For the week of Feb 5 - 12, 2002

County wells are not polluted, but more study needed

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By TRAVIS PURSER
Express Staff Writer

The groundwater that public and private agencies have tested in nine Wood River Valley wells shows no signs of pollution, a compilation of over 20 studies show. However, more work needs to be done before researchers will know for sure that groundwater throughout Blaine County remains uncontaminated by pollution from humans.

Isolated problems with contaminated wells, including five wells near McHanville just south of Ketchum that were found to contain E. coli bacteria last summer, have prompted the Blaine County Commission to focus its attention on the matter.

One result, might be a new county requirement that developers pay for groundwater studies before building subdivisions.

And, city and county governments might begin coordinating the way they regulate development in areas that could affect city water supplies, which often originate outside cities.

As a first step, the Blaine County Commission hired Lee Brown, a county resident and professor from San Diego State University with a Ph.D. in water resources, to gather and evaluate a dizzying array of local studies that have been completed over the last 80 years.

In a 32-page synopsis that he presented to the commission and about a dozen citizens Monday at the county courthouse, Brown concluded:

·  Extensive historical information on water resources in the Wood River Valley deals more with water quantity than quality and more with surface water than groundwater.

·  Testing for quality has increased since World War II. But, not enough testing focuses on the county government’s interest in the effects of possible pollution caused by the rapid growth of the human population.

·  Available information indicates quality is not yet at risk in the Wood River Valley. However, testing at more locations, and more often, needs to be done.

·  Due to the needs of agriculture, water resources in southern Blaine County have been studied much more than in the north. However, most studies looked at quantity more than quality.

·  Other local governments in Idaho appear to be further along in creating water quality management plans, ordinances and special districts. But, those governments were sometimes trying to discourage state and federal intervention.

Brown focused in his talk on the amount of nitrate found in tested wells. Nitrate is a naturally occurring substance that can increase to harmful levels in areas where humans use fertilizer and raise livestock.

Nitrate levels in the nine Wood River Valley wells were in fact lower than what scientists consider to be the naturally occurring amount, Brown said.

Five wells in the Carey area were at or above the naturally occurring level, but below what the Environmental Protection Agency considers dangerous, he said.

But nitrate is only one indicator of pollution.

Brown recommended that the county consider hiring a water quality technician who would constantly monitor nitrate, fecal bacteria and chloride levels in wells throughout the county. In regions of known bacterial problems, like McHanville, or areas of rapid growth, Brown said the technician should monitor 10 to 20 wells to get an accurate picture of what’s happening.

The commission considers the matter further on Feb. 11 when the South Central Health District discusses its septic system policies. The meeting is tentatively scheduled to begin at 3 p.m. at the county courthouse.

 

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