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Elk Watershed TMDLs West Virginia Department of Environmental Protection Draft TMDL Public Meetings September 27, 2011 Elkview Middle School
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TMDL/ water quality standards recap Overview of this TMDL effort Explanation/demonstration of electronic documents, spreadsheets, tools Questions and Answers Agenda
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What’s a TMDL? “ Total Maximum Daily Load” How much pollutant a stream can receive and remain healthy A Pollution Budget – prescribes reduction of pollutants (where needed) that result in the restoration of an impaired stream TMDL development is required by the Clean Water Act for all streams impaired by a pollutant
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What’s an Impaired Stream? Stream that doesn’t meet water quality standards WV Water Quality Standards are codified in 47CSR2 Standards include “Designated Uses” for WV waters and the criteria to protect those uses Water Quality Criteria can be numeric or narrative
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Criteria of Concern Fecal Coliform Water Contact Recreation; Public Water Supply 200 counts/100ml as a monthly geometric mean no more than 10% of samples in a month exceed 400 counts/100ml Total Iron Aquatic Life/Public Water Supply Not to exceed 1.5 mg/l as a 4 day average concentration more than once in a three year period Not to exceed 0.5 mg/l (troutwater) as a 4 day average concentration more than once in a three year period
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Criteria of Concern Dissolved Aluminum Aquatic life Not to exceed 750 ug/l as a 4 day average concentration more than once in a three year period Not to exceed 750 ug/l as a 1 hour average concentration more than once in a three year period Not to exceed 87 ug/l (troutwater)as a 4 day average concentration more than once in a three year period pH All uses No values below 6.0 nor above 9.0
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Criteria of Concern Total Selenium Aquatic Life, Public Water Supply Not to exceed 5 ug/l as a 4 day average more than once in a three year period Not to exceed 20 ug/l as a 1 hour average more than once in a three year period Not to exceed 50 ug/l (Public Drinking Water)
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Criteria of Concern Biological Impairment Conditions Not Allowable in State Waters (47 CSR 2-3.2i) “.....no significant adverse impact to the chemical, physical, hydrologic or biological components of aquatic ecosystems shall be allowed.” Benthic macroinvertebrate assessment West Virginia Stream Condition Index (WVSCI)
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TMDL = WLA + LA + MOS = “sum of” WLA = “wasteload allocations” LA = “load allocations” MOS = “margin of safety” WLAs - pollutant loads for “point sources” Discharge from distinct point Need NPDES permit LAs - pollutant loads for “nonpoint sources” and background Precipitation and runoff No permit required
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TMDL Development History Project Timeline: Proposed streams advertised for public comment April 2007 Initial Public Meetings (TMDL Intro) May 2007 Watershed Monitoring and Source Tracking July 2007 - June 2008 Allocation Philosophy Meeting October 2010 Draft TMDL Public Meeting - Today
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Impaired Waters 214 named streams – See Table 3-3 on page 10 of Main Report for a complete list of streams and impairments
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Modeling MDAS (Mining Data Analysis System) Fecal Coliform, total Iron, pH, dis. Aluminum Continuous, dynamic model with hourly time step Simulates low, medium and high flows Can handle point and nonpoint sources (representation and allocation) Recognizes exposure duration and exceedence frequency components of criteria Metals speciation component allows evaluation of dissolved aluminum and pH Selenium process different
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Modeling From Sutton Dam downstream to mouth
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Modeling 37 TMDL watersheds 440 subwatersheds
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Baseline Condition Design precipitation period Hourly precipitation data for a six-year period Design period includes wet and dry years Applied to present day land uses Permitted discharges equal to permit limits
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TMDL Condition Existing pollutant sources reduced such that TMDL endpoints are achieved in each modeled subwatershed recognizing Criteria value, duration & exceedence frequency Margin of safety
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Required component of TMDLs Explicit 5% used in most TMDLs TMDL endpoints for numeric criteria are 95% of criterion value (example 1.425 mg/ml for 1.5 mg/ml criterion) Margin of Safety
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Baseline/TMDL Example
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Seleinum TMDL Process Used subwatershed delineation and source info from Iron TMDL Sources related to mining activities Low flow critical situation Mass balance evaluation Implicit margin of safety
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Pollutant Sources (Iron) Abandoned Mine Lands Streambank Erosion Active mining permits/Bond Forfeiture Upland Sediment Sources Harvested Forest Oil and Gas Agriculture Urban Residential
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Iron Reduction Strategy AML sources Surface runoff reduced to values equal to undisturbed forest Seeps reduced to water quality criteria Streambank Erosion reduced to reference stream loadings Sediment Sources reduced to iron loadings equivalent to 100 mg/l TSS
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Iron Reduction Strategy continued In subs influenced by mining, discharges were reduced to meet criteria (majority met criteria at this point) Assessment of area by sediment source category and percent of total area within subwatershed subsequent reductions based on percent of total pollutant load contributed by each category (if one category is 75% or more of total area – reduce first)
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pH/Aluminum Pollutant Sources & Reduction Strategy Initial step – reduce Iron loadings to meet criteria Acid precipitation (Fivemile Fork, Horse Fork, Beech Fork and Pheasant Run) Additional alkalinity added as needed to increase pH and reduce dissolved aluminum Abandoned Mine Lands Add additional alkalinity to offset acid precipitation Reduce total aluminum loads from sediment sources, as needed, to meet dissolved aluminum water quality criteria
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Fecal Pollutant Sources & Strategy Fecal Coliform STP effluents represented at existing limits (200/400) Failing/nonexistent on-site sewage systems – 100% reductions Combined Sewer Overflows (CSOs) - reduced to water quality criteria (200/400 cts) Sensitivity Analysis Agriculture Urban Runoff
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Selenium Allocation Methodology Evaluate selenium concentration at pour points of all subwatersheds of Se impaired streams Use USGS “South Central” equation for 7Q10 flows at subwatershed pour points Add pumped discharges to 7Q10 for critical flow Partition critical flow to regulated (Per bd/pumped) discharges and dilutions components Mass balance to achieve criterion at each subwatershed pour point
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Selenium Allocation Methodology continued Resulting concentration applied to “on bench” outlets Criterion end-of-pipe WLA applicable to continuous discharges and instream treatment ponds (Implicit MOS) Ensures criterion are achieved at both pour points for all outlets and immediate discharge location for continuous discharges See Technical Report Appendix J for details
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Stressor identification Define potential stressors/pathways Evaluate chemistry, habitat, field notes, bugs Determine stressors Stressor/TMDL Linkage Organic Enrichment......FC surrogate Sediment …….Total Iron surrogate Metal Toxicity (Al) …….Dissolved Aluminum pH Toxicity ……..pH Ionic Stress……deferred Biological Impairment TMDLs Linkage Table 4-1, Page 24
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Organic Enrichment Stressor All biologically impaired streams for which organic enrichment is a significant stressor are also impaired for fecal coliform Implementation of fecal coliform TMDL will require removal of untreated sewage and animal wastes and remove organic enrichment stress Fecal TMDL is an appropriate surrogate
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Sedimentation Stressor All biologically-impaired streams for which sedimentation is a significant stressor are also impaired for iron Sediment reduction needed to meet iron water quality criteria is larger than that needed under reference watershed approach Iron TMDLs are appropriate surrogate
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Sedimentation Stressor Reference Stream Method (previous approach) Select unimpaired reference watershed with similar landuse, ecoregion, geomorphological characteristics Normalized sediment loading in reference watershed is TMDL target for biologically-impaired stream Present Sediment TMDL TSS/Iron correlation Method (current approach) Correlate TSS and Iron values Model Iron Present Iron TMDL Calculate TSS reduction for Fe Compare to TSS reduction for reference approach
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Sedimentation Stressor Table 9.1 on page 55 of draft report
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Ionic Stress Uncertainty exists about exact pollutants or combination of pollutants causing impairments and appropriate thresholds Streams are being retained on 303d list WVDEP and USEPA Region III have agreed upon a plan to develop these biological impairment TMDLs by 2014
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Future Growth Highlights New facility anywhere in watershed if meeting water quality criteria end of pipe New sewage discharges w/ 200/400 fecal coliform effluent limits Subwatershed-specific future growth allowances have been provided for site registrations under the Construction Stormwater General Permit Full details on Future Growth can be found on page 89 of the Draft report
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Public Comment Public Comment period ends October 14, 2011 Documents may be reviewed/downloaded from DEP webpage http://www.dep.wv.gov/WWE/watershed/TMDL/Pages/default.aspx CD available upon request – CD includes GIS Shapefiles and Technical Report Comments should be submitted to Steve Young at Stephen.A.Young@wv.gov Questions - contact Dave Montali, Jim Laine, Mike McDaniel, Ben Lowman (304) 926-0499 (Ext 1063, 1061, 1055, 1101) David.A.Montali@wv.gov, James.C.Laine@wv.gov, Michael.L.McDaniel@wv.gov, Ben.M.Lowman@wv.gov
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TMDL Products Main Report – Overall description of the TMDL for development process for streams in the Elk watershed Technical Report with detailed appendices
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TMDL Products Allocation spreadsheets: Fecal Coliform, Iron, Aluminum, etc TMDL for each stream, WLAs and LAs by SWS Filterable GIS shapefiles, along with Technical Report and Appendices, available on CD Coming soon – web access GIS
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CD /Spreadsheets/ GIS Demo
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