SITE INFORMATION AND CORRESPONDENCE_1988-1991

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ARARs and TBCs for Supe•Sites -7- • 17 May 1991 Pretreatment Standards under the Clean Water Act Discharges of treated waste to sanitary sewers may be proposed as part of a remedial actions. These discharges may be regulated under the pretreatment program of the appropriate county sanitation district. The Regional Board is involved in oversight of this pretreatment program and how this program relates to the district's WDRs issued by our Board. Remedial actions involving proposed discharges to the sanitary sewer are regulated by these pretreatment standards and the Regional Board would have oversight authority. This ARAB would be action-specific and could be chemical-specific, as well. A Compilation of Water Quality Goals Many of the water quality objectives, contained in the Basin Plans, for protection of beneficial uses of waters of the state (California's water quality standards) are stated in narrative terms`. To implement these narrative standards, Regional Board staff has produced a report entitled, A Compilation of Water Quality Goals. This report defines a procedure for selection of appropriate concentrations of chemical constituents and water quality parameters used to determine compliance with the narrative water quality objectives. Published numerical values, designed to protect various beneficial uses, have been compiled from a number of state and federal sources in the tables of this report. The procedures for selecting appropriate numerical values from the tables are detailed in the narrative "Selecting Water Quality Goals", found at the front of the report. This staff report is periodically updated to remain current with new and revised published numerical values. In conjunction with the Basin Plans, this document could be used at CERCLA sites to determine ground water and surface water cleanup levels and corresponding remedial actions. Therefore, the staff report would be a chemical-specific and location- specific TBC. The Designated Level Methodology for Waste Classification and Cleanup Level Determination The Designated Level Methodology staff report offers guidance on how to classify wastes under the definitions contained in the Chapter 15, Waste Discharge to Lard, regulations so as to select appropriate disposal practices protective of beneficial uses of waters of the state. The classification of a waste as a "designated waste" is based on concentrations of extractable waste constituents as they relate to water quality objectives or numerical values selected from the Water Quality Goals staff report. Waste constituent-specific and site-specific concentration limits called "Designated Levels" are calculated from numeric 6 Water quality objectives,both narrative and numeric,are ARARs because they are part of the Basin Plan. Examples of narrative objectives from the Basin Plans of the Central Valley Region include: "All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human,plant,animal,or aquatic life." "Ground waters designated for use as agricultural supply(AGR)shall not contain concentrations of chemical constituents in amounts that adversely affect such beneficial use." "Ground waters shall not contain state-or odor-producing substances in concentrations that cause nuisance or adversely affect beneficial uses."