PORTLAND — A high percentage of Maine residential wells reportedly contain levels of naturally occurring arsenic that exceed safety standards set by the state’s Department of Health and Human Services.

And even with greater access to a public water supply, nearly 38 percent of homes in Cumberland County still rely on well water, according to data collected by the Maine Center for Disease Control & Prevention.

In addition, the Maine CDC said, of the private wells tested in Cumberland County, more than 17 percent have arsenic levels that exceed Maine’s maximum exposure guideline of 10 micrograms per liter.

Arsenic has adverse impacts on human health, especially in children, which is why the Environmental Health Strategy Center in Portland is working with the Sadie and Harry Davis Foundation to improve access to safe drinking water.

With a recent $13,000 grant from the foundation, the center can “tackle the silent epidemic of arsenic-contaminated well water in Maine,” Sergio Cahueque, a community organizer with the center, said. “With this funding, we can address the threat of arsenic to the health of Maine children by working (with) impacted communities to increase the testing of well water and to help residents obtain safe water.”

According to the center, arsenic in well water has been linked to a reduction in children’s IQ levels, as well as an increase in the number of bladder cancer cases, among other impacts.

Cahueque said the new grant will allow the center to expand a pilot program that connects families with the resources and information they need to have their wells tested and treated.

“This funding will also allow us to work with existing community leaders and develop new ones, training them to become health advocates for their friends, families, and neighbors,” he said.

In all, according to Cahueque, an estimated one in six wells in Maine contain arsenic levels above the federal safety standard, “leaving tens of thousands of Maine people with unsafe water to drink.”

“Arsenic occurs naturally in some Maine bedrocks and can leach into wells and contaminate drinking water,” he said.

The problem, Cahueque added, is that “arsenic is a carcinogen, and there is no known safe level of exposure. Chronic exposure to low levels of arsenic has been linked to cancer and harm to children’s developing brains.”

In fact, he said, a 2014 study of Kennebec County schoolchildren “concluded that arsenic in well water could contribute to a lowering of IQ scores by an average of 5 to 6 points.”

Arsenic is also known to cause bladder, skin, and lung cancers and, according to Cahueque, Maine has a bladder cancer rate that’s 20 percent higher than the national average.

That’s why “everyone in Maine who relies on a well for drinking water should test their water for arsenic,” he said. “Arsenic is tasteless, colorless and odorless, so the only way to know that well water is safe is to test it.”

Cahueque said the Maine CDC recommends testing well water for arsenic every five years, “because concentrations can fluctuate.”

“Illnesses and other health harms from arsenic exposure can last a lifetime,” he said. “This is why we must prevent arsenic exposure from happening in the first place, particularly in vulnerable populations, such as children and pregnant women.”

Along with its education and outreach efforts, Cahueque said the Environmental Health Strategy Center promoted two new state laws last year specifically designed to address the problem of arsenic in well water.

One of those new laws provides funding for the installation of water treatment systems for those who cannot otherwise afford it.

“But much more is needed to ensure that all Maine children and families have safe water to drink,” Cahueque said. And, “with the generous funding from the (Davis) foundation, we will be able to make (important) strides in addressing this problem.”

Kate Irish Collins can be reached at 710-2336 or [email protected]. Follow Kate on Twitter: @KIrishCollins.

An arsenic test kit of the type used by the Environmental Health Strategy Center of Portland, which is working to improve Mainers’ access to safe drinking water.