EPA Numeric Criteria Where do we stand now? Mark W. Clark

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1 EPA Numeric Criteria Where do we stand now? Mark W. Clark Soil and Water Science Department University of Florida, Gainesville June 4, 2013

2 Clean Water Act 1972 As part of the Federal Clean Water Act 1972, USEPA requested states develop: Designated uses for waters of the state (lakes, reservoirs, rivers, streams, estuaries and wetlands), Criteria that would protect designated uses, Corrective process that would be implemented if a designated use was not being met (i.e. if the waterbody was determine to be impaired )

3 Designated Uses for Florida Waterbodies Class I Potable Water Supplies Class II Shellfish Propagation or Harvesting Class III Recreation, Propagation and Maintenance of a Healthy, Well-Balanced Population of Fish and Wildlife Class III-Limited Fish Consumption; Recreation or Limited Recreation; and/or Propagation and Maintenance of a Limited Population of Fish and Wildlife Class IV Agricultural Water Supplies Class V Navigation, Utility and Industrial Use F.A.C. Chapter Surface Water Quality Standards

4 Narrative vs. Numeric Nutrient Criteria Narrative criteria - Rule FAC in no case shall nutrient concentrations of a body of water be altered so as to cause an imbalance in natural populations of flora or fauna Numeric criteria theoretically provides a bright line that more effectively determines the point of designated use impairment.

5 History of Numeric Nutrient Criteria in Florida 1998 EPA initiates nation wide effort to establish more quantitative approach to nutrient standards FDEP begins development of NNC and in 2002 enters into an agreement with EPA to establish NNC EPA sued by Earthjustice on behalf of several Florida environmental organizations citing unacceptable delays and argued that EPA was obliged to propose criteria for Florida Although FDEP was making progress to establish NNC, EPA entered into a consent decree with Florida Wildlife Federation to establish NNC for Florida.

6 History of EPA s NNC for Florida January, EPA published Proposed Water Quality Standards for the State of Florida s Lakes and Flowing Waters (75 FR 4173). November, EPA Administrator signed Final Water Quality Standards for the State of Florida s Lakes and Flowing Waters. (did not include S. Florida flowing waters) March 6, Initial Implementation date of final rule after 15 month period to develop strategies for implementation. March 5, EPA promulgated an extension of the effective date of this rule by 4 months to July 6, 2012

7 State of Florida s Alternative Rule for NNC April 22, FDEP asked EPA to withdraw its NNC determination. EPA did not approve or deny request, June 13, November 10, FDEP developed alternative rule for rivers, streams, lakes and to estuaries from Tampa Bay to Biscayne Bay, including the Florida Keys. January and February, Florida Legislature and Governor approve amendments to chapters and , F.A.C. (numeric nutrient standards). November 30, EPA approved FDEP s alternative rule

8 Inland Waters not Included in State of Florida s Rule FDEP s numeric nutrient criteria apply to all Class III flowing waters unless the water body meets one of the exclusions under F.A.C (36), i.e., tidally influenced, a non-perennial stream, or an actively maintained conveyance, such as a canal or ditch. For these waters, the narrative criterion will continue to apply. EPA, as a result of consent decree, must have federal criteria in place for those Class III flowing waters that may not have numeric criteria until FDEP develops sitespecific criteria or conducts a use-attainability analysis to correctly classify the excluded waters. EPA has proposed (not set) draft federal NNC for these areas.

9 EPA Downstream Protection Value Requirement Amended EPA is amending 2009 CWA determination to indicate that numeric downstream protection values are not necessary to meet CWA requirements in Florida. Numeric downstream protection values (DPVs) are not necessary to meet CWA requirements in Florida. FDEP s interpretation of the narrative downstream protection provision results in appropriate numeric or other discharge permit limitations and allows the state to make timely and appropriate listing decisions.

10 What is presently covered by FDEP vs. EPA Criteria

11 What s next for FDEP FDEP does not have sufficient information to accurately interpret the NNC for waters such as Class III wetlands, Class III flowing waters in South Florida and Class III intermittent or highly altered streams. Therefore, narrative will continue to apply until sufficient data is available. FDEP to establish criteria for Panhandle estuaries by June 30, 2013 and remaining estuaries by June 30, 2015.

12 FDEP s Alternative Rule: A Hierarchical Approach to Interpret Narrative Criteria

13 Lake Numeric Nutrient Criteria Criteria based on strong stressor response relationship between TN or TP concentration and algae (chlorophyll-a)

14 Spring Numeric Nutrient Criteria Nitrate-Nitrite Criterion Not to exceed an annual geometric mean of 0.35 mg/l more than once in any three consecutive calendar year period. Criterion based on strong stressor response relationship between Nitrate+nitrite-N concentration and algal growth

15 Stream Numeric Nutrient Criteria The NNC shall be interpreted as being achieved in a stream segment if: Chlorophyll-a levels, algal mats or blooms, nuisance macropyte growth, and changes in algal species composition do not indicate an imbalance in flora or fauna; AND EITHER The average score of at least two temporally independent Stream Condition Indices (SCI) performed at representative locations and times is 40 or higher with neither of the two most recent SCI scores less than 35, OR The regional nutrient thresholds are not exceeded more than once in a three year period. This approach provides a biological confirmation of nutrient impairment.

16 Stream Numeric Nutrient Criteria Based on reference stream approach

17 Summary NNC provide a brighter line in determining nutrient related impairment to water resources. FDEP uses a hierarchical approach to quantitatively interpret existing narrative criteria that prioritizes site specific and response based criteria and use biological confirmation when reference/regional criteria are used. FDEP has established NNC for almost all inland waters and some coastal systems. FDEP has a plan to establish NNC for remaining coastal systems by June FDEP presently applies narrative criteria to some inland waters where information is limited. These waters are where EPA is likely to establish numeric criteria until FDEP provides an alternative approach.