SITE INFORMATION AND CORRESPONDENCE_CASE 2

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WASTE DISCHARGE REQUIREMENTS ORDER NO. R5-2007- 8 CITY OF TRACY AND LEPRINO FOODS COMPANY LAND DISCHARGE UNITS OF THE TRACY WASTEWATER TREATMENT PLANT SAN JOAQUIN COUNTY 27. On 15 June 2004, Regional Water Board staff issued a CWC Section 13267 Order requiring the City to (a) evaluate potential groundwater degradation from its sludge dewatering process, sludge storage practices, and industrial waste aeration ponds, (b) evaluate Best Practicable Treatment and Control (BPTC) practices for the sludge dewatering and storage practices, and (c) determine the appropriate classification for the wastewater in the industrial ponds. 28. The Discharger was unable to provide an adequate evaluation as to whether groundwater degradation has occurred as a result of the sludge dewatering, biosolids storage, and industrial waste aeration processes, because groundwater monitoring wells have not been installed downgradient of these treatment units. This Order requires that that analysis be completed. Provisions E.1.b. requires the Discharger to ensure the groundwater monitoring network includes one or more background monitoring wells and a sufficient number of monitoring wells downgradient of every treatment, storage, and disposal unit that does or may release waste constituents to groundwater. Antidegradation Analysis 29. State Water Board Resolution No. 68-16 (hereafter "Resolution 68-16" or the "Antidegradation Policy") requires the Regional Water Board in regulating the discharge of waste to maintain high quality waters of the state (i.e., background water quality) until it is demonstrated that any change in quality will be consistent with maximum benefit to the people of the state, will not unreasonably affect beneficial uses, and will not result in water quality less than that described in the Regional Water Board's policies (e.g. exceeds water quality objectives or naturally occurring background concentrations). 30. This Order requires that the discharge be consistent with Resolution 68-16. Groundwater Limitations D.1. prohibits the release of waste constituents from any storage, treatment, or disposal component associated with the Facility, in combination with other sources of the waste constituents, to cause underlying groundwater to contain waste constituents in concentrations statistically greater than background water quality (i.e. no degradation). The wastewater contained in the industrial ponds is primarily industrial wastewater from Leprino. Therefore, any groundwater degradation would not be consistent with maximum benefit to the people of the State. The sludge dewatering system is part of the domestic wastewater treatment plant. However, no groundwater degradation is allowed, because there are standard BPTC methods that will prevent degradation. 31. The Facility currently utilizes sand-lined sludge drying beds to dewater biosolids and the City stores dried biosolids in an unlined pond, which could allow wastewater to percolate to the groundwater. In addition, the Facility includes unlined industrial holding ponds, which contain high salinity wastewater that percolates to groundwater. Resolution 68-16 requires that these facilities meet best BPTC. Provision EA.c. of this Order requires the Discharger to evaluate and meet BPTC for these treatment units.