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Elk Watershed TMDLs
West Virginia Department of
Environmental Protection
Draft TMDL Public Meetings
September 27, 2011
Elkview Middle School
TMDL/ water quality standards recap
Overview of this TMDL effort
Explanation/demonstration of electronic
documents, spreadsheets, tools
Questions and Answers
Agenda
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
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
Criteria of Concern
Fecal ColiformWater Contact Recreation; Public Water Supply200 counts/100ml as a monthly geometric meanno more than 10% of samples in a month exceed
400 counts/100ml
Total IronAquatic Life/Public Water SupplyNot to exceed 1.5 mg/l as a 4 day average
concentration more than once in a three year periodNot to exceed 0.5 mg/l (troutwater) as a 4 day
average concentration more than once in a three year period
Criteria of ConcernDissolved 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
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)
Criteria of ConcernBiological ImpairmentConditions 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 assessmentWest Virginia Stream Condition Index (WVSCI)
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
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
Impaired Waters
214 named streams – See Table 3-3 on page 10 of Main Report for a complete list of streams and impairments
ModelingMDAS (Mining Data Analysis System)Fecal Coliform, total Iron, pH, dis. Aluminum Continuous, dynamic model with hourly time stepSimulates low, medium and high flowsCan handle point and nonpoint sources (representation and allocation)Recognizes exposure duration and exceedence frequency components of criteriaMetals speciation component allows evaluation of dissolved aluminum and pHSelenium process different
Modeling
From Sutton Dam downstream to mouth
Modeling
37 TMDL watersheds
440 subwatersheds
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
TMDL ConditionExisting pollutant sources
reduced such that TMDL endpoints are achieved in each modeled subwatershed recognizing
Criteria value, duration & exceedence frequency
Margin of safety
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
Baseline/TMDL Example
0.5
0.75
1
1.25
1.5
1.75
2
2.25
0 50 100 150 200 250 300 350
Simulation Period(Days)
Iron
, Tot
al (m
g/L)
Water Quality Criteria TMDL Target (WQ Criteria & 5%MOS)
Baseline Condition TMDL Condition
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
Pollutant Sources (Iron)
Abandoned Mine Lands
Streambank Erosion
Active mining permits/Bond Forfeiture
Upland Sediment Sources
Harvested Forest
Oil and Gas
Agriculture
Urban Residential
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
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)
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
Fecal Pollutant Sources & StrategyFecal 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
Selenium Allocation MethodologyEvaluate 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
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
Stressor identification
Define potential stressors/pathways
Evaluate chemistry, habitat,
field notes, bugs
Determine stressors
Stressor/TMDL LinkageOrganic 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
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
Sedimentation StressorAll 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
Sedimentation StressorReference 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 valuesModel IronPresent Iron TMDLCalculate TSS reduction for FeCompare to TSS reduction for reference approach
Sedimentation Stressor
Table 9.1 on page 55 of draft report
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
Future Growth HighlightsNew 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
Public CommentPublic Comment period ends October 14, 2011Documents 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 [email protected]
Questions - contact Dave Montali, Jim Laine, Mike McDaniel, Ben Lowman
(304) 926-0499 (Ext 1063, 1061, 1055, 1101)
TMDL Products
Main Report – Overall description of the TMDL for development process for streams in the Elk watershed
Technical Report with detailed appendices
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
CD /Spreadsheets/ GIS Demo
