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Determining the Probable Cause of an Impaired Benthic Community in the Naugatuck River

Determining the Probable Cause of an Impaired Benthic Community in the Naugatuck River. Chris Bellucci and Lee Dunbar Connecticut Department of Environmental Protection Bureau of Water Management Planning & Standards Division 79 Elm Street Hartford, CT 06106-5127. NAUGATUCK TMDL TEAM.

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Determining the Probable Cause of an Impaired Benthic Community in the Naugatuck River

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  1. Determining the Probable Cause of an Impaired Benthic Community in the Naugatuck River Chris Bellucci and Lee DunbarConnecticut Department of Environmental ProtectionBureau of Water ManagementPlanning & Standards Division79 Elm StreetHartford, CT 06106-5127

  2. NAUGATUCK TMDL TEAM TMDL Program Chris BellucciKelly Streich Monitoring & AssessmentErnie PizzutoGuy HoffmanMike Beauchene Watershed CoordinatorSusan Peterson Water Toxics LaboratoryTracy LizotteAl Iacobucci Aquatic ToxicityThom HazeRose Gatter-Evarts Municipal FacilitiesRowland Denny Inspection Ed Finger Watershed PermittingMelissa BlaisSteve EdwardsKevin Barrett EPAMike Marsh – Region 1Susan Cormier – ORD

  3. TMDL PROGRAM OVERVIEW Monitor and Assess Conditions List and Prioritize Impaired Waters for TMDLs Identify Cause(s) of Impairment Stressor ID Analysis Develop TMDL for pollutant causing impairment Point and non-point load allocations, margin of safety. Adopt TMDL Public Participation State establishes TMDL with revisions as warranted EPA reviews and approves TMDL Implement TMDL Re-issue NPDES permits

  4. TMDL Study Area Why Focus on the Upper Naugatuck? • Listed on CT 2002 Impaired Waters List for not meeting aquatic life use goals – Cause Unknown • Part of a larger effort to restore the Naugatuck River Watershed. Other projects include TMDLs on tributaries, dam removal projects, POTW upgrades • NPDES permit re-issuance – 3 industrial expire 9/04 • 1 municipal expired 3/03

  5. What is the Goal ? E P T

  6. Study Area: Naugatuck River near Thomaston Naugatuck R Leadmine Bk Rock Bk Northfield Bk USGS Discharge Branch Bk Q Route 6 • ~ 5-mile stretch of Naugatuck River • 3 Metals Finishing Discharges, 1 POTW • Two large dredge holes excavated in early 1970’s changed the river from wadable to 1-mile long lacustrine segment withmaximum depths of 30 ft Jericho Bk Reynolds Bridge W Nibbling Bk S Frost Bridge USGS Monitoring Dam Metal Finishing Discharge POTW

  7. Cause Unknown Investigation Conceptual Model Diagram • Review of Existing Data • Additional Samples from River and Effluents • Stressor ID Analysis

  8. Review of Existing Data • DMRs and ATMRs • ArcView coverages • Biological monitoring • Physical/chemical monitoring (CTDEP and USGS) • Hydrology (USGS Gage)

  9. Additional Sampling • 10 Rounds of Ambient Sampling at 4 sites during 2002 Sampling Season • 7 Acute Toxicity Tests in 2002 on each point source discharge • Jan 2003 Chronic Toxicity Test w/ EPA • 2002 and 2003 Macroinvertebrate Sampling

  10. What Did the Data Tell Us? • Hydrology is Important • The abundance of sensitive invertebrates declines downstream of each point discharge • Low D.O. may be an issue • Effluents toxic and extremely variable (job shops)

  11. Route 6 7Q10 = 12.6 cfs QRD THOMASTON POTW WHYCO SUMMIT Frost Bridge 7Q10 - 17.2 cfs Allocated ZOI Exceeds 7Q10 Zone Of Influence Allocations QRD = 11.4 cfs Whyco = 18 cfs Summit = 18 cfs Thomaston POTW = 6.8 cfs Total = 54.2 cfs ?

  12. Streamflows less than 7Q10 are Common

  13. The abundance of sensitive macroinvertebrates declines downstream of each point discharge

  14. SI Procedure DEP’s analysis was performed consistent with EPA Guidance and has been reviewed by the principal authors of the Guidance

  15. Sources Causal Pathway Surface run-off Dredge Holes Nutrient data from USGS Station at Frost Bridge and CTDEP standard site at Frost Bridge are at background levels Impairment X DO exceeded criteria at USGS Station and CTDEP station at Frost Bridge Decomposition leading to oxygen depletion X Conceptual Model of Low DO Low DO in hypolimnion Increased nutrients Transport of water from hypolimnion Increased algal growth Death or reproductive failure Loss of Sensitive invertebrate taxa

  16. Sources Causal Pathway Impairment Conceptual Model of Toxic Contamination Non-Point Sources Point Source Discharges 3. Complex Mixture 4. Episodic Events 1. Metals 2. Ammonia Acute toxicity Chronic toxicity Death or reproductive failure Loss of Sensitive invertebrate taxa

  17. Sources Causal Pathway Monte Carlo analysis shows low probability of individual metal parameters to cause toxic conditions instream Impairment X Metals data from USGS Station at Frost Bridge and CTDEP standard site at Frost Bridge did not exceed criteria No individual metal correlated with measured effluent toxicity Conceptual Model of Toxic Contamination Pathway 1: Metals Non-Point Sources Point Source Discharges 3. Complex Mixture 4. Episodic Events 1. Metals 2. Ammonia Acute toxicity Chronic toxicity Death or reproductive failure Loss of Sensitive invertebrate taxa

  18. Sources Causal Pathway Impairment X Ammonia data from USGS Station at Frost Bridge and CTDEP standard site are at background levels High ammonia concentrations in effluent not observed concurrent with measured toxicity Conceptual Model of Toxic Contamination Pathway 2: Ammonia Non-Point Sources Point Source Discharges 3. Complex Mixture 4. Episodic Events 1. Metals 2. Ammonia Acute toxicity Chronic toxicity Death or reproductive failure Loss of Sensitive invertebrate taxa

  19. Sources Causal Pathway Impairment Conceptual Model of Toxic Contamination Pathway 3: Complex Mixture Non-Point Sources Point Source Discharges Biological monitoring links impact with outfall locations 3. Complex Mixture 4. Episodic Events 1. Metals 2. Ammonia Inconsistent, complex array of chemicals in effluent samples measured with toxicity Monte Carlo analysis identified WET as the pollutant with highest probability to cause toxic impact Acute toxicity Chronic toxicity Effluents show acute and chronic toxicity in laboratory tests Death or reproductive failure Loss of Sensitive invertebrate taxa

  20. Monte Carlo Analysis DSconc = ((USflow x USconc) + (EFflow x EFconc)) / (USflow + EFflow) • Flow Data • USGS Gauge • Industrial Toxicity Database • LIS Nutrient Database • Concentration Data • USGS Monitoring Station • Industrial Toxicity Database • DEP Ambient Monitoring database

  21. Relative Probability (%) of Toxic Impact Location Toxicity Copper Lead Nickel Zinc Rte. 6 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 downstream QRD 1.80 0.20 < 0.01 < 0.01 < 0.01 downstream POTW 1.80 0.50 0.03 0.04 < 0.01 downstream Branch Bk. < 0.01 0.50 < 0.01 < 0.01 < 0.01 downstream Whyco 3.80 1.30 0.30 0.10 < 0.01 downstream Summit 13.30 4.50 0.70 < 0.01 < 0.01 Monte Carlo Analysis

  22. Sources Causal Pathway Impairment X Non point contributions not well characterized but not likely to cause observed impacts. Conceptual Model of Toxic Contamination Pathway 4: Episodic Events Non-Point Sources Point Source Discharges Unknown episodic event (e.g. treatment upset, illicit discharge) could contribute to impairment 3. Complex Mixture 4. Episodic Events 1. Metals 2. Ammonia Acute toxicity Chronic toxicity Death or reproductive failure Loss of Sensitive invertebrate taxa

  23. Recommendations • Develop TMDL for Whole Effluent Toxicity • Implement TMDL through NPDES Permits to Industries • Reassess metals limits for each facility • Monitor to measure compliance with TMDL • Reassess the need to iterate the SI Process

  24. 5 Reasons to Target Toxicity for TMDL 1. All 3 Metal Finishing Discharges Exhibit Acute Toxicity 2. Biological Monitoring Links Impact with Outfall Locations 3. No Excursions Above Numeric WQ Criteria Measured In-Stream 4. Current Allocations to ZOI Exceed 7Q10 Flow 5. No Individual Chemical Parameter Correlated with Toxicity in Discharge Monitoring

  25. TMDL – How Big is the Pie? 7Q10 = 12.6 cfs = 93 gps ATU = 100/LC 50 Acute Protection Chronic Protection 0.33 ATU is the maximum allowable amount of toxicity 1 CTU is the maximum allowable amount of toxicity Chronic TMDL = 93 gps * 1 CTU Chronic Toxic Units Acute TMDL = 93 gps * 0.33 ATU Acute Toxic Units Acute TMDL = 30.7 gATU/sec Chronic TMDL = 93 gCTU/sec

  26. Chronic TMDL Flow Proportions Acute TMDL QRD QRD QRD 14.9 4.9 100,000 gCTU/sec gATU/sec gpd SUM SUM SUM 49.4 WHY WHY WHY 16.3 330,000 gCTU/sec 195,000 gATU/sec gpd 28.9 9.5 gpd gCTU/sec gATU/sec TMDL – How to Split Up the Pie

  27. Naugatuck River Toxicity TMDL Location Streamflow TMDL WLA LA MOS @ Rte 6 12.60 93.24 0.00 0 93.24 @ QRD 12.76 94.42 15.02 0 79.40 @ NF Bk. 12.87 95.24 15.02 0 80.22 @ POTW 14.97 110.78 15.02 0 95.76 @ Branch Bk. 15.75 116.55 15.02 0 101.53 @ Whyco 16.05 118.77 44.07 0 74.70 @ Nibb. Bk. 16.12 120.00 44.07 0 75.93 @ Summit 16.63 123.06 93.24 0 29.82 @ Frost Br. 17.17 127.06 93.24 0 33.82 Streamflow in cfs, TMDL in gCTU/sec.

  28. Naugatuck River Toxicity TMDL

  29. Establishing The TMDL • Initiate Public Participation and formal comment period – Public Notice • Review comments from dischargers, other stakeholders and EPA, revise TMDL as warranted. • Establish TMDL and submit to EPA for review and approval. • Upon EPA approval, implement TMDL through revisions to NPDES permits.

  30. Implementation • NPDES permits expire for QRD, Whyco, and Summit in September 2004 • NPDES permit expired for Thomaston POTW in March 2003 • Significant reductions in Whole Effluent Toxicity will be required to achieve compliance with permit limits • Redirecting industrial discharges to the POTW is not a viable option

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