SITE INFORMATION AND CORRESPONDENCE_CASE 2

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WASTE DISCHARGE REQUIREMENTS ORDER NO. R5-2007- 2 CITY OF TRACY AND LEPRINO FOODS COMPANY LAND DISCHARGE UNITS OF THE TRACY WASTEWATER TREATMENT PLANT SAN JOAQUIN COUNTY 6. The Facility is composed of a main treatment facility and an industrial treatment facility. The main treatment facility is owned and operated by the City of Tracy and 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 final discharge to Old River. Biosolids are thickened by dissolved air flotation, anaerobically digested, and dewatered in unlined sand drying beds. The dried biosolids are disposed in a landfill or hauled off-site for land application. A flow schematic of the main treatment facility is shown in Attachment B, which is attached hereto and made part of this Order by reference. A plant layout of the main facility is shown in Attachment D, which is attached hereto and made part of this Order by reference. 7. The industrial facility consists, in part, of pretreatment units owned by the City of Tracy and operated by Leprino under an industrial pretreatment permit issued by the City of Tracy, and holding ponds located north east of the main treatment facility site. Leprino is authorized to discharge up to 850,000 gpd of pretreated wastewater in accordance with the industrial wastewater discharge permit. The pretreatment units operated by Leprino include two identical lagoons constructed in 1977 of compacted berms that rise above the base level of the surrounding ground. The berms are of 1.5:1 slope on the interior and meet a concrete floor 94-ft square, and the floor slab is between 8 — 12 inches thick. The concrete floor serves as the base for grouted threaded supports holding an EDI fine air tube diffuser system 18-inches off the floor. The sloped interior sides of the aerated lagoons are lined with an impermeable Hypalon/EPDM reinforced geotextile fabric specifically designed to seal active lagoon systems. The liner is sealed to the floor of the lagoons with a perimeter-bolted frame completely wrapped by the liner material and grouted in place, and the liner itself is vulcanized into a single continuous sheet. The top of the liner is buried in a trench dug 12-inches deep along the top perimeter of the lagoon system to prevent pullout of the liner top. The freeboard design allows for 2-feet of freeboard. The lagoon system is built almost entirely above the surrounding grade. This kind of construction ensures that any liner punctures below the water line will result in saturation of the berm and visual indications of leaking wastewater would be visible on the surrounding berm slopes. Leprino lowers the level of the lagoons periodically to inspect the aeration system and the lagoon liners for signs of wear, and replaces or repairs the lagoon components as needed. The purpose of the aerated, lined lagoon system is to allow for reduction of the organic components of the industrial wastewater produced from Leprino cheese and whey manufacturing process. The process is operated in an aerobic mode that promotes the natural growth of microscopic organisms that consume the soluble portion of the organic materials in the wastewater. The resulting reduction in organic loading is measured as a reduction in BODS in the clarified effluent. Following the active aerobic treatment, the pretreated industrial wastewater is transferred to one of the City owned lagoons located north east of the main plant site. The unlined