*New* An online interactive dashboard to view the technical information is now available (as of Oct. 30, 2023). See the sidebar with the light blue background for more information and a link.
EPA is implementing a strategy to aggressively continue progress on nitrogen reductions, in parallel with the States’ continued implementation of the 2000 Total Maximum Daily Load (TMDL), and achieve water quality standards throughout Long Island Sound and its embayments and nearshore coastal waters. The strategy recognizes that more work must be done to reduce nitrogen levels, further improve dissolved oxygen (DO) conditions, and address other nutrient-related impacts in Long Island Sound. The nitrogen reduction strategy complements the 2000 TMDL in important ways. Foremost, while the 2000 TMDL is premised on achieving water quality standards for DO in the open waters of Long Island Sound, the EPA strategy expands the focus to include other nutrient-related adverse impacts to water quality, such as loss of eelgrass, that affect many of the Sound’s embayments and nearshore coastal waters.
Ongoing Technical Coordination and Collaboration
EPA is working closely to share technical information, data, and approaches with other groups working on developing nitrogen reduction goals and strategies in the Long Island Sound watershed. Some examples include:
In 2018-2019 EPA conducted a public comment period and an independent technical review for two key deliverables of the Long Island Sound Nitrogen Reduction Strategy. The two products reviewed were: Subtask F/G: Summary of Establishing Nitrogen Endpoints for Three Long Island Sound Watershed Groupings, and Subtask E: Summary of the Hydrodynamic Analysis Conducted to Relate Tributary Loads to Areas of Influence and Relative Contributions to Embayments. Read a description of the purpose and scope of the External Review here. Find the External Review document here. See below for the revised subtask memos and detailed response to comments in the project deliverables list. Earlier deliverables were revised to make terms consistent throughout the subtask memo and to update the water quality data summary.
The following documents will help you learn more about the strategy:
EPA Nitrogen Strategy Subtask Memos and Supporting Documents (Updated 12/20/2022):
Project Map: a Study Area map of all watersheds evaluated in this memo.
The Long Island Sound Nitrogen Reduction Dashboard, produced by Tetra Tech, brings together technical work conducted by EPA to identify nitrogen target concentrations protective of water quality and designated uses in a number of the Sound’s embayments. The interactive tool enables users to view the technical information from the subtask memos (see documents section on this page), and visualize associated data, as well as support management responses. The dashboard was produced using Microsoft Power BI and is available here.
Want to keep up with the latest information on the Long Island Sound EPA Nitrogen Strategy? Go to the Nitrogen Reduction Strategy Update form to subscribe to Nitrogen Reduction Strategy Update to get notified in your inbox of the latest reports, presentations, and data that’s posted on the Long Island Sound Study nitrogen reduction strategy web page.
EPA encourages your technical feedback on the Long Island Sound EPA Nitrogen Reduction Strategy. Go to the Nitrogen Strategy Comment form to submit your comments about the reports and documents posted on this page. The comments will be sent to the EPA New England Regional office in Boston, which is helping to manage the Nitrogen Strategy.