The federal Clean Water Act (CWA) requires states to submit reports on the status of their waterbodies every two years. These reports are called "Integrated Lists of Waters" ("Integrated Reports", or IR). Section 303(d) of the CWA requires 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). A TMDL establishes the maximum amount of a pollutant that a waterbody can receive and still attain water quality standards. The development of the 303(d) List (category 5 of the IR) includes a public review and comment process. EPA reviews and approves the 303(d) list.
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Integrated Lists of Waters & Related Reports
Table of Contents
2024/2026 Integrated List of Waters
MassDEP plans to issue a combined 2024/2026 Integrated Report. The 2024/2026 Integrated Report will update all watersheds and coastal drainage areas for all Assessment Units statewide for the Secondary Contact Recreation use, as well as for the following uses: Primary Contact Recreation, Aesthetics, Shellfish Harvesting, and Fish Consumption. The data range for use attainment decisions for the 2024/2026 Integrated Report will be 2011 through 2022. Additionally, and as time allows, updates to the Aquatic Life use attainment decisions will be completed in the 12 remaining watersheds and coastal drainage areas that were not updated in the 2022 Integrated Report reporting cycle. Prioritization of basins for Aquatic Life use attainment decisions will be based upon the most recent assessment of the use and the timeline for data collection and data availability. MassDEP plans to complete this work and submit a draft 2024/2026 Integrated Report in Fall 2025.
Technical Basis for a single 2024/2026 Integrated Report:
In June 2023, EPA approved the vast majority of the final 303(d) list in MassDEP’s 2022 Integrated Report, but deferred action on Secondary Contact Recreation use attainment decisions. To address the deferred actions, MassDEP is reevaluating all readily available Escherichia coli (E. coli) and enterococci data according to updated bacteria evaluation procedures based on EPA guidance containing recommended Secondary Contact Recreation bacteria thresholds for Massachusetts. To complete a comprehensive statewide reassessment of the Secondary Contact Recreation use, MassDEP is combining the 2024 and 2026 reporting cycles into a single 2024/2026 Integrated Report. The methodology for this reevaluation will be described in detail in the draft 2024/2026 Integrated Report.
Final 2022 Integrated List of Waters
MassDEP submitted the proposed final 2022 Integrated Report to EPA in May 2023. In addition to the main narrative report and related appendices (1-5), documentation of the assessment and listing decisions made for the 2022 Integrated Report was provided in individual decision summary documents for each watershed and/or coastal drainage area assessed (Appendices 6-26). Each appendix summarized the most recent assessments for each existing assessment unit in the watershed and included a table with all impairments added, removed, or changed between the 2018/2020 and 2022 reporting cycles. Data and information supporting all decisions to remove impairments were included in the decision summaries. Also, Appendix 27 provided a summary of changes from the draft to final Integrated Report.
For the 2022 Integrated Report, quality-controlled data submitted to MassDEP prior to the pre-established deadline of January 15, 2021, were considered relative to the watersheds that were assessed. Data submitted after the deadline were not considered for the 2022 Integrated Report but will be reviewed and considered in a subsequent cycle, dependent on the planning for future Integrated Report cycles.
On June 30, 2023, MassDEP received a partial approval letter from EPA for the 2022 Integrated Report. The letter specified 303(d) list decisions that EPA approved, in addition to decisions related to secondary contact recreation that EPA deferred approving (i.e., “deferred action” on). As stated in EPA’s review document (EPA review-2022-303d-list), EPA approved the vast majority of the 303(d) list but deferred action on Secondary Contact Recreation use attainment decisions that met the following two conditions: 1) the waters were not included as impaired or threatened on the 303(d) list submitted by MassDEP, and 2) data and information pertaining to bacteria impairment status for the waters were available. EPA deferred action on these waters while EPA and MassDEP develop a consensus approach for assessing bacteria data and information for the Secondary Contact Recreation use. MassDEP is working with EPA on the methodology for utilizing bacteria data for Secondary Contact Use assessment to be implemented in the next Integrated Report.
Final 2018/2020 Integrated List of Waters
Final 2016 Integrated List of Waters
Prior Integrated Lists of Waters
Water Quality Data Viewer
For a geospatial view of current and historic water quality assessment and listing decisions, open WPP’s Water Quality Data Viewer (under the Integrated List of Waters view). This information can also be viewed using the MassMapper application (select “Regulated Areas” to access the individual data layers for the DEP Integrated List of Waters: rivers, lakes/estuaries, and watersheds) and can be downloaded at MassGIS (URL pending).
