On May 28th, 2020, the Massachusetts Department of Environmental Protection (MassDEP) and the U.S. Environmental Protection Agency (EPA) released the “Mystic River Watershed Alternative TMDL Development for Phosphorus Management - Final Report” that calls for reducing phosphorus inputs into the Mystic River watershed by 60%.
The Mystic River and nearly every water body in the watershed has a problem with too much of the nutrient phosphorus. With so many surfaces paved, we are sending pollutant-laden stormwater to the river, lakes, and ponds instead of into the ground. The result has been excessive growth of invasive plants, poor fish habitat, and blooms of toxic cyanobacteria that are a threat to public health.
A “TMDL”, short for Total Maximum Daily Load, describes the amount of a pollutant that a waterbody can absorb and still meet water quality standards. It then serves as a regulatory framework used to set limits and require compliance in reducing nutrients.
“The Mystic River and its 44 lakes and ponds, like most water bodies in the United States, are cleaner today than ever thanks in a large part to the clean water act passed in 1972,” said Andy Hrycyna, Watershed Scientist at the Mystic River Watershed Association. “With the newly released Alternative TMDL our local Mystic communities have another tool to help stop the growing problem of excessive phosphorus in our water bodies.”
The result of the MyRWA study that lead to the Alternative TMDL is sobering. It will require a 60% reduction in nutrient loads to bring the Mystic River and its tributaries into compliance with water quality standards. To achieve these reductions, municipalities will have to build green infrastructure and soak more of this stormwater into the ground.
The development of the Alternative TMDL was a collaboration of the EPA, MassDEP, Massachusetts Water Resources Authority, the United States Geologic Survey, and the Mystic River Watershed Association. It is a slightly different approach then the TMDLs found on the Charles River and other urban water bodies. The team created an “Alternative TMDL” which does not place binding requirements on municipalities, instead it promotes a flexible framework to begin work faster with iterative feedback on what works. Binding requirements are expected in future permits.
“No one agency or organization could have done this on their own,” said Patrick Herron, Executive Director, Mystic River Watershed. “Five years ago the Mystic River Watershed Association launched one of its most aggressive water quality efforts undertaken--to study the impacts of phosphorus on the Mystic. We are thrilled that the EPA and MASS DEP partnered with us on this effort, and even more thrilled to be working with our municipalities to decrease nutrient inputs and improve water quality with the implementation of nature-based solutions at a large scale.”
“EPA is proud of this innovative and collaborative plan to restore water quality and aquatic habitat in the Mystic River watershed. EPA staff worked closely with MassDEP, the Mystic River Watershed Association, and other stakeholders over the past several years to develop this adaptive tool that will allow local municipal leaders the flexibility they need to make decisions about how to reduce phosphorus levels in stormwater and other sources that are causing harmful algal blooms and the spread of invasive aquatic species watershed,” said U.S. Environmental Protection Agency Regional Administrator Dennis Deziel.
“We greatly value these partnerships, and view them as a key to developing plans and implementing actions to improve water quality in the Mystic River Watershed communities," said Commissioner Martin Suuberg of the Massachusetts Department of Environmental Protection. "The flexibility of this non-traditional approach allows communities to more quickly turn their attention and resources toward the implementation of actions that directly address nutrient impairments in the watershed."
Many Mystic municipalities are already working to reduce stormwater pollution ahead of any permit requirements. Arlington, Cambridge, Everett, Lexington, Medford, Melrose, Winchester and Woburn are among the communities that have active projects to design and install green infrastructure to reduce nutrient pollution.
"The Town of Arlington values Alewife Brook, Mill Brook, and the Mystic River and is committed to doing our part to improve them," says Emily Sullivan, Environmental Planner and Conservation Agent for the Town. "During the last year, we have installed 30 infiltration trenches and three rain gardens toward improving water quality. At the same time, we are participating in multiple regional collaboratives to coordinate stormwater management across jurisdictional boundaries. The Town is committed to supporting healthy rivers and streams in our area."
"The City of Medford considers the Mystic River one of its greatest resources and is committed to doing our part in addressing stormwater pollution," says Tim McGivern, City Engineer. "We are currently updating our stormwater regulations to better address pollutants like phosphorous, and partnering with MyRWA to pilot treatment practices. We're excited to see a healthier Mystic!" Additionally, Medford installed a rain garden at Wright’s Pond in 2019 to improve water quality at the beach and downstream.
On the heels of significant investments to reduce combined sewer overflows to Alewife Brook, Cambridge is doing even more to improve water quality. "The City of Cambridge takes the problem of stormwater pollution seriously," says Catherine Woodbury, Senior Project Manager for the City of Cambridge. "We will continue to address the difficult challenges created by nutrients and other pollutants in stormwater runoff and to do our part to improve water quality in the Alewife Brook and Mystic River."
On the Malden River and in the surrounding communities, there has been a growing recognition of the value of the river and parklands for recreation--and the importance of keeping it clean. "Stormwater runoff is the number one pollutant degrading our rivers and streams," says Mayor DeMaria. "That is why the City of Everett is investing in green infrastructure to divert runoff from storm drains and redirect it into the ground. We have built multiple rain gardens, bioswales, distributed rain barrels, updated our driveway ordinances, and maintained one of the most aggressive street sweeping programs of any community in the Commonwealth."
