Development of Numeric Nutrient Criteria for Florida

Transcription

1 Florida Department of Environmental Protection Development of Numeric Nutrient Criteria for Florida Ken Weaver Standards and Assessment Section Division of Environmental Assessment and Restoration

2 Nutrient Criteria Background EPA 6/25/98 Federal Register: "EPA expects all States and Tribes to adopt and implement numerical nutrient criteria into their water quality standards by December 31, 2003". FDEP Started Developing Numeric Criteria in 2001 May 2002: DEP submitted draft Plan (agreed upon 2004) Two subsequent revisions (2007, 2009) Page 2

3 Numeric Nutrient Criteria FDEP Started Developing Numeric Criteria in 2001 Aug 2008 EarthJustice filed suit to compel EPA to establish criteria Jan 2009 EPA declares numeric nutrient criteria "necessary" Nov 2009 Federal Court enters consent order containing implementation dates January 2010 EPA proposes numeric criteria for lakes & flowing waters Nov 2010 EPA must finalize numeric criteria for lakes & flowing waters November 2011 EPA must propose numeric criteria for estuaries & S. Fl flowing waters August 2012 EPA must finalize numeric criteria for estuaries & S. Fl flowing waters Oct-08 Jan-09 Apr-09 Jul-09 Oct-09 Jan-10 Apr-10 Jul-10 Oct-10 Jan-11 Apr-11 Jul-11 Oct-11 Jan-12 Apr-12 Jul-12 Aug-08 Aug-12 Page 3

4 Numeric Nutrient Criteria Considerations Protective of the most sensitive use; that is, prevent imbalances in natural populations of flora and fauna Nutrients exist naturally in the environment Nutrients are chemical elements and compounds found in the environment that plants and animals need to grow and survive Nutrients are not typically toxic Biological responses are highly site specific Page 4

5 Derivation of Protective Standards Plan A Attempt to find the amount of nutrients that causes harm to waterways Plan B Identify the amount of nutrients in the healthy and undisturbed waterways Annual Geometric Mean Chl-a (µg/l) Regression Line 50% Prediction Interval Ln (y) = Ln(x) R² = Annual Geometric Mean TP (mg/l) Page 5

6 Streams-Distributional Based Approaches No-more-than-one-in-three-years excursion frequency for the annual geometric mean criteria for streams Page 6

7 Lakes (Clear <40 PCU, Low Alkalinity < 20 mg/l) Empirical Model (Stressor-Response) Based Criteria maybe modified within these bounds if Chlorophyll a is attained. May not be modified above applicable stream criteria in outflow from lake. For a given waterbody, the annual geometric mean of chlorophyll a, TN or TP concentrations shall not exceed the applicable criterion concentration more than once in a threeyear period. Page 7

8 Lake Downstream Protection Values Criteria applied to streams to protect downstream lakes Requires modeling that accounts for both the volume of the receiving water and the flow contributed through the pour point. BATHTUB, WASP, or other information such as TMDL is acceptable Without model, stream criteria = lake criteria IPV or DPV Lake Criteria Downstream Lake Page 8

9 Springs Nitrate Criterion 0.35 mg/l as an annual geometric mean, not to be exceeded more than once in a three-year period. Spring is defined as a site at which ground water flows through a natural opening in the ground onto the land surface or into a body of surface water EPA says DEP will make site specific evaluation as to where criterion applies Page 9

10 Effective Date: April 14, 2012 Effective 15 months after publication in the Federal Register, except for the Federal site-specific alternative criteria (SSAC) provision of section (e), which is effective 60 days after publication in the Federal Register. Page 10

11 DEP Adoption DEP cannot currently implement criteria due to restrictions on non-rule policy Florida continues to have the option to adopt and submit to EPA numeric criteria for the State s Class I and Class III waters Pursuant to 40 CFR (c), EPA s promulgated WQS are applicable WQS for purposes of the CWA until EPA withdraws those federally-promulgated WQS. Page 11

12 Attainment Statistics Waterbody Type # Not Attaining for Nutrients Under Current IWR Assessment # of Listings Under EPA NNC % of Waters Not Attaining EPA's NNC Lakes % Streams % Springs 30 TBD TBD Lakes 377 total assessed for Nutrients Streams 432 total assessed for Nutrients Springs 43 total assessed for Nutrients Page 12

13 Attainment Statistics (continued) 199 WBIDs with at least 2 SCI samples. 107 out of the 199 exhibit healthy biology 40 out of the 107 (37.4%) healthy stream WBIDs do not attain EPA s NNC EPA NNC Attainment Status Number of WBIDs with Passing SCI WBIDs with at least 2 SCI Samples Attains both TN and TP Does not attain either TN or TP 7 18 Does not attain TN Does not attain TP Grand Total Page 13

14 Region IV SSACs The Federal SSAC procedure allows EPA to determine that a revised site-specific chlorophyll a, TN, TP, or nitrate-nitrite numeric criterion should apply in lieu of the generally applicable criteria promulgated in this final rule where that SSAC is demonstrated to be protective of the applicable designated use(s). Page 14

15 4 Allowable SSAC Approaches The first two approaches are replicating the approaches EPA used to develop stream and lake criteria and applying these methods to a smaller subset of waters. The third approach for is to conduct a biological, chemical, and physical assessment of waterbody conditions. The fourth approach for developing SSAC is a general provision for using another scientifically defensible approach that is protective of designated use. Page 15

16 Marine Criteria Page 16

17 Perdido Pensacola Choctawhatchee St. Andrews Emerald Coast Ochlockonee St. Joe Apalachee Apalachicola Suwannee/ Alligator HarborWaccasassa/ Withlacoochee Systems Were Logically Defined To Reflect Geography and Resources Springs Coast St. Joseph/Clearwater Tampa NEP Sarasota NEP Charlotte Harbor NEP Rookery Bay Nassau/ St. Marys St. Johns Guana/Tolomato/ Matanzas Halifax Indian River Lagoon Loxahatchee /St. Lucie Lake Worth SE Reef Tract 10,000 Islands Biscayne Page 17 Florida Bay Keys

18 Approaches Stressor-response (empirical models) Preferred approach Most applicable where a TMDL has been developed Limited utility in estuaries with healthy biology Healthy Existing Condition Demonstrate through a weight of evidence that the system supports healthy well-balanced biology Set criteria using distributional statistics Page 18

19 Approaches (continued) Historic Based on an affirmative demonstration that the system was biologically healthy during the reference period Set criteria using distributional statistics Link to DEP approaches and Estuary reports: nutrients/estuarine.htm Page 19

20 EPA Approaches Draft TSD provided on November 17, 2010 Reference conditions Predictive stressor-response relationships Water Quality Models (mechanistic) Remote sensing for coastal waters Submitted TSD to SAB Nutrient Review Panel Draft TSD provided on November 17, 2010 SAB meeting on December 13-14, 2010 Assigned sections due December 28, 2010 Draft SAB Report posted on January 25, 2011 Final report: mid-march to mid-june Page 20

21 Major SAB Concerns No clear definition of healthy well-balanced Insufficient time and data to adequately calibrate and validate water-quality models Insufficient attention to stressor-response approach Need for better decision criteria for acceptable changes in biological endpoints (e.g., Seagrass) Page 21

22 Major SAB Concerns EPA needs to better address uncertainty, it is essential that predictions explicitly state and detail the level of uncertainty, and that relationships between nutrients and responses be ground-truthed. Entire panel was not convinced that DPVs contribute to water quality protection beyond existing regulations (WQ Standards and TMDLs) Page 22

23 Questions? Ken Weaver Environmental Administrator Standards and Assessment (850) Page 23