Malden River Cleared for Public Boating

Everett, MA- For nearly 150 years, the Malden River served as the industrial sewer for oil refineries, coal processing, tanneries and chemical production. Despite the history of contamination, no reliable public information existed about health risks posed by recreation on the river. A team from the Friends of the Malden River, the City of Everett, and the Mystic River Watershed Association secured funding and project partners to complete an independent and comprehensive health risk assessment for the river. The results show health risks for cancer are negligible over a lifetime of recreational boating on the Malden River.

“In the absence of a rigorous health risk analysis, ‘stay away from the water’ has been the logical and appropriate precautionary advice given to the public in prior years. This report represents a breakthrough for the recreational use of the river,” said Kathy Vandiver of the Massachusetts Institute of Technology’s Center for Environmental Health Sciences (MIT CEHS) and a volunteer at Friends of the Malden River.

Overview of the work

This health risk study was completed by Gradient Corporation, MIT CEHS and the Mystic River Watershed Association.  For the purposes of this study, sediment samples from the Malden River were collected during the summer of 2017 and analyzed for contaminants in certified laboratories. The sediment samples were collected from nine locations (see map), seven from potential public boat launch locations and two from existing boathouse launches. These were the Malden High School and Tufts University sites, indicated on the map as (1)MRC and (2) RE Dock respectively.  Water samples were also collected from multiple locations along the river.

Health Risk Methods

With the concentrations of contaminants at these locations in hand, analysts calculated the health risks faced by boaters who might come in contact with the water and sediments. To do this, the analysts considered a

wide range of boaters, children, casual paddlers, and frequent competitive boaters. Importantly, they assumed that all boaters would be frequently be exposed to maximal amounts of sediments and water. For example, the analysts assumed that boaters would capsize every time they went out; they would wade through sediments up to their knees every time they launched; and they would swallow water and sediments on every trip as well. This kind of risk study is called a “conservative” study, because it incorporates maximal risk factors into the calculations, thus generating a wide margin of safety.  

Results favorable for boating    

Even while assuming maximal exposures, all boaters’ health risks met all state and federal standards for acceptable environmental health risks. The highest health risk over a lifetime of exposure to Malden River water and sediments in this study was calculated to be about 1 in 10 -5 (one chance in 100,000). This worst-case scenario falls well below a level set by the Environmental Protection Agency (EPA) that would usually require the cleanup of contaminated site (1 in 10 -4, or 1 in 10,000).

Furthermore, boaters will probably not ever experience the worst-case risk level because they will not be wading through the sediments or capsizing on every outing.  Launching from a dock--which is how boaters will likely use the water--will reduce the real risks even further.

“With this important information in hand—we now must turn to expanding access to the river through parks, paths and boat launches—priorities outlined in our community-driven Malden River Vision Plan,” said Patrick Herron, Executive Director of the Mystic River Watershed Association (MyRWA). “The great news is that there are awesome municipal and community partners that are committed to making a difference.”

Project Funders & Partners

This study was funded in part by the Lewellyn Foundation, the Fine Foundation, Preotle Lane & Associates, Mystic River Watershed Environmental Fund, and Mystic Valley Development Corp. The Mystic River Watershed Association, MIT CEHS, and Gradient Corp. provided in-kind support.

"The Human Health Risk Study on the Malden River is a prime example of an important collaboration initiated with an idea from our community,” said Karen Buck, Friends of the Malden River. “Since 2016, together with MyRWA, we formed partnerships that overcame the funding shortage.  This collaboration created a meticulous, independent, and unarguable study providing the community with assurance that yes, it is safe to boat on the Malden River.  The sense of relief and joy is palpable. Now, the work begins!" 

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About the Mystic River Watershed Association: The Mystic River Watershed Association (MyRWA) works to improve the lives of the more than half million residents of Mystic River communities through its efforts to protect and restore water quality, natural habitat and open space throughout the 76 square mile watershed. For more information