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Water Quality Monitoring

The Westport River Watershed Alliance has been sampling water quality at sites along the Westport River since the 1990’s. Our program monitors the river every week from the start of June to the end of August for Salinity, Turbidity, Temperature, pH, and Fecal Coliform Bacteria Parameters. For more information on WRWA's water quality program visit the River Monitoring page.

WRWA also partners with the Buzzards Bay Coalition to monitor Bay Health Indicators-the sum of five health indicators: nitrogen (organic and inorganic), dissolved oxygen, algal pigments, and water clarity. Nitrogen is a type of nutrient that controls plant production in the River. Some nitrogen is an essential part of any waterway. But when there’s too much nitrogen in the water, it can become pollutionThis program monitors two forms of nitrogen: inorganic and organic. Tracking both forms of nitrogen helps to identify their source and potential impact on our water. The nitrogen monitoring is conducted with the Marine Biological Laboratory in Woods Hole. Data on nitrogen testing in the Westport River can be found here.

Salt Marsh Degradation Studies

Salt marshes are an ecologically important habitat along the New England coastline.  They filter out pollution, provide habitat for wildlife, and protect homes from flooding.  Westport River marshes have declined by nearly 50% during the past 80 years.  A recent study suggests that this rate of decline has increased dramatically over the past 15 years.  The underlying cause of this accelerated loss is not fully understood.  A number of changes along the Westport River, including nitrogen pollution, sea level rise, dredging projects, coastal development, erosion from large storms, and grazing from crabs, are all potential drivers of marsh loss. WRWA worked with researchers from Brown University, Providence College and the University of Connecticut to study the biology and ecology of salt marsh plants to see if this could explain why salt marshes are degrading. A preliminary report has indicated that excess nitrogen is not the cause of salt marsh degradation. More information on salt marsh assessment work can be found here.


Tide Measurements in the River

There has been a long term trend of salt marsh loss in the Westport River and this degradation appears to have accelerated in recent years.  WRWA undertook an effort in 2019 to determine the cause(s) of the loss see.  Our study initially tested two hypotheses; 1) Excess nitrogen in the River is a prime driver of marsh loss, 2) Changes in “flow” within the River are prime drivers of marsh loss. Initial work of this ongoing study concluded that nitrogen was not a driver and that changes in flow (tidal heights and water velocities) were likely drivers.


Little information on tide heights and velocities exist within the River. WRWA deployed experimental tidal loggers at 10 sites in the Westport River to:

  • Determine inundation time for the marsh at each site and look for correlation with respect to marsh health.

  • Determine the tidal lag and attenuation at sites

More information on this project can be found here.

Westport Targeted Integrated Water Resource Management Plandy

The Westport River is polluted with nitrogen and drinking water wells in many areas of the town are unsafe due to high nitrogen levels as well as bacterial contamination, the BOH said. Each new home built in town adds even more nitrogen to the town’s overburdened resources.

In addition to the public health risk, excess nitrogen in the Westport River contributes to the growth of undesirable algae, reducing oxygen levels and water clarity and harming habitats like eelgrass and saltmarshes, and degrading the waters for shell fishing, recreation, and other public purposes.

In 2017, the US EPA established limits on how much nitrogen could be in the Westport Rivers and found that 71% of the nitrogen from existing on-site systems must be removed. The Town finalized the Targeted Integrated Water Resources Management Plan in an effort to address the nitrogen challenge.

WRWA continues to work with the Town committees and the consultants to insure scientifically valid approaches. WRWA will continue to follow the progress of this plan and take a position on individual elements as appropriate. You can view the plan on the Town's website.


Hix Bridge Debris Removal

Foundation and rubble from the 1938 Hix Bridge (destroyed by the hurricane of 1938 - and pushed aside and left in the river) is impeding the current velocities in the river at the bridge - causing a depositional environment that is burying the oyster that live there in fine sediments. The Town has worked with the Army Corp of Engineers to develop a feasibility study to determine logistics and costs for removal.WRWA supports the removal of the rubble at Hix Bridge and will keep in contact with the Army Corp. of Engineers (ACE). The final feasibility study is complete and can be found on the Town's website.

Information on Septic Systems and new Regulations

WRWA applauds the Town of Westport Board of Health for approving the Westport Local Septic System Regulation - Effective Oct. 15, 2022. The regulation considers both short term and long term goals with the eventual result that nitrogen from future growth must be limited, and nitrogen from existing sources must be reduced. Regionally, impacted embayments must be protected and restored through a combined strategy of managing growth, reducing fertilizer use, and promoting advanced onsite sewage treatment technologies capable of reducing nitrogen. WRWA is an active partner in this planning process.


Town of Westport Board of Health Frequently Asked Questions about Westport Local Septic System Regulation.

The WRWA Science Committee has created an overview of denitrifying septic systems for onsite wastewater treatment. This document outlines Innovative and Alternative (I/A) System types designed to reduce the level of nitrogen in the effluent and in the watershed. 

Summary - Conventional septic systems are a major source of unwanted nitrogen pollution in our watershed. How nitrogen gets into the water and how septic systems operate are described.  Systems that remove most of the nitrogen from septic system effluent (denitrifying) have been in service for decades and new approaches are being evaluated. Numerous technologies that meet the reduction goal are reviewed  As more cities and town move to require these denitrifying systems in order to meet federal and state requirements and protect our environment, these systems will become commonplace.

View the Document - Overview of Denitrifying Septic Systems for Onsite Wastewater Treatment


Cockeast Pond Study

Cockeast Pond is a salt pond tributary to the Westport River Estuary. As the only brackish pond in the Westport River watershed it provides a unique and diverse habitat for numerous species of plants and animals. However, past years of nutrient related water quality and macroalgal observations indicate a system that is currently showing clear signs of nutrient related habitat impairment from nitrogen enrichment and its restricted tidal exchange. Within the overall Westport River Estuary, Cockeast Pond is a net contributor of nitrogen to Westport Harbor/West Branch. WRWA partnered with the Coastal Systems Program at UMASS Dartmouth to determine how tidal flushing, Hurricane Sandy, surrounding land use, and other factors may be affecting the Pond’s health and develop an action plan to address any adverse changes. Learn more about the project here.

Cockeast Pond Oyster Aquaculture Experiment

Cockeast Pond Oyster Experiment-

The Coastal Systems Program at UMASS partnered with WRWA on a multi-year research project using Cockeast Pond as a “natural laboratory”. The project: “Quantifying potential for oyster aquaculture and impacts on estuarine nitrogen related water quality: Cockeast Pond and the East Branch of the Westport River."

Oyster aquaculture is a commonly-identified approach that is gaining momentum across the region for nutrient reduction. While the plans to use aquaculture continue to grow, there has been almost no quantification of the effectiveness of the approach. To address this gap, this project will analyze Cockeast Pond – a saltwater pond with a high level of nitrogen enrichment – by assessing baseline conditions from 9 years of monitoring, deploying and supporting an oyster population, and monitoring the resulting habitat and water quality, the project will assess and quantify the ability of aquaculture as a method. 

Learn more about the project here.


Stormwater Remediation Projects

Water in the form of rain is fairly clean when it leaves the clouds. When it hits the land it can be absorbed into plants and the ground, or it can hit hard surfaces, flowing off and picking up everything along the way; oil, bacteria, nitrogen, heavy metals, and other pollutants. What’s in the runoff (often called stormwater) can affect our drinking water, shellfish beds, fisheries, stream and river health, soil health, and other resources. Even when rain hits hot pavement it gets heated and then might flow into a cold stream, this has a specific negative impact. Several fish species, such as our rare and local sea-run brook trout, need cold and clean streams and are affected greatly by any large changes in temperature.

There are many ways of removing pollutants from stormwater to clean up the water re-entering our water supplies, streams, and rivers.  Many times the solutions involve slowing the stormwater down so that it can absorb into the soil, which will helps to filter out pollutants. In other situations plants or mushrooms can help remove oils, heavy metals, and some excess nutrients. Other areas might require chemical or mechanical filters. These are just a few examples of solutions to stormwater pollution, and each site needs the proper solution to be tailored for the location. 


Follow this link to learn more about WRWA projects that help clean up polluted runoff.

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