SITE INFORMATION AND CORRESPONDENCE CASE 2

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INFORMATION SHEET PAT MITCHELL AND CALIFORNIA NATURAL PRODUCTS WASTEWATER TREATMENT AND DISPOSAL FACILITY SAN JOAQUIN COUNTY California Natural Products (CNP)mainly processes rice and soy into food products such as rice syrup, rice milk, puddings, and rice syrup solids, but also processes soups from vegetables, coffees, and teas. The facility is in Lathrop, immediately south of Sharpe Army Depot, with surface water drainage to the San Joaquin River. Water is provided by the City of Lathrop's municipal supply. The plant does aseptic packaging under sterile conditions, requiring heated water from boilers and regular acid/caustic tank and equipment cleaning cycles. Reverse osmosis is used to treat boiler feed water. Operations are conducted year round, five days a week with three shifts per day, with a cleanup shift performed every other day. CNP has been operating and discharging process wastewater to land since 1985; however, at that time the discharge volume averaged less than 100 gallons per day. From the early 1980s to approximately mid-1996, the Discharger land-applied process wastewater to two disposal areas within 14 acres of land situated north of the present disposal area. The food processing facilities and wastewater discharge volume have grown greatly since the mid- 1990s. Odor complaints were received in October 1987, July 1997, July 1998, March 2000, and July 2000. The odor was related to the land application area. The wastewater generated from these processes is characterized by a high organic matter and solids content. CNP constructed a pretreatment facility in 1999 and 2000 to reduce the organic load in the process wastewater. Treatment of process wastewater consists of a holding/recycle tank; pH control, dissolved air flotation(DAF) clarifier; a 45-foot diameter, 20-foot high trickling filter; a 600 gallon per minute (gpm) lamella separator; and a centrifuge to dewater the solids from the lamella separator and the float from the DAF clarifier. Prior to discharge the wastewater is stored in a 13,000 gallon tank. The screened solids are contained in bins, transported off-site, and used for animal feed. The discharge flow rate is approximately 200,000 gallons per day(gpd) to a 17.6 acre land application area near the processing facility. The treatment and disposal field has been laser leveled and slightly bermed around the edges so that there is no runoff from the area. Approximately 50,000 to 150,000 gpd is also discharged to the City of Manteca's wastewater treatment plant. Groundwater at the land application area is monitored by three groundwater monitoring wells. Groundwater monitoring has been performed since July 1988, however the quality of the monitoring data is poor and may not be representative of site conditions. Two of the wells are located in the application area, the third well is located in an area previously used for land application which was developed for warehouse space. Three additional wells which were installed as part of a petroleum fuel leak investigation exist at the