Presentation on theme: "Whole Effluent Toxicity NPDES Program"— Presentation transcript:
1 Whole Effluent Toxicity NPDES Program Laura PhillipsUSEPA - Office of Wastewater Management,
2 What is Whole Effluent Toxicity (WET) Testing & Why Do it? What is it? -WQ-based toxics control method that directly measures the total or aggregate toxic effect (additive, synergistic and antagonistic) of an aqueous sample through the response(s) of exposed aquatic organisms.Why do it? -Protects Narrative Criterion (“no toxics in toxic amounts”) & was designed to predict the impact and toxicity of effluents to determine “safe effluent discharge concentrations” with respect to WQS (criteria).
3 EPA Whole Effluent Toxicity (WET) Program WET - Component of the WQ Integrated ApproachWQ WET Criteria & StandardsNPDES Regulations: 40 CFR Part 122(i.e., 40 CFR Part (d)(1)(iv) & (v))WET Methods (40 CFR Part 136)NPDES Permit & EPA Regions, Permitting Authorities (45 NPDES States) and PermitteesConsultants (i.e., Labs)
4 Whole Effluent Toxicity Criteria Applying toxicity criteriawith allowable dilutionNarrative - “no toxics in toxic amounts”Numeric TSD recommendations or numeric interpretation of NarrativeAcute = 0.3 TUa (e.g., 100/LC50)Chronic = 1.0 TUc (e.g., 100/NOEC)Outfall0.3 TUa1.0 TUc
5 Major Components of a NPDES Permit Cover PageEffluent limitationsMonitoring & Reporting RequirementsSpecial ConditionsStandard Conditions
6 With Regard to WET - - NPDES Permits Must Specify Test Species and Method(Fathead Minnow, Acute or Chronic)Testing Frequency(Representative of the Effluent)Statistical Endpoints(Acute: LC50 or IWC, Chronic: NOEC, ICp)Steps to Address Toxicity(Accelerated WET testing, TREs/TIEs)
7 WET Test Method Selection Approved acute and chronic methods (40 CFR Part 136)Must determine:Acute or chronic toxicity (based on calculatedlimits or available dilution)Freshwater or marine dischargeMost appropriate species (e.g., 3 species quarterlyfor 1 year)
8 WET MonitoringWET Monitoring Representative of Effluent Discharge: Important for WET reasonable potential determinations & evaluating WET NPDES permit limit complianceUSEPA NPDES Regulations: 40 CFR (g)(11) 40 CFR Part (j)(5) 40 CFR Part (i) 40 CFR Part (b)USEPA Guidance:Technical Support Document (TSD) (1991, OWM)Interim Guidance for Performance-Based Reductions of NPDES Monitoring Frequencies (4/19/96, OW/OECA)
9 WET Reasonable Potential (RP) Determinations No WET Data: Use EPA Technical Support Document’s (TSD) statistical approaches to determine if RP exists.Fewer than ten valid WET data points (per species): EPA’s TSD provides recommended coefficients of variation.Ten or more valid WET data points: With ten or more valid and representative effluent data points a robust WET RP determination can be done.
10 TSD Steps in Developing WET Permit Limitations WLA = Wasteload Allocation, LTA= Long Term AverageAcute & Chronic Wasteload AllocationsStep 1: Convert Acute WLA to Chronic WLA(WET only)Step 2: Calculate LTA for BothStep 3: Select Lowest LTAStep 4: Calculate Maximum Daily Load & Average Monthly Limits
11 NPDES Program Resources USEPA OWM Catalog of Publications (EPA 830/B )Basic Permit Writers’ Manual (EPA/833-B , 12/96)Technical Support Document (EPA/ , 3/91)USEPA Basic Permit Writer’s Course - Ca (1/03)OWM Web site: orSETAC WET Training CoursesWeb site: setac.org
12 NPDES Program Resources Under Development NPDES Permit Development Tool (NPDES/PDT):Electronic tool that will allow permit writers to interactively calculate water quality-based effluent limitations for large number of pollutants. Future versions will include the ability to calculate technology-based limits.Permit Application Software System (PASS):Phase I: Electronic system which allows permittees to electronically prepare NPDES permit applications, print, & mail it to their NPDES permitting authorities. Phase II: System will be enhanced to allow electronic submission to the NPDES permitting authority. (http://cfpub.epa.gov/npdes/pass)
13 WET National Program Technical Resources Information/Assistance:EPA OW/OWM Web site:EPA OW/OST Web site:EPA Regional ContactsSETAC Web site: including “Frequently Asked Questions” Bulletin BoardSETAC WET Expert Advisory Panel:USEPA WET Document Compendium
14 USEPA WET Document Compendium - Sample List WET Requirements in Municipal Permits (7/85)WET Sample Permitting & Enforcement Guidance (2/89)WET Control Policy (7/94)National Policy Regarding WET Enforcement (8/95)Clarifications Regarding Flexibility in WET Methods (4/96)Clarifications Regarding WET Test Methods & Guidance on Implementing WET Toxicity in Permits (7/97)TRE Municipal Guidance (8/99)WET Variability Guidance (6/00)WET Test Methods Guidance (7/00)TRE/TIE Clarifications Document (5/01)WET Test Methods Proposed Rule (9/01)
15 Where Do We Go From Here?Critical Crossroads - Require careful consideration of the issues, maintaining the NPDES base program, & identifying possibilities for appropriate flexibility within existing NPDES regs and the CWA.Review the Facts - Use facts to cull out non-productive issues so remaining issues are prioritized in a manner that produces results.Pursue Strategic Pathways or Decisions - To overcome ongoing barriers to effectively implementing the NPDES WET program.
16 Closing Remarks Move Program Forward Where possible, reduce controversies and implement the WET program in a manner that fulfills CWA objectives, complies with USEPA NPDES regulations, and is endorsed by stakeholders through their actions and support to the program.