READFIELD – When retired hydrologist Marc Loiselle built his home, getting safe drinking water was not one of his chief concerns.

“Then you drill a well, and surprise!” Loiselle said. “Most people assume it’s fresh, pure, natural water, and perfectly safe to drink.”

Loiselle found out his wasn’t — after he later had his well tested as part of a Columbia University study.

It showed arsenic levels of 30 parts per billion.

“It was below the contaminated level, so we didn’t do anything,” he said.

Then, in 2002, the U.S. Environmental Protection Agency strengthened the standard from 50 parts per billion to 10 parts per billion.


Loiselle’s is hardly the only home in Maine with what are now considered toxic levels of arsenic in their well water.

Using data from more than 11,000 wells in 530 Maine communities, a landmark U.S. Geological Survey study released in 2010 showed, for the first time, three high-arsenic clusters in the state: the southern coast, Down East and Greater Augusta.

Gorham and Scarborough are two of the 10 Maine communities showing the highest concentrations of arsenic in private well water, and five of the 10 are found in Kennebec County.

Columbia University’s study estimated 31 percent of private wells in Greater Augusta contain arsenic levels above the federal standard.

Using various analytical methods, Columbia researchers found that 12,293 to 15,561 Kennebec County residents are drinking from private wells containing toxic levels of arsenic, which has been linked to increased risk of skin, lung and bladder cancer; developmental problems in children; diabetes; and immune system disorders.

The problem — naturally occurring arsenic seeping from underlying rock — is particularly prevalent in Readfield and Manchester, and in a band along the western edge of the county from Winthrop and Monmouth south through Hallowell and Litchfield.


The solution is fairly simple: a water test for $15 to $25 and, if toxic levels are found, a filtration system that can cost as little as a few hundred dollars.

But many Mainers are still in the dark about the problem. Standards continue to evolve. And Maine does not require any testing of private wells, on which 74 percent of Kennebec County homes rely for potable water, according to U.S. Census data.


Arsenic is a part of the earth’s crust. State geologist Robert Marvinney said arsenic is absorbed into groundwater as it flows through fractured bedrock.

“Arsenic is common in many minerals found in Maine and other parts of the country, particularly … compounds with sulfur,” Marvinney said. “Sulfide minerals can be found throughout the metamorphic rocks that underlie much of central and southern Maine.”

Marvinney said Maine has known about its arsenic problem since at least the 1990s, when the Maine Geological Survey and Maine Centers for Disease Control first documented high levels in Buxton and Hollis.


The highest arsenic concentration found thus far in Maine well water is in Danforth: 3,100 parts per billion.

Marvinney said most of the occurrences in Maine are much lower than that. But health officials were alarmed nonetheless by some of the readings in the state.

The U.S. Geological Survey conducted the largest study of its kind in Maine from 2005 to 2009 to detect and map the state’s high-arsenic wells.

The findings were clear: Kennebec County is an arsenic hot spot.

Of the top 10 Maine municipalities with wells exceeding the federal limit for arsenic, half are in Kennebec County — with Manchester, at 62 percent of wells, the state’s worst.

Other local hot spots include Readfield, with 49 percent of wells exceeding federal limits; Winthrop, with 46 percent; Monmouth, 45 percent; and Litchfield, 42 percent.


The rest of the state’s top 10 hot-spot communities are Gorham, 57 percent; Blue Hill, 57 percent; Surry, 51 percent; Scarborough, 48 percent; and Danforth, 42 percent.


Arsenic — a known carcinogen — is found in a wide variety of chemical forms in the environment. It has been used for leather and wood treatments, pesticides, metals and alloys, petroleum refining and other industrial applications.

In powder form, it has been used as a rat poison. Arsenic was in the news in 2003, when a man poisoned the coffee urn at a New Sweden church, sickening 15 parishioners and killing one.

It’s also naturally occurring in many foods, including rice.

Following a five-year study of arsenic’s effects on children’s brain development in Bangladesh, Columbia University began a similar study in Maine and New Hampshire.


The results of the local study — which focused on children in Greater Augusta, southern Maine and New Hampshire — will be released in the next few months, said Joseph Graziano, program director for the Strategic Plan for Arsenic Research in Kids study in Maine.

He said little is known of the effects of short-term exposure. He said studies show people exposed to arsenic at the fetal stage have poor lung function as adults.

The National Research Council has concluded that even small amounts of arsenic over time can cause higher risks for skin, lung and bladder cancer.

Amanda Sears, an associate director of the Environmental Health Strategy Center, participated in a Maine Cancer Consortium work group that developed goals for the Maine Cancer Plan.

One of the goals was to promote testing for arsenic in well water through education and awareness.

Another was to increase the number of private testing laboratories.


Finally, the plan called on officials to ensure that at least 75 percent of Maine homes with private wells are tested for arsenic.

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

But none of these goals have been implemented.

The federal safety standard has been 10 parts per billion since 2002.

But it applies only to public water systems, not private wells, which are unregulated under the federal Safe Drinking Water Act. Well owners are responsible for testing their own water.

State toxicologist Andrew Smith said the level at which arsenic affects health depends on logical factors such as:


how high the levels are;

how much water a person drinks;

how long he or she has been drinking the water; and

who is drinking it, for example, pregnant women, infants or adults.

The estimated lifetime cancer risk for drinking water with arsenic at 10 parts per billion is one in 1,000, Smith said.

“On one hand, not a huge risk,” he said. “On the other hand, a much bigger risk than that associated with most other drinking water standards.”


Smith said the estimate assumes lifetime exposure and intake of about 2 quarts of water per day.

He said people ingest about 5 to 10 micrograms of arsenic each day from naturally occurring trace levels in foods, especially rice products, seafood, shellfish and algal products.

Charles Culbertson, a microbial ecologist with the U.S. Geological Survey’s Maine Water Science Center, said states can adopt their own limits — as New Jersey did — but they can’t be more lenient than the federal standard.

He said there are two forms of arsenic: organic and inorganic. The inorganic form is the most common by far, he said, and is most responsible for well water problems.

Andrews Tolman, assistant director of the state’s Drinking Water Program, said the Legislature has taken up the issue of private well testing in the past, but requiring it has met with opposition — mostly from the real estate industry.

There also have been discussions about licensing companies that install water mitigation systems, Tolman said.


Nothing has come of that, either.

Smith, the state toxicologist, said L.D. 1775, a bill to mandate water testing during housing transactions, failed in 2007.

He said the Maine Association of Realtors had issues with being placed in a position to ensure water testing occurs.

“They have been very helpful in getting both arsenic testing and radon testing listed on the standard purchase-and-sale agreement, so it is obvious to most buyers that this should be done,” he said. “But focusing on housing transactions or new well construction is at best a very limited way to promote well water testing.”

Linda Gifford, chief lobbyist for the Maine Association of Realtors, said her members pass out buyer education booklets with information about arsenic, and there is a box to check off in the purchase-and-sale agreement asking buyers if they want the well water tested for arsenic.

“So arsenic is well covered out there in the real estate market,” Gifford said. “To require a seller (to test) — who many of the times these days is in foreclosure or distressed, or may even be a bank — it made no sense.”


Public health advocates say voluntary education programs are working — but slowly.

In 2004, Smith said, only about 26 percent of Maine households reported knowing whether their wells had been tested for arsenic.

By 2009, he said, that number increased to more than 40 percent.

“We have another survey running now,” he said. “So we are making progress, though not as fast as we would like.”

Kennebec Journal Staff Writer Mechele Cooper can be contacted at 621-5663 or at:


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