CT DEP Developed an Interim Nutrient Management Strategy for Freshwater While Working to Develop Nutrient

Criteria

CT DEP Went to Public Notice with Beacon Falls NPDES Permit

EPA Evaluated and Objected to the Permit Primarily Based on Concerns with Phosphorus

Limits CT DEP Analyzed Preliminary Data Collected in Efforts to Develop Nutrient Criteria and is Proposing a Shift Based on the Best Available Science to Address EPA Concerns CT DEP Will Continue to Study Nutrient Dynamics in Streams and May Modify the Strategy Based on Future Findings (Adaptive Management) 

# Addressing EPA

Concerns: CT NPDES Phosphorus 

# Limits

# Addressing EPA Concerns: CT NPDES Phosphorus Limits

 “The Naugatuck River is listed as impaired for aquatic life , and municipal point source discharges are listed as one of the causes of impairment.”



###  “No analyses of (aquatic life) data relative to general impairment status or eutrophication impacts was presented.”

 “CTDEP must conduct an appropriate analysis of the potential that phosphorus in the discharge will cause or contribute to a violation of water quality standard and, if so, must establish a WQBEL ...” EPA Concerns (Re: Beacon Fall CT NPDES Draft Permit Letter June 18, 2010)

# Addressing EPA Concerns: CT NPDES Phosphorus Limits

 Using best available science, we shifted the strategy to develop biologically based Phosphorus Limits for WWTPs that meet aquatic life designated uses CT DEP Response (Re: Beacon Fall CT NPDES Draft Permit Letter June 18, 2010)Anthropogenic Input of Nutrients:  Sewage Treatment Plants  Non-Point Sources  Canopy Cover  Temperature  Flow  Natural Nutrient Loading 

### Sources Habitat Conditions Changes in Algal Community and Biomass 

### Response

 Changes in Habitat Structure (Smothering Rocks, Reduction of food Sources)  Changes in Water Chemistry (pH, Dissolved Oxygen) Changes in Other Biological Communities (i.e. Macroinvertebrate and Fish) 

### Physical /Chemical 

### Changes Secondary Response  Develop Criteria to Support Aquatic Life Uses in CT Fresh Waters by Linking Excess Nutrients with Direct Aquatic Life Responses  Capture Spatial and Temporal Variation  Account for Excess Nutrients Interactions with Habitat Conditions  Create Model to Establish Site- Specific Goals on a Statewide Scale that can be Continually Modified with Monitoring Data 

# CT DEP Nutrient Management / Criteria Strategy

Currently Working on Project to Better Link Excess Nutrients to Aquatic Life Under an EPA 104(b)3 Grant. Additional funding for next year provided by EPA 604(b) Grant.Anthropogenic Input of Nutrients:  Sewage Treatment Plants  Non-Point Sources  Canopy Cover  Temperature  Flow  Natural Nutrient Loading 

### Sources Habitat Conditions Changes in Algal Community and Biomass 

### Response



## Stream Benthic 

## Algal Community: Epilithic Diatoms 

# CT DEP Nutrient Management / Criteria Strategy
 Develop Criteria to Support Aquatic Life Uses in CT Fresh Waters by Linking Excess Nutrients with Direct Aquatic Life Responses  Capture Spatial and Temporal Variation  Account for Excess Nutrients Interactions with Habitat Conditions  Create Model to Establish Site- Specific Goals on a Statewide Scale that can be Continually Modified with Monitoring DataAnthropogenic Input of Nutrients:  Sewage Treatment Plants  Non-Point Sources  Canopy Cover  Temperature  Flow  Natural Nutrient Loading 

### Sources Habitat Conditions Changes in Algal Community and Biomass 

### Response

Current In-Stream Phosphorus Load At Point of Discharge: Total Forested Condition Phosphorus Load Current Load (lbs/day) 205.3 Forested Load (lbs/day) 4.80 Enrichment Factor 42.79 

### Enrichment Factor (EF) Example: 

# CT DEP Nutrient Management / Criteria Strategy
 Develop Criteria to Support Aquatic Life Uses in CT Fresh Waters by Linking Excess Nutrients with Direct Aquatic Life Responses  Capture Spatial and Temporal Variation  Account for Excess Nutrients Interactions with Habitat Conditions  Create Model to Establish Site- Specific Goals on a Statewide Scale that can be Continually Modified with Monitoring Data

# Exploratory Data Analysis: Existing Data

 Diatom Species Data Collected From 2002

– 2004
 78 Sites


###  2002

– 2003 Probabilistic Sites
 2004 Additional Sites at Established Reference and Known Highly Enriched 

### Sites
 Readily Available GIS Data and Tools

Diatom Images From : ANSP Algae Image Database from the Phycology Section, Patrick Center for Environmental Research, The Academy of Natural Sciences at http://diatom.acnatsci.org/AlgaeImage/Community plot shows additive response of diatom species

 Curve height shows signal strength  Evidence for community threshold comes from synchronous taxa response  Sharp peaks denote threshold changes in community  Z
- (black dots) are individual diatom (algae) species that decrease when the Enrichment Factor (EF) increases  Z+ (red dots) are individual diatom (algae) species that increase when EF increases Preliminary Work (Best Available Science): Making the Biological Connection to Phosphorus Threshold Indicator Taxa Analysis (TITAN)Community plot shows additive response of diatom species

 This analysis indicates a community threshold in the EF range of 4.5
– 8.4  This means there is little change in the biological community after an EF of 8.4 (reduction in biodiversity) and dominance by only a few „tolerant‟ species Preliminary Work (Best Available Science): Making the Biological Connection to Phosphorus TITAN Analysis Observed Change Point Bootstrap Replicate Change Points At Quantiles 0.05 0.1 0.5 0.9 0.95 sumz - 1.9 1.9 1.9 2.305 4.1665 4.27 sumz+ 6.16 4.485 4.845 5.89 7.55 8.435

8.4 EFTITAN Analysis - Macro -invertebrate Community and Phosphorus Concentration  Very Weak Relationship Between Phosphorus and Macroinvertebrate Community  Very Few Significant Species  No Strong „Change‟ Signals Preliminary Work (Best Available Science): Making the Biological Connection to PhosphorusPreliminary Work (Best Available Science): Making the Biological Connection to Phosphorus 

# Beach Brook in Granby (Drainage Basin = 1.2 mi 2

# )

 Small Drainage Basin  Highly Forested BasinPreliminary Work (Best Available Science): Making the Biological Connection to Phosphorus 

# Farmington River in Canton (Drainage Basin = 354 mi 2

# )

 Premier Trout Fishery  Healthy Macro
- Invertebrate Community  Average Seasonal Phosphorus Concentration: 0.02 mg/LPreliminary Work (Best Available Science): Making the Biological Connection to Phosphorus 

# Thoughts for Future Work...

B C G T i e r 2 B C G T i e r 3 B C G T i e r 4Preliminary Work (Best Available Science): Making the Biological Connection to Phosphorus 

# Naugatuck River in Beacon Falls (Drainage Basin = 259 mi2

# )

8.4 EF

# DEP Interim Strategy for Issuing NPDES Permits Until Full Nutrient Strategy Criteria is Developed 

# Best Available Science : The 

# preliminary work presented in the previous slides along with other exploratory analyses 

## suggests that the 

# diatom community is 

# indicative of enrichment conditions and that an 

# enrichment factor of 8.4 may be an appropriate biological goal to maintain diatom community diversity

# DEP Interim Strategy for Issuing NPDES Permits Until Full Nutrient Strategy Criteria is Developed

 Maintain an in
- stream enrichment factor of 8.4 throughout the drainage basin Margin of Safety

 Conservatively Assumed No Reductions in 

### Current Land Cover / Use Loadings

 Assumed Worst Case Steady

– State Land Cover / Use Loadings Based on Export 

### During „First Flush‟ Storm (Much Higher than Normal) Conditions

 Assumed No Attenuation

 WWTP Load Based on Current Flow Rate (Increases in Flow Rate Would Require WWTP to Lower Limits) East Branch Naugatuck River in Torrington. July 2010.Facility Original

Strategy (mg/L) Modified

Strategy (mg/L) Modified STP Load

At Current Flows (lbs/day) Enrichment Factor* At

Discharge TORRINGTON WPCF 0.7 0.4 17.29 7.94 THOMASTON WPCF 0.7 1 7.35 6.84 WATERBURY WPCF 0.7 0.2 34.26 7.96 NAUGATUCK WPCF 0.7 0.4 16.43 8.39 BEACON FALLS WPCF Cap 1 2.67 8.07 SEYMOUR WPCF Cap 0.7 7.54 7.90 ANSONIA WPCF Cap 0.7 11.92 8.36 * No Reduction in Land Cover/Use Loading Maintain an EF of 8.4 or lower throughout the Naugatuck River 

### Naugatuck River Modified Strategy