Developing a Plan to Improve Water Quality in the Lower Vermillion River

Transcription

1 Developing a Plan to Improve Water Quality in the Lower Vermillion River Public Meeting for the Turbidity Total Maximum Daily Load Study March 19, 2008 Hastings, Minnesota :30 PM 1

2 MPCA: Minnesota Pollution Control Agency PCB: Polychlorinated biphenyls 2

3 Agenda Welcome and Introductions Background Information TMDLs, Turbidity, Vermillion River Project Update and Review Recommendations Next Steps Discussion Goal: Info Exchange 3

4 Welcome Introductions Minnesota Pollution Control Agency (MPCA) Tetra Tech Stakeholders 4

5 Background TMDLs, Turbidity, Vermillion River 5

6 Background: TMDLs In the 1970 s, the Clean Water Act provided motivation and funding to identify water quality problems and to develop solutions to correct these problems States have a responsibility to create water quality standards and assess water bodies (such as a lakes, rivers, and streams) Based on the specific use of the water bodies, States must identify waters not meeting water quality standards (303d list)

7 TMDLs Continued Total Maximum Daily Loads (TMDLs) are required to be developed for each pollutant in a water body on the 303d list (also known as the impaired waters list) In general terms, a TMDL is the amount of a specific pollutant that a water body can receive and attain and maintain a given water quality standard A strategy for achieving the water quality standard must be developed, approved, and then implemented 7

8 What is the Process for Developing a TMDL? Stakeholder Involvement Collect and Analyze Data Develop and Test Options for Reducing Pollutants Select Best Option and Develop Implementation Strategy Implement and Monitor Progress Stakeholder Involvement 8

9 Translation Techie & Acronym-Laden Explained Designated Uses What You Do WQ Standards Pollution Limit Impaired Waters Polluted Waters TMDLs Problem Investigation Implementation Fix the Problem Aggressive terminology and plenty of acronyms, but this is a basic process that is our best available tool for cleaning up our waters. 9

10 Background: Vermillion River 10

11 Upper Vermillion: Trophy Brown Trout Fishery Salmo trutta 11

12 12

13 MN State Record Black Crappie 1940, Vermillion River 5 pounds, 0 ounces 21 inches long 13

14 The Vermillion River High Water Inundation in Floodplain Forest July 2001

15 The Vermillion River Looking downstream from Etter Bridge November

16 The Vermillion River Vegetated Shoreline Lakes Segment July

17 Background: Turbidity In general terms, turbidity is a measure of the clarity of a liquid. It is a surrogate parameter, that suggests the presence of suspended solids or dissolved matter. 17

18 nephelo-, nephel-, nepho- neph- (Greek: cloud, clouds, cloudiness) Some related words: Nephelogical: Related to clouds or cloudiness. Isonephelic: An indication of the equality of cloudiness. Hypernephelist: Someone who goes above the clouds. Nephalism: Total abstinence from alcoholic beverages. 18

19 Turbidity Background Con t Minnesota s turbidity water quality standard = 25 NTU Waters with turbidity over 25 NTU can stress aquatic life Waters that go over 25 NTU repeatedly are considered impaired 19

20 Turbidity Visuals ~0-3 NTU ~0-3 NTU ~12-20 NTU ~12-30 NTU?? 20

21 Why is Turbidity an Issue? Impacts to Recreation Reduced visibility for swimmers and boaters Reduced sportfish populations Impacts to Health Increased potential for waterborne diseases from recreation Increased need for drinking water treatment Impacts to Aquatic Life Reduced light for submerged aquatic plants Increased temperatures Reduced oxygen levels 21

22 Affected Use: Aquatic Life i.e. keep eye on prize 22

23 23

24 24

25 Stonefly Genus Agnetina (Golden Stones) 25

26 Behavioral Changes Salvelinus fontinalis SSC Conc: 4.5 mg/l (~3-4 FNU) Duration: 18 hours Overhead cover abandoned Gradall & Swenson

27 Mortality Salmo trutta SSC Conc: 110 mg/l (~80 FNU) Duration: 1440 hours 98% mortality of eggs Scullion & Edwards

28 Warmwater too 28

29 29

30 How Much is Too Much? TURBIDITY (NTU) MS221 MS297 MS299 VR002 VM00.1 WQS

31 Goals of the Turbidity TMDL Study To define the nature and extent of the turbidity impairment To understand how sediment is transported and how it affects aquatic life To evaluate the total sediment load for an "unimpaired Vermillion River To better understand how various sources influence turbidity levels To integrate TMDL efforts with long-range Pool 3 planning and management efforts To ultimately find a solution to the impairment 31

32 Lower Vermillion River Turbidity TMDL MPCA contract with Tetra Tech Phased Approach Phase I: Data Gathering and Model Development (2003/2004) Phase II: Sampling and Model Development (200/2007) Phase III: Model Refinement and TMDL Development (2007/2008) 32

33 Phase I Tasks Compiled all available water quality and biological data Researched information on numerous manmade structures that control flow between Pool 3 and Lower Vermillion River Statistical analysis of relationship between TSS, nutrients, chlorophyll a, and turbidity Developed conceptual understanding of LVR turbidity 33

34 Conceptual Model Turbidity Inorganic Solids Algae Organic Detritus Sediment Input Phosphorus Input Algal & Detrital Input Channel Erosion Local Watersheds Upper Vermillion Mississippi River 34

35 Phase I Findings Inorganic sediment appears to be the primary cause of elevated turbidity (2 percent) Pathways involving algae and organic detritus contribute about 38 percent (on average) of the observed turbidity in the LVR 35

36 Phase I Findings (continued) Scoping Level Estimates of Sediment Inputs Mississippi Pool 3 (2 percent) Upper Vermillion River (21 percent) Local tributaries (17 percent) Internal sources unknown Algal growth within the LVR is a secondary contributor to turbidity and is sensitive to concentrations of phosphorus 3

37 Monitoring and Field Work Update 37

38 Dike Functionality Truedale Slough Dike: functional with rusty culvert DNR Dike: nonfunctional dike bypassed by water Three Bridges Dike: nonfunctional dike no longer intact Spot Dike K: nonfunctional dike located in wetland area 38

39 Example Cross Sections Cross-Section 1 Elevation (feet MSL) Distance (feet) Cross-Section T Elevation (feet MSL) Distance (feet) Cross-Section 15 Elevation (feet MSL) Distance (feet) 39

40 Modeling What is a model? Mathematical formulation describing the physical behavior of a waterbody and its temporal variability Inputs Weather Stream channel characteristics Boundary flows and concentrations Outputs Time varying (e.g., hourly, daily, monthly, annual) flow and concentrations Multiple locations 40

41 Modeling Update (continued) Why model? Determine load reductions needed to meet water quality goals Evaluate potential pollutant sources Assess potential restoration scenarios Modeling used in combination with other data/information to inform policy and make final management decisions 41

42 Phase 2 and 3 Modeling Soil and Water Assessment Tool (SWAT) Model to Estimate Loads from Local Tributaries FLUX Model to Estimate Loads from Upper Vermillion River CE-QUAL-W2 Model to Estimate Conditions in the Lower Vermillion River 42

43 43

44 Modeling Process Step 1. Set up model Acquire and organize model inputs Step 2. Calibrate and validate models to available flow and water quality data Adjust model parameters to obtain best possible fit to observed data Step 3. Run models for various scenarios to evaluate management alternatives Identify key sources of pollution Identify potential impact of various alternatives 44

45 Modeling Results Sources of Flow Sources of Sediment Carter Slough 21% Pool 4 1% Local Tributaries 5% Internal Sources % Upper Vermillion River 21% Vermillion Slough 15% Carter Slough 21% Local Tributaries 1% Pool 4 1% Internal Sources 3% Upper Vermillion River 8% Vermillion Slough 1% Truedale Slough 31% Truedale Slough 35% 45

46 Modeling Results (continued) Distinctly different conditions depending on stage of Mississippi River Mode 0: insignificant inflow from the Mississippi Mode 1: Mississippi River inflows dominate conditions Vermillion Slough: Stagnant Truedale Slough: Inflow through culvert Carter Slough: Stagnant Etter Bridge: Free flowing Mouth: Free discharge Hastings Vermillion Slough Truedale/Carter Slough Etter Bridge Mouth 50 Mode 0 4

47 Modeling Results (continued) Distinctly different conditions depending on stage of Mississippi River Mode 0: insignificant inflow from the Mississippi Mode 1: Mississippi River inflows dominate conditions Vermillion Slough: Inflow at 75.3 Truedale Slough: Inflow at 77.5 Carter Slough: Inflow at 77.5 Etter Bridge: Free flowing or backwater Mouth: Backwater Hastings Vermillion Slough Truedale/Carter Slough Etter Bridge Mouth 50 Mode 1 47

48 Modeling Results (continued) Following combination of load reductions found to achieve water quality standards during both modes Turbidity in Pool 3 simulated as achieving water quality standards Loads from internal sources reduced 8 percent during Mode 0 No reductions to Pool 4 loads No reductions to Upper Vermillion River loads (other than removing Empire WWTP load) 48

49 TMDL Allocations Clean Water Act requires that TMDLs be allocated as follows: TMDL = WLA + LA + MOS Wasteload Allocations (WLA) for point sources (regulated under NPDES) Load Allocations (LA) for nonpoint sources and natural background MOS for Margin of Safety 49

50 TMDL Allocations (continued) Allocation Component: Source Existing TSS Load (kg/day) Mode 0 (Minimal Pool 3 Inflow) Allowable TSS Load (kg/day) Percent Reduction Existing TSS Load (kg/day) Mode 1 (Significant Pool 3 Inflow) Allowable TSS Load (kg/day) Percent Reduction TMDL= LA+WLA+MOS 12,117 5,19 54% 234, ,87 48% LA: UVR % % LA: Pool % 204,913 94,20 54% LA: Pool % 1 1 0% LA: Internal Sources, % 1 1 0% WLA: Facilities % % WLA: MS4s % 5,229 5,229 0% MOS (Local Tributaries) 2,48 2,250 15% 14,892 12,58 15% 50

51 What Are Possible Solutions? Lake Pepin TMDL Reduce Mississippi loads at major inlets Water Level Management Reduce sediment re-suspension consolidation of sediments (periodic drawdowns) island building Perennial vegetation Fish Management Rural and Urban BMPs Reduce streambank erosion with stabilization projects Soil conservation on row-crop land 51

52 Lake Pepin TMDL Identified impairments include excess nutrients (eutrophication) and turbidity Multi-year project to develop TMDL Modeling ongoing TMDL scheduled to be completed in 2009 Lake Pepin TMDL Forum Wednesday, April 1, :30 a.m. to 3:30 p.m. St. James Hotel, Red Wing, MN 52

53 Water Level Management Help restore the natural seasonal fluctuation in water levels that the plants desire MDNR has identified three potential strategies: Pool-wide Pool 4 summer drawdowns Vermillion Bottoms/Goose Lake HREP type drawdowns of the LVR Individual LVR backwater lake drawdowns 53

54 Fish Management Any attempt to actively remove rough fish from the system would be ongoing, expensive and unlikely to succeed DNR believes it may be possible to induce rough fish to leave and largely stay out of backwater lakes following the spring flood pulse if the rough fish sense they will be trapped by lowering water levels Any rough fish control ideas to implement the TMDL should be implemented using an adaptive management approach Conduct initial projects as experiments or pilot efforts Implement future efforts based on the success (or failure) of the initial efforts 54

55 Rural and Urban BMPs Rural BMPs Conservation Tillage Filter Strips Riparian Buffers Grade Stabilization Structures Urban BMPs Proactive stormwater management Future loads from MS4s should remain equal to or less than current levels 55

56 Next Steps Public Meeting: March 2008 Draft TMDL Report: March/April 2008 Final TMDL Report: May/June 2008 Implementation Plan Development 5

57 Contact Information Justin Watkins MPCA (507) Kevin Kratt Tetra Tech (21)