Arsenic in Maine

While an undergrad, I studied the role of arsenic in water systems with a particular emphasis on Maine. Arsenic has long been acknowledged to have an adverse effect on human health. Found naturally in the Earth’s crust, the World Health Organization (WHO) estimates that over 200 million people worldwide are exposed to elevated levels of arsenic in drinking water. The WHO and US Environmental Protection Agency set a safety standard of 10 ug/L of arsenic, yet in large portions of developing countries like Bangladesh, Vietnam, and Chile, As concentrations regularly exceed the safety standard. In the United States, the US Geological Survey (USGS) considers Maine, along with much of New England to be part of “the Arsenic Belt.” In a 2010 study conducted by the USGS of 174 towns with 20 or more sampled wells in Maine, more than 25 percent of the sampled wells in 44 towns exceeded 10 μg/L. In 19 towns, more than 10 percent of the sampled wells had arsenic concentration over 50 μg/L. While prior studies estimated that nearly 10 percent of domestic wells in Maine contained arsenic, the presence of “hot spot” regions of wells with more than five times the MCL for arsenic in the US had not been well characterized. This is particularly worrisome because nearly 40% of people in Maine rely on wells for their water supply.

The Top-Down Approach

In order to address the arsenic problem in Maine State legislators produced two pieces of legislation to promote well water testing; L.D. 1775 (2007) and L.D. 1162 (2015). Both pieces of legislation gained bipartisan support, yet both were ultimately vetoed by separate governors. L.D. 1775 required well-testing as a component of a contract of sale of real estate property and suffered stiff opposition from the Maine Association of Realtors who had issues with being placed in a quasi-enforcement position to ensure that water testing occurs. L.D. 1162 was a more modest bill to provide state funding for educational outreach to motivate people to get their wells tested and was vetoed by the Governor for ideological reasons.

The Island Approach

The duty of private water sanitation ultimately rests on well owners. Water use from a well can either be treated at the point-of-entry into the household or at the point-of-use. Point-of-entry treatment is typically done with anionic exchange systems. This method works by chelating contaminates to a resin bed and requires very little maintenance.  Unfortunately, these systems also run the very small risk of total failure where all of the captured contamination can be released at once. The most cost-effective method of point-of-use treatment is reverse osmosis, which uses a microscopic membrane to trap contaminants. This method is very effective at removing arsenic, more so than anionic exchange systems. Nevertheless, due to their small size, they can only produce a few gallons of treated water per day. Prices typically range in the $800-$3000 for arsenic specific treatment filters in either range, with point-of-entry systems running in the higher bound and reverse osmosis in the lower bound. Residents of rural areas, where well use is prevalent, typically have lower socioeconomic means than those living in more populous regions. As one might expect, this, in turn, affects the decision to invest in well remediation even in light of the known health risk.

Reflection

Neither option really provided me with a sense that the arsenic dilemma in Maine was adequately managed or handled. The legislative ‘solution’ seemed broken and the technological ‘fix’ was too cost-prohibitive. For me, then a student in Chicago with a clear line of sight to the greatest surface freshwater system in World, I didn’t feel it was my place to tell Mainers water to do. But perhaps at my vantage point, I could work to bring awareness to the issue.

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