Data Summary for Primary Tier Watersheds

Draft, Deliberative, and Predecisional Data Summary For Primary Tier Watersheds

DATA SUMMARY FOR PRIMARY TIER WATERSHEDS (EMBAYMENT LOADINGS, POINT SOURCE DISCHARGES, AND TRIBUTARY LOADINGS) JUNE 2, 2017 Introduction

Tetra Tech was tasked with determining embayment loadings, point source discharges, and tributary loadings for Long Island Sound (LIS). The immediate task focused on a set of 13 embayments, one large riverine system (Connecticut River), and Western LIS that EPA classified as primary tier watersheds. This memo provides a summary of the work conducted and findings made under Subtasks A through C of the LIS Task Order for all primary tier watersheds, as further described below.  Section 1 (Subtask A) provides a summary of nitrogen loads by embayment for primary tier watersheds. Additional embayments are covered under the next option year of the Task Order (secondary tier watersheds).  Section 2 (Subtask B) provides a summary of regulated point source discharges to LIS.  Section 3 (Subtask C) provides a summary of tributary loadings to LIS, specifically the Connecticut River (primary tier watershed). The Housatonic and Thames are covered under the next option year of the Task Order (secondary tier watersheds).

See Figure 1 for a map of all primary tier watersheds addressed in this memo.

1 Draft, Deliberative, and Predecisional Data Summary For Primary Tier Watersheds

Figure 1. Map of Primary Tier Watersheds in LIS

2 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Introduction and Methods Overview The purpose of this subtask was to summarize nitrogen loading data for primary tier watersheds identified by EPA, which include 13 embayments and waters in western LIS (Eastern and Western Narrows). These 13 embayments and western LIS waters will be referred to as primary tier watersheds. Nitrogen loads will be used in at least two ways: (1) they will be related to response indicator values in the priority waters to develop protective thresholds in the embayments and western LIS and (2) they will be used for calculating and allocating load reductions as required to meet these protective nitrogen thresholds.

Tetra Tech relied primarily on data from Dr. Jaime Vaudrey from the University of Connecticut, who developed a model using land use and population patterns to estimate nitrogen loads and yields for 116 embayments to LIS. Dr. Vaudrey’s team used input data from 2010–2014 to run the model. These embayments cover all primary tier watersheds described above. Dr. Vaudrey’s team normalized loads and yields by both area of open water embayment and watershed area.

Additionally, Dr. Vaudrey's team allocated nitrogen loads by source contributions, which include atmospheric deposition, fertilizer, sewer, combined sewer overflows, septic and cesspools, and wastewater. Load scenarios were primarily developed using Center for Land Use Education and Research [CLEAR] 2010 land use data, however National Land Cover Dataset [NLCD] 2011 land use data were used for three embayments with incomplete CLEAR coverage (Pawcatuck River, East River, and Goldsmith’s Inlet) (Vaudrey et al. 2016). Vaudrey et al. (2016) estimated embayment nitrogen loading following the approach presented by Valiela et al. (1997). In the Valiela et al. (1997) model, inputs of nitrogen from various sources (e.g., atmospheric deposition, CSOs, fertilizer, wastewater treatment plants, septic systems) are estimated based on major land uses and population patterns. Nitrogen losses are then estimated based on the various watershed ecosystem land uses (natural vegetation, turf, agricultural land, residential areas, and impervious surfaces). For diffuse sources such as atmospheric deposition and fertilizer nitrogen, nitrogen losses occur through transport through the vegetation, soil, vadose zone and aquifer. Losses in septic systems also include attenuation through aquifer transport. Attenuation is calculated separately for each major land use since processes and loss rates vary among land uses. The number of people within sewered and CSO areas were determined by analyzing U.S. Census Bureau data within defined sewer or CSO areas. Remaining people not in defined sewer areas were assumed to be on traditional septic systems. Model attenuation factors and loading rates were updated to reflect local conditions for LIS.

Estimates for atmospheric deposition do not always appear proportional to the embayment area because atmospheric deposition is a function of average rainfall, watershed and embayment surface area, and land use. Greater average rainfalls result in greater deposition. Vaudrey (2016) modeled attenuation of nitrogen deposition based on land use and the transport of nitrogen through the soil, vadose zone, and aquifer with urbanized lands having lower attenuation. She also adjusted attenuation to reflect locally relevant information, such as insufficient organic carbon to support denitrification in the Northport Bay area, as reported by Young et al. (2013)

Note that in some cases, the data presented below for each embayment for sewer nitrogen loadings (Vaudrey et al. 2016) and point sources (ICIS 2015) differ. CSOs may no longer exist, ICIS data is more recent than the Vaudrey data, and/or methodology might result in different estimates. For total nitrogen loadings, Vaudrey et al. (2016) used a four‐year average (2011–2014) of the nitrogen loads

A‐1 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading from wastewater treatment facilities, except where upgrades to the facility were completed. In these cases, only data for the resulting lower contribution of nitrogen were included. Nitrogen load data were obtained from CT DEEP and RI DEM. For point sources, Tetra Tech estimated annual loads based on data provided by EPA and supplemented by ICIS through the most recent year 2015, not a four‐year average like Vaudrey used. More detail about how Tetra Tech calculated point source values from ICIS is available in Section B below.Tetra Tech also extracted data from the Nature Conservancy (TNC), which applied the Nitrogen Loading Model (NLM) to 13 embayments along the north shore of Nassau County, NY and northwestern Suffolk County, NY. TNC used input data from 2010–2015 to run its model. The model provided nitrogen load and yield estimates normalized by both area of open water embayment and watershed area. TNC broke down the loads by source contributions, including atmospheric deposition, fertilizer (lawns, recreation, agriculture), and wastewater (sewage treatment plants, septic, and cesspools). Among primary tier embayments, TNC estimates were available for only the Northport‐ Centerport Harbor Complex, NY (Lloyd et al. 2016).

Tetra Tech extracted nitrogen loads, yields, and source contributions from both the University of Connecticut (Vaudrey et al. 2016) and TNC (Lloyd et al. 2016) datasets for each primary tier watershed. Additional source data were considered, but were not on the same spatial or numeric scales to be included in the compiled data. All collected data are included in Embayment Loads.xlsx. The Vaudrey et al. (2016) load estimates provided comprehensive load estimates for all primary tier watersheds compared to only one primary tier embayment load estimate included with the TNC dataset. Due to extensive data availability of the Vaudrey et al. (2016) estimates and the comparability of a consistent method across embayments, the following summary focuses on the Vaudrey et al. (2016) data.

Note that in some cases, individual watersheds specified in the Task Order corresponded to multiple embayments defined by Vaudrey et al. (2016). For example, the Northport‐Centerport Harbor Complex, NY watershed specified by EPA in the Task Order consists of three Vaudrey et al. (2016) embayments: Centerport Harbor, NY; Northport Bay, NY; and Northport Harbor, NY. In these cases loads, yields, and land use characteristics calculated in Vaudrey et al. (2016) were aggregated to the watersheds specified by EPA in the Task Order.

In addition to nitrogen data, summary information (e.g., drainage area, land use characteristics) was also compiled and calculated for each of the primary tier watersheds. Compiled data, which are summarized under the results section, include data extracted directly from Vaudrey et al. (2016) as well as information found in technical reports, peer‐reviewed literature sources, and Tetra Tech‐calculated information, as described in Table A‐1.

Table A-1. Sources of Information for Summary Statistics Calculated by Tetra Tech or Obtained Summary Statistic Directly from a Source? Notes Total Drainage Area of Literature source Vaudrey et al. 2016 Watershed Total Area of Priority Literature source Vaudrey et al. 2016 Embayment Main Tributaries Literature source Various literature and Geographical Information System (GIS) sources; see the results section below for specific citations

A‐2 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Calculated by Tetra Tech or Obtained Summary Statistic Directly from a Source? Notes Residence Time Calculated by Tetra Tech A rough estimate of freshwater residence time was calculated using a residence time empirical model for southern New England embayments (Abdelrhman 2005). The model relates flushing time to the readily available physical properties embayment length (km) and surface area (km2). Open water embayment areas and lengths were estimated in GIS using the embayments delineated by Vaudrey et al. (2016). Depth at Mean Lower Low Calculated by Tetra Tech The NOAA Coastal Relief Model bathymetry was used to Water (MLLW) approximate average and maximum MLLW depths (i.e., mean at low tide) for each watershed as a rough estimate (NOAA 2015). See Appendix A for a description of methods used for bathymetric estimates. Land Use Characteristics Literature source Vaudrey et al. 2016 (e.g., % Watershed in Developed, Forest, or Agriculture Lands) MS4s (Name, Number, Calculated by Tetra Tech See Dischargers Compiled.xlsx and the Subtask B section and Percent of watershed) of this memo for a description of methods. Point Sources (Name, Calculated by Tetra Tech See Dischargers Compiled.xlsx and the Subtask B section Number, and Loading) of this memo for a description of methods. Total Nitrogen Loading Literature source Vaudrey et al. 2016 (Entire Watershed and by Source)

Results Nitrogen loads, yields, open water area, and watershed area for the 13 primary tier priority embayments, the Eastern Narrows, Western Narrows, and western LIS (Eastern and Western Narrows combined) are summarized in Table A‐2. The loads reported are for total nitrogen load including atmospheric loading to the watershed and embayment. A more detailed description and summary statistics for each primary tier watershed follows the table.

Nitrogen loads to primary embayments ranged from 7,155 kg N/year for Stonington Harbor, CT to 335,698 kg N/year for Nissequogue River, NY. The Eastern Narrows watershed includes 35 Vaudrey embayments with an estimated total load of 1,937,052 kg N/year. The Western Narrows includes seven Vaudrey embayments with an estimated total load of 16,541,950 kg N/year; 99% of which is from the East River, NY embayment (16,297,860 kg N/year).

Table A‐2 also includes total nitrogen yields (loads normalized to the area of open water embayment and to watershed area). Coupled with considerations of degree of flushing (residence time), yield normalized to open water embayment area can be an indication of areas where one might expect localized effects of nitrogen entering LIS, such as the Pawcatuck River, Southport Harbor/Sasco Brook, Nissequogue River, and the Western Narrows. Yield normalized to watershed area corrects total watershed load for differences in total area, thus indicating watersheds with relatively higher areal nitrogen generation such as in the Western Narrows and Nissequogue River watersheds.

A‐3 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Table A-2. Summary of Nitrogen Loads and Yields by Primary Tier Watershed Yield, Normalized Yield, Open Watershed to Embayment Normalized to Water Area Area Load Area Watershed Area Primary Tier Watershed [km2] [km2] [kg N/yr] [kg N/yr-km2] [kg N/yr-km2] Pawcatuck River, RI 2.6 674.6 243,928 92,451 356 Stonington Harbor, CT 1.8 6.2 7,155 3,980 753 Saugatuck Estuary, CT* 2.5 225.6 102,692 41,115 425 Norwalk Harbor, CT 6.9 155.5 189,593 27,675 1,152 Mystic River, CT 1.2 67.2 29,825 25,455 420 Niantic Bay, CT* 11.4 76.2 35,757 3,149 242 Farm River, CT 0.4 67.4 34,678 82,290 505 Southport Harbor/ Sasco 0.3 111.6 48,632 152,762 432 Brook, CT* Northport-Centerport Harbor 12.0 21.2 73,375 6,101 2,597 Complex, NY* Port Jefferson Harbor, NY 5.0 15.5 58,623 11,790 3,286 Nissequogue River, NY 2.0 97.4 335,698 171,940 3,414 Stony Brook Harbor, NY 3.7 19.9 34,756 9,433 1,466 Mt. Sinai Harbor, NY 1.6 13.3 39,043 23,736 2,749 Eastern Narrows 347.0 711.1 1,937,052 28,961 2,626 Western Narrows 56.1 408.4 16,541,950 325,607 40,324 Western LIS (Eastern and 403.1 1,119.5 18,479,002 157,017 16,481 Western Narrows Combined) *Includes multiple Vaudrey et al. (2016) embayments. See detailed description sections below.

The following summaries provide nitrogen loads for each primary tier watershed, for comparison, as well as summary watershed information that may be useful in future analysis and allocation efforts.

A‐4 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.1 Pawcatuck River, RI Figure A‐1 shows a map of the Pawcatuck River watershed. Summary statistics are included in Table A‐3.

Figure A-1. Pawcatuck River Watershed, RI

Table A-3. Summary Information for the Pawcatuck River Watershed, RI Total Drainage Area of Watershed 674.6 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 2.6 km2 (Vaudrey et al. 2016) Main Tributaries Shunock River (FB Environmental Associates, Inc. Ashaway River 2011) Tomaquag Brook Wood River Meadow Brook Beaver River Queen/Usquepaug River Chipuxet River Residence Time (days) Abdelrhman 2005 derived: 4.3 Depth at MLLW (m) Average: 1.4 (NOAA 2015) Maximum: 4 Land Use Characteristics Developed: 12% (Vaudrey et al. 2016; NLCD 2011 Forested: 75% land use data) Agricultural: 8% Water: 2% Grass: 2% Barren: 1% MS4s: Percent of watershed with MS4: 8%

Ashaway New London Pawcatuck Washington Westerly

A‐5 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Point Sources kg N/year lbs N/day (ICIS 2015) Stonington/Pawcatuck Water Pollution Control 1,822 11 Facility (WPCF) Kenyon Industries, Inc. 26,627 161 Westerly Waste Water Treatment Facility (WWTF) 48,282 292 Sum of point sources 76,731 464 Total Nitrogen Loading kg N/year lbs N/day (Vaudrey et al. 2016)1 Atmospheric deposition 39,715 240 Fertilizer 85,602 517 Sewer 69,849 422 CSOs N/A N/A Septic and cesspools 48,763 294 Entire embayment 243,929 1473 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐6 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.2 Stonington Harbor, CT Figure A‐2 shows a map of the Stonington Harbor watershed. Summary statistics are included in Table A‐4.

Figure A-2. Stonington Harbor Watershed, CT

Table A-4. Summary Information for Stonington Harbor Watershed, CT Total Drainage Area of Watershed 6.2 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 1.8 km2 (Vaudrey et al. 2016) Main Tributaries Stony Brook (ESRI 2017) Residence Time (days) Abdelrhman 2005 derived: 2.5

Depth at MLLW (m) Average: 2.4 (NOAA 2015) Maximum: 6 Land Use Characteristics Developed: 24% (Vaudrey et al. 2016; CLEAR 2010 land Forested: 53% use data) Agricultural: 2% Water: 7% Grass: 13% Barren: 1% MS4s: Percent of watershed with MS4: 35%

New London Stonington Point Sources kg N/year lbs N/day (ICIS 2015) Stonington Borough WPCF 663 4

A‐7 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Total Nitrogen Loading kg N/year lbs N/year (Vaudrey et al. 2016)1 Atmospheric deposition 3,061 18 Fertilizer 1,131 7 Sewer 2,070 13 CSOs 894 5 Septic and cesspools N/A N/A Entire embayment 7,156 43 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐8 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.3 Saugatuck Estuary, CT1 Figure A‐3 shows a map of the Saugatuck Estuary watershed. Summary statistics are included in Table A‐5.

Figure A-3. Saugatuck Estuary Watershed, CT

Table A-5. Summary Information for Saugatuck Estuary Watershed, CT Total Drainage Area of Watershed 225.6 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 2.5 km2 (Vaudrey et al. 2016) Main Tributaries West Branch (AKRF, Inc. 2012) Jennings Brook Beaver Brook Stony Brook Little River Aspetuck River Residence Time (days) Abdelrhman 2005 derived: 4.3 Depth at MLLW (m) Average: 1.0 (NOAA 2015) Maximum: 8 Land Use Characteristics Developed: 20% (Vaudrey et al. 2016; CLEAR 2010 Forested: 64% land use data) Agricultural: 2% Water: 3% Grass: 11% Barren: 0%

1 Includes two Vaudrey et al. (2016) embayments: Saugatuck River, CT and Saugatuck River, North, CT (freshwater)

A‐9 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

MS4s: Percent of watershed with MS4  Saugatuck River, CT embayment: 100% Bethel  Saugatuck River, North, CT (freshwater) embayment: 36% Danbury Easton Fairfield Georgetown Newtown Norwalk Redding Ridgefield Weston Westport Wilton Point Sources kg N/year lbs N/day (ICIS 2015) Westport WPCF 3,313 20 Total Nitrogen Loading kg N/year lbs N/year (Vaudrey et al. 2016)1 Atmospheric deposition 24,685 149 Fertilizer 30,214 183 Sewer 4,760 29 CSOs2 238 1 Septic and cesspools 42,795 258 Entire embayment 102,692 620 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

2 Vaudrey estimates are from data that represent the 2010–2014. More recent data from CT DEEP (http://www.ct.gov/deep/cwp/view.asp?a=2719&q=525758&deepNav_GID=1654) show that there are presently no CSOs in the Saugatuck Estuary.

A‐10 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.4 Norwalk Harbor, CT Figure A‐4 shows a map of the Norwalk Harbor watershed. Summary statistics are included in Table A‐6.

Figure A-4. Norwalk Harbor Watershed, CT

Table A-6. Summary Information for Norwalk Harbor Watershed, CT Total Drainage Area of Watershed 155.5 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 6.9 km2 (Vaudrey et al. 2016) Main Tributaries Silvermine River (NRWI 1998) Comstock Brook Cooper Pond Brook Residence Time (days) Abdelrhman 2005 derived: 4.8

Depth at MLLW (m) Average: 1.5 (NOAA 2015) Maximum: 10 Land Use Characteristics Developed: 33% (Vaudrey et al. 2016; CLEAR 2010 Forested: 50% land use data) Agricultural: 1% Water: 2% Grass: 14% Barren: 0% MS4s: Percent of watershed with MS4: 94%

Fairfield Georgetown Lewisboro New Canaan Norwalk Redding Ridgefield Weston Wilton

A‐11 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Point Sources kg N/year lbs N/day (ICIS 2015) Norwalk WPCF 96,588 583 Total Nitrogen Loading kg N/year lbs N/day (Vaudrey et al. 2016)1 Atmospheric deposition 23,356 141 Fertilizer 19,450 117 Sewer 121,472 734 CSOs2 6,074 37 Septic and cesspools 19,241 116 Entire embayment 189,593 1,145 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐12 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.5 Mystic Harbor, CT Figure A‐5 shows a map of the Mystic Harbor watershed. Summary statistics are included in Table A‐7.

Figure A-5. Mystic Harbor Watershed, CT

Table A-7. Summary Information for Mystic Harbor Watershed, CT Total Drainage Area of Watershed 67.2 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 1.2 km2 (Vaudrey et al. 2016) Main Tributaries Whitford Brook (ESRI 2017) Haleys Brook Residence Time (days) Abdelrhman 2005 derived: 3.5

Depth at MLLW (m) Average: 0.5 (NOAA 2015) Maximum: 4 Land Use Characteristics Developed: 15% (Vaudrey et al. 2016; CLEAR 2010 Forested: 67% land use data) Agricultural: 6% Water: 2% Grass: 9% Barren: 1% MS4s: Percent of watershed with MS4: 34%

Groton Ledyard Mystic New London Old Mystic Stonington

A‐13 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Point Sources kg N/year lbs N/day (ICIS 2015) Ledyard WPCF 663 4 Stonington Mystic WPCF 2,485 15 Sum of point sources 3,148 19 Total Nitrogen Loading kg N/year lbs N/day (Vaudrey et al. 2016)1 Atmospheric deposition 5,855 35 Fertilizer 8,258 50 Sewer 8,030 49 CSOs N/A N/A Septic and cesspools 7,682 46 Entire embayment 29,825 180 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐14 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.6 Niantic Bay, CT2 Figure A‐6 shows a map of the Niantic Bay watershed. Summary statistics are included in Table A‐8

Figure A-6. Niantic Bay Watershed, CT

Table A-8. Summary Information for Niantic Bay Watershed, CT Total Drainage Area of Watershed 76.2 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 11.4 km2 (Vaudrey et al. 2016) Main Tributaries Latimer Brook (ECCD 2009) Oil Mill Brook Stony Brook Residence Time (days) Abdelrhman 2005 derived: 3.92

Depth at MLLW (m) Average: 4.5 (NOAA 2015) Maximum: 14 Land Use Characteristics Developed: 16% (Vaudrey et al. 2016; CLEAR 2010 Forested: 67% land use data) Agricultural: 3% Water: 4% Grass: 7% Barren: 3% MS4s: Percent of watershed with MS4  Niantic River, CT embayment: 24% East Lyme  Niantic Bay, CT embayment: 100% Montville New London Niantic Waterford Point Sources No identified point sources within the embayment watershed

2 Includes two Vaudrey et al. (2016) embayments: Niantic River, CT and Niantic Bay, CT

A‐15 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Total Nitrogen Loading kg N/year lbs N/year (Vaudrey et al. 2016)1 Atmospheric deposition 24,292 147 Fertilizer 6,508 39 Sewer N/A N/A CSOs N/A N/A Septic and cesspools 4,957 30 Entire embayment 35,757 216 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐16 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.7 Farm River, CT Figure A‐7 shows a map of the Farm River watershed. Summary statistics are included in Table A‐9.

Figure A-7. Farm River Watershed, CT

Table A-9. Summary Information for Farm River Watershed, CT Total Drainage Area of Watershed 67.4 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 0.4 km2 (Vaudrey et al. 2016) Main Tributaries Maloney Brook (ESRI 2017) Burrs Brook Gulf Brook Residence Time (days) Abdelrhman 2005 derived: 3.2 Depth at MLLW (m) Not available Land Use Characteristics Developed: 25% (Vaudrey et al. 2016; CLEAR 2010 Forested: 44% land use data) Agricultural: 9% Water: 6% Grass: 12% Barren: 4% MS4s: Percent of watershed with MS4: 71%

Branford East Haven Guilford New Haven North Branford North Haven Wallingford Point Sources No identified point sources within the embayment watershed

A‐17 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Total Nitrogen Loading kg N/year lbs N/year (Vaudrey et al. 2016)1 Atmospheric deposition 7,482 45 Fertilizer 12,460 75 Sewer N/A N/A CSOs N/A N/A Septic and cesspools 14,737 89 Entire embayment 34,679 209 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐18 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.8 Southport Harbor/ Sasco Brook, CT3 Figure A‐8 shows a map of the Southport Harbor/ Sasco Brook watershed. Summary statistics are included in Table A‐10.

Figure A-8. Southport Harbor/Sasco Brook Watershed, CT

Table A-10. Summary Information for Southport Harbor/Sasco Brook Watershed, CT Total Drainage Area of Watershed 111.6 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 0.3 km2 (Vaudrey et al. 2016) Main Tributaries To Mill River: (ESRI 2017)  Browns Brook  Cricker Brook  Morehouse Brook  Canoe Brook  Chub Brook  Tatetuck Brook

To Sasco Brook:  Great Brook Residence Time (days) Mill River (Abdelrhman 2005 derived): 2.4 Sasco Brook (Abdelrhman 2005 derived): 1.5 Depth at MLLW (m) Southport Harbor (NOAA 2015) Average 0.5 Maximum: 6 Land Use Characteristics Developed: 26% (Vaudrey et al. 2016; CLEAR 2010 Forested: 47% land use data) Agricultural: 3% Water: 5% Grass: 19% Barren: 0%

3 Includes two Vaudrey et al. (2016) embayments: Mill River, CT and Sasco Brook, CT

A‐19 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

MS4s: Percent of watershed with MS4  Mill River, CT embayment: 50% Bridgeport  Sasco Brook, CT embayment: 99% Easton Fairfield Monroe Trumbull Westport Point Sources No identified point sources within the embayment watershed Total Nitrogen Loading kg N/year lbs N/year (Vaudrey et al. 2016)1 Atmospheric deposition 9,211 56 Fertilizer 22,187 134 Sewer N/A N/A CSOs N/A N/A Septic and cesspools 17,234 104 Entire embayment 48,632 294 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐20 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.9 Northport‐Centerport Harbor Complex, NY4 Figure A‐9 shows a map of the Northport‐Centerport Harbor Complex watershed. Summary statistics are included in Table A‐11.

Figure A-9. Northport-Centerport Harbor Complex Watershed, NY

Table A-11. Summary Information for Northport-Centerport Harbor Complex Watershed, NY Total Drainage Area of Watershed 21.2 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 12.0 km2 (Vaudrey et al. 2016) Main Tributaries No major tributaries identified (ESRI 2017) Residence Time (days) Centerport Harbor (Abdelrhman 2005 derived): 1.9 Northport Bay (Abdelrhman 2005 derived): 4.3 Northport Harbor (Abdelrhman 2005 derived): 2.4 Depth at MLLW (m) Average: 3.7 (NOAA 2015) Maximum: 21 Land Use Characteristics Developed: 47% (Vaudrey et al. 2016; CLEAR 2010 Forested: 37% land use data) Agricultural: 0% Water: 2% Grass: 12% Barren: 2% MS4s: Percent of watershed with MS4  Centerport Harbor, NY embayment: 100% Asharokan  Northport Bay, NY embayment: 98% Huntington  Northport Harbor, NY embayment: 99% Huntington Bay Northport

4 Includes three Vaudrey et al. (2016) embayments: Centerport Harbor, NY; Northport Bay, NY; and Northport Harbor, NY

A‐21 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Point Sources kg N/year lbs N/day (ICIS 2015) Northport (Village) 1,491 9 Total Nitrogen Loading kg N/year lbs N/day (Vaudrey et al. 2016)1 Atmospheric deposition 21,243 128 Fertilizer 3,662 22 Sewer 2,925 18 CSOs N/A N/A Septic and cesspools 45,545 275 Entire embayment 73,375 443 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐22 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.10 Port Jefferson Harbor, NY Figure A‐10 shows a map of the Port Jefferson Harbor watershed. Summary statistics are included in Table A‐12.

Figure A-10. Port Jefferson Harbor Watershed, NY

Table A-12. Summary Information for Port Jefferson Harbor Watershed, NY Total Drainage Area of Watershed 15.5 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 5.0 km2 (Vaudrey et al. 2016) Main Tributaries Conscience Bay (Cashin Associations 2009; ESRI 2017) Setauket Harbor Residence Time (days) Abdelrhman 2005 derived: 3.1 Depth at MLLW (m) Average: 3.8 (NOAA 2015) Maximum: 13 Land Use Characteristics Developed: 40% (Vaudrey et al. 2016; CLEAR 2010 land Forested: 41% use data) Agricultural: 0% Water: 2% Grass: 12% Barren: 5% MS4s: Percent of watershed with MS4: 98%

Belle Terre Brookhaven Old Field Poquott Port Jefferson

A‐23 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Point Sources kg N/year lbs N/day (ICIS 2015) Port Jefferson, Suffolk County Sewer District [SCSD] #1 3,645 22 SUNY SCSD #21 6,627 40 Sum of point sources 10,272 62 Total Nitrogen Loading kg N/year lbs N/year (Vaudrey et al. 2016)1 Atmospheric deposition 10,077 61 Fertilizer 2,109 13 Sewer 16,404 99 CSOs2 757 4 Septic and cesspools 29,276 177 Entire embayment 58,623 354 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

2 Vaudrey estimates are from data that represent the 2010–2014. More recent data from NY State (https://data.ny.gov/Energy- Environment/Combined-Sewer-Overflows-CSOs-Map/i8hd-rmbi/data) show that there are presently no CSOs in Port Jefferson Harbor.

A‐24 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.11 Nissequogue River, NY Figure A‐11 shows a map of the Nissequogue River watershed. Summary statistics are included in Table A‐13.

Figure A-11. Nissequogue River Watershed, NY

Table A-13. Summary Information for Nissequogue River Watershed, NY Total Drainage Area of Watershed 97.4 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 2.0 km2 (Vaudrey et al. 2016) Main Tributaries Sunken Meadow Creek (ESRI 2017) Northeast Branch Residence Time (days) Abdelrhman 2005 derived: 4.5 Depth at MLLW (m) Average: 0.1 (NOAA 2015) Maximum: 3 Land Use Characteristics Developed: 48% (Vaudrey et al. 2016; CLEAR 2010 Forested: 34% land use data) Agricultural: 0% Water: 2% Grass: 15% Barren: 1% MS4s: Percent of watershed with MS4: 99%

Head of Harbor Islip Nissequogue Smithtown The Branch Point Sources kg N/year lbs N/day (ICIS 2015) Kings Park SCSD #6 1,491 9

A‐25 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Total Nitrogen Loading kg N/year lbs N/day (Vaudrey et al. 2016)1 Atmospheric deposition 11,917 72 Fertilizer 16,789 101 Sewer N/A N/A CSOs2 127,442 770 Septic and cesspools 179,549 1,085 Entire embayment 335,698 2,028 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐26 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.12 Stony Brook Harbor, NY Figure A‐12 shows a map of the Stony Brook Harbor watershed. Summary statistics are included in Table A‐14.

Figure A-12. Stony Brook Harbor Watershed, NY

Table A-14. Summary Information for Stony Brook Harbor Watershed, NY Total Drainage Area of Watershed 19.9 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 3.7 km2 (Vaudrey et al. 2016) Main Tributaries (Robbins 1977) West Meadow Creek Residence Time (days) Abdelrhman 2005 derived: 4.0 Depth at MLLW (m) Average: 0.7 (NOAA 2015) Maximum: 4 Land Use Characteristics Developed: 30% (Vaudrey et al. 2016; CLEAR 2010 Forested: 48% land use data) Agricultural: 3% Water: 7% Grass: 10% Barren: 2% MS4s: Percent of watershed with MS4: 96%

Brookhaven Head of Harbor Nissequogue Old Field Smithtown Point Sources No identified point sources within the embayment watershed

A‐27 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Total Nitrogen Loading kg N/year lbs N/day (Vaudrey et al. 2016)1 Atmospheric deposition 8,376 51 Fertilizer 4,348 26 Sewer N/A N/A CSOs N/A N/A Septic and cesspools 22,032 133 Entire embayment 34,756 210 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐28 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.13 Mt. Sinai Harbor, NY Figure A‐13 shows a map of the Mt. Sinai Harbor watershed. Summary statistics are included in Table A‐15.

Figure A-13. Mt. Sinai Harbor Watershed, NY

Table A-15. Summary Information for Mt. Sinai Harbor Watershed, NY Total Drainage Area of Watershed 13.3 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 1.6 km2 (Vaudrey et al. 2016) Main Tributaries (ESRI 2017) No major tributaries identified Residence Time (days) Abdelrhman 2005 derived: 2.0 Depth at MLLW (m) Average 2.1 (NOAA 2015) Maximum: 11 Land Use Characteristics Developed: 41% (Vaudrey et al. 2016; CLEAR 2010 Forested: 43% land use data) Agricultural: 0% Water: 3% Grass: 12% Barren: 1% MS4s: Percent of watershed with MS4: 98%

Belle Terre Brookhaven Port Jefferson Point Sources No identified point sources within the embayment watershed Total Nitrogen Loading kg N/year lbs N/day (Vaudrey et al. 2016)1 Atmospheric deposition 4,345 26 Fertilizer 2,604 16 Sewer N/A N/A CSOs N/A N/A Septic and cesspools 32,094 194 Entire embayment 39,043 236 1Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐29 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.14 Eastern Narrows, CT and NY Figure A‐14 shows a map of the Eastern Narrows watershed. Summary statistics are included in Table A‐16.

Figure A-14. Eastern Narrows Watershed, CT and NY

Table A-16. Summary Information for Eastern Narrows Watershed, CT and NY Total Drainage Area of Watershed 711.1 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 347.0 km2 (Vaudrey et al. 2016) Main Tributaries Mamaroneck River (ESRI 2017) Fivemile River Gorhams Pond Noroton River Rippowam River Mianus River Premium River Beaver Swamp Brook Blind Brook Byram River Greenwich Creek Residence Time (days) Abdelrhman 2005 derived: 17.5 Depth at MLLW (m) Average: 14.1 (NOAA 2015) Maximum: 55 Land Use Characteristics Developed: 37% (Vaudrey et al. 2016, CLEAR 2010 Forested: 37% land use data) Agricultural: 0% Water: 2% Grass: 23% Barren: 1% MS4s: Percent of watershed with MS4: 93%

See Dischargers Compiled.xlsx for the 48 MS4s in this watershed

A‐30 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Point Sources kg N/year lbs N/day (ICIS 2015) Blind Brook WPCF 33,963 205 Glen Cove 25,514 154 Greenwich WPCF 73,063 441 Huntington NY 9,112 55 Mamaroneck WPCF 51,359 310 New Canaan WPCF 2,816 17 New Rochelle WPCF 48,046 290 North Castle WPCF 1,325 8 Northport Village 1,491 9 Oyster Bay 8,284 50 Port Chester WPCF 128,066 774 Stamford WPCF 46,058 278 Sum of point sources 429,097 2,591 Total Nitrogen Loading kg N/year lbs N/day (Vaudrey et al. 2016)1 Atmospheric deposition 161,908 978 Fertilizer 220,465 1,332 Sewer 138,942 839 CSOs2 1,152,887 6,963 Septic and cesspools 262,851 1,588 Entire embayment 1,937,053 11,700 1 Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

2 Vaudrey estimates are from data that represent the 2010–2014. More recent data from CT DEEP (http://www.ct.gov/deep/cwp/view.asp?a=2719&q=525758&deepNav_GID=1654) and NY State (https://data.ny.gov/Energy- Environment/Combined-Sewer-Overflows-CSOs-Map/i8hd-rmbi/data) show that there are presently no CSOs in the Eastern Narrows.

A‐31 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.15 Western Narrows, NY Figure A‐15 shows a map of the Western Narrows watershed. Summary statistics are included in Table A‐17.

Figure A-15. Western Narrows Watershed, NY

Table A-17. Summary Information for Western Narrows Watershed, NY Total Drainage Area of Watershed 408.4 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 56.1 km2 (Vaudrey et al. 2016) Main Tributaries East River (ESRI 2017) Bronx River Westchester Creek Hutchinson River Flushing Creek Residence Time (days) Abdelrhman 2005 derived: 4.4 Depth at MLLW (m) Average: 8.6 (NOAA 2015) Maximum: 35 Land Use Characteristics Developed: 86% (Vaudrey et al. 2016; CLEAR 2010 Forested: 6% land use data; NLCD 2011 land use Agricultural: 0% data) Water: 2% Grass: 6% Barren: 0% MS4s: Percent of watershed with MS4: 99%

See Dischargers Compiled.xlsx for the 34 MS4s in this watershed

A‐32 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Point Sources kg N/year lbs N/day (ICIS 2015) Belgrave 14,082 85 Bowery Bay 1,888,691 11,408 Great Neck Water Pollution Control 36,614 221 District (WPCD) Hunts Point 1,358,532 8,206 Newtown Creek 5,483,830 33,123 Port Washington 28,827 174 Red Hook 646,131 3,903 Tallman Island 778,671 4,703 Wards Island 2,468,552 14,910 Sum of point sources 12,703,930 76,733 Total Nitrogen Loading kg N/year lbs N/day (Vaudrey et al. 2016)1 Atmospheric deposition 189,684 1,146 Fertilizer 182,142 1,100 Sewer 14,677,204 88,651 CSOs2 1,432,874 8,654 Septic and cesspools 60,046 363 Entire embayment 16,541,950 99,914 1 Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

2 Recent data from NY State (https://data.ny.gov/Energy-Environment/Combined-Sewer-Overflows-CSOs-Map/i8hd-rmbi/data) show that there are CSOs in the Western Narrows.

A‐33 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

A.16 Eastern and Western Narrows (Combined), CT and NY Figure A‐16 shows a map of the Eastern and Western Narrows watersheds. Summary statistics are included in Table A‐18.

Figure A-16. Eastern and Western Narrows (Combined) Watersheds, CT and NY

Table A-18. Summary Information for Eastern and Western Narrows (Combined) Watersheds, CT and NY Total Drainage Area of Watershed 1,119.5 km2 (Vaudrey et al. 2016) Total Area of Priority Embayment 403.1 km2 (Vaudrey et al. 2016) Main Tributaries East River (ESRI 2017) Bronx River Westchester Creek Hutchinson River Flushing Creek Mamaroneck River Fivemile River Gorhams Pond Noroton River Rippowam River Mianus River Premium River Beaver Swamp Brook Blind Brook Byram River Greenwich Creek Residence Time (days) Abdelrhman 2005 derived: 22 Depth at MLLW (m) Average: 13.3 (NOAA 2015) Maximum: 55

A‐34 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Land Use Characteristics Developed: 56% (Vaudrey et al. 2016; CLEAR 2010 Forested: 25% land use data; NLCD 2011 land use Agricultural: 0% data) Water: 2% Grass: 17% Barren: 0% MS4s: Percent of watershed with MS4: 95%

See Dischargers Compiled.xlsx for the 74 MS4s in this watershed Point Sources kg N/year lbs N/year (ICIS 2015) Blind Brook WPCF 33,963 205 Glen Cove 25,514 154 Greenwich WPCF 73,063 441 Huntington NY 9,112 55 Mamaroneck WPCF 51,359 310 New Canaan WPCF 2,816 17 New Rochelle WPCF 48,046 290 North Castle WPCF 1,325 8 Northport Village 1,491 9 Oyster Bay 8,284 50 Port Chester WPCF 128,066 774 Stamford WPCF 46,058 278 Belgrave 14,082 85 Bowery Bay 1,888,691 11,408 Great Neck WPCD 36,614 221 Hunts Point 1,358,532 8,206 Newtown Creek 5,483,830 33,123 Port Washington 28,827 174 Red Hook 646,131 3,903 Tallman Island 778,671 4,703 Wards Island 2,468,552 14,910 Sum of point sources 13,133,027 79,324 Total Nitrogen Loading kg N/year lbs N/year (Vaudrey et al. 2016)1 Atmospheric deposition 351,592 2,124 Fertilizer 402,607 2,432 Sewer 14,816,145 89,490 CSOs2 2,585,761 15,618 Septic and cesspools 322,897 1,950 Entire embayment 18,479,002 111,614 1 Total nitrogen loadings were calculated based on Vaudrey’s work, using data from 2010–2014, as described on page A-1.

A‐35 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Sources Cited Abdelrhman, M.A. 2005. Simplified modeling of flushing and residence times in 42 embayments in New England, USA, with special attention to Greenwich Bay, Rhode Island. Estuarine Coastal and Shelf Science 62:339–351.

AKRF, Inc. 2012. Saugatuck River Watershed Based Plan. The South Western Regional Planning Agency, Stamford, CT. Accessed February 2017. http://www.westportct.gov/modules/showdocument.aspx?documentid=5707.

Cashin Associations, P.C., 2009. Town of Brookhaven Final Conscience Bay and Setauket Harbor Stormwater Management Plan. Hauppauge, NY. Accessed February 2017. https://www.brookhavenny.gov/DesktopModules/Bring2mind/DMX/Download.aspx?Command=C ore_Download&EntryId=10031&language=en‐US&PortalId=0&TabId=134.

ECCD. 2009. Niantic River Watershed Protection Plan: Guided Summary. Eastern Connecticut Conservation District. Funded by Connecticut Department of Environmental Protection. Accessed February 2017. http://www.waterfordct.org/sites/waterfordct/files/file/file/1._niantic_river_watershed_protectio n_plan_‐_summary.pdf.

ESRI. 2017. National Geographic World Map Service. Environmental Systems Research Institute. Accessed February 2017. Last updated February 9, 2017. http://www.arcgis.com/home/item.html?id=b9b1b422198944fbbd5250b3241691b6.

FB Environmental Associates, Inc. 2011. Rhode Island Statewide Total Maximum Daily Load (TMDL) for Bacteria Impaired Waters, Pawcatuck River Segment 18B Watershed Summary. Prepared for State of Rhode Island and Providence Plantations Department of Environmental Management and USEPA New England, Region 1. Accessed February 2017. http://www.dem.ri.gov/programs/benviron/water/quality/swbpdf/paw18b.pdf.

Lloyd, S., G. Mollod, C. LoBue, and M. Lindberg. 2016. Modeling Nitrogen Source Loads on the North Shore of Long Island. The Nature Conservancy. Accessed December 2016. http://www.conservationgateway.org/ConservationByGeography/NorthAmerica/UnitedStates/edc /Documents/TNC%20REPORT%20‐ %20Modeling%20nitrogen%20source%20loads%20on%20the%20north%20shore%20of%20LI%200 3‐01‐2016.pdf.

Nelson, Pope, and Voorhis, LLC. 2006. Mount Sinai Harbor Management Plan. New York State Department of State, Albany, New York. Accessed February, 2017. https://www.brookhavenny.gov/DesktopModules/Bring2mind/DMX/Download.aspx?Command=C ore_Download&EntryId=10034&language=en‐US&PortalId=0&TabId=134.

NOAA National Centers for Environmental Information. 2015. U.S. Coastal Relief Model. Accessed February 2017. https://www.ngdc.noaa.gov/mgg/coastal/crm.html.

NRWI. 1998. The Norwalk River Watershed Action Plan; it’s Out Watershed – Let’s Take Care of It. Norwalk River Watershed Initiative. Accessed February 2017. http://www.ct.gov/deep/lib/deep/water/watershed_management/wm_plans/norwalk_rwi_supp.pdf.

A‐36 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Robbins, S.K., 1977. Stony Brook Harbor. Stony Brook Environmental Conservancy. Accessed February 2017. http://www.gushi.org/~sbec/trailSBH.shtml.

Valiela I., G. Collins, J.N. Kremer, K. Lajtha, M. Geist, B. Seely, J. Brawley, and C‐H. Sham. 1997. Nitrogen loading from coastal watersheds to receiving estuaries: new method and application. Ecological Applications 7(2):358–380. Accessed 4/25/2017 from http://bioeeos660‐f12‐ bowen.wikispaces.umb.edu/file/view/Valiela%20et%20al.%201997a.pdf.

Vaudrey, J.M.P. 2008. Establishing Restoration Objectives for Eelgrass in Long Island Sound, Part II: Case Studies. University of Connecticut. Final Grant Report to the Connecticut Department of Environmental Protection, Bureau of Water Protection and Land Reuse and the U.S. Environmental Protection Agency. Accessed January 2017. http://www.lisrc.uconn.edu/eelgrass/documents/LIS%20Eelgrass%20Case%20Studies.pdf.

Vaudrey, J.M.P, C. Yarish, J.K. Kim, C. Pickerell, L. Brousseau, J. Eddings, M. Sautkulis. 2016. Connecticut Sea Grant Project Report: Comparative Analysis and Model Development for Determining the Susceptibility to Eutrophication of Long Island Sound Embayments. Project number R/CE‐34‐CTNY. 46 p. Accessed February 2017. http://longislandsoundstudy.net/wp‐ content/uploads/2013/08/Vaudrey_R‐CE‐34‐CTNY_FinalReport_2016.pdf.

Woods Hole Group, Inc. 2014. Southern New England and New York Seagrass Research Towards Restoration – Phase II. The Nature Conservancy, Cold Spring Harbor, NY. Accessed February 2017. https://www.conservationgateway.org/Documents/Seagrass%20Report_Phase%20II_Final_05May14 .pdf.

Wiley, M. 1976. Estuarine Processes, Vol. 1: Uses, Stresses, and Adaptation to the Estuary. Academic Press, New York, NY.

Young, C., K. Kroeger, G. Hanson. 2013. Limited denitrification in glacial deposit aquifers having thick unsaturated zones (Long Island, USA). Hydrogeology Journal 21(8):1773–1786. DOI:10.1007/s10040‐013‐1038‐4. http://dx.doi.org/10.1007/s10040‐013‐1038‐4.

A‐37 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading

Appendix A: Bathymetry Data

Summary Tetra Tech used the NOAA Coastal Relief Model (CRM) to provide estimated embayment average and maximum depths as an overview.

Background To compute estimated embayment average and maximum depths as an overview, a source was needed to quickly analyze data for all priority embayments in LIS. Tetra Tech considered CT DEEP contour data5, however these data do not fully cover near‐shore embayments and do not provide coverage of eastern LIS (east of Mystic River). Tetra Tech also considered more site‐specific NOAA bathymetry data available through NOAA’s Bathymetric Data Viewer6. These data are available for a reasonable portion of embayments, however access is in small pieces of the Sound and the data are not consistent among embayments. Due to the purpose of these estimates (quick overview) and level‐of‐effort concerns, this was not pursued. Ultimately Tetra Tech used the NOAA CRM7 to provide an estimate for most priority embayments. The CRM is an integrated effort to cover the elevation of land and water boundaries of the U.S. coastal zone. While this resolution is a little coarse (90 m2 pixels, with 1 meter increments), more complete coverage is available and the resolution is sufficient for to compute average and maximum depth estimates for most embayments.

Coastal Relief Model Description8 NOAA’s 3 arc‐second CRM provides the first comprehensive view of the U.S. coastal zone, integrating offshore bathymetry with land topography into a seamless representation of the coast. The CRM spans the U.S. East and West Coasts, the northern coast of the Gulf of Mexico, Puerto Rico, and Hawaii, reaching out to, and in places even beyond, the continental slope.

Bathymetric data sources include the U.S. National Ocean Service Hydrographic Database, the U.S. Geological Survey (USGS), the Monterey Bay Aquarium Research Institute, the U.S. Army Corps of Engineers, and various other academic institutions. Topographic data are from the USGS and the Shuttle Radar Topography Mission (SRTM). The CRM database contains grids, or digital elevation models (DEMs), of the entire coastal zone of the conterminous United States, as well as Hawaii and Puerto Rico.

The vertical datum of the CRM is “sea level.” Source elevation data were not converted to a common vertical datum due to the large cell size of the CRM (3 arc‐second; ~90 meters). This means that the vertical uncertainty of CRM elevations (greater than one meter) exceeds the differences between vertical datums (usually less than a meter). The vertical datum for the source bathymetric data was generally Mean Lower Low Water (MLLW). Source topographic data were in NAVD 88. MLLW is defined as “The average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch. For stations with shorter series, comparison of simultaneous observations with a control tide

5 http://www.ct.gov/deep/cwp/view.asp?a=2698&q=322898&deepNav_GID=1707%20 6 https://maps.ngdc.noaa.gov/viewers/bathymetry/ 7 https://maps.ngdc.noaa.gov/viewers/wcs‐client/ 8 Overview: https://www.ngdc.noaa.gov/mgg/coastal/crm.html and Volume I metadata: https://www.ngdc.noaa.gov/metadata/published/NOAA/NESDIS/NGDC/MGG/DEM/iso/xml/us_crm.xml

A‐38 Draft, Deliberative, and Predecisional Subtask A. Summary of Embayment and Western LIS Nitrogen Loading station is made in order to derive the equivalent datum of the National Tidal Datum Epoch.” 9 The depths can be considered as during low tide, but are only accurate to within about 1 meter.

Methods 1. Extracted coastal relief data for a bounded area containing the LIS. 2. Reprojected to ‘NAD_1983_StatePlane_Connecticut_FIPS_0600_Feet. 3. Resampled from 266 feet x 266 feet (~90 m pixels) to 33 feet x 33 feet (~10 m pixels) using a bilinear interpolation. This should better capture and differentiate small polygons such as the smaller embayments. 4. Selected only values < 1 to remove non‐water areas that happen to be within the open water boundaries due to mapping inconsistencies. 5. Computed zonal statistics by open water embayment. 6. Computed zonal statistics by western and eastern narrows.

9 https://tidesandcurrents.noaa.gov/datum_options.html

A‐39 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Subtask B. Regulated Point Source Discharges

Introduction and Methods Overview The purpose of this subtask was to estimate nitrogen contributions to LIS from regulated point source discharges, including wastewater plant discharges, major industrial point source discharges, and MS4 stormwater discharges. In addition to this summary information, Tetra Tech has also provided all collected data as an Excel file (Dischargers Compiled.xlsx). These data will be used in setting load reductions and allocation options after nitrogen thresholds are developed.

Traditional Point Sources EPA provided nitrogen loads, concentrations, and flows for municipal dischargers in Connecticut, Massachusetts, New Hampshire, New York, and Vermont to Tetra Tech. Tetra Tech performed the following steps to process and summarize the data:  Created a unique name corresponding to each facility for the master list (because some of the facility names in each spreadsheet differed).  Converted loads from lbs/day to kg/yr.  Populated the NPDES ID and coordinates from EPA‐provided GIS data; Mullaney and Schwarz (2013) for Connecticut dischargers; EPA Envirofacts10 or Enforcement and Compliance History Online (ECHO)11 searches; and the NY/NJ Harbor Estuary Program.12 Coordinates were also geocoded from EPA Region 1 Massachusetts NPDES permit13 addresses or other addresses found in NPDES permits. These data were populated because they were not consistently included in EPA’s dataset. Coordinates were verified and corrected to all be within the correct state and general geographic vicinity.

To determine industrial load estimates, Tetra Tech queried the Integrated Compliance Information System (ICIS) for non‐POTW facilities with total nitrogen load or concentration monitoring data in Connecticut, Massachusetts, New Hampshire, New York, and Vermont, and all facilities in Rhode Island. Tetra Tech mapped facilities in GIS and selected those within the LIS watershed for further analysis. Additionally, Tetra Tech summarized nitrogen loads, concentrations, and flows on an annual basis from 2006–2015 (as data were available). For those facilities where two of three components (load, concentration, and flow) were available, Tetra Tech calculated the third component (e.g., load = concentration * flow).

EPA provided data for some facilities that were found to be industrial sources; conversely, some non‐ POTWs queried in ICIS were found to be municipal or already captured in the EPA provided data. Therefore, some duplication existed between the EPA provided data and the ICIS queried data. Tetra Tech selected the EPA‐provided data, where available, and summarized the ICIS data where EPA data were not available for a facility. Facilities with ICIS‐reported loads less than 100 kg N/yr or with no load reported in the past three years were not summarized in the final table of point source dischargers, as they were not considered current major industrial point sources. Data from the most recent year for each facility are summarized in Table B‐1 and Table B‐2.

10 https://www3.epa.gov/enviro/facts/multisystem.html 11 https://echo.epa.gov/ 12 https://fusiontables.google.com/DataSource?docid=10LNWV5NtgO40QSCjjtIj_mzpQ0LzUCHKJ_YSWLkw#rows:id=1 13 https://www3.epa.gov/region1/npdes/permits_listing_ma.html

B‐1 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Tetra Tech also summarized annual nitrogen loads from facilities in Connecticut from a USGS report (Mullaney and Schwarz 2013). This report contained annual nitrogen loads from 1999 to 2009 for 82 Connecticut wastewater treatment facilities. Units for all loads were standardized to kg/yr, concentrations to mg/L, and flows to millions of gallons per day (MGD). No further processing was performed. See Dischargers Compiled.xlsx for results. These results are included as background, but are not summarized further here because data were available for only one state (Connecticut) and as only as recently 2009.

Municipal Separate Storm Sewer Systems (MS4s) EPA provided contacts in New York, Massachusetts, and Connecticut from whom Tetra Tech could request existing MS4 nitrogen loading estimates. Only New York provided existing MS4 nitrogen load estimates. State contacts did not identify existing MS4 nitrogen load estimates for Massachusetts, Connecticut, or Rhode Island. Tetra Tech did not identify any MS4s within the LIS watershed in New Hampshire and Vermont. The following describes the methods used or proposed to provide MS4 load estimates for each State with MS4s identified.

New York MS4s New York State Department of Environmental Conservation (NYSDEC) provided a June 2015 report entitled Determination of Regulated and Non‐regulated Stormwater Loads to LIS from New York State prepared under contract with the Long Island Sound Study (NYSDEC 2015). The purpose of the project was to assess the stormwater loads from the New York state portion of the LIS watershed, including quantifying the regulated stormwater load from the watershed load. NYSDEC established a methodology for determining the subwatershed loads, the load from the municipal boundaries, and the load from the actual MS4 systems. NYSDEC also completed estimates of the stormwater load from the sub‐watershed, the municipal boundaries, and the MS4 systems for Port Jefferson Village and New York City. The DEC was not able to quantify the MS4 loads from all systems due to the lack of available data, specifically electronic availability of MS4 stormwater sewersheds and, for Nassau and Suffolk Counties where stormwater infiltration is a significant management practice within the MS4 system, data to be able to quantify the locations of these infiltration management practices within the MS4 system to remove that load from the surface water load. To estimate nitrogen loads, NYSDEC used the Watershed Treatment Model (WTM), a spreadsheet based model that calculates annual pollutant loads using land use, precipitation, soils, impervious, and pollutant coefficients. These estimates are based on municipal boundaries, not on sewersheds (except for New York City, NY and Port Jefferson, NY where these data were available). Therefore, NYSDEC believes these estimates are likely on the high end. For instance, comparing rates for Port Jefferson, NY where both were available, about 21% of the estimated municipal boundary load was attributable to the sewershed load. NYSDEC also provided a spatial coverage of regulated MS4s within the LIS watershed.

Massachusetts MS4s Because Massachusetts did not identify existing MS4 nitrogen loading rates, Tetra Tech estimated MS4 loads using a similar approach as NYSDEC. Tetra Tech estimated MS4 loading rates based on land use categories using Opti‐Tool. Opti‐Tool is a regional Excel‐based stormwater and nutrient BMP optimization tool developed by Tetra Tech and EPA Region 114. Opti‐Tool has land‐use specific nitrogen loading rates developed based on the Storm Water Management Model (SWMM) calibrated with local precipitation data from Logan Airport in Boston. This approach required the following spatial datasets:

14 https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=289305

B‐2 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

 Land use  Impervious surface  Hydrologic soil groups (soil permeability)  MS4 boundaries

In Massachusetts, the following datasets were used to derive categories consistent with Opti‐Tool regional loading rates:  Mass GIS 2005 Land Use polygon shapefile (0.5 m resolution) (accessed on 1/13/2017)  MassGIS 2005 Impervious Surface Raster (1 m resolution) (accessed on 1/13/2017)  NRCS SSURGO‐Certified Soils polygon shapefile (accessed on 1/13/2017)  MassGIS 2016 Town Boundaries (accessed on 1/13/2017)  2000 and 2010 Urbanized Areas data were provided by Newton Tedder (EPA R1) on 1/13/2017 (UA2010_UA2000_merge.shp)

Tetra Tech processed and combined these data to be representative of the Opti‐Tool loading rate categories and then clipped the estimates to Massachusetts MS4 boundaries. Areas were estimated for each loading rate category, multiplied by the appropriate areal loading rate, and summed to generate an estimated total nitrogen load for each MS4 in Massachusetts.

Connecticut MS4s While Connecticut did not identify existing MS4 nitrogen loads, Connecticut Department of Energy and Environmental Protection (CT DEEP) is beginning to develop such load estimates using either nitrogen concentration data collected for each town or the WinSLAMM model. CT DEEP has collected stormwater monitoring data and provided these data to Tetra Tech; however, CT DEEP has not settled on an approach. Based on EPA’s direction, Tetra Tech did not pursue further load estimations for Connecticut at this stage. If EPA requests an alternative approach to CT DEEP’s efforts, Tetra Tech proposes applying Opti‐Tool regional nitrogen loads in a manner similar to that used for Massachusetts. The proposed method for Connecticut would differ because Connecticut has neither as finely resolved land use data nor readily available large‐scale parcel data as Massachusetts. Tetra Tech proposes to use NLCD 2011 land use data (30 meter resolution) and percent Impervious data15, SSURGO soils16, and buffered roads data (no source identified) as the input files similar to those for Massachusetts. The Opti‐Tool regional loading rates are distinct for residential (14.1 lb/ac/yr) and commercial (15.08 lb/ac/yr) development. However, because the loading rates are similar and no statewide parcel data are available for Connecticut to readily differentiate these development categories, Tetra Tech proposes that one average loading rate be applied to both residential and commercial developed areas.

Rhode Island MS4s A small portion of the Pawcatuck embayment extends into Rhode Island, which overlaps with MS4s in Rhode Island. Due to the small overlap, Tetra Tech proposes applying the same approach from Connecticut to Rhode Island. Based on EPA’s direction, Tetra Tech did not pursue load estimations for Rhode Island at this stage.

15 https://www.mrlc.gov/nlcd2011.php 16 https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm

B‐3 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Results Table B‐1 summarizes, by state, the number of point and MS4 sources, their total estimated load, and their percent contribution to the overall total. Tetra Tech identified 235 municipal and industrial point source dischargers with estimated nitrogen loads within the LIS watershed. The majority of these are municipal dischargers (211), with 19 industrial dischargers, and five government facilities including a state‐operated school (Southbury Training School), and four state‐operated fish hatcheries. These 235 facilities discharged a combined 19.2 million kg N/yr to the LIS watershed based on the most recent year of available data; with 68% of the total load from facilities in New York and 18% from facilities in Connecticut.

Tetra Tech identified 340 regulated MS4s within the LIS watershed including 202 in Connecticut, 86 in New York, 47 in Massachusetts, and 5 in Rhode Island. Loads from New York and Massachusetts were estimated at over 1.3 million kg N/yr. Figure B‐1 and Figure B‐2 show all point source discharges and MS4s for the entire LIS watershed respectively. Figure B‐3 and Figure B‐4 provide close‐up views of the same point source discharges and MS4s, but focus instead on the immediate vicinity of the LIS watershed.

Table B-1. Point Sources and MS4s in the LIS Watershed Total Estimated Point Source Load % Total Point Total Estimated MS4 Load State Facilities (kg N/yr) Source Load MS4s (kg N/yr) CT 91 3,507,385 18% 202 Not estimated MA 60 2,037,921 11% 47 430,402 NH 26 255,105 1% 0 No MS4s in LIS watershed NY 22 13,025,669 68% 86 924,217 RI 2 74,909 0.4% 5 Not estimated VT 34 255,437 1% 0 No MS4s in LIS watershed Total 235 19,156,426 340 N/A17

17 The total estimated MS4 load for all states is not provided because loads were not estimated for Connecticut or Rhode Island at this time.

B‐4 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Figure B-1. Point Sources in the LIS Watershed

B‐5 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Figure B-2. MS4s in the LIS Watershed

B‐6 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Figure B-3. Close-up of Point Sources in the Immediate Vicinity of the LIS Watershed

Figure B-4. Close-up of MS4s in the Immediate Vicinity of the LIS Watershed

B‐7 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Table B‐2 provides a summary of all 235 point sources, including the facility name, NPDES ID, name of the priority embayment watershed that the point source is located in (if applicable), receiving water name, design flow and actual flow from the point source, and total nitrogen load and concentration from the point source. Actual flow, load, and concentration reported in Table B‐2 are from the most recent reported year (typically 2015). See Dischargers Compiled.xlsx for the most recent data year as well as compiled annual loads concentrations and flows from 1994–2015.

Table B-2. Summary of Municipal and Industrial Point Sources in LIS Facility (WN=Western Narrows; EN=Eastern Narrows; CRW=Connecticut River Watershed; Design Actual Concen PTW=Primary Tier Embayment Flow Flow Load tration Watershed) NPDES ID Watershed Receiving Water (MGD) (MGD) (kg N/yr) (mg/L) Connecticut Aluminum Finishing Company CTCIU0004 Black Rock Unknown N/A 0.008 151 14.05 Inc. Harbor, CT Ansonia WPCF CT0100013 N/A Naugatuck River 3.5 1.58 8,615 3.94 Beacon Falls WPCF CT0101061 N/A Naugatuck River 0.71 0.287 8,284 20.85 Branford WPCF CT0100048 Branford Harbor, Branford Harbor 4.9 3.09 15,242 3.56 CT Bridgeport East WPCF CT0101010 Bridgeport Bridgeport Harbor 10 6.383 59,146 6.69 Harbor, CT Bridgeport West WPCF CT0100056 Black Rock Long Island Sound, 40 21.9 170,479 5.62 Harbor, CT Cedar Creek Bristol WPCF CRW CT0100374 N/A Pequabuck River 10.5 5.88 70,743 8.69 Canton WPCF CRW CT0100072 N/A Farmington River 0.95 0.519 9,775 13.61 Cheshire WPCF CT0100081 New Haven Quinnipiac River 3.5 2.23 9,940 3.22 Harbor, CT Cytec (Industrial) (P) CT0000086 New Haven Quinnipiac River N/A N/A 34,460 N/A Harbor, CT Danbury WPCF CT0100145 N/A Seth Williams Brook 15.5 8.34 56,164 4.86 Derby WPCF CT0100161 N/A Housatonic River 3.5 1.2 11,266 6.78 East Hampton WPCF CRW CT0024694 N/A Connecticut River 3.8 1.21 13,254 7.91 East Hartford WPCF CRW CT0100170 N/A Connecticut River 12.5 5.52 51,193 6.70 East Windsor WPCF CRW CT0100196 N/A Connecticut River 2.5 0.765 4,639 4.38 Electric Boat Corporation CT0003824 Thames River, Thames River N/A 0.254 2,900 10.81 CT Enfield WPCF CRW CT0100200 N/A Connecticut River 10 5.03 39,431 5.66 Fairfield WPCF CT0101044 Pine Creek, CT Long Island Sound 9 7.412 49,040 4.78 Farmington WPCF CRW CT0100218 N/A Farmington River 5.56 3.39 61,797 13.17 Glastonbury WPCF CRW CT0100226 N/A Connecticut River 3.64 2.04 8,118 2.87 Greenwich WPCF EN CT0100234 Greenwich Long Island Sound 12 8.09 73,063 6.52 Harbor, CT Groton City WPCF CT0101184 Mumford Cove, Thames River 3.1 1.78 13,254 5.38 CT Groton Town WPCF CT0100242 Mumford Cove, Thames River 7.5 2.69 39,762 10.68 CT Hartford WPCF CRW CT0100251 N/A Connecticut River 80 50 722,341 10.44 Jewett City WPCF CT0100269 N/A Quinebaug River 0.5 0.33 1,491 3.26 Killingly WPCF CT0101257 N/A Quinebaug River 8 2.74 21,372 5.63

B‐8 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Facility (WN=Western Narrows; EN=Eastern Narrows; CRW=Connecticut River Watershed; Design Actual Concen PTW=Primary Tier Embayment Flow Flow Load tration Watershed) NPDES ID Watershed Receiving Water (MGD) (MGD) (kg N/yr) (mg/L) Kimberly-Clark Corporation CT0003212 N/A Housatonic River N/A 2.955 7,324 1.79 Ledyard WPCF PTW CT0101681 Mystic River, CT Seth Williams Brook 0.26 0.131 663 3.65 Litchfield WPCF CT0100803 N/A Bantam River 0.8 0.423 2,651 4.53 Manchester WPCF CRW CT0100293 N/A Hockanum River 8.25 5.33 48,543 6.58 Marsam Metal Finishing CRW CTCIU0001 N/A Unnamed Stream N/A 0.005 182 27.23 Mattabasset WPCF CRW CT0100307 N/A Connecticut River 20 16.1 136,185 6.11 Meriden WPCF CT0100315 New Haven Quinnipiac River 11.6 8.84 19,218 1.57 Harbor, CT Middletown WPCF CRW CT0100323 N/A Connecticut River 6.75 3.63 83,003 16.52 Milford Beaver Brook WPCF CT0100749 Housatonic Housatonic River 3.1 1.45 8,449 4.21 River, CT Milford Housatonic WPCF CT0101656 Housatonic Housatonic River 8 5.76 43,407 5.44 River, CT Montville WPCF CT0100935 Thames River, Thames River 7.2 1.408 9,112 4.68 CT Naugatuck WPCF CT0100641 N/A Naugatuck River 10.3 5.341 30,153 4.08 New Canaan WPCF EN CT0101273 Five Mile River, Five Mile River 1.7 0.881 2,816 2.31 CT New Hartford CRW CT0100331 N/A Farmington River 0.4 N/A 166 N/A New Haven East WPCF CT0100366 New Haven New Haven Harbor 40 23.45 527,342 16.25 Harbor, CT New London WPCF CT0100382 Thames River, Thames River 10 5.66 46,389 5.92 CT New Milford WPCF CT0100391 N/A Housatonic River 1.02 0.56 3,976 5.13 Newtown WPCF CT0101788 N/A Pootactuck River 0.932 0.466 2,485 3.85 Norfolk WPCF CT0101231 N/A Blackberry River 0.35 0.306 1,988 4.69 North Canaan WPCF CT0100064 N/A Blackberry River 0.4 0.28 4,473 11.54 North Haven WPCF CT0100404 New Haven Quinnipiac River 4.5 2.79 22,863 5.92 Harbor, CT Norwalk WPCF PTW CT0101249 Norwalk Harbor, Norwalk River 18 12.525 96,588 5.57 CT Norwich WPCF CT0100412 Thames River, Thames River 8.5 3.32 74,885 16.29 CT Pape Electroplating Co. CRW CTCIU0013 N/A Unnamed Stream N/A 0.029 1,027 25.31 Pharmacia & Upjohn CT0001341 New Haven Quinnipiac River N/A 0.132 1,070 5.87 Company, LLC Harbor, CT Plainfield North WPCF CT0100447 N/A Moosup River 1.08 0.587 10,438 12.84 Plainfield Village WPCF CT0100439 N/A Mill Brook 0.7 0.35 9,278 19.15 Plainville WPCF CRW CT0100455 N/A Pequabuck River 3.8 1.958 13,585 5.01 Plymouth WPCF CRW CT0100463 N/A Pequabuck River 1.75 0.696 9,443 9.80 Portland WPCF CRW CT0101150 N/A Connecticut River 1.2 0.399 3,811 6.90 Putnam WPCF CT0100960 N/A Quinebaug River 2.91 1.051 7,124 4.90 Ridgefield South St. WPCF CT0100854 N/A Great Swamp 1 0.726 7,124 7.09 Rocky Hill WPCF CRW CT0100480 N/A Connecticut River 7.5 3.058 75,713 17.89 Salisbury WPCF CT0100498 N/A Factory Brook 0.67 0.304 3,645 8.66

B‐9 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Facility (WN=Western Narrows; EN=Eastern Narrows; CRW=Connecticut River Watershed; Design Actual Concen PTW=Primary Tier Embayment Flow Flow Load tration Watershed) NPDES ID Watershed Receiving Water (MGD) (MGD) (kg N/yr) (mg/L) Seidel Incorporated CTCIU0016 N/A Naugatuck River N/A 0.027 282 7.81 Seymour WPCF CT0100501 N/A Naugatuck River 2.93 1.071 8,781 5.92 Shelton WPCF CT0100714 N/A Housatonic River 4 2.083 14,414 5.00 Simsbury WPCF CRW CT0100919 N/A Farmington River 3.8 1.883 6,130 2.35 South Windsor WPCF CRW CT0100510 N/A Connecticut River 3.75 2.317 17,230 5.37 Southbury Tr. School WPCF CT0100528 N/A Transylvania Brook N/A N/A 497 N/A Southington WPCF CT0100536 New Haven Quinnipiac River 7.4 5.003 13,751 1.99 Harbor, CT Sprague WPCF CT0100978 N/A Shetucket River 0.4 0.116 1,491 9.29 Stafford Springs WPCF CT0101214 N/A Willimantic River 2 0.784 12,260 11.30 Stamford WPCF EN CT0101087 Stamford Harbor, Stamford Harbor 24 15.416 46,058 2.16 CT Stonington Borough WPCF CT0101281 Stonington Stonington Harbor 0.66 0.103 663 4.65 PTW Harbor, CT Stonington Mystic WPCF PTW CT0100544 Mystic River, CT Mystic River 0.8 0.477 2,485 3.76 Stonington/Pawcatuck WPCF CT0101290 Pawcatuck Pawcatuck River 1.3 0.48 1,822 2.74 PTW River, RI Stratford WPCF CT0101036 Housatonic Housatonic River 14 6.675 40,590 4.39 River, CT Suffield WPCF CRW CT0100552 N/A Connecticut River 20.2 1.211 3,645 2.17 Summit Corporation of CT0001180 N/A Naugatuck River N/A 0.085 1,154 9.84 America The Bass Plating Company CTCIU0011 N/A Mill Brook N/A 0.013 606 32.64 CRW Thomaston WPCF CT0100781 N/A Naugatuck River 1.38 0.833 3,479 3.02 Thompson WPCF CT0100706 N/A Quinebaug River 1.35 0.29 5,964 14.86 Torrington WPCF CT0100579 N/A Naugatuck River 7 4.952 45,395 6.62 UCONN WPCF CT0101320 N/A Willimantic River 3 0.17 9,443 40.13 UniMetal Surface Finishing, CT0025305 N/A Naugatuck River N/A 0.071 6,231 63.91 LLC Vernon WPCF CRW CT0100609 N/A Hockanum River 7.1 2.869 65,441 16.48 Wallingford WPCF CT0100617 New Haven Quinnipiac River 8 4.95 76,707 11.19 Harbor, CT Waterbury WPCF CT0100625 N/A Naugatuck River 27.05 16.477 94,600 4.15 West Haven WPCF CT0101079 New Haven New Haven Harbor 12.5 5.358 34,957 4.71 Harbor, CT Westport WPCF PTW CT0100684 Saugatuck River, Saugatuck River 3.25 1.351 3,313 1.77 CT Windham WPCF CT0101001 N/A Shetucket River 5.5 1.674 15,242 6.58 Windsor Locks WPCF CRW CT0101591 N/A Connecticut River 2.12 1.158 8,449 5.27 Windsor Poquonock WPCF CT0100994 N/A Farmington River 5 1.917 83,334 31.40 CRW Winsted WPCF CRW CT0101222 N/A Still River 3.5 1.258 11,929 6.85

B‐10 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Facility (WN=Western Narrows; EN=Eastern Narrows; CRW=Connecticut River Watershed; Design Actual Concen PTW=Primary Tier Embayment Flow Flow Load tration Watershed) NPDES ID Watershed Receiving Water (MGD) (MGD) (kg N/yr) (mg/L) Massachusetts Amherst CRW MA0100218 N/A Connecticut River 7.1 3.959 72,098 13.18 Athol CRW MA0100005 N/A Millers River 1.75 0.926 20,779 16.24 Australis Aquaculture, LLC MA0110264 N/A Connecticut River N/A 0.112 22,880 147.61 CRW Barre CRW MA0103152 N/A Ware River 0.3 0.202 12,579 45.07 Belchertown CRW MA0102148 N/A Lampson Brook to 1 0.37 5,787 11.32 Connecticut River C.L. Mclaughlin State Trout MA0110043 N/A Swift River N/A 5.121 7,252 1.03 Hatchery/Belchertown CRW C.L. Mclaughlin State Trout MA0110051 N/A Unnamed Stream N/A 1.373 2,054 1.08 Hatchery/Blitzer CRW Charlemont CRW MA0103101 N/A Deerfield River 0.05 0.015 808 39.00 Charlton MA0101141 N/A Cady Brook 0.45 0.2 3,510 12.70 Chicopee CRW MA0101508 N/A Chicopee River, 15.5 8.5 346,468 29.50 Connecticut River Crane MA0000671 N/A Housatonic River 4.7 3.1 35,123 8.20 Easthampton CRW MA0101478 N/A Manhan River, 3.8 1.67 33,620 14.57 Connecticut River Erving #1 CRW MA0101516 N/A Millers River 1.02 0.133 1,329 7.23 Erving #2 CRW MA0101052 N/A Millers River 2.7 1.83 5,790 2.29 Erving #3 CRW MA0102776 N/A Millers River 0.01 0.0061 303 36.00 Gardner CRW MA0100994 N/A Otter River 5 3.04 70,147 16.70 Great Barrington MA0101524 N/A Housatonic River 3.2 2.6 61,072 17.00 Greenfield CRW MA0101214 N/A Deerfield River 3.4 3.27 67,277 14.89 Hadley CRW MA0100099 N/A Connecticut River 0.54 0.383 13,161 24.87 Hardwick Gilbertville CRW MA0100102 N/A Ware River 0.23 0.1249 1,973 11.43 Hardwick Wheelright CRW MA0102431 N/A Ware River 0.04 0.0167 738 32.00 Hatfield CRW MA0101290 N/A Connecticut River 0.5 0.192 8,312 31.33 Holyoke CRW MA0101630 N/A Connecticut River 17.5 7.6 89,260 8.50 Huntington (MA) CRW MA0101265 N/A West Branch 0.2 0.0618 1,674 19.60 Westfield River Lee MA0100153 N/A Housatonic River 1 0.87 17,430 14.50 Leicester MA0101796 N/A French River 0.35 0.29 6,211 15.50 Lenox MA0100935 N/A Housatonic River 1.19 0.79 12,880 11.80 Mead Laurel Mill MA0001716 N/A Housatonic River N/A 1.5 13,265 6.40 Mead Willow Mill MA0001848 N/A Housatonic River N/A 1.1 6,992 4.60 Monroe CRW MA0100188 N/A Deerfield River 0.02 0.011 387 25.48 Montague CRW MA0100137 N/A Connecticut River 1.83 0.856 17,848 15.09 North Brookfield CRW MA0101061 N/A Forget-Me-Not Brook 0.76 0.339 12,647 27.00 Northampton CRW MA0101818 N/A Connecticut River 8.6 4.1 85,543 15.10 Northfield CRW MA0100200 N/A Connecticut River 0.28 0.087 707 5.88 Northfield School CRW MA0032573 N/A Connecticut River 0.45 0.08 1,470 13.30 Old Deerfield CRW MA0101940 N/A Deerfield River 0.25 0.0695 2,133 22.21

B‐11 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Facility (WN=Western Narrows; EN=Eastern Narrows; CRW=Connecticut River Watershed; Design Actual Concen PTW=Primary Tier Embayment Flow Flow Load tration Watershed) NPDES ID Watershed Receiving Water (MGD) (MGD) (kg N/yr) (mg/L) Orange CRW MA0101257 N/A Millers River 1.1 0.99 14,773 10.80 Oxford MA0100170 N/A French River 0.5 0.23 4,926 15.50 Palmer CRW MA0101168 N/A Chicopee River, 5.6 1.5 21,244 10.25 Quaboag River, Ware River Pittsfield MA0101681 N/A Housatonic River 17 12 205,601 12.40 Royalston CRW MA0100161 N/A Millers River 0.04 0.0187 506 19.60 Russell CRW MA0100960 N/A Westfield River 0.24 0.117 3,169 19.60 Seaman Paper Co of Mass MA0000469 N/A Otter River N/A 0.917 13,310 10.51 Inc CRW Shelburne Falls CRW MA0101044 N/A Deerfield River 0.25 0.16 3,592 16.25 South Deerfield CRW MA0101648 N/A Connecticut River 0.85 0.4 2,360 4.27 South Hadley CRW MA0100455 N/A Connecticut River 4.2 2.53 69,216 19.80 Southbridge MA0100901 N/A Quinebaug River 3.77 2.9 62,109 15.50 (French and Quinebaug Rivers Watershed) Spencer CRW MA0100919 N/A Cranberry Brook 1.08 0.82 14,956 13.20 Springfield (MA) CRW MA0101613 N/A Mill River, Chicopee 67 40 387,989 7.02 River, Connecticut River Stockbridge MA0101087 N/A Housatonic River 0.3 0.24 3,681 11.10 Sturbridge MA0100421 N/A Quinebaug River 0.75 0.6 8,622 10.40 Sunderland CRW MA0101079 N/A Connecticut River 0.5 0.169 3,428 14.68 Templeton CRW MA0100340 N/A Otter River, Millers 2.8 0.282 1,804 4.63 River Ware CRW MA0100889 N/A Ware River 1 0.592 10,699 13.08 Warren CRW MA0101567 N/A Quaboag River 1.5 0.286 7,512 19.01 (Chicopee River Basin) Webster MA0100439 N/A French River 6 3.44 82,705 17.40 West Stockbridge MA0103110 N/A Williams River 0.076 0.018 386 15.50 Westfield CRW MA0101800 N/A Westfield River 6.1 3.3 46,144 10.12 Winchendon CRW MA0100862 N/A Millers River 1.1 0.563 7,600 9.77 Woronoco Village CRW MA0103233 N/A Westfield River 0.02 0.003 81 19.60 New Hampshire Bethlehem Village District CRW NH0100501 N/A Ammonoosuc River 0.34 0.22 4,107 13.51 Charlestown WWTF CRW NH0100765 N/A Connecticut River 1.1 0.31 8,644 20.18 Cheshire County Complex NHG580391 N/A Connecticut River N/A 0.015 260 12.34 CRW Claremont WWTF CRW NH0101257 N/A Sugar River 3.89 1.54 29,790 14.00 Colebrook WWTF CRW NH0100315 N/A Connecticut River 0.45 0.2 4,234 15.32 Groveton WWTF CRW NH0100226 N/A Upper Ammonoosuc 0.37 0.14 2,778 14.36 River Hanover WWTF CRW NH0100099 N/A Connecticut River 2.3 0.69 28,602 30.00

B‐12 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Facility (WN=Western Narrows; EN=Eastern Narrows; CRW=Connecticut River Watershed; Design Actual Concen PTW=Primary Tier Embayment Flow Flow Load tration Watershed) NPDES ID Watershed Receiving Water (MGD) (MGD) (kg N/yr) (mg/L) Hinsdale WWTF CRW NH0100382 N/A Ashuelot River 0.3 0.23 4,926 15.50 Keene WWTF CRW NH0100790 N/A Ashuelot River 6 3.26 57,206 12.70 Lancaster Grange Facility CRW NHG581249 N/A Otter Brook N/A 0.004 87 17.15 Lancaster POTW CRW NH0100145 N/A Connecticut River 1.2 0.89 12,814 10.42 Lebanon WWTF CRW NH0100366 N/A Connecticut River, 3.18 1.74 47,122 19.60 Mascoma River, Great Brook Lisbon WWTF CRW NH0100421 N/A Ammonoosuc River 0.32 0.14 4,126 21.33 Littleton WWTF CRW NH0100153 N/A Ammonoosuc River 1.5 0.76 5,293 5.04 Newport WWTF CRW NH0100200 N/A Sugar River 1.3 0.74 20,041 19.60 NH Fish & Game-Berlin Fish NH0000621 N/A No. 9 Brook, York N/A 1.824 520 0.21 Hatchery CRW Pond, Cold Brook and West Branch Upper Ammonoosuc River NH Fish & Game-Twin NH0000744 N/A Carroll Stream N/A 0.731 960 0.95 Mountain Fish Hatchery CRW Northumberland Village NH0101206 N/A Connecticut River 0.06 0.03 401 9.67 WPCF CRW Stratford Millhouse System NHG581214 N/A Connecticut River N/A 0.006 249 28.73 CRW Stratford Village WWTP CRW NHG580536 N/A Connecticut River N/A 0.011 316 20.47 Sunapee WPCF CRW NH0100544 N/A Sugar River 0.64 0.49 10,494 15.50 Swanzey WWTP CRW NH0101150 N/A Ashuelot River 0.167 0.07 1,499 15.50 Troy WWTF CRW NH0101052 N/A Ashuelot River 0.265 0.07 2,198 22.73 Whitefield WWTF CRW NH0100510 N/A Johns River 0.185 0.07 3,675 38.00 Winchester WWTP CRW NH0100404 N/A Ashuelot River 0.28 0.17 991 4.22 Woodsville Fire District CRW NH0100978 N/A Connecticut River 0.33 0.17 3,772 16.06 New York Belgrave WN NY0026841 Little Neck Bay, Little Neck Bay 2 1.4 14,082 8.50 NY Blind Brook WPCF EN NY0026719 Milton Harbor, Blind Brook 5 2.8 33,963 8.60 NY Bowery Bay WN NY0026158 East River, NY East River 150 106 1,888,691 13.00 Glen Cove EN NY0026620 Hempstead Glen Cove Creek 5.5 2.8 25,514 6.60 Harbor, NY Great Neck WPCD WN NY0026999 Manhasset Bay, Manhasset Bay 3.8 2.9 36,614 8.10 NY Greenport (Village) NY0020079 N/A Long Island Sound 0.65 0.6 2,816 3.49 Huntington (NY) EN NY0021342 Huntington Huntington Harbor 2.5 2.2 9,112 3.40 Harbor, NY Hunts Point WN NY0026191 East River, NY East River 200 124 1,358,532 7.80 Kings Park (SCSD #6) PTW NY0023311 Nissequogue Nissequogue River 0.6 0.3 1,491 3.30 River, NY Mamaroneck WPCF EN NY0026701 Mamaroneck Long Island Sound 20.6 13.3 51,359 2.70 River, NY New Rochelle WPCF EN NY0026697 N/A Mamaroneck Harbor 13.6 12.4 48,046 2.80

B‐13 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Facility (WN=Western Narrows; EN=Eastern Narrows; CRW=Connecticut River Watershed; Design Actual Concen PTW=Primary Tier Embayment Flow Flow Load tration Watershed) NPDES ID Watershed Receiving Water (MGD) (MGD) (kg N/yr) (mg/L) Newtown Creek WN NY0026204 East River, NY Newtown Creek 310 215 5,483,830 18.80 North Castle WPCF EN NY0109584 N/A Byram River 0.45 0.4 1,325 2.70 Northport (Village) EN NY0024881 Northport Northport Harbor 0.45 0.2 1,491 3.90 Harbor, NY Northport (Village) PTW NY0024881 Northport Northport Harbor 0.45 0.2 1,491 3.90 Harbor, NY Oyster Bay EN NY0021822 Oyster Bay, NY Oyster Bay 1.8 1.3 8,284 3.90 Port Chester WPCF EN NY0026786 Byram River, CT Long Island Sound 6 4.3 128,066 22.00 Port Jefferson (SCSD#1) PTW NY0021750 Port Jefferson Port Jefferson Harbor 1.15 0.7 3,645 4.50 Harbor, NY Port Washington WN NY0026778 Manhasset Bay, Manhasset Bay 3.8 2.6 28,827 7.80 NY Red Hook WN NY0027073 East River, NY East River 60 26 646,131 17.90 SUNY (SCSD #21) NY0206644 Port Jefferson Port Jefferson Harbor 2.5 167.33 6,627 0.05 Harbor, NY Tallman Island WN NY0026239 East River, NY East River 80 57 778,671 9.80 Wards island WN NY0026131 East River, NY East River 275 206.5 2,468,552 8.60 Rhode Island Kenyon Industries, Inc. PTW RI0000191 Pawcatuck Pawcatuck River N/A 0.310 26,627 61.97 River, RI Westerly WWTF PTW RI0100064 Pawcatuck Pawcatuck River 3.3 2.22 48,282 15.73 River, RI Vermont Bellows Falls CRW VT0100013 N/A Connecticut River 1.405 0.49 14,399 21.06 Bethel CRW VT0100048 N/A White River 0.125 0.12 3,250 19.60 Bradford CRW VT0100803 N/A Waits River 0.145 0.14 3,791 19.60 Brattleboro CRW VT0100064 N/A Connecticut River 3.005 1.82 50,540 20.06 Bridgewater CRW VT0100846 N/A Ottauquechee River 0.045 0.04 748 13.53 Canaan CRW VT0100625 N/A Connecticut River 0.185 0.18 4,967 19.97 Cavendish CRW VT0100862 N/A Black River 0.155 0.15 4,062 19.60 Chelsea CRW VT0100943 N/A White River 0.065 0.06 1,625 19.60 Chester CRW VT0100081 N/A Williams River 0.185 0.18 4,875 19.60 Cold Brook Fire Department VT0101214 N/A Deerfield River 0.055 0.05 1,354 19.60 CRW Danville CRW VT0100633 N/A Water Andric 0.065 0.06 1,625 19.60 FiberMark North America Inc. VT0000248 N/A Connecticut River 0.888 13,509 10.88 CRW Hartford (Quechee WWTF) VT0100978 N/A Ottauquechee River 0.305 0.3 2,769 6.68 CRW Hartford (White River VT0101010 N/A Connecticut River 1.225 0.932 7,353 5.71 Junction WWTF) CRW Ludlow CRW VT0100145 N/A Black River 0.705 0.7 1,141 1.18 Lunenburg CRW VT0101061 N/A Connecticut River 0.085 0.08 1,452 13.14 Lyndon CRW VT0100595 N/A Passumpsic River 0.755 0.75 20,311 19.60 Putney CRW VT0100277 N/A Sackett’s Brook 0.085 0.08 2,167 19.60

B‐14 Draft, Deliberative, and Predecisional Subtask B. Regulated Point Source Discharges

Facility (WN=Western Narrows; EN=Eastern Narrows; CRW=Connecticut River Watershed; Design Actual Concen PTW=Primary Tier Embayment Flow Flow Load tration Watershed) NPDES ID Watershed Receiving Water (MGD) (MGD) (kg N/yr) (mg/L) Randolph CRW VT0100285 N/A Third Branch of the 0.405 0.4 10,833 19.60 White River Readsboro CRW VT0100731 N/A Deerfield River 0.755 0.75 20,311 19.60 Royalton CRW VT0100854 N/A White River 0.075 0.07 2,431 25.13 Saxtons River CRW VT0100609 N/A Saxtons River 0.105 0.1 2,708 19.60 Sherburne Fire District CRW VT0101141 N/A Ottauquechee River 0.305 0.3 8,125 19.60 Soundview Vermont Holdings VT0000108 N/A Connecticut River N/A 0.180 4,334 17.15 LLC CRW Springfield (VT) CRW VT0100374 N/A Black River 2.2 1.08 18,022 12.06 St. Johnsbury CRW VT0020826 N/A Stiles Brook 1.6 1.17 19,442 12.06 Whitingham CRW VT0101109 N/A Harriman Reservoir 0.015 0.01 302 21.84 Whitingham Jacksonville CRW VT0101044 N/A North River 0.055 0.05 1,354 19.60 Wilmington CRW VT0100706 N/A North Branch 0.145 0.14 3,791 19.60 Deerfield River Windsor CRW VT0100919 N/A Connecticut River 1.135 0.35 9,562 19.60 Windsor-Weston CRW VT0100447 N/A Connecticut River 0.025 0.02 542 19.60 Woodstock WTP CRW VT0100757 N/A Ottauquechee River 0.455 0.45 12,187 19.60 Woodstock WWTP CRW VT0100749 N/A Kedron Brook 0.055 0.05 1,354 19.60 Woodstock-Taftsville CRW VT0100765 N/A Ottauquechee River 0.015 0.01 199 14.43

Sources Cited Mullaney, J.R. and G.E. Schwarz. 2013. Estimated Nitrogen Loads from Selected Tributaries in Connecticut Draining to Long Island Sound, 1999–2009. USGS Scientific Investigations Report 2013‐ 5171, Accessed November 2016. https://pubs.usgs.gov/sir/2013/5171/pdf/sir2013‐5171.pdf.

NYSDEC. 2015. Determination of Regulated and Non‐regulated Stormwater Loads to LIS from New York State. New York Department of Environmental Conservation, Division of Water.

B‐15 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River

Subtask C. Summary of Tributary Loading for the Connecticut River

Introduction and Methods Overview The purpose of this subtask was to estimate annual nitrogen loading from the Connecticut River, the largest tributary to LIS. These loads will be used in at least two ways: (1) they will be related to response indicator values in the tributary area of influence and (2) they will be used for calculating and allocating load reductions as required to meet emergent nitrogen thresholds.

The Connecticut River is New England’s longest river, approximately 410 miles in length, and it drains areas of Quebec, New Hampshire, Vermont, Massachusetts, and Connecticut (Figure C‐1, Garvine 1974; CRWC Figure C-1. Connecticut River Watershed 2017). Summary statistics of the hydraulic and physical factors for the Connecticut River and its watershed are summarized in Table C‐1.

Table C-1. Hydraulic and Physical Factors of the Connecticut River and its Watershed Geographic Watershed Characteristics Total Drainage Area1 29,166 km2 Land Use (Percent Coverage)2 Forested 77% Agricultural 9% Developed 5% Wetlands 5% Water or Other 4% Connecticut River—Average Annual Discharge Mouth of the Connecticut River3 544 m3/s USGS Gauge 01193050 at Middle Haddam, CT (about 25 miles from 618 m3/s (Range: 553 m3/s to 804 m3/s) the Connecticut River mouth)4 Percent of Total Freshwater Discharge to LIS5 70% Dischargers Within the Watershed Number of MS4s 128 Portion Defined as MS4 9% Number of Point Sources 132 Range of Discharge from Point Sources 0.01 to 80 MGD 1 Moore et al. 2011 2 Clay et al. 2006 3 Data from 1992 to 1995; Garabedian et al. 1998 4 Data from 2010 to 2014; USGS 2017 5 CRWC 2017

To determine tributary nitrogen loadings delivered to LIS from the Connecticut River, Tetra Tech used data from EPA‐provided literature sources and additional sources found during literature review. Values were extracted from those studies and are reported here. Any processing beyond simple literature extraction is described below to enable replication as needed. In addition to the summary information

C‐1 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River provided below, Tetra Tech has provided all data in an associated Excel file (Tributary Load Summary.xlsx).

Summary Load Sources Load estimates from the Connecticut River were available at three different spatial scales: the entire Connecticut River watershed, specific USGS gauges, and subwatersheds within the greater LIS watershed according to two regional SPAtially Referenced Regressions on Watershed attributes (SPARROW) models. Note that some sources of data include data at multiple spatial scales, so are named in multiple sections below. Each load estimate was based on nitrogen load delivered to LIS standardized to kg N/yr using conditions representative of one period of time (as indicated). Load estimates were extracted directly from the sources indicated with minimal processing except to standardize units or report average conditions.

Entire Connecticut River Watershed Nitrogen load estimates for the entire Connecticut River watershed were available from the following sources (recent data are listed first):  USGS annual nitrogen load estimates from 1999 to 2009 for nitrogen management zones that correspond closely with the Connecticut River watershed (Mullaney and Schwarz 2013)  ArcView GIS Generalized Watershed Loading Function (AVGWLF) model data representing 1999–2005 (Evans 2008)  NOAA National Estuarine Eutrophication Assessment (NEEA) representing 1994–2004 (Bricker et al. 2007)  2002 Northeastern and Mid‐Atlantic regional SPARROW model (Moore et al. 2011)  Load estimates from USGS reports including data from 1988 to 1998 (Mullaney et al. 2002)  A Hydrological Simulation Program–Fortran (HSPF) deterministic model for Connecticut representing 1991–1995 (AQUA TERRA and HydroQual 2001)  1992–1993 New England SPARROW model (Moore et al. 2004)  LIS TMDL nitrogen load estimates using input data from 1988 to 1990 (NYSDEC/CTDEEP 2000)

Specific USGS Gauges throughout the Watershed Nitrogen loading data were also available from specific gauge sites within the watershed. Tetra Tech summarized annual nitrogen load (kg N/yr) and yield (kg N/yr‐km2) calculated at specific USGS gauges using the most recent USGS report on a gauge‐specific basis (Mullaney and Schwarz 2013; Mullaney 2016a, 2016b) (see Tributary Load Summary.xlsx). Data were available from 1974–2013, but for uniformity with the other datasets, and because of data availability, gauge load estimates were limited to data ranging from 1999 to 2013. No further processing was necessary. A map of the 19 gauges within the Connecticut River watershed is provided in Figure C‐2.  The Mullaney (2016a) USGS report included annual nitrogen loads and yields from 1974–2013 using weighted regressions on time, discharge, and season for six gauges within the Connecticut River watershed.  A second Mullaney (2016b) USGS report included annual nitrogen loads and yields from 2006– 2013 for one gauge using the USGS load estimator, LOADEST, within the Connecticut River watershed.  Mullaney and Schwarz (2013) included annual nitrogen loads and yields from 1999–2009 for 12 gauges, also using LOADEST within the Connecticut River watershed.

C‐2 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River

Subwatersheds Based on SPARROW Models Tetra Tech also summarized nitrogen loads, yields, and concentrations by subwatershed within the greater LIS watershed from both the 2002 Northeastern and Mid‐Atlantic regional SPARROW model18 and the 1992–1993 New England regional SPARROW model19. This allows subwatershed specific load allocations if desired or needed. Tetra Tech selected data from both models within the Connecticut River watershed using a GIS and linked the statistics of interest by catchment ID as compiled in Tributary Load Summary.xlsx. No further processing was necessary. An example of the 2002 incremental nitrogen loads aggregated by HUC8 watersheds is included in Figure C‐3.

Results Watershed‐wide nitrogen load estimates to LIS from the Connecticut River watershed were available from the literature over the time period of 1988–2009, and ranged between 11,051,000 to 16,215,000 kg N/yr. All compiled estimates are included in Table C‐2. Differences in estimates can be attributed to differences in watershed delineation, time periods (reflecting flow variability), and methodology. Note that Table C‐2 does not include gauge‐ or subwatershed‐specific loads. Results by monitoring gauge and subwatershed are included in the Tributary Load Summary.xlsx document as well as summarized visually in Figure C‐2 and Figure C‐3.

Table C-2. Connecticut River Watershed Data Sources and Corresponding Nitrogen Load Estimates (Total Load was apportioned based on contributing land area) Estimated Nitrogen Load by State or Province Source Nitrogen Load Description [kg N/yr] Source Quebec NH VT MA CT Mullaney 158,856 3,971,398 5,127,628 3,544,096 1,860,022 USGS Report and 1999–2009 14,662,000 Schwarz Average1 2013 AVGWLF 1999– 141,076 3,526,911 4,553,734 3,147,434 1,651,845 13,021,000 Evans 2008 2005 NOAA NEEA 1994– Bricker et 168,585 4,214,633 5,441,679 3,761,160 1,973,942 15,560,000 2004 al. 2007 Northeastern and 169,463 4,236,573 5,470,006 3,780,740 1,984,218 Moore et al. Mid-Atlantic 15,641,000 2011 SPARROW 2002 Mullaney 1988– Mullaney et 119,732 2,993,311 3,864,781 2,671,246 1,401,930 11,051,000 1998 al. 2002 AQUA 144,175 3,604,378 4,653,754 3,216,566 1,688,127 Connecticut HSPF TERRA and 13,307,000 1991–1995 HydroQual 2001 New England 175,682 4,392,049 5,670,747 3,919,487 2,057,036 Moore et al. SPARROW 1992– 16,215,000 2004 1993 NYSDEC and CT NYSDEC/C 135,896 3,397,412 4,386,532 3,031,867 1,591,193 DEEP TMDL 1988– 12,542,900 TDEEP 1990 2000 1Recommended estimate 2 Sources: 40.6% nonpoint sources, 35.3% point sources, 13.5% agricultural areas, and 10.6% urban areas 3 Sources: 33.5% atmospheric deposition, 26.9% point sources, 22.6% developed lands, and 17.0% agricultural

18 Downloaded from the SPARROW Decision Support System https://cida.usgs.gov/sparrow/#modelid=51 19 Downloaded from the USGS New England SPARROW Data Viewer https://nh.water.usgs.gov/projects/sparrow/data.htm

C‐3 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River

Load Estimate Consistency among Datasets Tetra Tech found Connecticut River watershed nitrogen load estimates to be relatively consistent among datasets. Available data from 1999 forward was used to characterize the most recent watershed loading conditions available. Including a range of recent data rather than the most recent year helps account for significant interannual variability during especially wet or dry years. Loading estimates prior to 1999 are provided for comparison.

Estimates reported since 1999 are within 20% of each other and ranged from 13,021,000 to 15,641,000 kg N/yr with an average of 14,721,000 kg N/yr. One source of recent load estimates from Table C‐2, Mullaney and Schwarz (2013), provided annual loads for each year from 1999–2009. Average watershed loads were calculated using the LOADEST program, while unmonitored sites and area loads were calculated via regression. The annual loads reported by Mullaney and Schwarz (2013) range from a low of 10,995,192 kg N/yr in 2002 to a high of 19,150,866 kg N/yr in 2006. The 95% confidence interval for the mean annual load reported by Mullaney and Schwarz (2013) from 1999–2009 is 14,662,000±1,477,000 kg N/yr. While all of the load estimates from Table C‐2 are similar, the Mullaney and Schwarz (2013) average load estimate of 14,662,000 kg N/yr is recommended because confidence intervals could be computed with the data to establish an estimate of variability.

Other recent estimates since 1999 were, as noted above, comparable to the recommended annual load estimate. Dr. Barry Evans estimated Connecticut River nitrogen loads using in‐stream water quality data and flow data from a USGS station just below the Massachusetts state line (Thompsonville gauge 1184000) along with a GIS‐based watershed model (AVGWLF). Evans (2008) estimated an average annual load of 13,021,000 kg N/yr from the Connecticut River to LIS over the period of 1999–2005, which is nearly within the 95% confidence interval of the annual average from Mullaney and Schwarz (2013).

The NOAA NEEA program estimated average annual nitrogen load estimates for nine coastal rivers including the Connecticut River (15,560,000 kg N/yr) over the period 1994–2004 using monitoring data and other local data sources, and was also within the 95% confidence interval of the recommended load estimate (Bricker et al. 2007). In addition, the most recent regional SPARROW model, the 2002 Northeastern and Mid‐Atlantic model, estimated annual Connecticut River nitrogen loads to LIS as 15,641,000 kg N/yr, again within the 95% confidence interval of Mullaney and Schwarz (2013). An average streamflow hydrograph was used for the SPARROW model to account for year‐to‐year fluctuations in streamflow, so the model is representative of water quality conditions specific to 2002 but combined with longer‐term average annual streamflow conditions. The regional model improves accuracy of previous models with the addition of updated stream networks, monitoring data, and more detailed estimates of sources and delivery factors (e.g., agriculture, wet deposition) (Moore et al. 2011).

Estimates prior to 1999 are included in Table C‐2 as well, for comparison, and span the range reported in Mullaney and Schwarz (2013). These estimates include a USGS report with a load estimate from 1988– 1998 (Mullaney et al. 2002), an HSPF model estimate from 1991–1995 (AQUA TERRA and HydroQual 2001), a New England SPARROW model from 1992–1993 (Moore et al. 2004), and the 2000 LIS Dissolved Oxygen TMDL load estimate based on 1988–1990 data (NYSDEC/CTDEEP 2000).

Nitrogen Loading Summary A visual summary of incremental nitrogen loads by HUC8 subwatershed using the 2002 Northeastern and Mid‐Atlantic regional SPARROW model is provided in Figure C‐3. Incremental load refers to the mean annual nitrogen load leaving the drainage area of a particular watershed. As shown in the legend,

C‐4 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River different colors distinguish incremental nitrogen loads at each HUC8 pour point. Within the greater Connecticut River watershed, incremental nitrogen load ranged from 514,895 kg N/yr for the Miller watershed (01080202) to 4,472,710 kg N/yr for the Lower Connecticut River watershed (01080205). Finer NHD+ subwatershed resolution loading estimates are available, but were not shown due to difficulty of viewing. This can make very fine scale allocation possible.

The number and location of point sources and MS4s, respectively, along the Connecticut River, are also shown (Figure C‐4 and Figure C‐5). MS4 discharges are focused in the developed areas of Connecticut (greater Hartford area) and Massachusetts (greater Springfield area), in the southern portions of the watershed. No regulated MS4s were identified in the Vermont and New Hampshire portions of the LIS watershed.

C‐5 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River

Figure C-2. USGS Gauges with Annual Nitrogen Loads (1999–2013) Shown Along the Connecticut River Watershed

C‐6 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River

Figure C-3. LIS Nitrogen Load Estimates by HUC8 Watersheds from the 2002 Northeastern and Mid-Atlantic Regional SPARROW Model Shown Along the Connecticut River Watershed

C‐7 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River

Figure C-4. LIS Watershed Point Source Dischargers Shown Along the Connecticut River Watershed

C‐8 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River

Figure C-5. LIS Watershed Point Sources by MS4 Boundaries Shown Along the Connecticut River Watershed

C‐9 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River

Sources Cited AQUA TERRA and HydroQual. 2001. Modeling Nutrient Loads to Long Island Sound from Connecticut Watersheds, and Impacts of Future Buildout and Management Scenarios. Prepared for CT Department of Environmental Protection.

Bricker, S., B. Longstaff, W. Dennison, A. Jones, K. Boicourt, C. Wicks, and J. Woerner. 2007. Effects of Nutrient Enrichment in the Nation’s Estuaries: A Decade of Change. Decision Analysis Series No. 26. NOAA Coastal Ocean Program, National Centers for Coastal Ocean Science. Silver Spring, MD. Accessed February 2017. http://ccma.nos.noaa.gov/publications/eutroupdate/.

Clay, C., M. Deininger, and J. Hafner. 2006. The Connecticut River Watershed: Conserving the Heart of New England. The Trust for Public Land. Accessed February 2017. http://cloud.tpl.org/pubs/local_ct_river_report.pdf.

CRWC. 2017. Watershed Facts. Connecticut River Watershed Council. Accessed February 2017. http://www.ctriver.org/river‐resources/about‐our‐rivers/watershed‐facts/.

Evans, B.M. 2008. An Evaluation of Potential Nitrogen Load Reductions to Long Island Sound from the Connecticut River Basin. New England Interstate Water Pollution Control Commission. Accessed February 2017. http://www.neiwpcc.org/neiwpcc_docs/CT%20River%20Cost‐ Benefit%20Final%20Report.pdf.

Garabedian, S.P., J.F. Coles, S.J. Grady, E.C.T. Trench, and M.J. Zimmerman. 1998. Water Quality in the Connecticut, Housatonic, and Thames River Basins, Connecticut, Massachusetts, New Hampshire, and Vermont, 1992–95. U.S. Geological Survey Circular 1155, 32 p.

Garvine, R.W. 1974. Physical Features of the Connecticut River Outflow During High Discharge. Journal of Geophysical Research 9(6):831‐846.

Moore, R.B., C.M. Johnston, K.W. Robinson, and J.R. Deacon. 2004. Estimation of Total Nitrogen and Phosphorus in New England Streams Using Spatially Referenced Regression Models. USGS Scientific Investigations Report 2004‐5012. Accessed December 2016. https://pubs.usgs.gov/sir/2004/5012/SIR2004‐5012_report.pdf.

Moore, R.B., C.M. Johnston, R.A. Smith, and B. Milstead. 2011. Source and delivery of nutrients to receiving waters in the northeastern and mid‐atlantic regions of the United States. Journal of the American Water Resources Association 47(5):965–990.

Mullaney, J.R., G.E. Schwarz, and E.C.T. Trench. 2002. Estimation of Nitrogen Yields and Loads from Basins Draining to Long Island Sound, 1988–98. USGS Water‐Resources Investigations Report 2002‐ 4044. Accessed November 2016. https://pubs.er.usgs.gov/publication/wri024044.

Mullaney, J.R. and G.E. Schwarz. 2013. Estimated Nitrogen Loads from Selected Tributaries in Connecticut Draining to Long Island Sound, 1999–2009. USGS Scientific Investigations Report 2013‐ 5171, Accessed November 2016. https://pubs.usgs.gov/sir/2013/5171/pdf/sir2013‐5171.pdf.

Mullaney, J.R. 2016a. Nutrient, Organic Carbon, and Chloride Concentrations and Loads in Selected Long Island Sound Tributaries—Four Decades of Change following the Passage of the Federal Clean Water Act. USGS Scientific Investigations Report 2015‐5189, Accessed November 2016. https://pubs.er.usgs.gov/publication/sir20155189.

C‐10 Draft, Deliberative, and Predecisional Subtask C: Summary of Tributary Loading for the Connecticut River

Mullaney, J.R. 2016b. Nitrogen Loads from Selected Rivers in the Long Island Sound Basin, 2005–13, Connecticut and Massachusetts. USGS Open‐File Report 2016–1007. Accessed November 2016. https://pubs.er.usgs.gov/publication/ofr20161007.

NYSDEC/CTDEEP. 2000. A Total Maximum Daily Load Analysis to Achieve Water Quality Standards for Dissolved Oxygen in Long Island Sound. New York State Department of Environmental Conservation and Connecticut Department of Environmental Protection. Accessed December 2016. http://www.dec.ny.gov/docs/water_pdf/tmdllis.pdf.

USGS. 2017. National Water Information System. Data available through the USGS Water Data for the Nation. U.S. Geological Survey. Accessed February 2017. http://waterdata.usgs.gov/nwis/.

C‐11