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Improving Water Quality in the Lemhi River by Staff Idaho Farm Bureau News, July 2002

For several years, conservation districts in Idaho have received water pollution control funding. The Lemhi Soil and Water Conservation district took this responsibility seriously and devoted the financial support to an ambitious study of water quality on the Lemhi River.

Since 1994, the district has been sampling water from designated sites on the Lemhi River every three weeks. Sampling is suspended during the winter months as ice and freezing temperatures taint the samples. The purpose of this monitoring effort is to identify possible water quality degradation and provide data for future evaluation and planning.

Contributors to the program include the Idaho Soil Conservation Commission, who purchased a hydro-lab through Bonneville Power Administration funding; the Bureau of Reclamation who analyzes water samples; and the Natural Resources Conservation Service who helps compile the information.

Eight parameters are collected at six different sites along the 45-mile length of the River between Salmon and Leadore. Potential pollutants in the stream include sediment and suspended solids, phosphorus, nitrogen and pathogens. These pollutants may contribute to undesirable conditions of elevated water temperature and insufficient dissolved oxygen.

The Idaho Department of Environmental Quality has listed the Lemhi River and several tributaries as water quality limited and included them on the list of 303(d) water bodies of concern. This study has established baseline data to refer to when it is time to develop a watershed implementation plan.

The District plans to continue this program so trends can be observed and results used for future requirements of the Clean Water Act and to determine best management practices for the watershed.

Overall, the water quality of the Lemhi river is within the standards of the Environmental Protection Agency. The site near the City of Salon is the most concern. It shows a high level of coliform bacteria, especially during high water. It is suspected that malfunctioning septic systems contribute to the problem. Other sites fluctuate in quality and correspond to water levels and land use.