SITE INFORMATION AND CORRESPONDENCE_CASE 2

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INFORMATION SHEET 2 ORDER NO. R5-2007-_ CITY OF TRACY AND LEPRINO FOODS COMPANY LAND DISCHARGE UNITS OF THE TRACY WASTEWATER TREATMENT PLANT SAN JOAQUIN COUNTY it. Facility Description A. Description of Wastewater and Biosolids Treatment or Controls 1. The Discharger provides wastewater treatment and disposal services for residences, businesses, and industries within the Tracy area. The Facility was originally constructed in 1930 and has experienced three major expansions. The last expansion was completed in 1987, expanding treatment capacity from 5.5 mgd to 9.0 mgd. 2. The Facility consists of a main treatment facility and an industrial facility, and includes two separate systems for the collection and conveyance of wastewater to the Facility. The main treatment facility accepts domestic and commercial wastewater via the City of Tracy's wastewater collection system. The industrial facility accepts industrial food processing wastewater through a segregated pipeline from Leprino. The main treatment facility consists of raw influent bar screening, primary sedimentation, biofiltration, conventional activated sludge, and secondary sedimentation. Secondary effluent is disinfected by chlorination and dechlorinated prior to discharge. Biosolids are thickened by dissolved air flotation, anaerobically digested, and dewatered in unlined sand drying beds. The dried biosolids are hauled off-site for land application or disposed in a landfill. A flow schematic of the main treatment facility is shown in Attachment B. The industrial facility consists of four unlined industrial ponds (approximately 52 acres), operated by the City of Tracy, and two lined aerated lagoons and one unlined oxidation pond (8 acres) leased by Leprino from the City of Tracy for preliminary treatment of its industrial food processing wastewater. Although the aerated lagoons are lined, the technical specifications for the liner materials are not available, and the integrity of the liner is not known. Leprino discharges to the unlined industrial ponds under an industrial pretreatment permit issued by the City of Tracy. Leprino transports its industrial wastewater to the Facility via a segregated industrial waste line. Leprino employees operate and maintain the industrial wastewater pipeline and leased pretreatment units. Leprino's industrial pretreatment program permit allows for a discharge of up to 850,000 gallons per day of industrial food- processing wastewater. Compliance with Leprino's industrial pretreatment permit is measured prior to discharge to Pond 1 (see Figure 1). The unlined industrial ponds provide evaporation and percolation prior to the wastewater entering the main treatment facility at the primary sedimentation basins. A flow schematic of the industrial facilities is shown in Attachment C. B. Planned Changes The Discharger is upgrading the Facility to improve treatment and expand capacity. The treatment system capacity will be expanded to 16 mgd through a four-phase expansion.