Monday, March 04, 2024

Lake Cd'A under microscope, take 2

Staff Writer | May 4, 2021 1:07 AM

The second series of National Academy of Sciences meetings on a study of Lake Coeur d’Alene’s water quality will be open this week for public viewing. 

The roughly 18-month, $770,000 study began last December. The first panel discussions were held in February.

Committee members and field specialists meet again this week with presentations from experts and two open-mic stakeholder sessions. 

Meetings run through Thursday and are accessible to the public through a virtual zoom link:

Presentation topics include watershed nutrient inventory, in-lake processes, climate change, and forest fire impacts on the region. 

Public session one is today from 11 a.m. to 3 p.m. and will feature representatives from the U.S. Geological Survey, University of Idaho, NAS committee members, and the Idaho Department of Environmental Quality. 

Public session two is Wednesday from 10 a.m. to noon and includes:

• Several presentations about climate change

• The impacts of forest fires

• Wastewater treatment

Public session three on Thursday is a question-and-answer conversation with speakers from the previous two days, from 11 a.m. to noon.

IDEQ and Kootenai County contracted with the NAS last year to conduct the assessment, which is expected to be completed by summer 2022.

No recommendations for remedial action will come from the committee. If there is a need for action from the state, another study could be conducted in the future. 

The NAS’s designated tasks for the committee are to:

• Evaluate current water quality in the lake, lower rivers and lateral lakes, focusing on observed trends in nutrient loading and metal concentrations while considering how changes in temperature or precipitation could affect those trends.

• Consider the impacts of current summertime anoxia on the fate of the metals and nutrients.

• Consider whether reduced levels of zinc entering the lake resulting from the upgrade to the Central Treatment Plant and other upstream activities remove essential control on algal growth.

• Discuss whether the metal found in the lake sediments will be released into the lake if the current trends continue. If sufficient data is not available, the National Academies will identify the additional data required to achieve an appropriate confidence level.

• Discuss the relevance of metals released in the lake to human and ecological health.

The study is endorsed by the Coeur d’Alene Tribe and the Our Gem Collaborative.