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INFORMATION SHEET <br /> J. R. SIMPLOT COMPANY <br /> STORMWATER SURFACE IMPOUNDMENT AND <br /> CLASS H SURFACE IMPOUNDMENTS <br /> SAN JOAQUIN COUNTY <br /> J. R. Simplot Company (Simplot) manufactures and formulates fertilizer at this facility in <br /> Lathrop California. Simplot discharges wastewater to both unlined and lined surface <br /> impoundments. The following is a description of Simplot's wastewater system and <br /> rationale for some of the requirements set forth in these waste discharge requirements. <br /> 1. Facility description: <br /> Simplot's Lathrop facility is south of the city of Stockton in south central San <br /> Joaquin County, Section 35, TIS, R6E MDB&M on approximately 341 acres. <br /> This facility was previously owned by Occidental Chemical Company. Occidental <br /> manufactured and formulated both fertilizers and pesticides at this facility. In the <br /> late 1970s, prior to transfer of the facility to Simplot, ground water at this site was <br /> found to be contaminated with some organic pesticides (primarily <br /> dibromochloropropane and ethylene dibromide). A Stipulated Agreement for <br /> investigation and cleanup of the site was approved by the Court in the early 1980s <br /> as described in findings Nos. 6 and 7 of these requirements. Essentially, <br /> Occidental is responsible for site cleanup while Simplot is responsible for managing <br /> wastes discharged subsequent to the transfer of the facility. Simplot no longer <br /> formulates pesticides at the Lathrop facility. <br /> Simplot is proposing to discharge up to 0.05 million gallons per day (mgd) of <br /> process waters and washdown water to lined ponds. (These lined ponds consist of <br /> one 3.5-acre asphalt and sealant lined pond and two single lined (Hypalon) ponds <br /> (3.2 and 2.8 acres, respectively.) Simplot discharges an average of 0.3 mgd of <br /> stormwater runoff from the fertilizer process area and zeolite softener backwash <br /> water to these lined ponds also. This wastewater generally has high concentrations <br /> of total dissolved solids (TDS), primarily ammonium sulfate and calcium oxide. <br /> This water is recycled for use in the manufacture of fertilizers and is classified as <br /> 'designated' using the criteria set forth in Chapter 15. Simplot also discharges an <br /> average of 0.089 mgd of stormwater runoff, cooling tower blowdown, reverse <br /> osmosis and boiler blowdown, and wastewater from a small package sewage <br /> treatment plant to a 7.8-acre unlined pond. This wastewater is exempt from the <br /> requirements of Chapter 15 as described in finding No. 14, but is also regulated by <br /> these waste discharge requirements. <br /> Simplot's existing ground water monitoring at this site indicates that water quality <br /> may have been impacted from discharges from the asphalt- lined pond containing <br /> elevated levels of TDS and sulfates. (Shallow ground water in the area has elevated <br /> concentrations of TDS above the primary drinking water standard of 500 mg/l.) <br /> Simplot is proposing to retrofit the existing ponds with double-liner systems to <br /> conform to the requirements of Chapter 15 as part of the Corrective Action for this <br /> facility. <br />