Charles River Conditions Should Serve as Wake-Up Call

The oil sheen, dead fish and foul smell found along the Charles River should be a wake-up call for the Medfield community, which is 100 percent dependent on its wells, which are in turn, fed by local waterways.

As a national groundwater expert recently shared with the Medfield community: No stormwater management system, regardless of how advanced, can prevent all contaminants from entering our aquifers and lowering the quality of our drinking water. Research shows this point is especially true with extreme rainfall.

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Even more important, this point was also shared: A water treatment plant can only handle so much, and Medfield does not have the ability to test its water for pharmaceuticals, for example. PFAS filtering was also not included in the $12-million water treatment plant design. As a result, during extreme rainfall, undetected and untreated contaminants can enter our water much too easily. Conversion of open, green space to pavement and buildings only makes the situation worse.
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Neponset River Watershed Association (NepRWA), one of Medfield's watershed partners (along with Charles River Watershed Association), regularly studies the health of our local waterways, including Mine Brook, off Elm Street, which ultimately feeds into the Neponset River. NepRWA has consistently deemed its watershed a "stressed basin." NepRWA studies have shown Mine Brook stressed at times to the point of not being unable to sustain aquatic life.

While studies show precipitation can improve drought-induced oxygen levels, what's currently happening with the Charles River shows that at the other extreme, with intense rainstorms, runoff from pavement and buildings all too easily washes vehicle oil, fertilizers, pesticides and trash into waterways that also can cause oxygen levels to drop, killing fish.
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Even with state-of-the-art stormwater management systems installed by developers, meadows, fields and other natural vegetation are more effective at filtering out water contaminants, and if those natural resources are destroyed, more artificial mitigation is needed.

All of these considerations are especially important in a town like Medfield, where according to the Annual Water Report (recently mailed to residents), a susceptibility to contamination ranking of high has consistently been assigned to the Medfield Water System based on a Massachusetts Department of Environmental Protection (MA DEP) assessment.

The significant increase in parking lots and buildings with the proposed school on the Wheelock site, combined with the loss of natural habitat and open space, will only increase the likelihood of harm to Mine Brook, and hence, increase the risk to natural habitat and Medfield water quality. Beyond contaminants, hot summer water running off school roofs, into stormwater systems and into streams, has been shown to increase water temperature beyond safe levels for aquatic life. Studies show higher water temperatures also contribute to climate change.

Last summer, NepRWA reported that all three sampled sites along Mill Brook (which includes Mine Brook) surpassed the acceptable 68 °F threshold. NepRWA reported, "The highest average of weekly maximum temperatures was 73.57ºF, which occurred on July 8th, 2020."

Given scientific facts about groundwater, MA DEP assessment of water risk, and the changes planned for the Wheelock site, concerns expressed by Medfield watershed partners and local experts include:

1) Keeping the grade 4-5 school at its current Dale Street site would be preferable to building a second school on the Wheelock site.

2) Beyond the proposed school site being located in a Well Protection District, it is also in a much larger Massachusetts Department of Environmental Protection-designated Zone II, which is specifically designed to protect water resources.

3) Solar panels contribute to the increase in impervious surface, and water runoff can be problematic from a groundwater recharge perspective. Plans to address other sustainability issues related to anticipated increased emissions from traffic in the Elm Street area, choice of building materials, and use of conservation strategies, have yet to be presented.
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Medfield residents can gain basic groundwater knowledge and become more informed about local water concerns by viewing the recent Dale@Dale talks with national and local experts.

Unlike the letter touted by the Dale Street School Building Committee chair as coming from an "independent, third-party" (but written by an environmental engineer under contract with the town for a different municipal project), the Dale@Dale guest speakers are unbiased, and volunteered to share their water expertise simply to help educate the public. Both videos have been posted to the new Dale@Dale YouTube channel.

The author of this article is chair of the Dale@Dale Coalition.