Lake Pepin Watershed TMDL: Looking Ahead. August 2008 Sector Meetings. Lake Pepin Photo by Guy Schmickle

Transcription

1 Lake Pepin Watershed TMDL: Looking Ahead August 2008 Sector Meetings Lake Pepin Photo by Guy Schmickle

2 Three Questions What are the critical issues to face moving forward? How can we as a sector address the critical issues? What are the needs of this group to address the critical issues?

3 Critical Distinction: TMDL vs. Implementation Plan TMDL Report to EPA Must Meet Water Quality Standard Implications for Sectors Regulated under NPDES WLA reflected in permits Implications for nonregulated sectors LA reflected in programs such as CWLA Reasonable assurance of meeting LA Largely voluntary, incentive-based programs TMDL Implementation Plan Not required or reviewed by EPA Required by state for access to certain funds Implementation can be phased in stages 20% - 40%- 60% - 80% Harmonize scales Pepin Watershed Drainage Basin Major watershed

4 Lake Pepin TMDL Timeline Auxiliary Projects Develop Water Quality Model Complete Lake Pepin Model Model Pollutant Source Reduction Scenarios Develop & Submit TMDL 1/06 6/07 10/07-3/08 02/08 07/08 07/08 06/09

5 August Sector Meetings Environment: August 6, Dakota Lodge Municipal: August 7, Dakota Lodge Agriculture: August 18, Waseca Draft Modeling Report Complete SAP and MPCA Review Revisions, Completion

6 September SAC/Basin Team Meeting Input on scenarios/sectors Plan by scale:pepin watershed/river basin/major watersheds Model Alternative Scenarios Coordinated Modeling of Mississippi/Minnesota River Lake Pepin Tech. Conference Sept Final Report from LTI: Sept. 30

7 October SAC Draft TMDL Component Review WLA & LA revisions MOS Future Growth/Trading Reasonable Assurances for NPS Minnesota Water: Oct Lake Pepin TMDL Segment

8 November-December November: Complete Draft TMDL SAC Meeting: Draft TMDL Review December 08 Public Notice of Revised Draft TMDL

9 2009 Begin Implementation Planning Wastewater Stormwater River Ecosystem Nonpoint Source/Rural Complete Public Review Finalize TMDL Report Submit to USEPA

10 Critical Issues (ag) Turbidity Standard Natural Background Load Allocation Size and Shape Implementation Strategy Targeting Timeline

11 Turbidity Standard TSS Load Reduction Requirement for Mississippi at L&D2: 50/20 Attainability? Significance to River Health? 25 NTU Standard Rule needs more definition: duration, averaging period, etc. Some interpretation needed: 10%-tile

12 Critical Issues: Natural Background Sediment/Turbidity: 10% of sediment load delivered to Lake Pepin Phosphorus: ppb of TP concentration in Lake Pepin Implications of natural background allocation: Current Load TSS: 10% NB 50% Reduced Load TSS: 20%

13 Geological (Historical) Definition of Background Sediment Flux (1000 T/yr) Cultural Natural Background Date

14 Percent of Diatoms 100% 80% 60% 40% 20% 0% Total Phosphorus (ug/l) Benthic Species Planktonic Species Total Phosphorus Lake Pepin Sediment Cores Diatom-reconstruction of P concentrations & sedimentation rates

15 Total Maximum Daily Load (TMDL) TMDL Natural Background (NB) TMDL NB Margin of Safety Stream Bank and Bluff Field Stream Bank and Bluff Field Stream Bank and Bluff Field Ravine Ravine Ravine

16 Critical Issues (Municipal) Size of WLA for Urban Stormwater and Wastewater Converting Gross Allocations into Individual Permits Schedules of Compliance Equity and cost vs. Nonpoint sources Deminimus considerations Pollutant Trading

17 Size of WLA: Urban Stormwater WLA for MS4s proportionate to share of watershed area 6.5% of total watershed is municipal 2.5% of total watershed is built up 0.x% of total watershed is impervious surface Assumes equal runoff from urban & rural land. Current contribution = surface runoff x.025. Aggregate WLA = Current cont. x 0.75

18 Converting Gross WLA into Individual MS4 Permit Limits Will be done in the Implementation Plan in the year following TMDL approval. Committee of PCA/Stakeholders forming soon. Contact Mike Trojan, MPCA

19 Critical Issues: Wastewater Size of WLA Phosphorus Low Flow Year Loading Capacity 1000 metric tons TP Natural Background ~ 300 metric tons TP Current vs. Capacity Loads Phased Implementation 1 mg/l effluent limit max Freeze loads with increase to design flow Harmonizing with upstream TMDLs

20 Critical Issues: Wastewater Point vs. Nonpoint Source Load Reductions Respective shares Cost of Reductions Reasonable Assurance of NPS Reductions Pollutant Trading Potential New Trading Rule being prepared Point-nonpoint tradeoff potential

21 Critical Issues (environmental) Does the TMDL meet Water Quality Standards? Will both regulated and non-regulated sources achieve load reductions? What are the environmental benefits of removing/reducing the water quality impairment? Benefits of Water Quality improvement Benefits of Landscape improvement

22 Reasonable Assurances Point Sources NPDES permit compliance Nonpoint Sources Use existing authorities Economic incentives Education

23 Does the TMDL meet WQ Standards? 25 NTU standard Needs interpretation Options Season average All daily values less than 25 NTU Listing/delisting criterion (10% exceedance of 25 NTU) Implications Eutrophication Site-specific standard TP, chl a, Secchi Lake Pepin acts a lot like a river Dominated by diatoms Low residence time River nutrient standards coming soon

24 Turbidity Standard Supports Aquatic Vegetation Mississippi River Turbidity Standard 25 NTU Aquatic Life Support Rooted vegetation Habitat for fish & waterfowl Confluence of St. Croix & Mississippi

25 Full-Cost Accounting Study Purpose: To evaluate which set of land-use changes can meet the TMDL pollutant load reduction percentage targets yielding the greatest net social benefit.

26 Project Strategy In small watershed settings, estimate market plus non-market values and costs associated with alternative means of achieving TMDL reductions at the local level.

27 Three-Stage Analysis Stage One: Biophysical modeling of alternative land-use changes to meet TMDL targets. Stage Two: For land-use scenarios meeting water quality targets, use models to estimate impacts on ecosystem services. Stage Three: Quantify market and non-market values associated with each land-use alternative. Use results to evaluate which set of changes yields the highest net social benefits.

28 Swift Sherburne Anoka Chippewa Kandiyohi West Meeker Fork Beaver Wright Hennepin Ramsey Washington McLeod Carver Renville Sibley Scott Little Cannon Dakota Redwood Nicollet Le Sueur Rice Goodhue Brown Seven Mile Cottonwood Watonwan Blue Earth Waseca Steele Dodge Jackson Faribault Martin Freeborn Mower

29 Critical Distinction: TMDL vs. Implementation Plan TMDL Report to EPA Must Meet Water Quality Standard Implications for Sectors Regulated under NPDES WLA reflected in permits Implications for non- regulated sectors LA reflected in programs such as CWLA Reasonable assurance of meeting LA Largely voluntary, incentive-based programs TMDL Implementation Plan Not required or reviewed by EPA Required by state for access to certain funds Implementation can be phased in stages 20% - 40%- 60% - 80% Harmonize scales Pepin Watershed Drainage Basin Major watershed Integrate TMDL & Ecosystem Restoration

30 Adaptive Approach for Meeting Turbidity Standard and Vegetation Objectives Achieve 20 NTRU Existing conditions Implement 20/20 reduction and ecosystem restoration (ER) Monitor turbidity and aquatic vegetation Implement 50/80 reduction and ER Vegetation objectives are met success?? Monitor turbidity and aquatic vegetation Achieve 40 NTRU Achieve 30 NTRU Monitor turbidity and aquatic vegetation Implement 50/50 reduction and ER

31 Beneficiaries of restored Mississippi ecosystem pg

32 For more information.. Norman Senjem, TMDL Project Manager MPCA Web Site: l-development.html

33 T ogether (with Wisconsin) M innesotans D eveloping L egacies Rep. Dennis Ozment, 2004