Final Pathogen TMDL for the Boston Harbor, Weymouth-Weir, and Mystic Watersheds October 2018 (Control Number CN 157.1) Boston Harbor Watershed Prepared as a cooperative effort by: Massachusetts DEP USEPA New England Region 1 1 Winter Street 1 Congress Street, Suite 1100 Boston, Massachusetts 02108 Boston, Massachusetts 02114 ENSR International (now AECOM) 2 Technology Park Drive, Westford, MA 01886 NOTICE OF AVAILABILITY Limited copies of this report are available at no cost by written request to: Massachusetts Department of Environmental Protection (MassDEP) Division of Watershed Management 8 New Bond Street Worcester, Massachusetts 01606 This report is also available on MassDEP’s web page http://www.mass.gov/eea/agencies/massdep/water/watersheds/total-maximum-daily-loads- tmdls.html. A complete list of reports published since 1963 is updated annually and printed in July. This list, titled “Publications of the Massachusetts Division of Watershed Management (DWM) – Watershed Planning Program, 1963-(current year)”, is also available by contacting Robin Murphy at [email protected] or by writing to the DWM at the address above. DISCLAIMER References to trade names, commercial products, manufacturers, or distributors in this report constituted neither endorsement nor recommendations by the Division of Watershed Management for use. Acknowledgement This report was developed by ENSR through a partnership with Resource Triangle Institute (RTI) contracting with the United States Environmental Protection Agency (EPA) and the Massachusetts Department of Environmental Protection Agency under the National Watershed Protection Program. The report follows the same format and methodology for previously approved bacteria TMDLs (Charles, Cape Cod, Buzzards Bay, North Coastal, and South Coastal). ii Total Maximum Daily Loads for Pathogens Boston Harbor, Weymouth-Weir, and Mystic Watersheds Location of the Boston Harbor Watersheds Key Features: Pathogen TMDL for the Boston Harbor, Weymouth-Weir, and Mystic Watersheds Location: EPA Region 1 Land Type: New England Coastal 303(d) Listings: Pathogens Boston Harbor Sub-basin: Winthrop Bay (MA70-10) Boston Inner Harbor (MA70-02) Pleasure Bay (MA70-11) Dorchester Bay (MA70-03) Quincy Bay (MA70-04; MA70-05) Hingham Bay (MA70-06; MA70-07) Hull Bay (MA70-09) Boston Harbor (MA70-01) Weymouth-Weir Sub-basin: Cochato River (MA74-06) Monatiquot River (MA74-08) Town Brook (MA74-09) Town River Bay (MA74-15) Hingham Harbor (MA74-18 (formerly MA70-08)) Weymouth Fore River (MA74-14) Old Swamp River (MA74-03) Mill River (MA74-04) Weymouth Back River (MA74-05; MA74-13) Weir River (MA74-02; MA74-11) Mystic River Sub-basin1: iii Aberjona River (MA71-01) Mystic River (MA71-02; MA71-03) Alewife Brook (MA71-04) Malden River (MA71-05) Mill Brook (MA71-07) Chelsea River (MA71-06) Winn Brook (MA71-09)2 Mill Creek (MA71-08)2 Unnamed Tributary (MA71-13)2 Belle Isle Inlet (MA71-14)2 1 Ell Pond (MA71014) and Judkins Pond (MA71021) were removed from the 2005 Draft Boston Harbor Watershed TMDL. The methodology used to determine the TMDLs provided in this report is for rivers and estuaries and is not appropriate for lakes and ponds. 2 New Pathogen Impaired Segments that were identified in the Integrated Report (2006 through 2016) after the public comment period for this TMDL are included in the Boston Harbor Addendum, CN# 157.2 that is in the process of being developed. Data Sources: . MassDEP “Boston Harbor 1999, and 2004-2008 Water Quality Assessment Reports” . Massachusetts Water Resources Authority (MWRA) . Massachusetts Division of Marine Fisheries (DMF) . Department of Public Health Beaches Data (DPH) . Massachusetts Coastal Zone Management (CZM) . Department of Conservation and Recreation (DCR) . Boston Water and Sewer Commission, CSO and Stormwater Control Progress Information . Mystic River Watershed Association (MyRWA); . Environmental Monitoring for Public Access and Community Tracking Project (EMPACT) Water Quality Data Data Mechanism: Massachusetts Surface Water Quality Standards for Bacteria; The Federal Beach Act; Massachusetts Department of Public Health Bathing Beaches; Massachusetts Division of Marine Fisheries Shellfish Sanitation and Management; Massachusetts Coastal Zone Management Monitoring Plan: Massachusetts Watershed Five-Year Cycle; Division of Marine Fisheries; Massachusetts Coastal Zone Management Control Measures: Watershed Management; Phase I and Phase II Stormwater Management (e.g., illicit discharge removals, public education/behavior modification); Combined Sewer Overflow (CSO) & Sanitary Sewer Overflow (SSO) Abatement; Best iv Management Practices (BMPs); No Discharge Areas; By-laws; Ordinances; Septic System Maintenance/Upgrades ACRONYM LIST 7Q10 Seven Day Ten Year Low Flow ACEC Area of Critical Environmental Concern BMP Best Management Practice cfu colony forming units CSO Combined Sewer Overflow CWA Clean Water Act, Federal CWA § 303(d) Section 303 (d) of the CWA and the implementing regulations at 40 CFR 130.7 require states to identify those waterbodies that are not expected to meet surface water quality standards after the implementation of technology-based controls and to prioritize and schedule them for the development of a total maximum daily load (TMDL). CZM Coastal Zone Management DCR Department of Conservation and Recreation DFG or MA DFG Division of Fish and Game DMF or MA DMF Division of Marine Fisheries DWM Division of Watershed Management EEA Energy and Environmental Affairs EMC Event Mean Concentration EPA or US EPA United States Environmental Protection Agency EQIP Environmental Quality Incentive Program GIS Geographic Information System IDDE Illicit Discharge Detection and Elimination System LA Load Allocation LID Low Impact Development LTCP Long Term Control Plan MassBays Massachusetts Bays Estuary Program DPH or MADPH Massachusetts Department of Public Health MassDEP Massachusetts Department of Environmental Protection MWRA Massachusetts Water Resources Authority MDC Metropolitan District Commission MEP Maximum Extent Practicable MEPA Massachusetts Environmental Policy Act MG Million Gallons MHD Massachusetts Highway Department MOS Margin of Safety MPN Most Probable Number MSD Marine Sanitary Device MS4 Municipal Separate Storm Sewer Systems NDA No Discharge Area NPDES National Pollutant Discharge Elimination System NRCS Natural Resource Conservation Service ORW Outstanding Resource Water POTW Publically Owned Treatment Works SRF State Revolving Fund SSO Sanitary Sewer Overflows SWMP Stormwater Management Plan SWPP Stormwater Program Plan TBHA The Boston Harbor Association TMDL Total Maximum Daily Load v TSS Total Suspended Solids USACOE United States Army Corps of Engineers WLA Waste Load Allocation WPP Watershed Planning Program WQA Water Quality Assessment WQS Water Quality Standards WWTP Wastewater Treatment Plant vi Executive Summary Purpose and Intended Audience This document provides a framework to address bacterial pathogens and other fecal-related pollution in surface waters of Massachusetts. Pathogens refers to the set of indicator bacterial organisms that includes fecal coliform, Escherichia coli (E. coli), and enterococci, and represent a threat to human health and the environment. Although not all bacteria are pathogenic the words “pathogens” and “bacteria” are used interchangeably in this TMDL. Pathogen contamination of our surface waters is most often a direct result of the improper management of human wastes, excrement from barnyard animals, pet feces and agricultural applications of manure. It can also result from large congregations of birds such as geese and gulls. Discharges of inadequately treated boat waste are of particular concern in urban coastal areas. Inappropriate disposal of human and animal wastes can degrade aquatic ecosystems and negatively affect public health. Pathogen contamination can also result in closures of shellfish beds, bathing beaches, and drinking water supplies. The closure of such important public resources can erode quality of life and diminish property values. Coastal communities rely on clean, productive, aesthetically pleasing marine and estuarine waters for swimming, boating, fishing and tourism. Failure to reduce and control bacterial contamination results in illness in humans, closures of shellfishing areas and bathing beaches, fish kills, unpleasant odors and visible scum. Total Maximum Daily Loads (TMDLs) for pathogens have been established for waterbody segments within the Boston Harbor, Mystic, Weir and Weymouth Watersheds. This TMDL will be used to set permit limits and provide stakeholders a document to identify bacterial sources and take appropriate actions to reduce their effects. Who should read this document? The following groups and individuals can benefit from the information in this report: a) Towns and municipalities, especially National Pollutant Discharge Elimination System (NPDES) Phase I and Phase II regulated communities, that are required by law to address stormwater and/or combined sewage overflows (CSOs), Sanitary Sewer Overflows (SSO) and other sources of contamination (e.g., broken sewerage pipes and illicit connections) that contribute to a waterbody’s failure to meet Massachusetts Water Quality Standards for pathogens; b) watershed groups that wish to pursue funding to identify and/or mitigate sources of pathogens in their watersheds; c) harbormasters, public health officials and/or municipalities that are responsible for monitoring, enforcing or otherwise mitigating contamination