The bad news: The water in all five Blaine County cities has at least traces of three contaminants.
The good news: All of Blaine County's municipal water districts, except Carey, have passed without one contaminant exceeding health guideline standards. But the difference between Carey and the other cities may be only that Carey conducted more rigorous testing.
That information is part of a database recently compiled by the nonprofit Environmental Working Group, which has spent the last three years amassing a database of drinking-water quality tests for 48,000 communities, using 2004-to-2009 information submitted by drinking-water offices of 45 states that made data available. That included Idaho's cities and Blaine County water districts. The organization released the results of its investigation earlier this month.
Legal limits are established by the Safe Drinking Water Act, the main federal law that ensures the quality of Americans' drinking water. Under the act, the Environmental Protection Agency sets standards for drinking water quality and oversees the states and water suppliers that implement those standards. Health guidelines are usually stricter than the legal limits.
Ketchum and Hailey
Of the region's municipalities, Ketchum and Hailey scored highest. Of 25 contaminants tested for in Ketchum and 26 in Hailey, only three were found: nitrate, total haloacetic acids and total trihalomethanes. All have been found in more than 40 states over the last five years.
Nitrate is a naturally occurring chemical that is an important plant nutrient often used in fertilizers. Bacteria in the gut convert nitrate to nitrite, which is mostly responsible for any toxic effects observed.
Haloacetic acids and trihalomethanes are byproducts of chlorinated disinfectants added to drinking water to control pathogens. According to the EPA, long-term exposure to these in drinking water above the legal limit could increase the risk of cancer.
But Ketchum and Hailey were never close to the limit, with average nitrate results of less than one part per billion, the limit being 10 parts per billion. Average results for haloacetic acids and trihalomethanes were up to 4 ppb for the two towns, with legal limits being 60 and 80 ppb, respectively.
Sun Valley and Bellevue
Of the 36 contaminants tested for in Sun Valley's water supplies and 62 in Bellevue's, only four were found. The same three were found as in Ketchum and Hailey, but nitrite was also found in Sun Valley. Di(2-ethylhexyl) phthalate—a pollutant from rubber and industrial chemical factories and something that leaches from PVC pipes—was also found in Bellevue. The EPA classifies it as a probable human carcinogen. These four contaminants were found in levels far below legal limits.
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Carey
Of the 70 contaminants tested for in Carey, six were found within health guidelines, but three exceeded health guidelines while remaining below legal limits.
The three contaminants that exceeded health guidelines were radium-226, radium-228, and these two combined. Radium-226 and radium-228 are radioactive elements usually found around uranium deposits. Both were found in tap water of about 8,000 utilities in 36 states serving about 90 million people in the last five years.
None of the other cities in the county tested for radium.
The six contaminants found at concentrations within health guidelines were nitrate, nitrite, combined uranium, alpha particle activity including radon and uranium, alpha particle activity excluding radon and uranium, and beta particle activity.
Combined uranium, a radioactive element commonly found in most rocks, is a suspected carcinogen detected in the water of 3,100 utilities in 28 states serving 64.5 million people. Beta particles are a form of radiation frequently associated with nuclear testing and radioactive mineral deposits, and were found in the water of 4,800 utilities in 31 states serving 65.6 million people. Radon is a radioactive breakdown product of radium and uranium in soil, rock and water, and is often present in groundwater. It was detected in the water of 1,300 utilities in 22 states serving 32.7 million people.
The bigger picture and Idaho
While these five cities have all tested positive for traces of harmful chemicals—Carey possibly being the worst off—none had serious problems compared to many other utilities throughout the state.
Carey wasn't even close to the 20 worst utilities. United Water Idaho Inc. in Boise was the worst off and tested positive for 32 chemicals, with 21 exceeding health guidelines. Second and third worst were Meridian Water Department and the city of Pocatello. Even Elm Park Water System in Twin Falls, at No. 20, had six chemicals exceeding health guidelines—double that of Carey.
In Idaho, about 950,000 people drank water at some time within the past five years with chemical levels exceeding health guidelines. About 440,000 people drank water with chemicals above legal limits.
From 2004 to 2009, 61 contaminants were detected in Idaho tap water, including agricultural pollutants arsenic, cyanide and nitrate; urban pollutants lead, mercury and cadmium; industrial pollutants aluminum and combined uranium; various water treatment byproducts and naturally occurring contaminants like nitrate used in fertilizer.
For a look at water utilities' results, go to www.ewg.org/tap-water.
Trevon Milliard: tmilliard@mtexpress.com
Blaine County’s water passed most of the quality tests conducted in recent years but was not found to be totally free of contaminants. Photo by David N. Seelig
