County wells are
not polluted, but more study needed
Express Staff Writer
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.
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.
might be a new county requirement that developers pay for groundwater
studies before building subdivisions.
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.
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
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
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.
levels in the nine Wood River Valley wells were in fact lower than what
scientists consider to be the naturally occurring amount, Brown said.
in the Carey area were at or above the naturally occurring level, but
below what the Environmental Protection Agency considers dangerous, he
is only one indicator of pollution.
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.
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.