AUGUSTA — Nearly half of Mainers get their drinking water from private wells – the highest proportion in the country.

But only 40 percent of Maine’s private wells have been tested for arsenic, in part because federal, state and county authorities do not require it.

Meanwhile, scientists mapping arsenic levels in Maine say the toxin is showing up in more locations than previously suspected, with levels in some wells exceeding the federal safety standard by 10 times or more.

Martha Nielsen, a U.S. Geological Survey scientist who co-authored a landmark 2010 study on arsenic in central Maine, said “heat maps” showing the locations of high-arsenic wells can be used as a guide. But with so many differences in concentrations from well to well, she said households need to be diligent and test their own wells.

“This study shows the difficulty of predicting arsenic concentrations at the local level,” said Nielsen, “and should signal to everyone with a private well that the only way to know about arsenic concentrations in their well is to have their water tested.”

Andy Smith, state toxicologist, said educational programs are working to raise awareness.

In 2004, only about 26 percent of Maine households reported knowing if they had tested their wells for arsenic. That number increased to over 40 percent in 2009 after the state expanded its efforts.

But while public agencies have the legal duty, infrastructure, investment, resources and tax revenue to protect users of public water, Maine has debated but failed to establish a dedicated well-water program for private users, even though nearly one in two Mainers rely on wells for drinking water.

“It’s viewed as an individual’s responsibility,” said Smith. “In the real world, how do we get more people to test?”


Mike Gelberg, owner of Air & Water Quality Inc., a Freeport-based company that installs filtration systems, said his technicians encourage customers to test their water supplies on a regular basis.

“It takes two seconds,” Gelberg said. “But they won’t do it.”

Testing is fairly easy and, at $25 per test, fairly inexpensive. But reading the results may be a little more difficult, Smith said.

A lab will report most results in measurement units such as mg/L, milligrams per liter; or mcg/L or ug/L, micrograms per liter.

When you compare your results with the safe limits, make sure those letters match. If they don’t, or you have other questions, call Maine Center for Disease Control at 1-(866) 292-3474.

Smith said well-water quality can change over time, so a good well test result doesn’t mean the water you’re drinking today will be safe tomorrow.

“Check with labs on cost of typical comprehensive water tests, around $70 I think, and arsenic-only tests, between $16 and $25,” he said. “Most people collect the water sample themselves, and this is generally OK for arsenic.”

When purchasing a house, buyers should make sure a comprehensive water test, which covers many contaminants, is done, even if the home has a treatment system, Smith said.

“If you are selling a house, you should make sure you have your test results available, and information on treatment systems available,” he said.

Andrews Tolman, assistant director of the Maine Drinking Water Program, said testing water is pretty simple.

“You call the lab and order the bottles for the tests you need,” Tolman said. “We recommend a test that the state lab calls ‘BA,’ which includes arsenic and uranium, as well as other common water-quality parameters. If (arsenic is) present, the homeowner will need to know what other elements are in the water to design a treatment system.”


There are two main types of arsenic removal systems.

One is reverse osmosis, a membrane-based system that excludes arsenic based on its charge and molecular size.

The other is metal oxide media: It removes arsenic by binding it to a substance with a strong chemical affinity.

“For most people, because most people have arsenic levels below 50 ppb, a point-of-use system at the cost of $300 to $1,700 makes the most sense,” said Smith.

“Point-of-use” refers to under-the-sink systems that treat one tap; “point-of-entry” refers to systems that treat all the water entering a house.

Point-of-entry systems, which can run to $8,000, are recommended only when arsenic levels are very high – for example, 100 parts per billion, though “we are still analyzing data to better define this cut point for recommending (point- of-entry) systems,” Smith said.

After discovering arsenic, the search begins for a company to install a mitigation system.

Unfortunately, the state does not require contractors to be licensed, something Gelberg, the Freeport contractor, said needs to be changed.

Only radon-mitigation contractors currently are licensed in Maine, he said.

“To do plumbing, you need to be a licensed plumber,” Gelberg said. “To deal with arsenic, there’s nothing.”

There are other pitfallls to avoid.

Gelberg said his technicians also see a lot of systems installed improperly, and others that have never been tested.

And some systems may be ineffective in removing certain forms of arsenic found in wells.

There are two dominant forms of inorganic arsenic: arsenic-5 and arsenite-3. Some systems will remove arsenic-5, Gelberg said, but not arsenite-3.

He said a “speciate test” determines which type of arsenic you have.


Yan Zheng – the Columbia University scientist and project leader for a study that found as many as 15,561 Kennebec County residents have wells with high levels of arsenic – believes insurance companies could help motivate people to test their wells.

It’s the insurance companies that end up paying for cancer treatment, which is very expensive, and other diseases caused by preventable toxics.

One way to do it, she said, is to reduce premiums for those who test their wells and install mitigation systems.

Katherine Pelletreau, of the Maine Association of Health Plans, scoffed at that approach.

“Should it be up to health insurers to pay for bike helmets? Should it be up to insurers to pay for cars that have higher safety ratings with better protection for passengers?” Pelletreau said.

Linda Gifford, lobbyist and legal counsel for the Maine Realtors Association, said her members hand out a 25-page buyers guide that talks about harmful contaminants in water. Arsenic also is mentioned in the standard purchase-and-sale form, she said.

If arsenic in water is found, then she said it becomes a point of negotiation between buyer and seller over who covers the cost of a treatment system.

Gifford said her members are not opposed to making people aware of arsenic, or any other contaminants. They just don’t want it to be mandatory for home sellers.

“There’s all kinds of factors that are safety issues (when buying a home),” Gifford said. “Is the roof OK? And then there’s the septic system and water. Many homes in Maine are on wells so you’ve got your lead, radon, uranium and chloroform in the water along with nitrates and nitrites. We don’t want buyers to just focus on one (contaminant).”

Chris Pinkham, president of the Maine Bankers Association, said banks do not routinely require well-water testing for mortgages.

“We rely on the potential buyer to do their due diligence,” Pinkham said.

But some mortgages – for example, a Federal Housing Administration loan – do require testing, under certain conditions: when mandated by state or local jurisdiction, for example, or if there is knowledge that well water may be contaminated.


Charles Culbertson, U.S. Geological Survey scientist, said given what is known about the human health impacts of exposure to toxic compounds – particularly on infants, children and pregnant women – lawmakers should step up and address the situation now.

A home inspection prior to a real estate transaction is one way to find out if well water is polluted, he said.

But Kurt Tramposch, an environmental planner who has researched private well regulation since 2003, said larger policy changes are needed in Maine.

He said the state needs a law to require routine testing of private well water for arsenic, especially when a home is sold or rented.

Tramposch said Maine legislators should look to the New Jersey Private Well Testing Act as a model.

Under that act, certain wells must be tested before a house can be sold and landlords of certain properties must test wells and provide a written copy of the results to their tenants.

Tramposch said the public will bear the costs of toxic water, one way or the other.

“If there’s a spill or landfill leak or arsenic situation, (states) have to go out and test at great expense,” he said. “That money is being spent after the fact, rather than proactively, where it could be helping stem contamination issues in the future.”


Kennebec Journal Staff Writer Mechele Cooper can be contacted at 621-5663 or at: [email protected]


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