Scientific Review of Water Quality Begins

This story was written by the Our Gem Collaborative team for the CDA Press on Sunday, Feb. 14, 2021. Read the original article.

What is the future of Coeur d’Alene Lake’s water quality? That is the question on the minds of many in North Idaho, including state and tribal governments tasked with monitoring and improving water quality, elected officials with jurisdiction on the lake, shoreline property owners, the local tourism industry and concerned citizens.

Historical mining activities deposited millions of tons of contaminated and potentially toxic sediment including zinc, cadmium and lead into Coeur d’Alene Lake and its tributaries. Since the implementation of environmental regulations in the mid-1970s, metal concentrations have declined, but lakeshore development, increased recreational and boating use, land use changes, and increased nutrient loads could reverse this success.

In 2018, the Coeur d’Alene Tribe questioned whether the Coeur d’Alene Lake Management Plan was enough to protect the future of the lake. In 2020, in response to a recommendation of Governor Little, the Idaho Department of Environmental Quality (IDEQ), Kootenai County and the U.S. Environmental Protection Agency, with support of the tribe, asked the National Academy of Sciences (NAS) to conduct a comprehensive water quality analysis and provide recommendations to address issues of concern.

The NAS Committee includes experts from across the country. This distinguished group will evaluate the quality of data that has been collected by IDEQ, the tribe and other highly reputable sources. The committee will address the ability of experts to effectively interpret, model and act on data collected. They will also make recommendations for collecting additional data.

The NAS Committee is convened to take a rigorous scientific approach to complex questions related to lake water quality, summertime oxygen deficiencies in lake bottom waters, the impacts of zinc levels on algal growth, the fate of metals found in lakebed sediments, and the relevance of metals release from sediments to human and ecological health. Their series of meetings, deliberations and related analyses will culminate in a final report in mid-2022.

For more information visit the NAS website. You can also contact Jamie Brunner, Coeur d’Alene Lake Management Supervisor with the Idaho Department of Environmental Quality at Jamie.brunner@deq.idaho.gov or 208-946-0174.