River Monitoring

2022 Water Quality Monitoring Data Summary



2021 River Testing Summary

The WRWA has been sampling water quality at 19 sites along the Westport River and contributing streams for Rivers for more than 20 years to evaluate the health of the rivers. We test the Westport River weekly from June-August. Bacteria levels can change by the day, each week’s results refer only to the morning on which the samples were taken. We monitor a type of bacteria used for swimming and shellfishing standards, which have specific concentrations of bacteria that are considered safe for humans, reported in cfu or colony forming units. This summer areas in the upper East Branch failed standards for recreational contact many times (see chart).

Summer 2020 – Summary of Results

Thankfully, we were able to proceed with our water quality monitoring this summer. WRWA has been measuring bacteria levels in the River since 1991. Bacteria levels can change by the day. We test the Westport River weekly from June-August. So, you might be wondering, what’s the diagnosis? Bacteria levels can change by the day, each week’s results refer only to the morning on which the samples were taken. This summer with the dry weather we saw low levels of fecal coliform for most of the River, except at the Head of Westport.


Bacteria levels are typically elevated during wet weather events, a good precaution to take includes avoiding swimming right after a heavy rain. During dry weather, bacteria levels are typically low and the River is usually considered safe for swimming. A fecal coliform test is used to determine whether water has been contaminated with fecal matter. The presence of fecal coliform indicates the possible presence of organisms that can cause illness. The EPA has set acceptable limits for fecal coliform in water based upon the use of the water. For example, drinking water cannot contain any fecal coliform but water for swimming may contain up to 200 fecal coliform colonies/ 100 ml.

What is going on at the Head of Westport? This summer there was lots of activity at the Head of Westport including resetting and repair of the stone walls that line the River at the Head. Also this spring and summer a gaggle of Canada geese have taken up residence at the Head Landing. The group totaling 18 or so geese have been staying around the area all summer. Their waste/dropping have been located all over the grassy areas of the landing.

Canada geese pose a potential threat to human health and safety. There has been speculation from public resource managers, citizens, and the media that Canada geese can transmit diseases to humans through direct contact with feces or through waterborne disease transmission. Although scientific studies have shown Canada goose feces to possess human pathogens such as Cryptosporidium species, Giardia species, Salmonella species, and E. coli, the potential risk of transmission to humans is not well understood. However, drinking water reservoirs and swimming areas have been temporarily closed due to high levels of bacteria attributed to goose feces.

Why are the geese hanging out? The geese causing  problems were thought to be near extinction not so long ago, so they were protected, and populations have grown in Massachusetts. These are not the migratory geese seen flying south in a V-formation every fall. The Canada geese that hang around all year are called resident geese and tend to be bigger than migratory geese, live longer and have more young. They eat grass voraciously, and each adult can produce a pound or more of feces per day. 


2019 Water Quality Summary

The Westport River Watershed Alliance has been sampling water quality at 19 sites along the Westport River since the 1990’s. This program monitors the river every week from the beginning of June to the end of August.  Bacteria levels can change by the day, each week’s results refer only to the morning on which the samples were taken. This summer we saw elevated levels of fecal coliform, especially during wet weather events. Bacteria levels are typically elevated during wet weather events, a good precaution to take includes avoiding swimming right after a heavy rain. During dry weather, bacteria levels are typically low and the entire River is usually considered safe for swimming.

Fecal coliform bacteria testing is used by regulators and scientists to assess surface waters for recreational use, shell fishing, and potability (ability to be safely consumed). Federal regulations stipulate maximum allowable numbers of these bacteria for various uses. If fecal coliform counts are high (over 200 colonies per 100 ml of water sample) in the river or stream, there is a greater chance that pathogenic organisms are also present. A person swimming in such water has a greater chance of getting sick from swallowing disease-causing organisms, or from pathogens entering the body through cuts in skin, the nose, mouth, or the ears. Diseases and illnesses such as typhoid fever, hepatitis, gastroenteritis, dysentery, and ear infections can be contracted in waters with high fecal coliform counts.



Over the years bacteria counts have diminished in the river due to Title V septic improvements, better manure management and farming practices, and improved treatment and minimization of stormwater runoff – all of which the WRWA has advocated for, using our data to make the case for reducing pollution sources.








WRWA Bacteria Sample Site Locations


So, what’s polluting the water and how can this be fixed? What we need to come to terms with is that water resource ailments have one thing in common: the source of contamination. That source is mainly us.

Through our daily activities, we inadvertently pollute our own precious water resources with the many pollutants we leave on the landscape that wash into the water. These include lawn and agricultural fertilizers, antifreeze and oil from our cars, pet waste and our own waste. Much of the damage is done by water washing off streets and parking lots. Because the rainwater in the streets can’t be absorbed into the ground where the soil filters and treats most of the pollution, it simply washes the pollution off of these hard surfaces and into our waterways.

Another big contributor to water pollution is failing and inadequate septic systems, and cesspools that contaminate the groundwater that feeds into our rivers, ponds, and beaches.

The good news is: This can all be fixed. In contrast to when the area was originally developed, we now understand the process of water pollution and how to treat it. The challenge is that it will take money, effort and a lot of political will to make it happen. Water needs to be diverted into vegetated soils rather than into rivers. Streets and parking lots need to be redesigned. And we need to be more careful about what we put onto the landscape. We need to pick up after our pets, use less lawn fertilizer and keep our cars leak-free. We need to stress to our political leaders that clean water is important our health, recreation and quality of life.

During dry weather, bacteria levels are low enough that it’s safe for swimming, boating and shellfishing (in approved areas). Bacteria levels are typically elevated during wet weather events, and good precautions to take include avoiding swimming right after a heavy rain.  The big news is that 10 years ago this wasn’t true.

The Bad News – Nutrient Pollution – A Different Beast: 

The Westport River should have clean water, abundant eelgrass and vibrant estuarine life. Increasingly we have seen cloudy water, excess algae, and sometimes fishkills, the canary in the coal mine for water quality problems. The problem is nitrogen pollution and it is the greatest long-term threat to the health Westport River. We also work each year with the Buzzards Bay Coalition to monitor and measure this pollutant. For more information on results of nitrogen/nutrient testing visit: http://www.savebuzzardsbay.org/bay-health/westport/


The Westport River Watershed

Map of the Westport WatershedThe Westport River Watershed encompasses parts of Westport, Dartmouth, Fall River, and Freetown in Massachusetts, and Tiverton and Little Compton in Rhode Island.  Eighty-five percent of the watershed’s landmass drains into the two branches, East and West, of the Westport River.  The river is comprised of two major drowned river estuaries that are connected to Buzzards Bay tidal waters by a single inlet.  The Westport River is one of the Commonwealth’s greatest coastal assets in both habitat quality and scenic beauty.  Nutrient loading and pathogen contamination are major water quality concerns, particularly in the upper reaches of the 35 mile shoreline. Bacteria Bacteria are a big water quality problem in our nation’s waters. Not all bacteria are harmful (yogurt contains live bacteria cultures!), but the presence of some indicator bacteria is a clue that other germs and viruses that can make you sick might be in the water too. Where do the bacteria come from? Total rainfall, salinity, temperature, and tide are the most important involved in determining the fecal coliform count in the river. Rainfall is responsible for washing fecal coliform into the river. The amount of rainfall directly affects the amount of fecal coliform in the river. During periods of drought, fecal coliform counts in the river tend to drop significantly. When there is prolonged or large amounts of rain, the effect on fecal coliform is two-fold. First the increase in rainfall simply adds more fecal coliform to the river. Second, the rain decreases the salinity in the estuary, making it more favorable for bacterial growth. Temperature affects fecal coliform growth only when it is extremely cold. In January and February, bacterial growth is inhibited as a result of the cold water temperatures. In the months of May through December, temperature does not seem to play a role in limiting or fostering bacterial growth. During this period the amount of rainfall is the most important factor.




Nutrients were listed as the number one cause of water quality pollution in our lakes, ponds, and reservoirs. They caused impairment in more than 3.8 million acres! (That’s more than 2.9 million football fields!) The two most common nutrients are nitrogen and phosphorus, which cause algae to grow and can turn the water green. Where do nutrients come from? The major sources of nutrients are runoff of fertilizers and animal waste from farms and cities (lawn fertilizers can wash away in heavy rain), sewage treatment plants, and septic systems.

What’s being done to control nutrients? Farmers are learning new ways to apply fertilizers and manage livestock. Homeowners are being educated about maintaining their lawns and septic systems. Cities and towns are fixing their sewage treatment plants. For more information visit our page: https://westportwatershed.org/whats-being-done/issues/