Surveys in Idaho show that nitrates are being found in several major aquifers. Groundwater is an important resource in Fremont County as a majority of the residents obtain their drinking water from the Eastern Snake River Plain Aquifer. Nearly 200,000 acres of land in Fremont County are planted with crops. Fremont County is the largest potato seed producing county in the U.S. Fifty percent of the population depend on private wells for drinking water. Fremont County has a large recreation area in Island Park.
Many homes there are on private wells and private septic systems.
Intensive and extensive N fertilizer use on irrigated acreage. No baseline wellhead data exists to determine trends or to evaluate the need for BMPs. Eleven percent of the sampled wells in Fremont county contained nitrate-N levels greater than 10 ppm, which is the National Public Health Service U.S. drinking water standard. Compared to the EPA's National Survey for Nitrates conducted in 1988 a higher percentage of wells in Fremont county exceed the Federal Health Standard for nitrates than the national average. Another 30 percent of rural domestic wells contained detectable levels of nitrates.