Month: April 2025
THE DIRT: Fish consumption advisory for the Cd’A Basin
North Idaho offers some of the best fishing opportunities in the region, with Lake Coeur d’Alene and surrounding waters providing a rich habitat for a variety of fish species. Unfortunately, like many water bodies across the country, some fish species in this area have been found to contain elevated levels of mercury. To ensure safe and enjoyable fishing experiences, health officials have issued guidelines to help anglers monitor their fish consumption.
Studies conducted by the Idaho Department of Health and Welfare (DHW), the Department of Environmental Quality (DEQ), Panhandle Health District, Fish and Game and the Coeur d’Alene Tribe have detected elevated mercury levels in species such as northern pike, bass and kokanee. Mercury is a naturally occurring element that can also be introduced through industrial activity. It is a neurotoxin that can impact brain development and nervous system function, particularly in pregnant women and young children. Mercury is the main contaminant of concern driving fish consumption meal limit recommendations.
To minimize exposure to these contaminants, health officials recommend limiting your intake to no more than the following per month:
• 2-5 servings of northern pike
• 3-11 servings of panfish
• 6-20 servings of kokanee
• 1-4 servings of bass
Serving size and quantity varies depending upon your inclusion in the general adult population, if you are pregnant or if you are a child. The location where a fish was caught can also affect the amount of mercury accumulated within a fish. For more specific recommendations please visit: http://fishadvisory.dhw.idaho.gov.
The advisory recommends eating younger fish and those lower in the food chain, such as trout and kokanee, because they are generally less contaminated. Fat should be trimmed and skin and organs removed before cooking fish to reduce the likelihood of contaminants. Cooking methods such as grilling or broiling do not reduce mercury content, making it essential to follow these guidelines when consuming local fish.
Beyond mercury, legacy contamination from historical mining activities has introduced heavy metals like lead, arsenic and cadmium into the Coeur d’Alene Basin. These pollutants settle in lakebed sediments and accumulate in fish, further increasing potential health risks. Levels of cadmium, arsenic and lead found in fish tissue are not expected to harm people’s health when following meal recommendations.
The DHW recognizes the health benefits of eating fish and is providing this advisory to encourage safe consumption. Fishing remains a beloved activity in North Idaho, and by staying informed, residents and visitors can continue to enjoy the sport while making health-conscious choices about fish consumption.
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The Dirt is a series of informative articles focused on all aspects of cleanup efforts associated with the Bunker Hill Superfund Site. Our goal is to promote community awareness of contamination issues, to provide tools for protecting public health, and to keep the community informed of current and future cleanup projects. The Dirt is a group of committed and local experts from multiple agencies including the Basin Environmental Improvement Project Commission, Panhandle Health District, Shoshone County, Silver Valley Economic Development Corporation, and the Idaho Department of Environmental Quality.
THE DIRT: What you need to know about ICP Permits
Spring is in the air, and you know that means; it’s time to swap snow boots for sneakers and get back outside, residents of North Idaho are eager to get outside and work in their yards. Before heading out to work, are you confident you have everything you need? Sure, you have your shovel, your gloves, and your freshly applied sunscreen. But what about your permit?
If you live within the Bunker Hill Superfund Site (BHSS) and you have projects that involve digging, grading, and/or excavation, you may also need an ICP excavation permit from Panhandle Health District.
Residents of the BHSS live in a geographic region that was impacted by lead and other heavy metals from historic mining, milling, and smelting practices. Cleanup measures taken at the BHSS are unique because contamination is so widespread and so deep in some areas that total removals could not be completed.
After the establishment of the Site in 1983, EPA collaborated closely with the community as they conducted Remedial Investigations and Feasibility Studies to determine the most effective, efficient, and logistically attainable cleanup method. After considering numerous options, it was determined that partially removing contaminated materials and replacing them with clean materials was the most feasible option available.
Soil sampling criteria were developed and remedial action levels established. After property owners provided consent, soil samples were collected from each property and cleanup decisions were made based on those sample results. To date, over 7,000 properties have undergone some form of remedial cleanup.
Not every property located within the BHSS qualified for remediation, but that does not mean these properties are completely contaminant free. And those that did qualify may have a variety of barrier types and depths. Typical barriers range in depth from six to twelve inches and consist of either gravel or topsoil.
Because only partial removals could be performed, contaminated materials can still exist beneath these barriers. Barrier fabric was often, but not always, used to mark the transition between clean barrier material and the contaminated material that remains. Dirt disturbing projects can compromise or damage clean barriers, thereby creating a health risk for individuals living near these compromised barriers, with children and pregnant women at highest risk. The Institutional Controls Program (ICP) was established under Panhandle Health District to issue permits and oversee dirt disturbance activities, and to ensure that barriers are properly maintained and reinstalled if disturbed.
Free ICP permits are required anytime a remediated barrier, or contaminated materials are disturbed, or if one cubic yard or more of soils containing contaminants must be moved. An ICP permit will provide you with sample data available for your property, records of any remediation work, and guidelines for safely completing your project. These permits also give you access to free soil disposal repositories and supplies to help you safely complete your project. Permits are a legal requirement and help protect homeowners from future legal ramifications of compromised barriers when their property is sold.
So, before you head outside and start your spring and summer projects, be sure to contact the ICP to see if you need a permit. Inquiries and permit requests can be made through our website cdabasin.idaho.gov, over the phone at (208)783-0707, or in person at 35 Wildcat Way in Kellogg.
The Dirt is a series of informative articles focused on all aspects of cleanup efforts associated with the Bunker Hill Superfund Site. Our goal is to promote community awareness of contamination issues, to provide tools for protecting public health, and to keep the community informed of current and future cleanup projects. The Dirt is a group of committed and local experts from multiple agencies including the Basin Environmental Improvement Project Commission, Panhandle Health District, Shoshone County, Silver Valley Economic Development Corporation, and the Idaho Department of Environmental Quality.
THE DIRT: EPA conducting waterfowl survey
The Environmental Protection Agency (EPA), in collaboration with wildlife management staff from State, Federal, and Tribal organizations, is conducting a study to develop tools for monitoring waterfowl health and exposure to lead contamination in the Lower Coeur d’Alene River Basin. The team includes scientists from the U.S. Fish and Wildlife Service, the Coeur d’Alene Tribe, Idaho Fish and Game, the U.S. Geological Survey, and EPA. The study aims to assess the effectiveness of remediation and restoration efforts by tracking changes with new biomonitoring tools.
Tundra swans migrating between California and Alaska stop in the Coeur d’Alene Basin each spring. While foraging in contaminated wetlands for food buried in the sediment, they incidentally ingest toxic levels of lead from the sediment. Wood ducks, a species that nests in the Basin, are also vulnerable to lead ingestion while foraging for insects and submerged plants. Lead exposure results from ingestion of sediments contaminated by historic mine tailings that were once discharged directly into waterways by mining companies operating in the Silver Valley. This practice spread contaminants throughout the Lower Basin of the Coeur d’Alene River. Despite changes in mining practices, previously discharged toxic sediments remain accessible to waterfowl throughout most of their habitat.
The number of tundra swan deaths fluctuates annually. In 2022, 388 swans were found dead likely due to lead exposure from prolonged stays in the contaminated Basin. The swans may have been more vulnerable to exposure than in previous years due to a greater need for food after encountering limited feeding habitats in California from drought. Furthermore, feeding habitats in the Basin were also limited due to ice, forcing them to feed in areas with heightened risks for exposure to contaminated sediments. While the continental swan population remains stable, ongoing efforts aim to reduce lead exposure to improve swan health.
Field teams are collecting and testing blood and feces from trapped birds, while also monitoring exposure by placing GPS or radio collars on swans and wood ducks. Scientists will also collect and analyze samples from additional waterfowl, invertebrates, sediment, and water across wetlands, ranging from clean areas in the St. Joe River watershed to heavily contaminated sites in the Coeur d’Alene River Basin. Sampling will continue through mid-March 2025 for swans and from late March through June for wood ducks.
A key goal of the study is to develop noninvasive biomonitoring methods to measure lead exposure. Rather than relying on expensive traditional blood sample measurements which require specialized experience and extensive permitting, researchers are testing the use of fecal material and eggshells to assess aquatic waterfowl exposure to metals and track changes over time as remediation and restoration work create clean habitat in the Lower Coeur d’Alene Basin. The study may also provide information to aid in future wetland cleanup efforts, ensuring that waterfowl are attracted to clean habitats rather than toxic ones. EPA and the Restoration Partnership are already working on projects such as Gray’s Meadow, where soil cleanup and habitat restoration are underway, with completion expected by the end of 2025.
Public involvement is encouraged. If individuals encounter a dead tundra swan or a wood duck with a neck collar or satellite transmitter, they are asked to report sightings to Idaho Fish and Game at (208)-769-1414. The study findings will be made available to the public by EPA when complete.
The Dirt is a series of informative articles focused on all aspects of cleanup efforts associated with the Bunker Hill Superfund Site. Our goal is to promote community awareness of contamination issues, to provide tools for protecting public health, and to keep the community informed of current and future cleanup projects. The Dirt is a group of committed and local experts from multiple agencies including the Basin Environmental Improvement Project Commission, Panhandle Health District, Shoshone County, Silver Valley Economic Development Corporation, and the Idaho Department of Environmental Quality.
