COEUR D’ALENE, Idaho — As warmer weather approaches North Idaho, families are eager to enjoy the beaches of Lake Coeur d’Alene, but lingering questions about water safety due to historic mining contamination have prompted the first comprehensive beach testing study in more than two decades.
The Idaho Department of Environmental Quality (DEQ) is currently testing more than 30 popular beaches along Lake Coeur d’Alene and the Spokane River for harmful contaminants, particularly lead and arsenic, which could pose health risks to visitors, especially children.
“We know that every year when sediments are stirred up from spring runoff and flood events, the stuff gets moved around,” said Dan McCracken, Regional Administrator for the Idaho Department of Environmental Quality. “We have done spot sampling over the years, kind of at individual sites, but no comprehensive study has been done since about 20 years ago.”
The study comes in response to recommendations from a 2022 National Academies of Sciences report and is being funded through Governor Brad Little’s office.
Researchers are collecting samples from multiple areas of each beach: the dry sand where people might lay towels, shallow areas where children build sandcastles, and deeper swimming zones to create a comprehensive picture of contamination levels.
For local residents like Rochelle Mamelli of Post Falls, who was recently enjoying a sunny May day at the lake with her family, the study provides reassurance.
“It’s getting nice out and we love the water,” Mamelli said while watching her children play near the shoreline.
Mamelli, who grew up in Idaho’s Silver Valley, is familiar with the region’s history of mining contamination. “I come from an area where it is heavily polluted by lead, you know, from all of the mines. So, when I look out here we’re not as close to those kind of things,” she explained. “So, it’s not my number one concern, but it is something I would think about.”
The contamination stems from decades of mining operations that dumped runoff into the Coeur d’Alene River, which eventually flows into Lake Coeur d’Alene and the Spokane River.
While previous testing has consistently shown that Lake Coeur d’Alene beaches are safe for public use, officials want updated data to track any changes in contamination levels.
McCracken emphasized that the primary health concerns are focused on lead and arsenic exposure, particularly for children who might ingest contaminated sand or sediment while playing.
“We’re most concerned from a human health standpoint… lead and arsenic are the metals that tend to stay in higher concentrations than you would see in natural sediments, and we’re concerned mostly with kids getting exposed to those,” McCracken said.
The DEQ official noted that while Lake Coeur d’Alene beaches have historically tested at safe levels, there are areas along the Coeur d’Alene River that require more caution.
“The human health challenges related specifically with lead and arsenic are really focused on the Coeur d’Alene River from the mouth at Harrison up to where the south fork of the Coeur d’Alene comes in,” McCracken explained. “The concentrations that we see of the metals of concern along the shorelines of Coeur d’Alene Lake typically are 50 times less than what you see up in the Coeur d’Alene River.”
This significant difference in contamination levels provides some reassurance for lake users, though the new study will provide more definitive data on current conditions.
The comprehensive beach testing comes at a critical time as the region prepares for the summer recreation season. For expectant mother Mamelli, who also has young children, the ongoing monitoring efforts provide peace of mind.
“I’ve got a baby on the way and I’ve got little ones that don’t know any better, so to know that they are checking it and keeping an eye on that kind of stuff does make me feel very safe,” she said.
The study’s initial samples were collected in summer 2024, with preliminary findings expected later this summer. A final comprehensive report is scheduled for publication in 2026.
You can look for those results here.
The results will help inform both public health officials and families about which areas of Lake Coeur d’Alene and the Spokane River are safest for recreation, potentially guiding decisions about where to enjoy the water this summer and in future years.
For now, officials are not expressing immediate concerns about Lake Coeur d’Alene beaches, but they emphasize the importance of staying informed about water quality, particularly in areas closer to the Coeur d’Alene River where contamination levels are known to be higher.
As summer approaches and more families head to North Idaho’s popular beaches, this study represents an important step in ensuring that one of the region’s most beloved natural resources remains safe for generations to come.
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