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

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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
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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
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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

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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

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What is the Goal ?
E
P
T
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Study Area Naugatuck River near Thomaston
Leadmine Bk
Naugatuck R
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 1970s
  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
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Cause Unknown Investigation
Conceptual Model Diagram

• Review of Existing Data
• Additional Samples from River and Effluents
• Stressor ID Analysis

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Review of Existing Data

• DMRs and ATMRs
• ArcView coverages
• Biological monitoring
• Physical/chemical monitoring (CTDEP and USGS)
• Hydrology (USGS Gage)

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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

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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)

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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
?
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Streamflows less than 7Q10 are Common
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The abundance of sensitive macroinvertebrates
declines downstream of each point discharge
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SI Procedure
DEPs analysis was performed consistent with EPA
Guidance and has been reviewed by the principal
authors of the Guidance
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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
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Conceptual Model of Toxic Contamination
Non-Point Sources
Point Source Discharges
3. Complex Mixture
4. Episodic Events
2. Ammonia
1. Metals
Acute toxicity
Chronic toxicity
Death or reproductive failure
Loss of Sensitive invertebrate taxa
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Pathway 1 Metals
Conceptual Model of Toxic Contamination
Non-Point Sources
Point Source Discharges
3. Complex Mixture
4. Episodic Events
2. Ammonia
1. Metals
Acute toxicity
Chronic toxicity
Death or reproductive failure
Loss of Sensitive invertebrate taxa
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Pathway 2 Ammonia
Conceptual Model of Toxic Contamination
Non-Point Sources
Point Source Discharges
3. Complex Mixture
4. Episodic Events
2. Ammonia
1. Metals
Acute toxicity
Chronic toxicity
Death or reproductive failure
Loss of Sensitive invertebrate taxa
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Pathway 3 Complex Mixture
Conceptual Model of Toxic Contamination
Non-Point Sources
Point Source Discharges
Biological monitoring links impact with outfall
locations
3. Complex Mixture
4. Episodic Events
2. Ammonia
1. Metals
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
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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

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Monte Carlo Analysis
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Pathway 4 Episodic Events
Conceptual Model of Toxic Contamination
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
2. Ammonia
1. Metals
Acute toxicity
Chronic toxicity
Death or reproductive failure
Loss of Sensitive invertebrate taxa
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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

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

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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