Increasing the Role of Statistic in Water Quality Management Decisions

1. Increasing the Role of Statistic in Water Quality Management Decisions Dan McKenzie ORD Western Ecology Division Corvallis, Oregon Sept. 10, 2004

2. Outline • Clean Water Act Requirements • Past – Before EMAP • Present – Transition (Implementation) • Future – Opportunities (Needs)

3. Clean Water Act(CWA) • Objective: “restore and maintain the physical, chemical, and biological integrity of the Nation’s waters” • Section 303(c) – State Water Quality Standards, Designated Uses & Criteria • Section 305(b) – Report Condition of Nation’s waters • Section 303(d) – List of Impaired waters and Restoration Plans

4. Past CWA Reports • EPA Reports to Congress (2 yrs) • 305(b): State Data – Inconsistent (Designated Uses, Criteria, Indicators, Methods) • 303(d): State’s Assessed Waters (Selected Sites, Listing Criteria) • All Reviews Identified Major Shortcomings

5. Florida – Summary The state has approximately 50,000 miles of streams, 3,000 square miles of lakes, and 4,000 square miles of estuaries. For this report, water quality was summarized by determining the degree of attainment for designated use for the state’s different water body types. FDEP assessed 9,016 miles of rivers and streams, 1,302,976 acres of lakes, and 3,658 square miles of estuaries. Of the assessed miles, 29 percent of total river miles, 20 percent of total lake areas, and 69 percent of total estuarine areas clearly attain their designated use (Figure 1).

6. Environmental Monitoring and Assessment Program (EMAP) • Estimate Current Status, Trends and Changes – Regional Basis – Known Confidence • Estimate Geographic Coverage and Extent – Known Confidence • Seek Associations – Indicators of Stresses and Condition • Statistical Summaries & Assessments

7. EMAP’s Original Guiding Figure Status & Association Questions Status Associations Extent of Resource (number, length, area) Condition Good Fair Poor Nominal Unknown Acidity Toxicity Eutrophication Habitat

8. Geographic TargetingWhere does Fish IBI suggest problems? (Insufficient Data) Western Appalachians North-Central Appalachians Ridge and Blue Ridge Valleys

9. Good Relative Ranking of Stressors Fish Index of Biotic Integrity (Insufficient Data) Fair Poor Proportion of Stream Length EMAP Probability Survey Example Results (complex) 4

10. 2002 State Report Included: Basin - % Stream Impairment 75 <25% 25-49 50-74 >74 No Est. 37 28 23 10 27 20 67

11. CWA 305(b) -- Status • States Implementing Probability Surveys • Streams (30+ States) • Estuaries (Coastal States) • EPA Office of Water • Probability Survey or Census • Integration of 305(b) and 303(d) • Conducting National Stream Survey • Aquatic Resources Monitoring • www.epa.gov/nheerl/arm

12. Integrated Monitoring – Part 1 303(d) Assessment Process Target Population Condition & Stressors (status) (1) EMAP Design (probability survey) 305(b) Report FoundSites • (2) Estimated Status [Probabilities] • Spatially Explicit Estimation • Aggregation • Classification • Modeling Attainment-Impairment NAS “planning” list waterbody attaining all uses waterbody has high probability of impairment Insufficient, No Information waterbody attaining some uses, no threatened uses Where do I need to do follow up monitoring? Impaired waterbody (3) Targeted Surveys

13. Example: Extending EMAP StatusEstimated IBI Condition at Reach Scale Good Poor Fair

14. Extending EMAP Associations Stressors Associated with IBI Status at Reach Scale Nominal Unknown Acidity Toxicity Eutrophication Riparian Habitat

15. Potential Areas for Target Surveys High Prob. Non-Impairment Riparian Habitat Associations Acidic Associations Eutrophication Associations Toxicity & Eutrophication Associations

16. Potential Target Survey Design Target Population: Stream Reaches within Area Associated with Acidic Stressors Survey Design: Weighted by Estimated IBI Condition (Good, Fair, Poor)

17. Integrated Monitoring – Part 2 303(d) Assessment Process (3) Targeted Surveys Results: Combining intensified survey designs, gradient sampling, site-specific designs as appropriate Attainment-Impairment waterbody attaining all uses waterbody attaining some uses, no threatened uses Waterbody impairment confirmed ? 303(d) List Is there an existing TMDL, or impairment not caused by pollutant? TMDL development Other Plans Expected to Achieve Attainment? Management Action (4) Probability survey designs to establish attainment How to delist?

18. Key Concepts & Elements • 303(d) Requires Site Scale Information • Observations, Estimates, Forecasts • Objective Basis to Categorize all Waters, Assign Priorities • Known Confidence – Uncertainty • Sequential Processes

19. Information sources • Probability Survey Results • Existing Non-Probability Stations • Fixed Station (Intensive, Few Sites) • Traditional Monitoring Program (Extensive, Few Observations) • Special Study & Research Areas • Complete Coverage (LuLc, etc.)

20. Potential Strategies • Sequential Estimation Approaches (WQ, Stressors, IBI) • Endpoint Estimation (IBI) • Estimate Probability of Condition (Good, Fair, Poor)

21. Some Challenges • Cause and Effect Relationships • What to Fix/Change to Restore or Protect • Assignment of Sources • Impairment Decisions (10% Obs. Exceed Criteria) • De-Listing Criteria

22. Total Maximum Daily Load (TMDL) • Original Focus: Point Sources • Issues Shifted to Non-Point Sources • Multiple Sources & Stressors • ~10,000 TMDLs Completed • Substantial Workload • Implementation, Effectiveness (?)

23. RIPARIAN • Producer: woody plants • 1° Consumer: birds • 2° Consumer: birds • Decomposers WATER COLUMN • Producer: macrophytes • 1° Consumer: fish • 2° Consumers: herptiles, fish • Decomposers BENTHIC • Producer: algae • 1° Consumer: benthos • 2° Consumer: benthos, herptiles, fish • Decomposers: microbes FUNCTIONAL COMPONENTS OF A STREAM ECOSYSTEM ATMOSPHERE STREAM USE LAND USE Stressor Sources WATER TABLE Movement of Materials RELEVANCE TO ECOLOGICAL FUNCTION

24. CONCEPTUAL MODEL: WADEABLE STREAMS ANTHROPOGENIC STRESSORS Angling Pressure Stocking Agriculture Manufacturing Mining Riparian Alterations Invasion of non-native spp. HUMAN USES Consumption Waste Receptor Recreation/Aestethics Harvesting ANTHROPOGENIC STRESSORS Agriculture Manufacturing Mining Forestry Practices Population Density Road Density Channelization Dams ECOSYSTEM SUSTAINABILITY HABITAT INTEGRITY BIOTIC INTEGRITY ABIOTIC CHARACTERISTICS BIOLOGICAL CHARACTERISTICS • WATER QUALITY • Temperature • Turbidity • Nutrients • Organic/inorganic Chemicals • Toxics • pH • HABITAT QUALITY • Substrate type • Depth and Velocity • Volume • Flow regime • Habitat heterogeneity • Instream Cover RELEVANCE TO ECOLOGICAL FUNCTION

25. Temp • O2 CONCEPTUAL RELATIONSHIP: STRESSORS vs. RICHNESS, ABUNDANCE, AND HABITAT METRICS Stressor Exposure Measurements Response Metrics • SO4 • pH ðé Metals • Family, Spp. Richness • Abundance • Nutrients • NO3 • Sensitive spp. • Population • Roads • Livestock • Row Crops • Logging • Dams • Tolerant spp. é Turbidity, Sedimentation • Benthic spp. • Water Column spp. • Riparian Modifications • Long-lived spp. • Chemicals • Ichthyocides • Stocking • Instream Fish Cover • Non-indigenous spp. RELEVANCE TO ECOLOGICAL FUNCTION

26. Opportunities • Incorporation of Conceptual Model Information • Objective Evidence on Causes – Sources • Multiple Stressors • Epidemiological Tools? • Forecast Restoration – Effort/Change, Time Sequences

27. Summary • Major Improvements Occurring • Significant Short Term Contributions Possible • Longer Term Opportunities Require Innovation and Creativity • Statistical Foundation Critical