DISPERSAL 2011

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Diamond Pet Food Processors of Ripon,LLC June 30,2011 Report of Waste Discharge Page 8 of 17 HYDRAULIC CONDUCTIVITY Hydraulic conductivity, based on aquifer testing of onsite wells ranges from about 40 to 100 feet/day in the aquifer units, and 0.1 to 5 feet/day in the confining units. Appendix B contains more information on hydraulic conductivity for the site. CAPILLARY RISE Based on values of capillary rise in sediments typical of those observed beneath the site, capillary rise beneath the site could range from 1.5 (gravel) to 750 (fine silt) cm(0.6 inches to 24 feet).6 SPRINGS There are no springs in the Plant vicinity. GROUNDWATER QUALITY During the past year,Neenah and then Diamond were still accepting, diluting, and disposing the brine stream from the adjacent cogeneration plant. Cogen brine is discharged to Diamond's clarifier where it is mixed with lower TDS water from production wells PW-6 through PW-8 before being discharged, in sequence, into aeration stabilization basins ASB-1 and ASB-2, and then pumped to irrigation and percolation fields around the site for disposal. In 2010,the maximum average monthly TDS concentration measured in discharge from ASB-2 was 643 mg/L (January), which is below the 713 mg/L water-quality protection standard(WQPS) for TDS established for the semiperched aquifer (Table 3). Currently, groundwater chemistry under portions of the site does not meet water-quality protection limits established for this site, although groundwater quality is continuing to improve. Figures 13, 14, and 15 show contour maps of TDS for the three aquifers, from October 2010 data. In October 2010, the highest onsite TDS in the semiperched aquifer was measured in wells located in and adjacent to the eucalyptus grove in the northeast quadrant of the site; in wells located around ASB-1, and wells located along the western property boundary. The area of lowest TDS was in the southeastern corner of the site along the Stanislaus River(Figure 13). The highest TDS levels in the upper aquifer were in wells M-11-A and TH-2 (820 to 917 mg/L). The area of lowest TDS was in the northwestern corner of the site in well TH-7 (59 µmhos/cm). All wells screened in the upper aquifer were in compliance with the WQPS of 1,030 µmhos/cm(Figure 14). 6 Fetter, C.W., 1988,3rd.ed.,Applied Hydrogeology, Table 6.1,p. 182. 010107.00, Task I Lawrence&Associates w:Iclientsl diamond pet foods1010107.00-ripon rowdldiamondpet_rowdjune2011_draft.docx