What's in our water?
By Justin R. Wolf
On a well or public utility, here’s what to know and how to test for unwanted contaminants in your home’s water supply
Whether your home is connected to a private well or a municipal water system, understanding what contaminants might be coming out of the tap can have important health impacts.
Upwards of half of all Maine homes use groundwater wells, according to the state’s Department of Health and Human Services. The percentages tick up significantly in rural counties such as Hancock, Washington and Penobscot, where a majority of homes rely on private wells. This raises important questions about water quality, testing and what people should know in place of what they can’t see, taste or smell.
The Maine Centers for Disease Control and Prevention estimates that 1 in 10 wells in the state contain too much arsenic, uranium, radon or other harmful chemicals like per-and polyfluoroalkyl substances (PFAS), all of which are undetectable without test kits. And yet private wells are not regulated by the state, Environmental Protection Agency or other third party.
Whether the well type is dug (shallow), drilled (large diameter drilling into an aquifer), or driven point (aka sand point well that taps a high water table in sandy soil), no one but the homeowner is responsible for the quality of that water, says Will Chappell, president of Air & Water Quality, Inc. in Freeport.
General recommendations are to perform a comprehensive well test every three to five years, on average. This helps detect the presence of bacteria, health-harming chemicals like PFAS, metallic elements like copper and lead that raise the water’s acidity level and can damage plumbing, and trace metals like iron and manganese that are common sources of water hardness.
“Every water chemistry is slightly different,” Chappell says. He stresses that regular testing is critical even in instances where little has changed on the land surrounding the well. Periods of drought or heavy precipitation can alter soil compositions. “The quality won’t change dramatically, but there can be changes in the aquifer over time,” he says, noting outside factors like a neighbor drilling a well, or the construction of a nearby home or road, all of which can disrupt how the aquifer treats and feeds the well. And in parts of the state with large population increases during the summer months, “the aquifer gets saltier as the water level drops,” Chappell says. “Salt water has a higher density and sits on the bottom when there are both fresh and saltwater sources.”
Chappell’s company offers home testing, at no cost, and customized treatment solutions. The most common treatment involves an ion exchange process, which involves adding a water softener to remove hardness that can cause scaling and spotting in sinks, glassware and tubs. A treatment of reverse osmosis can remove minerals, metals and other contaminants. Homeowners can also order home test kits through the Maine Department of Health & Human Services.
For homes connected to public water rather than a well, Chappell finds the most common treatment needed is a carbon absorption process to remove excess chlorine and other volatile organic compounds (VOCs).
Municipal systems, which are tested regularly, are required by law to report issues of concern to homeowners. However, “continuous monitoring” is still important, says Caroline Blazovsky, CEO of My Healthy Home, a healthy home consultancy specializing in the identification and removal of mold, allergens and chemicals in home environments. Blazovsky says that even with radon mitigation and other safeguards in place in the home, a regimen of consistent water quality testing can detect chlorination byproducts. “These occur when the chlorine used to treat municipal water comes into contact with all kinds of organic materials in your plumbing supply,” Blazovsky says. The byproducts, which can include ionizing radiation or uranium, have the potential to cause cancer, she says.
Complicating matters, the Maine Water Environment Association announced in February 2025 that the federal government was cutting $32 million in State Revolving Funds, which are low-interest loans that fund regular maintenance and water facility improvement projects, like updating decades-old water mains. (Historically, for every dollar the state spends the federal government matched it five-fold.)
However water arrives, it is continuously vulnerable to contamination. And considering the impending shortfall in federal funding to help upgrade much of the state’s critical water infrastructure, each turn of the faucet should serve as a gentle reminder to always keep water quality in mind.
Resources:
Private water and air test kits - Maine Department of Health & Human Services
Public water testing results by state - Environmental Working Group
This article appeared in the Fall 2025 edition of Green & Healthy Maine HOMES. Subscribe today!
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