01Ohio · OUR FIRST LEARNING FOCUS
East Palestine derailment area
East Palestine
WaterLandAir
The February 2023 train derailment released hazardous materials, including vinyl chloride and acrylates, prompting a major emergency response and environmental cleanup.
Why attention matters
Long-term sampling and clear public reporting help residents understand environmental conditions after a major industrial accident.
Recovery progress
EPA’s September 2026 update identifies a monitoring, maintenance and reporting phase, including quarterly groundwater, surface-water and drinking-water sampling.
A question to learn from
What can long-term monitoring teach us about selecting research questions and explaining evidence to communities before proposing any new treatment?
EPA: East Palestine, Ohio Train Derailment — September 2026 update ↗Source reviewed September 27, 2026
Cuyahoga River Area of Concern
Cleveland–Akron corridor
WaterLand
Historic industrial contamination, stormwater, sewer overflows and erosion have affected river sediment, water quality and habitat.
Why attention matters
Contaminated sediment and damaged habitat can undermine the river’s recovery even as overall water quality improves.
Recovery progress
EPA reports Gorge sediment remediation began in 2025 and is expected through 2027. Old Channel cleanup design and other restoration projects continue.
A question to learn from
How could carefully tested vegetation and runoff management complement existing sediment cleanup and habitat restoration?
EPA: Cuyahoga River AOC ↗Source reviewed September 27, 2026
Maumee Area of Concern
Toledo and surrounding watersheds
WaterLand
Legacy industrial pollution, sediment contamination and extensive wetland loss affect watersheds entering western Lake Erie.
Why attention matters
Persistent sediment pollutants and lost habitat limit ecological recovery; some impairment categories remain despite substantial completed cleanup.
Recovery progress
EPA reports continuing sediment and habitat work. An August 2026 agreement supports design for remaining PCB contamination in part of the Ottawa River.
A question to learn from
Where could monitored wetland or root-zone systems help manage runoff while preserving established cleanup responsibilities?
EPA: Maumee AOC — August 2026 update ↗Source reviewed September 27, 2026
Ashtabula River recovery
Ashtabula
WaterLand
Decades of industrial activity left contaminated sediment and reduced natural riverbank habitat.
Why attention matters
This river demonstrates that coordinated cleanup can restore beneficial uses. Protecting the gains matters as much as identifying new needs.
Recovery progress
The Area of Concern was delisted in 2021 after all designated beneficial-use impairments were removed. It is a recovery example, not an untreated site.
A question to learn from
Which lessons from sediment removal, habitat work and long-term evaluation could guide realistic future restoration plans?
EPA: Ashtabula River AOC — Delisted ↗Source reviewed September 27, 2026
Black River recovery
Lorain
WaterLand
Historic industrial discharges and urban and agricultural activity degraded water quality, habitat and sediment.
Why attention matters
Recovery depends on sustained cleanup and habitat investment. This river’s progress provides evidence that long-term environmental work can deliver results.
Recovery progress
EPA reports all beneficial-use impairments were removed by June 2026, allowing the formal Area of Concern delisting process to begin.
A question to learn from
How can communities maintain recovered habitat and use monitoring to detect new pressures early?
EPA: Black River AOC ↗Source reviewed September 27, 2026
Hudson River PCBs
Fort Edward–Troy and Lower Hudson
WaterLand
Historic PCB releases contaminated river sediment and entered the aquatic food chain.
Why attention matters
Pollution can persist in fish after major cleanup. Recovery must be measured over time rather than inferred from clear-looking water.
Recovery progress
Upper River dredging has been completed; monitoring, five-year reviews and Lower River investigations continue. EPA maintains links to fish-consumption advisories.
A question to learn from
What evidence would show lasting reductions in contamination across sediment, water and the food web?
EPA: Hudson River cleanup ↗Source reviewed September 27, 2026
Gowanus Canal
Brooklyn
WaterLand
Industrial discharges and combined-sewer overflows left canal sediment contaminated with PAHs, PCBs and metals.
Why attention matters
Cleaning sediment without controlling incoming pollution can compromise recovery. Both historic waste and continuing sources require attention.
Recovery progress
EPA’s remedy combines dredging, stabilization, capping and source controls. Most upper-canal work finished in 2024; middle-section design was finalized in 2025.
A question to learn from
What could source-control and post-cleanup monitoring teach us about designing complementary natural treatment research?
EPA: Gowanus Canal cleanup activities ↗Source reviewed September 27, 2026
Newtown Creek
Brooklyn and Queens
WaterLand
The heavily industrialized creek has contaminated sediment, with cleanup concerns including PCBs, PAHs and copper.
Why attention matters
Sediment contamination and movement of pollutants between water, sediment and organisms complicate the recovery of urban waterways.
Recovery progress
EPA selected an East Branch interim cleanup in January 2025 involving dredging and sediment stabilization. Broader creek studies and cleanup design continue.
A question to learn from
Which contaminant-specific measurements would be essential before evaluating any biological method alongside engineered cleanup?
EPA: Newtown Creek cleanup activities ↗Source reviewed September 27, 2026
Onondaga Lake and tributary sites
Syracuse area
WaterLand
Historical industrial and municipal discharges contaminated the lake and nearby sites, including mercury-bearing wastes and other pollutants.
Why attention matters
Lake recovery also depends on upland and tributary sources; completed lake-bottom work does not resolve every surrounding contamination problem.
Recovery progress
Lake-bottom dredging, capping and habitat restoration are complete. Many subsites are monitored, while investigations, design or additional cleanup continue at others.
A question to learn from
How can watershed-scale planning connect source control, restored habitat and measurable water-quality improvement?
EPA: Onondaga Lake cleanup activities ↗Source reviewed September 27, 2026
Lower Passaic River / Diamond Alkali
Newark and neighboring river communities
WaterLand
The river forms part of the Diamond Alkali Superfund site, where extensive contaminated sediment requires a coordinated, long-term remedy.
Why attention matters
Large river cleanups depend on infrastructure for safely handling dredged material as well as the eventual in-river work.
Recovery progress
EPA announced a proposed September 2026 settlement for upland processing and support facilities. The agreement requires court approval before those commitments take effect.
A question to learn from
What can major river cleanup planning teach us about responsible waste handling and the real costs of any treatment approach?
EPA: Proposed Lower Passaic River settlement — September 10, 2026 ↗Source reviewed September 27, 2026
GE–Pittsfield / Housatonic River
Pittsfield and downstream communities
WaterLand
PCB contamination affects river sediment and floodplain soil, requiring cleanup that also protects ecological functions.
Why attention matters
Removing contamination can disturb habitat, making restoration, erosion control and post-cleanup monitoring integral parts of the remedy.
Recovery progress
In May 2026, EPA opened review of the Reach 5A final cleanup work plan and a separate habitat-restoration plan.
A question to learn from
How can native vegetation and riverbank design support recovery after regulated sediment and soil remediation?
EPA: Housatonic River Reach 5A work-plan review — May 12, 2026 ↗Source reviewed September 27, 2026
New Bedford Harbor
New Bedford
WaterLand
Historic electrical manufacturing left PCBs and metals in harbor sediment; PCB accumulation in seafood led to fishing restrictions and advisories.
Why attention matters
Major sediment removal does not end the need for seafood guidance, cap maintenance and ecological monitoring.
Recovery progress
Large-scale dredging was substantially completed in 2020; shoreline restoration finished in 2024. EPA lists continued maintenance, monitoring and remaining facility work for 2026.
A question to learn from
Which monitoring measures best show whether cleanup benefits persist in habitat and the aquatic food web?
EPA: General information about the New Bedford Harbor cleanup ↗Source reviewed September 27, 2026
Centredale Manor Restoration Project
North Providence and Johnston
WaterLand
Past chemical production and drum reconditioning contaminated soil, sediment and the Woonasquatucket River with dioxin and other chemicals.
Why attention matters
Floodplain and river contamination can move beyond an original industrial property, requiring coordinated work across connected areas.
Recovery progress
EPA describes a phased remedy involving source-area capping, sediment and floodplain excavation, wetland cover, and long-term monitoring under EPA and Rhode Island oversight.
A question to learn from
How can habitat-sensitive cleanup plans limit erosion and preserve recovery while contaminated materials are safely managed?
EPA: Centredale Manor cleanup activities ↗Source reviewed September 27, 2026
Raymark Industries
Stratford
LandWaterAir
Manufacturing waste containing asbestos, lead, PCBs and other contaminants was spread as fill across multiple properties and wetlands.
Why attention matters
Historic disposal can create many separate cleanup needs across soil, sediment, wetlands and groundwater.
Recovery progress
EPA celebrated completion of the former Raybestos Memorial Ballfield cleanup in June 2026 while Shore Road cleanup remained underway; other units have separate remedies.
A question to learn from
How should research distinguish habitat restoration from hazardous-waste work that requires specialized remediation and containment?
EPA: Raymark cleanup milestone — June 17, 2026 ↗Source reviewed September 27, 2026
Palmerton Zinc Pile
Palmerton
LandWater
Historic zinc smelting left a large waste pile and metal-contaminated land requiring remediation and land-use controls.
Why attention matters
Revegetation and containment need continued protection, while groundwater, surface-water and ecological questions require their own investigation.
Recovery progress
EPA oversees ongoing investigation of water and ecological conditions, alongside five-year reviews and controls on groundwater use and soil excavation.
A question to learn from
How can revegetation stabilize contaminated ground while monitoring confirms that metals remain controlled rather than merely hidden?
EPA: Palmerton Zinc Pile cleanup activities ↗Source reviewed September 27, 2026
BoRit Asbestos
Ambler
LandAirWater
Historic asbestos-product waste required capping and streambank stabilization to prevent release of asbestos-containing material.
Why attention matters
Protective covers need inspection and repair after erosion or severe weather. Vegetation is part of containment, not proof that hazardous material disappeared.
Recovery progress
Cleanup construction is complete. EPA describes ongoing inspections, cap maintenance, land-use controls and environmental sampling to verify the remedy remains protective.
A question to learn from
What can long-term cover and vegetation maintenance teach us about protecting completed remedies without disturbing hazardous waste?
EPA: BoRit Asbestos cleanup activities ↗Source reviewed September 27, 2026
Lower Darby Creek Area
Darby Township, Folcroft and Philadelphia
WaterLand
Clearview and Folcroft landfill wastes contaminated surrounding environmental media; groundwater and aquatic areas remain separate cleanup concerns.
Why attention matters
Groundwater migration and contaminated fish tissue need attention even after residential soil cleanup and landfill-cover construction.
Recovery progress
Residential cleanup is complete and Clearview has a forested evapotranspiration cover. EPA continues groundwater treatment evaluations, Folcroft studies and aquatic-environment investigations.
A question to learn from
What can this real use of a vegetated landfill cover teach us about measuring natural systems within an engineered remedy?
EPA: Lower Darby Creek Area cleanup activities ↗Source reviewed September 27, 2026
River Raisin Area of Concern
Monroe
WaterLand
Historic industrial discharges left PCBs and other pollutants in sediment near the river's Lake Erie outlet.
Why attention matters
Sediment contamination and remaining ecological impairments make recovery monitoring important for fish, wildlife and community use.
Recovery progress
Major dredging and habitat projects are complete. EPA lists five impairments removed and four remaining; monitoring tracks continued recovery.
A question to learn from
What can completed sediment cleanup and fish-passage restoration teach us about measuring recovery over time?
EPA: River Raisin Area of Concern ↗Source reviewed September 27, 2026
Allied Paper / Kalamazoo River
Kalamazoo and Allegan counties
WaterLand
Historic paper-industry wastes contaminated river sediments, banks and floodplains with PCBs across a large river system.
Why attention matters
Contaminated sediment can remain a source of exposure for aquatic food webs unless managed and monitored.
Recovery progress
EPA reports extensive sediment removal, riverbank restoration and landfill capping. Cleanup and planning continue in remaining areas, while completed areas are monitored.
A question to learn from
How should a research program compare proposed biological approaches with established sediment remedies and untreated controls?
EPA: Allied Paper / Portage Creek / Kalamazoo River cleanup activities ↗Source reviewed September 27, 2026
Saginaw River and Bay
Saginaw and Bay City
WaterLand
Legacy sediment contaminants combine with nutrient runoff and habitat loss across the river and bay.
Why attention matters
Fish-consumption restrictions and degraded habitats show why sediment management and watershed pollution prevention must work together.
Recovery progress
EPA identifies sediment remediation, pollution control and wetland restoration as priorities. Three of the original twelve impairments have been removed.
A question to learn from
Where could well-designed root-zone treatment help intercept runoff, and what pollutants would require other remedies?
EPA: Saginaw River and Bay Area of Concern ↗Source reviewed September 27, 2026
Grand Calumet River
Gary, Hammond and East Chicago
WaterLand
Industrial history left PCBs, PAHs and heavy metals in river sediments, alongside substantial habitat loss.
Why attention matters
Sediment management and habitat recovery matter for aquatic food webs and community access to healthier waterways.
Recovery progress
EPA reports six sediment and two habitat management actions completed; additional dredging, capping and restoration actions remain.
A question to learn from
How can restoration vegetation complement engineered containment without disturbing contaminated sediments?
EPA: Grand Calumet River Area of Concern ↗Source reviewed September 27, 2026
Indiana Harbor and Ship Canal
East Chicago
WaterAirLand
Legacy industrial sediments require controlled dredging and disposal; monitoring addresses potential air and water impacts during this work.
Why attention matters
Moving contaminated sediment demands safeguards as well as removal, protecting neighboring communities and the connected Lake Michigan system.
Recovery progress
The USACE project publishes particulate, ambient-air and water-quality monitoring alongside dredging information. This canal is within the broader Grand Calumet Area of Concern.
A question to learn from
What monitoring would show whether a proposed treatment prevents pollution transfer between sediment, water and air?
USACE / Argonne: Indiana Harbor and Canal Dredging and Disposal Project ↗Source reviewed September 27, 2026
Lower Fox River
Green Bay to Menasha
WaterLand
Historic paper-mill operations contaminated sediment with PCBs along the Lower Fox River.
Why attention matters
Completed cleanup still needs stewardship: sediment, water and fish data help verify that benefits persist.
Recovery progress
Cleanup was completed in 2020 and certified by EPA in 2022. Long-term monitoring and maintenance continue after addressing more than six million cubic yards of contaminated sediment.
A question to learn from
What can this completed cleanup teach us about long-term sampling, cap maintenance and transparent reporting?
EPA: Fox River PCB cleanup activities ↗Source reviewed September 27, 2026
Milwaukee Estuary
Milwaukee
WaterLand
Historic industrial discharges and watershed runoff contributed PCBs, PAHs and metals to estuary sediments.
Why attention matters
Restoration supports aquatic habitat, fish passage and the communities connected to Milwaukee's rivers and harbor.
Recovery progress
EPA and partners continue sediment remediation and habitat restoration. Completed projects have removed contaminated sediment, restored wetlands and reopened upstream fish passage.
A question to learn from
How could native planting and runoff management support river recovery after contaminated sediment is addressed?
EPA: Milwaukee Estuary Area of Concern ↗Source reviewed September 27, 2026
St. Louis River Estuary
Duluth and Superior
WaterLand
Historic industry contaminated sediments with mercury, dioxins, PCBs and PAHs, while habitat was lost.
Why attention matters
Recovery matters for fish-spawning grounds, recreation and places of cultural significance to the Fond du Lac Band.
Recovery progress
In May 2026, EPA announced all Minnesota-side sediment cleanup projects complete. Across the estuary, substantial habitat restoration has occurred; recovery criteria and monitoring remain important.
A question to learn from
What can coordinated cleanup, native habitat restoration and long-term stewardship teach a future community research program?
EPA: Completion of St. Louis River cleanup projects in Minnesota, May 2026 ↗Source reviewed September 27, 2026
Waukegan Harbor
Waukegan
WaterLand
Historic manufacturing contaminated harbor sediment, especially with PCBs that can accumulate in aquatic food webs.
Why attention matters
Maintaining cleanup gains and tracking fish contamination are essential parts of recovery, even after major construction ends.
Recovery progress
Sediment management actions are complete and five of six impairments have been removed. Fish-consumption restrictions remain; related Superfund work continues nearby.
A question to learn from
How can habitat monitoring distinguish genuine ecological recovery from simply finishing a construction project?
EPA: Waukegan Harbor Area of Concern ↗Source reviewed September 27, 2026
West Lake Landfill
Bridgeton
LandWater
Parts of the landfill contain radiologically impacted material; groundwater is addressed through a separate investigation.
Why attention matters
Radioactive material requires specialized containment, excavation and disposal expertise. Biological growth cannot eliminate radioactivity.
Recovery progress
EPA's September 2026 dashboard reports remedial-design work underway and a separate groundwater investigation. Cleanup planning includes engineered controls.
A question to learn from
What can this site teach us about recognizing when specialist remediation, rather than a biological method, is required?
EPA: West Lake Landfill progress dashboard, September 2026 ↗Source reviewed September 27, 2026
Big River Mine Tailings
Desloge and the Old Lead Belt
LandWater
Historic lead mining left large waste areas and contaminated residential soils, river sediments and floodplain areas.
Why attention matters
Mine-waste erosion can move metals through a watershed. Soil protection and source control help reduce opportunities for contact and transport.
Recovery progress
Residential soil cleanup and river investigation continue. Stabilized waste areas receive maintenance; EPA is developing actions for high-priority river and floodplain areas.
A question to learn from
Could approved vegetation help stabilize clean cover and reduce erosion without moving metals into a new exposure pathway?
EPA: Big River Mine Tailings cleanup activities ↗Source reviewed September 27, 2026
Anniston PCB Site
Anniston and surrounding waterways
LandWaterAir
Historic PCB manufacturing contaminated properties and downstream waterways, with several environmental media investigated.
Why attention matters
Persistent PCBs require attention to soil contact, food-web pathways and restrictions identified by public-health and environmental agencies.
Recovery progress
Most contaminated residential properties have been cleaned up. Remaining remedies are being designed or implemented; a creek-and-floodplain cleanup decision was signed in December 2024.
A question to learn from
How can a research team respect existing cleanup decisions while evaluating contaminant-specific evidence and community priorities?
EPA: Anniston PCB Site cleanup activities ↗Source reviewed September 27, 2026
Tennessee Products / Chattanooga Creek
Chattanooga
WaterLand
Historic industrial waste contaminated creek sediment; completed remedies removed sediment and capped part of the channel.
Why attention matters
Maintaining protective remedies and following the creek's fish advisory remain important after a site leaves the Superfund list.
Recovery progress
EPA deleted the site from the National Priorities List in 2019 and anticipates no further cleanup actions. Maintenance and monitoring continue.
A question to learn from
What can a completed cleanup teach us about long-term stewardship, protective caps and honest reporting of remaining restrictions?
EPA: Tennessee Products cleanup activities ↗Source reviewed September 27, 2026
USS Lead Site
East Chicago
LandWater
Lead and arsenic contamination affected former industrial property and nearby residential areas; groundwater is a separate investigation area.
Why attention matters
Protecting neighborhoods requires verified soil remedies, clear communication and continued attention to remaining contamination.
Recovery progress
EPA's September 2026 update proposes deleting cleaned Zone 1 from the Superfund list. Facility and groundwater investigations are separate ongoing work.
A question to learn from
How can future restoration planning support safe reuse after certified soil cleanup, without disturbing remaining contamination?
EPA: USS Lead Superfund Site ↗Source reviewed September 27, 2026
San Jacinto River Waste Pits
Channelview / Harris County
WaterLand
Former paper-mill waste pits contain dioxins and furans beside, and partly submerged in, the San Jacinto River.
Why attention matters
River conditions and persistent waste make containment integrity, controlled removal and monitoring important for protecting the surrounding environment.
Recovery progress
Southern impoundment construction finished in 2023. Northern cleanup design was conditionally approved in 2025; EPA's 2026 updates describe remedy changes and next steps.
A question to learn from
What evidence and controls would be required before any proposed biological treatment could be evaluated for persistent industrial waste?
EPA: San Jacinto River Waste Pits site updates ↗Source reviewed September 27, 2026
St. Regis Paper Site
Cass Lake / Leech Lake Reservation
LandWater
Former wood-treatment operations left contamination in soil and groundwater, including areas of the Fox Creek Valley.
Why attention matters
Understanding groundwater movement and remaining sources supports protective cleanup planning with affected residents and the Leech Lake Band of Ojibwe.
Recovery progress
EPA's March 2026 newsletter describes groundwater and soil investigations, coordination with Tribal and state partners, and development of a community advisory group.
A question to learn from
How should a future research program seek Tribal guidance and evaluate contained treatment questions without interfering with the official cleanup?
EPA: St. Regis Superfund Site newsletter, March 2026 ↗Source reviewed September 27, 2026
Palos Verdes Shelf
Offshore Palos Verdes Peninsula
Water
Historic pesticide manufacturing discharges contaminated offshore sediment. This nearshore cleanup area is distinct from the separate deep-ocean Disposal Site #2 investigation.
Why attention matters
EPA identifies contaminated seafood consumption as an exposure concern. Sediment and food-web contamination require sustained attention beyond the original industrial release.
Recovery progress
EPA describes fish-consumption outreach, multilingual signs, market inspections and partner engagement to reduce exposure while Superfund work continues.
A question to learn from
What can sediment monitoring and seafood-risk communication teach a future research team about measuring ecological recovery without confusing it with immediate safety?
EPA: Southern California ocean disposal investigation and Palos Verdes Shelf distinction ↗Source reviewed September 27, 2026
New Idria Mercury Mine
Idria, San Benito County
WaterLand
Historic mercury mining left waste piles and acidic drainage. Flooded underground workings generate water that moves through the mine and into downstream creeks.
Why attention matters
Controlling erosion and drainage helps limit movement of mercury and other metals. Mining can leave continuing pollution pathways long after operations end.
Recovery progress
EPA reports completed drainage diversions and settling measures, with investigations continuing to define contamination and inform longer-term cleanup.
A question to learn from
How could erosion control and carefully assessed revegetation support an engineered remedy? Mercury cannot be destroyed by fungi or plants.
EPA: New Idria Mercury Mine cleanup activities ↗Source reviewed September 27, 2026
Iron Mountain Mine
Near Redding
WaterLand
Mining exposed mineral-bearing rock to water and oxygen, producing acidic drainage containing copper, cadmium, zinc and other metals.
Why attention matters
Before cleanup, metal-rich drainage severely damaged nearby aquatic life. Maintaining collection and treatment protects connected streams and the Sacramento River ecosystem.
Recovery progress
EPA lists active drainage collection, reservoir management, pipelines and treatment in 2026, with planning for continued operation after current settlement obligations end.
A question to learn from
What can long-running treatment teach us about maintenance costs, water monitoring and the limits of nature-based additions to complex mine cleanup?
EPA: Iron Mountain Mine cleanup activities ↗Source reviewed September 27, 2026
Leviathan Mine
Near Markleeville, Alpine County
WaterLand
The inactive sulfur mine generates acid mine drainage affecting Leviathan Creek. Historic mining left a continuing water-quality management problem.
Why attention matters
Treatment infrastructure and drainage controls need sustained upkeep. A closed mine can continue affecting downstream environments unless pollution pathways remain controlled.
Recovery progress
California's Water Board maintains pollution-abatement infrastructure and works with EPA and Atlantic Richfield on investigations and development of a final remedy.
A question to learn from
Could carefully evaluated revegetation reduce erosion alongside required treatment? Any ecological approach would need compatibility with the agency-selected mine-water remedy.
California Lahontan Water Board: Leviathan Mine Project ↗Source reviewed September 27, 2026
Montrose Chemical former factory area
Los Angeles, Harbor Gateway area
LandWater
Decades of pesticide manufacturing left contamination on and around the former facility. This entry focuses on the land and groundwater areas, separate from Palos Verdes Shelf.
Why attention matters
Source-area contamination can require prolonged treatment and monitoring. Past soil removals do not by themselves complete groundwater cleanup.
Recovery progress
EPA describes ongoing groundwater treatment, electrical resistance heating, soil-vapor extraction, monitoring and maintenance within the wider Superfund cleanup program.
A question to learn from
Which organic pollutants might warrant controlled biological-treatment research, and which conditions require established chemical, thermal or hydraulic treatment methods?
EPA: Montrose Chemical Corp. cleanup and reuse summary ↗Source reviewed September 27, 2026
Portland Harbor
Portland
WaterLand
Contamination in sediment, surface water and groundwater affects an approximately ten-mile stretch of the Lower Willamette River.
Why attention matters
River cleanup must also address incoming pollution from upstream and adjacent land. Otherwise, new contamination can undermine sediment improvements.
Recovery progress
EPA's September 2025 update reports all areas designated for active in-water remediation in design, alongside Oregon DEQ's continuing work on pollution sources.
A question to learn from
How can future research combine source control, sediment testing and ecological monitoring, while learning from established dredging, capping and recovery plans?
EPA: Portland Harbor site and remedial-design update, September 2025 ↗Source reviewed September 27, 2026
Lower Duwamish Waterway
Seattle
WaterLand
Industrial discharges and urban runoff left contaminated sediment along five miles of the Duwamish, including PCBs, arsenic, carcinogenic PAHs, dioxins and furans.
Why attention matters
EPA identifies significant human-health and ecological risks from sediment contamination. Recovery requires coordinated control of sediment and incoming pollution.
Recovery progress
EPA announced a proposed $668 million settlement in March 2026 for dredging, capping and other cleanup measures, with work expected to take at least ten years.
A question to learn from
What can coordinated river cleanup teach us about monitoring, community participation and selecting techniques for different pollutants instead of assuming one biological solution?
EPA: Proposed Lower Duwamish Waterway cleanup settlement, March 2026 ↗Source reviewed September 27, 2026
Hanford Site
Near Richland, Benton County
WaterLand
Chemical and radiological groundwater contamination at this nuclear-production legacy site requires extensive engineered treatment and monitoring.
Why attention matters
The scale and persistence of contaminated groundwater show why cleanup needs long-term stewardship, specialist expertise and clear measurements of progress.
Recovery progress
DOE operates multiple groundwater pump-and-treat systems. Its July 2026 overview describes ongoing treatment and public access to monitoring data and annual reports.
A question to learn from
What can transparent long-term monitoring teach us? Hanford is a specialist nuclear-remediation case, not a proposed fungal treatment project; organisms cannot eliminate radioactivity.
U.S. Department of Energy: Hanford groundwater treatment ↗Source reviewed September 27, 2026
Coeur d'Alene Basin
Coeur d'Alene River Basin, including Cataldo
WaterLand
Historic mining and dredging spread lead and other metals through river sediments and floodplain areas, including Mission Flats near Cataldo.
Why attention matters
Removing contaminated soil creates another responsibility: safely containing it. Long-term protection includes engineered storage, clean covers and monitoring.
Recovery progress
EPA selected the Dredge Road property for a new lower-basin waste consolidation area in 2025, with design planned for 2026–2027 before construction.
A question to learn from
How can ecological restoration complement secure waste management without redistributing metals into water or wildlife? Community and Tribal priorities would need to guide any future involvement.
EPA: New waste consolidation location for lower Coeur d'Alene Basin cleanup ↗Source reviewed September 27, 2026
Silver Bow Creek / Butte Area
Butte and surrounding watershed
WaterLand
Historic mining left tailings along Silver Bow Creek, contaminated soils and polluted water in flooded mine workings, including the Berkeley Pit.
Why attention matters
Cleanup involves different pathways across a large watershed. Restored stream sections still need monitoring, while other mine and soil areas require continuing work.
Recovery progress
EPA and Montana DEQ oversee separate cleanup areas, with stream restoration, soil investigations, water management and ongoing environmental monitoring.
A question to learn from
How can long-term measurements show whether restored vegetation and stream habitat remain healthy after mine-waste controls are installed?
EPA: Silver Bow Creek / Butte Area current site status ↗Source reviewed September 27, 2026
Anaconda Smelter
Anaconda and southern Deer Lodge Valley
LandWater
Historic ore processing and smelting left arsenic, lead and other metals in soil, groundwater and surface water across a large area.
Why attention matters
Protecting reclaimed land requires maintaining caps, vegetation and drainage controls. The remaining work should be understood alongside substantial cleanup already completed.
Recovery progress
EPA reports completed cleanup in several areas and continuing work elsewhere. Reclamation includes capped and revegetated land, wetlands, stream restoration and property cleanup.
A question to learn from
What can established revegetation and wetland restoration teach us about rebuilding habitat after contamination is contained? Metals remain materials to manage, not substances plants destroy.
EPA: Anaconda Co. Smelter cleanup activities ↗Source reviewed September 27, 2026
Libby Asbestos site
Libby, Troy and former mine area
LandAir
Historic vermiculite mining spread amphibole asbestos. Residual contamination is especially relevant around the former mine and surrounding forested land.
Why attention matters
Disturbance of contaminated material requires specialized precautions. The 2025 response plan also addresses asbestos in ash during wildfires near the mine.
Recovery progress
Extensive cleanup has reduced exposure potential in Libby and Troy. Agencies maintain coordination, monitoring and public-information plans for residual hazards.
A question to learn from
How can clear public information help people follow specialist guidance? This is a lesson in exposure prevention, not a proposed mushroom or plant treatment for asbestos.
Lincoln County and partner agencies: Libby Asbestos Response Plan, 2025 ↗Source reviewed September 27, 2026
Carson River Mercury site
Dayton and Carson River corridor
WaterLand
Mercury used in historic gold and silver processing contaminated former mill sites, floodplain soil and river sediment across multiple counties.
Why attention matters
Mercury can move through waterways and accumulate in fish and wildlife. Site-specific consumption advice and soil controls remain important exposure protections.
Recovery progress
EPA and Nevada manage sampling, soil removal or capping, and long-term response planning. EPA also investigates mercury movement and impacts in the river system.
A question to learn from
Could erosion-control research help reduce contaminated sediment movement without increasing mercury availability? No fungal or plant method can destroy mercury itself.
EPA: Carson River Mercury site cleanup activities ↗Source reviewed September 27, 2026
California Gulch / Leadville
Leadville and upper Arkansas River area
WaterLand
Historic mining contaminated soils, sediment and water with metals. The cleanup area includes Leadville, former mining lands and an Arkansas River reach.
Why attention matters
EPA reports cleanup complete across more than 90 percent of the site. Continued maintenance and treatment protect those gains while remaining work advances.
Recovery progress
Two treatment plants address metal-contaminated water. Completed remedies are maintained and monitored; the remaining Stray Horse area cleanup is still being implemented.
A question to learn from
What can successful cleanup and revegetation teach us about measuring sustained recovery, controlling runoff and supporting safe land use after mining?
EPA: California Gulch cleanup activities ↗Source reviewed September 27, 2026
Summitville Mine
Rio Grande County
WaterLand
Former gold-mining operations contaminated soil and water with metals. Acidic mine water affected Wightman Fork and the Alamosa River.
Why attention matters
Completed construction does not end the need for treatment. Capturing mine water and maintaining reclaimed land help prevent renewed downstream damage.
Recovery progress
Mine wastes were capped and revegetated, and historic heap-leach cyanide was treated. Captured mine water still passes through a treatment plant, with ongoing monitoring.
A question to learn from
How can revegetation and lower-impact operations complement long-term water treatment? This site illustrates maintenance needs as well as ecological recovery.
EPA: Summitville Mine cleanup activities ↗Source reviewed September 27, 2026
Tar Creek
Ottawa County
Land
Historic lead and zinc mining left large amounts of waste, including chat that was also used as fill. Lead contamination affects some residential soils.
Why attention matters
Young children are especially sensitive to lead. Preventing contact with contaminated soil is an immediate practical priority alongside the wider site's cleanup.
Recovery progress
Oklahoma DEQ's April 2026 fact sheet offers voluntary residential sampling and free cleanup where contamination is found, continuing earlier EPA work.
A question to learn from
How can community outreach connect people to existing cleanup services? Future vegetation research would have to support, never substitute for, required lead-soil remediation.
Oklahoma DEQ: Tar Creek residential yard cleanup, April 2026 ↗Source reviewed September 27, 2026
50Arizona / New Mexico / Utah
Navajo Nation abandoned uranium mines
Navajo Nation and nearby mine areas (regional scope)
LandWaterAir
Hundreds of abandoned uranium mines form a regional legacy of chemical and radiological contamination, including affected structures and some water sources.
Why attention matters
Mine waste, radioactive particles and contaminated water can create exposure pathways. Conditions differ by location; this entry does not characterize all Navajo Nation land or water.
Recovery progress
EPA and Navajo Nation partners conduct mine assessments, priority cleanups and community engagement. Settlement-funded work covers only part of the regional mine inventory.
A question to learn from
How can research respect Tribal leadership and support transparent information? Uranium cleanup requires specialist controls; fungi cannot remove radioactivity or replace approved remedies.
EPA: Navajo Nation abandoned uranium mines cleanup ↗Source reviewed September 27, 2026