Public Health & Recreation

Toxic Algae Blooms Ruin Popular Recreational Pond

Grants awarded to projects designed to help protect greater Narragansett Bay watershed


West Monponsett Pond’s water quality problems are obvious. Thick mats of blue-green algae suffocate the Halifax, Mass., waterway for much of the year, emitting a foul odor and making the pond unsafe for recreational uses. This aerial photo was taken last August by Halifax Police Chief Ted Broderick.

HALIFAX, Mass. — The town’s two popular aquatic attractions are separated by Route 58. This asphalt divide, however, isn’t the only thing that separates East and West Monponsett ponds.

For the past decade, blue-green algae blooms in West Monponsett Pond have put an early end to summer fun and rendered a new boat ramp mostly useless. Shoreline residents are routinely cautioned about using the pond to the west of Route 58, because of the harmful health effects linked to cyanobacteria. They’re advised to do their swimming and water skiing across the street.

The Fire Department, especially in the summer, routinely receives calls about gas odors, but the stink is inevitably traced to the algae, according Cathy Drinan, the local health agent.

Odor, however, is only part of the problem. Significant levels of pollutants have resulted in algal blooms that have closed beaches and caused fish kills.

Swallowing water contaminated by blue-green algae guarantees major digestive discomfort. Children can become ill, and pets can die from ingesting it. Cyanobacteria also can cause skin rashes, hives and blisters, and inhaling droplets of it can cause sore throats, sinus and ear infections.

Drinan said the problems have worsened in the past eight years. “It’s getting worse every summer,” she said. “The odors are terrible … they cause headaches.”

Both ponds, which are relatively shallow — about 13 feet at their greatest depths — provide flood control and drinking water. The natural water flow is from East to West Monponsett Pond, but the city of Brockton, allowed by a 1964 state law to use the ponds as part of its drinking supply for 10 months a year, draws water in the opposite direction.

Basically, by law, Brockton is allowed to draw contaminated water into a non-contaminated body of water, which poses a risk of algae pollution in East Monponsett Pond. The current setup makes little sense. Drinan said state and local officials are working to improve this situation.

Since 2009 the Massachusetts Department of Public Health has been regularly testing West Monponsett Pond’s summer water quality, but the problem was recognized long before that. The fixes are expensive.

A report issued in July 1987 regarding the health of the ponds found increasing aquatic weed growth, nutrient pollution from septic-system leachate, siltation from solids carried in by storm drains, and fecal contamination from storm drains.

Today, nearly three decades later, the same problems — nutrient pollution caused by too much nitrogen and phosphorous getting into West Monponsett Pond — is leading to destructive algae blooms. Cold weather hasn’t done enough to solve the problem, which lasts beyond the summer months.

Algal blooms with results as high as 1,900,000 cells per milliliter have been discovered; a threshold of 70,000 is enough to close a beach.

The town recently received a $57,338 grant from the Narragansett Bay Estuary Program and the New England Interstate Water Pollution Control Commission to identify, map and prioritize the stormwater outfalls and other sources discharging to the East and West Monponsett ponds. The ponds are in the Taunton River watershed, which eventually drains into Narragansett Bay.

The Board of Health’s project will include field verification and mapping of outfalls, prioritization and conceptual design for sites, and permit level design and cost estimates for the three highest priority sites.

Drinan said the long-term solution is the elimination of the nutrient sources, such as failed septic systems, stormwater runoff carrying fertilizers and animal waste, and phosphorous from bog operations.

“Dense development and the creation of impervious areas around the ponds have created a source of stormwater pollution entering the ponds, further degrading the already impaired habitat,” according to the town’s grant application.

Drinan also noted that the grant and the work it will fund will provide the community with an educational opportunity. “All these waterways are connected,” she said. “Our pollutants are draining all the way to Narragansett Bay. This isn’t a problem that only effects our town.

The grants funded 11 projects in the greater Narragansett Bay watershed. (NBEP)

Other projects
The Narragansett Bay Estuary Program and the New England Interstate Water Pollution Control Commission awarded a total of $815,000 in grant money to 11 projects, including the one in Halifax, designed to protect and restore water quality in the Narragansett Bay watershed.

These recently awarded grants will support municipalities and nonprofits, in both Massachusetts and Rhode Island, with a focus on projects to address nutrient overloading, pathogens and stormwater. These grants are funded through the Environmental Protection Agency, specifically the EPA’s Southeast New England Coastal Watershed Restoration Program — a program that brings together partnerships to protect and restore the coastal watersheds of southeast New England, from Westerly, R.I., to Chatham.

Here is a brief look at the projects that were recently funded:

The town of Avon ($24,000) is examining stormwater pollution in an important local waterway: Trout Brook. The town relies on multiple groundwater sources and the town’s wells rely exclusively on the recharge of stormwater as the source of fresh water. The work will assess potential contributions to the impairments in the Trout Brook watershed, including examining stormwater outfalls that discharge directly into the brook. The analysis will include land-use surveys within the five largest catchment areas and water-quality sampling to assess discharges to Trout Brook. The project also will include preliminary design of stormwater projects for nutrient and pathogen removal.

The town of East Bridgewater ($30,000) is examining solutions to provide limited sewer extensions to serve the densely developed town center. East Bridgewater High School’s existing wastewater treatment facility has the opportunity to serve additional downtown properties. This project would reduce nitrogen and phosphorus contributions to nearby surface waters, including Meadow Brook, Salisbury Plain River and Matfield River. The Board of Health will review the capacity of the school’s treatment facility, assess the flows from other town buildings, project available system capacity for serving town center properties, and develop a Capital Improvements Plan for limited sewer service areas.

The town of Barrington, R.I., ($19,260) is collecting water-quality and sediment data and designing green infrastructure projects in and around Brickyard Pond to address water-quality impairments. Connected to Narragansett Bay through Mussachuck Creek, Brickyard Pond hosts an annual run of anadromous river herring. The town will complete a conceptual design study for green infrastructure/stormwater best management practices for five town-owned priority outfalls. The goal is to significantly reduce phosphorus loadings.

Clean Ocean Access, in Newport and Middletown, R.I., ($45,900) will implement a project, “Stormwater Pathogens: Find It and Fix It,” to identify sources of pathogens impacting Easton’s Beach. This project includes a partnership with the city of Newport, the town of Middletown and the Rhode Island Department of Health. The project will include water-quality testing and sediment sampling at key locations during dry weather (low flow of stormwater) and wet weather (high flow of stormwater). The goal is to track down the sources of bacteria that close the beaches to swimming and develop solutions to fix these recurring problems.

The city of Cranston, R.I., ($99,100) will plan and build one or more stormwater infiltration projects in the Stillhouse Cove portion of the Providence River. This cove in upper Narragansett Bay experiences severe algal blooms during the summer because of excess nutrients. Stillhouse Cove is an integral part of the community and provides Cranston’s only public access to Narragansett Bay.  Building green infrastructure projects will help reduce stormwater pollution loadings. The project will also include planning assistance, public outreach and education through Cranston’s partners: Save The Bay and the Edgewood Waterfront Preservation Association.

The city of East Providence, R.I., ($100,000) will build a stormwater mitigation project at Sabin Point Park on the Providence River to help address elevated bacterial levels. Sabin Point Park is an urban park and beach that is popular for boaters, beachcombers, walkers and playground use. However, swimming hasn’t been allowed there in decades because of water-quality impairments. The goal is the opening of the first swimmable beach in Greater Providence in decades. The city will partner with Brown University and the Rhode Island Department of Health staff to monitor nutrient and bacteria levels. In addition, Save The Bay will provide outreach to the surrounding communities regarding controls to stormwater runoff.

The town of Jamestown, R.I., ($118,200) will build an innovative stormwater system to protect Sheffield Cove. The cove is a recreationally important shellfishing ground that was closed in 2009 by excessive bacterial contamination.   The project with be a combination of bioretention and sand filtration to treat pathogens from stormwater and dry-weather background flows. The sand filter’s design combines StormCrete (pervious concrete) and sand filtration. The town also will conduct sampling using microbial source tracking to differentiate specific impacts from various source types such as wildlife and domestic animals.

The city of Pawtucket, R.I., ($83,510) will focus on stormwater mapping and green infrastructure design to prioritize projects for the city’s 45 stormwater outfalls. The city will characterize the outfall drainage areas (soils groups, impervious cover, topography) and will then select the 10 most important drainage areas. These priority sites will undergo intensive field assessment of catch basins, manholes and interconnected drain lines. The city will then prepare conceptual designs for future stormwater improvement projects.

The city of Warwick, R.I., ($180,000) will install a series of bioretention basins and vegetated swales within the medians of Suburban Parkway to help improve water quality in the vicinity of Oakland Beach and City Park Beach. The total project will be about 2,000 feet long, on city‐owned property, and it will help reduce the amount of contaminants entering Greenwich Bay. The city, using Community Development Block Grant funding, previously hired a design group to design the project and provide biddable construction documents for the stormwater treatment facilities.

The town of Westerly, R.I., ($57,884) will identify, prioritize and implement water-quality improvements in Little Narragansett Bay and the lower portion of the Pawcatuck River. Presently, these waters have high nutrient loads, elevated bacteria levels, lower water clarity, and low dissolved oxygen concentrations. This grant will support the town’s work with Save The Bay to identify pollutant sources and develop an implementation plan to address the Phase 1 study area, which includes downtown Westerly. This plan will include recommendations for both structural and non-structural water-quality improvements and an interactive map showing the results.

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  1. Algae generally provides a number of benefits to a pond or lake, it is essential to keep the natural balance of ecosystem of those bodies of water, however, if the type of algae in your pond is the toxic kind, like the blue-green one which can cause illnesses in pets, livestock, and wildlife, there is a need to manage its growth, to keep its population to an acceptable level if not totally eliminate it. Based on a discussion at, excessive algae growth can drastically change ponds, lakes, lagoons and other bodies of water from being scenic to something visually depressing. There are several things you can do to resolve this issue. you can either add plants, pond dye, apply algaecide, filter and bacterial treatment

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