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Integrated Lists of Waters & Related Reports

Proposed and approved lists of impaired water bodies in Massachusetts.

The federal Clean Water Act (CWA) requires states to submit reports on the status of their water bodies every 2 years. These reports are called "Integrated Lists of Waters" ("Integrated Reports"). After a public comment period, MassDEP submits these reports to the US Environmental Protection Agency in fulfillment of the CWA's reporting requirements. MassDEP uses these reports to develop Total Maximum Daily Loads (TMDLs).

Draft 2018/2020 Integrated List of Waters

On 4/28/2021, the Draft 2018/2020 Integrated Report (IR) was made available to the public for a 30-day comment period. On 5/12/2021, the public comment period was extended to June 21, 2021.

EPA has approved states combining IR cycle submissions. MassDEP coordinated with EPA-Region 1 to seek approval for combining the 2018 and 2020 reporting cycles into one submittal.

For the combined 2018/2020 reporting cycle, MassDEP focused its efforts on the assessment of the aquatic life use for the 18 watersheds that were not completed in the 2016 IR cycle. The draft 2018/2020 IR package consists of:

  • Narrative Integrated Report (IR) document containing summary tables for each integrated list category
  • IR Appendices 1-5 document, presenting the following additional information, including the proposed changes from the 2016 IR:
    • List of EPA-approved “Actions”
    • Assessment units and integrated list categories presented alphabetically by major watershed
    • Impairments added to the 2018/2020 integrated list
    • Impairments removed from the 2018/2020 integrated list
    • Impairments changed from the prior reporting cycle
  • IR Appendices 6-24 are watershed-based Assessment and Listing Decision Summaries for each of the 18 watersheds that we focused on in this cycle, as well as for Mount Hope Bay. Each document contains supporting data and rationales for each delisting decision.
  • Summary of changes worksheet (w/ filter ON; can be used to search for changes from the 2016 to 2018/2020 IRs, based on watershed, waterbody, AU category, impairment cause, etc.)

For MassDEP’s 2018/2020 Integrated Report, quality-controlled data submitted to DEP prior to the pre-established deadline of 11/1/2019 were considered, relative to the 18 watersheds assessed. Data submitted after the 11/1/2019 deadline will not be considered for the 2018/2020 Integrated Report but will be reviewed and considered in a subsequent cycle, dependent on the workloads planned for future assessment cycles.

Written comments should be submitted via email (preferred) no later than 5:00 PM on June 21 (Note: the original deadline of May 28, 2021 was revised on 5/12) to or mailed to

Richard Chase
Bureau of Water Resources - Watershed Planning Program
8 New Bond Street
Worcester, MA 01606

MassDEP plans to address all public comments in a Responses to Comments document that will be posted with the final IR.

Table of Contents

Draft 2018/2020 Integrated List of Waters

2016 Integrated List of Waters

Prior Integrated Lists of Waters

US EPA TMDL Information

MassDEP Publicly-owned Treatment Works Nitrogen Evaluation Study