DEM is holding a public workshop to present and discuss study findings and strategies for restoring water quality for Upper and Lower Melville Pond and Melville Pond Tributary in Portsmouth. The meeting will also include an overview of the draft ‘Aquidneck Island Watershed Plan.’

The meeting will be both in-person and virtual. DEM staff will present study findings and answer questions.

When: Tuesday, October 7, from 5–6:30 PM
Where: Portsmouth Town Hall, 2200 East Main Road
Virtual: Register for the Zoom Meeting

Why this matters:

Melville Ponds are on the state’s 303(d) Impaired Waters List because of excessive phosphorus (a nutrient)
High phosphorus levels cause algae blooms, cloudy water, low oxygen, and other problems that harm fish, wildlife, and recreation
The draft TMDL study sets a limit on how much of a pollutant the ponds can handle and outlines what reductions are needed to restore water quality
The draft Aquidneck Island Watershed Plan provides a broader roadmap to protect and restore water quality across Aquidneck Island

How to comment:
The draft study will be posted online on October 7 at dem.ri.gov/tmdl. The public comment period is open October 7 – November 7, 2025. Written comments can be sent to brian.zalewsky@dem.ri.gov or mailed to: Brian Zalewsky, RIDEM Office of Water Resources, 235 Promenade Street, Providence, RI 02908

Background

The federal Clean Water Act requires states to develop a watershed cleanup study (known as a total maximum daily load or TMDL) for waters that are on the 303(d) Impaired Water List. TMDLs establish the maximum amounts of specific pollutants that can be discharged to a water body and still meet water quality standards.

Upper and Lower Melville Ponds have too many nutrients, especially phosphorus. This causes problems like frequent algae and blue-green algae (cyanobacteria) blooms, overgrowth of aquatic plants, low oxygen in the water, poor water clarity, and water quality conditions that harm both wildlife and recreation. Most of the phosphorus comes from stormwater runoff. Other sources include phosphorus released from pond sediments and decaying plants.

For the reservoirs, the TMDL study looked at:

How much phosphorus is entering the water, and where it’s coming from
Identifying the target phosphorus levels to meet water quality standards
Estimates of how much phosphorus must be reduced to reach target levels
How to divide the needed reductions among the different pollution sources

The results of these studies will provide important information for the Town of Portsmouth, RIDOT, Naval Station Newport, and individual property owners to make meaningful water quality improvements in these waterbodies. Public and stakeholder input are important to the success of water quality improvements.

The draft Aquidneck Island Watershed Plan provides a framework for managing efforts to both restore water quality in degraded areas and to protect overall watershed health. Watershed plans assist states and municipalities in addressing nonpoint source pollution by providing a comprehensive assessment of nonpoint source pollution and a set of management measures to address them. View more information on watershed plans at https://dem.ri.gov/non-point-pollution