1. Use Attainability Analyses & Criteria Development
Cara Cowan Watts
Graduate Student
Biosystems Engineering

2. Source of Class Materials
Presentations and Handouts
adapted from
The U.S. EPA’s
Water Quality Standards Academy
November 27-December 1, 2006
Washington, DC

3. Use Attainability Analyses (UAAs)
“Getting uses right” requires an effective process for conducting credible, defensible UAAs
There is nothing wrong with changing designated uses after completing a credible UAA
Change may bring more or less protective criteria
The UAA process should integrate with TMDL development
Improved public communication leads to acceptance

4. WQS Process 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)
Establish Source
Controls
(Point Source, NPS)
Evaluate Appropriateness
of WQS for Specific Waters
(Reaffirm WQS)
Define and Allocate
Control Responsibilities
(TMDL/WLA/LA)

5. When to do UAAs
Designating uses that do not include CWA 101(a)(2) goals
Revising designated uses to remove 101(a)(2) goal uses
Adopting sub-categories of 101(a)(2) uses for specific water bodies which require less stringent criteria
UAA is NOT necessary when establishing a sub-category structure

6. Designated Uses Review (40 CFR 131.10)
Protection and Propagation of fish, shellfish and wildlife
Recreation in and on the water
Public water supply
Agriculture
Industry
Navigation
Ceremonial Uses
Shellfish Grazing Areas
Wildlife Protection
Endangered Species Protection
Drinking Water Source Protection
Hydroelectric Power

7. Definition of UAA
“A Structured Scientific Assessment of the Factors Affecting the Attainment of the Use, Which May Include the Physical, Chemical, Biological, and Economic Factors as Described in 40 CFR (g).”
Determining the feasibility of attaining the use in the future

8. Functions of UAAs
Meet the “fishable/swimmable where attainable” goals of CWA
Identify existing uses
Identify “highest attainable” use
Identify cause(s) of impairment
Establish a defensible rationale and record of decision when adopting a new or revised WQS for a waterbody

9. Determination of Attainable
At a minimum, a use is attainable IF:
It is an existing use, OR
It can be attained with:
technology-based controls (sec. 301 and 306 of CWA) and
cost effective and reasonable best management practices for nonpoint source control
No, IF
Use not feasible due to any factor at (g)

10. Reasons for Unattainable
Naturally occurring pollutant concentrations
Low flow conditions or water levels
Human caused conditions or pollutant sources
Dams or other hydrologic modifications
Natural physical conditions for aquatic life
Substantial and widespread economic and social impact

11. Potential Roadblocks for UAAs
Site Specific Conditions
Amount of Data Available
Degree of Accuracy and Precision Desired
Size of Resource
Value of Resource to Community
Degree of Change from current designation
Degree of Change from 101 (a) goals

12. Aquatic Life UAA Biological Factors Physical Factors
Biological Inventory
Biological Gradient
Physical Factors
Temperature, Turbidity, pH, Color, etc.
Substrate - Instream cover and conditions
Channel Quality and sinuosity
Riparian Erosion
Relevant Chemical Factors, such as
Dissolved Oxygen
Nutrients
Metals

13. Recreation UAA Water Quality How and when do people use the waterbody?
Bacteria levels
Secchi depths
Nutrients and chlorophyll-a
Narrative “free froms” (floatables, etc)
How and when do people use the waterbody?
Primary and/or Secondary Contact?
Seasonally?
Safety and Access
Do signs or fences restrict or prohibit access?
Are certain uses dangerous?

14. Evaluating Future Usage
Where do we go?
How we get there?
Feasible uses
Required Treatment(s)
Engineering analyses
Non-point source management
Likelihood of success
Economic analyses

15. Process Steps Involve State, Federal and local constituencies
Agree on problem statement and objectives
Analyze existing data or establish data needs
Identify statistical requirements
Agree on an evaluation approach/select reference sites, if appropriate

16. Process Steps…cont’d Collect any new data and conduct analyses
Evaluate and summarize results
Identify uncertainties and evaluate adequacy of information
Make recommendations – propose new or revised uses
Provide opportunity for public comment
Submit the revised standards and supporting analysis to EPA after State/Tribal adoption

17. Critical Details
Any (revised) WQS shall provide for attainment and maintenance of WQS in downstream waters
If seasonal criteria are adopted, such criteria shall not preclude the attainment and maintenance of a more protective use in another season

18. Criteria Development Concentration, Level or Statement in WQSs
Intended to Protect and Support a Designated Use
Two meanings
Scientifically defensible guidance developed and published by EPA per CWA Section 304(a)
Basis for Federal promulgation when necessary
Adopted part of State/Tribal WQS
Section 303(c)

19. Criteria Requirements
States/Tribes must adopt criteria which protect the Designated Use
Based on sound scientific rationale
Sufficient parameters or constituents to protect Designated Use
Support the most sensitive use

20. Water Quality Parameter
Criteria vs Risk
Water Quality Parameter
Designated Use Threatened
Human Health and/or Aquatic Life May be at Risk
CRITERION LEVEL
Designated Use Protected
No Significant Risk Posed

21. Numeric and Narrative Numeric Example Narrative Example
For the protection of aquatic life, the 4-day average concentration of dissolved selenium shall not exceed 4.6 ug/L more than once every 3 years, on the average.
Narrative Example
State waters shall be free from floating debris, oil, scum, and other floating materials attributable to sewage, industrial wastes or other wastes in amounts sufficient to be unsightly or interfere directly or indirectly with any classified use.

22. Types of Criteria Human Health Criteria Bacteriological Criteria
Aquatic Life Criteria
Sediment Quality Assessments
Biological Criteria
Nutrient Criteria

23. Equations Deriving AWQC
Noncancer Effects:
Cancer Effects:
Nonlinear
Linear

24. Questions?