Implementation of Water Quality Standards and the WQ Based Approach 5-12-08 Implementation of Water Quality Standards and the WQ Based Approach How are WQS used in determining if uses are attained ? Under what circumstances must a water be placed on the “Impaired Waters” list? What is a Total Maximum Daily Load (TMDL)? When must one be developed? - How are permit limits for point sources developed ? Other Questions: What are the roles of the various offices? OW, OST, SHPD, HECD ? What are Laws, What are Regulations, What is Guidance?, Policy? What are the objectives and major provisions of CWA? What is the purpose of Water Quality Standards and the Standards Program? What is EPA’s role in Implementing WQS ? What are we going to cover in this Water Quality Standards Academy? What are Waters of the US? How have water pollution control laws changed over the years? WQSA Module: Implementation and the WQ-Based Approach

Water Quality Based Approach 5-12-08 Water Quality Based Approach Determine Protection Level (EPA Criteria/State WQS) Measure Progress Conduct WQ Assessment (Identify Impaired Waters) Monitor and Enforce Compliance (Self Monitoring, Agency Monitoring) Set Priorities (Rank/Target Waterbodies) Handout 2-5 Water Quality Based Approach is outlined in Sec. 302 of the Act Show Video? (Do we need to review transcript to make sure it is OK?) Establish Source Controls (Point Source, NPS) Evaluate Appropriateness of WQS for Specific Waters (Reaffirm WQS) Define and Allocate Control Responsibilities (TMDL/WLA/LA) WQSA Module: Implementation and the WQ-Based Approach

Monitoring and Reporting: CWA Sections 305 (b) and 303 (d) 5-12-08 Monitoring and Reporting: CWA Sections 305 (b) and 303 (d) Document assessment methodology for WQS attainment decisions Categorize all state waters based on WQS attainment status Present results of probability-based design at state or watershed scale Establish monitoring priorities for next 2 years Establish TMDL development priorities for all Category 5 waters WQSA Module: Implementation and the WQ-Based Approach

California Listing Policy 5-12-08 California Listing Policy Data Quality Number of exceedances of Magnitude, Duration, Frequency Age of data Temporal and Spatial representativeness Aggregation of data by reach/area How to interpret numeric objective How to interpret narrative objectives WQSA Module: Implementation and the WQ-Based Approach

Monitoring and Reporting: Integrated Reporting Categories 5-12-08 Monitoring and Reporting: Integrated Reporting Categories Attaining all designated uses Attaining some designated uses, and insufficient or no data and information to determine if remaining uses are attained Insufficient or no data and information to determine if the standard is attained Impaired or threatened for one or more designated uses but not needing a TMDL because -- a. TMDL has been completed b. Expected to meet standards c. Not impaired by a pollutant Impaired or threatened by pollutant(s) for one or more designated uses and requiring a TMDL 305 (b) Report 303(d) List WQSA Module: Implementation and the WQ-Based Approach

California and the Integrated Reporting Categories 5-12-08 California and the Integrated Reporting Categories Evidence all uses supporting Evidence some uses supporting (and no evidence other uses not supporting) Evidence insufficient to make use support determinations Evidence at least one use not supported (but TMDL not needed) Evidence at least one use not supported (and TMDL needed) WQSA Module: Implementation and the WQ-Based Approach

TMDL = SWLAi + SLAi + MOS TMDL Definition 5-12-08 TMDL Definition TMDL = SWLAi + SLAi + MOS SWLAi: Sum of waste load allocations (point sources) SLAi: Sum of load allocations (nonpoint sources) MOS: Margin of Safety - Extra measure of protection due to uncertainty - Can be explicit (e.g., 10%) or implicit (safety factors and assumptions in modeling, etc.) WQSA Module: Implementation and the WQ-Based Approach

Standards-to-Permits Process 5-12-08 Standards-to-Permits Process 40 CFR §122.44(d) Technical Support Document for Water Quality-based Toxics Control (EPA/505/2-90-001), March 1991 WQSA Module: Implementation and the WQ-Based Approach

Standards-to-Permits Process 5-12-08 Develop Tech. Based Limit for POC Tech. Based Limits / collect more data TMDL for POC ? “Reasonable Potential” ? Yes No No Yes (Calculate) Wasteload Allocation (WLA) Continued WQSA Module: Implementation and the WQ-Based Approach

Standards-to-Permits Process (Continued) 5-12-08 Waste Loa d Allocation (WLA) Use statistics to develop Long Term Average (LTA) Statistics to develop Maximum Daily Limit (MDL) and Average Monthly Limit (AML) WQ- based MDL / AML more stringent than Tech. Based limits ? Water Quality-Based limits in permit Yes No Tech. Based limits in Permit 167D-6C-4 WQSA Module: Implementation and the WQ-Based Approach