More than 20 million Americans live within one mile of toxic waste sites that have been linked to infant deaths, cancer and long-term health conditions.
Areas called Superfund sites are so contaminated they require years of government cleanup. Recently released federal records show there are more than 1,340 across the US.
These sites contain hazardous chemicals that had been dumped into soil and groundwater, often decades ago, and continue to threaten drinking water along with general public health.
The Superfund Act was first established on December 11, 1980, under President Jimmy Carter, and new locations are still being discovered as scientists reassess older industrial areas and improve monitoring technology.
The nation's list of highest-priority cleanup areas includes sites across New Jersey, California, Pennsylvania and more. In March 2026, federal regulators added another major contamination site in Michigan to the list.
The Gelman Sciences groundwater plume in Ann Arbor spans roughly three miles long and one mile wide, spreading beneath neighborhoods and drinking water sources. In this case, the contaminant is industrial solvent 1,4-Dioxane, which has been linked to cancer as well as liver and kidney damage.
But experts warned that the real concern is not just how many toxic sites exist, but how many communities may not even realize they are living near one.
'Awareness among the general public is uneven,' Dr Farshid Vahedifard, a professor of civil and environmental engineering at Tufts University, told the Daily Mail. 'In some cases, especially for well-known or long-standing Superfund sites, local communities are often quite informed due to media coverage, public meetings and regulatory outreach. However, for less prominent sites, awareness can be limited.'
The US Environmental Protection Agency (EPA) currently maintains the Superfund National Priorities List (NPL), which identifies the nation's most dangerous hazardous waste locations and determines which ones require long-term federal cleanup efforts.
'The Superfund program cleans up the nation's most contaminated land to protect public health and the environment from harmful contamination and legacy industrial waste,' Jacob Murphy, senior advisor for external affairs at the EPA, told the Daily Mail.
'These cleanups provide health and economic benefits to communities and are credited with significant reductions in birth defects and blood-lead levels among children living near sites [along with] increasing residential property values up to 24 percent within three miles of sites after cleanup.'
As for health impacts, according to Vahedifard, that depends heavily on the type of contaminants, exposure pathways (such as groundwater, soil or air) and duration of exposure.
Potential health effects can range from respiratory issues and skin irritation to more serious long-term outcomes such as cancer or developmental effects.
So far this year, recent federal data shows dozens more sites have been proposed or under review as environmental investigations continue.
'It is likely that the Superfund list will continue to grow,' Vahedifard said. 'The current [Superfund Enterprise Management System] database indicates that the last update was in April 2026. The list will likely continue to evolve over time.'
'While many of the most prominent and historically contaminated sites have already been identified, new sites are still being discovered as monitoring technologies improve, legacy contamination is reassessed and regulatory thresholds change.'
Vahedifard added that the program has reached a point 'where the remaining sites tend to be more complex, sometimes smaller in scale, or previously under-recognized,' as opposed to simply being unknown altogether.
Recently, the Gelman Sciences Inc site in Ann Arbor, Michigan, was added to the Superfund National Priorities List
In that sense, additions like the Gelman Sciences Inc site are not entirely surprising.
Many of these sites date back to the industrial boom of the mid-20th century, when chemical waste was often dumped into unlined ponds, landfills or directly into waterways.
New Jersey has historically had one of the highest numbers of Superfund sites, reflecting decades of heavy industry and chemical manufacturing along major rivers and coastal areas.
The environmental crisis became impossible to ignore in 1979, when waters in what became known as the Tar Creek Superfund site in Oklahoma suddenly turned bright orange as acidic water poured out of abandoned mines.
The Superfund program came in its wake - along with other major environmental disasters, such as Love Canal in New York, where toxic waste from the Hooker Chemical and Plastics Corporation was buried beneath homes, causing widespread illness and birth defects.
In Centralia, Pennsylvania - a coal-mining town founded in 1866 that once thrived with thousands of residents - a landfill fire caused similar environmental catastrophe. The fire was intentionally ignited on May 27, 1962, to clear a local dump. It released toxic gases and destabilized the ground, ultimately forcing nearly all residents to evacuate, leaving behind one of America's most famous ghost towns.
There are hundreds of stories like these, all of which mark the reasons why sites end up on the National Priorities List.
Once a site is added to the NPL, it becomes eligible for federal funding and long-term environmental monitoring, while regulators also attempt to force the responsible companies to cover cleanup costs.
The Gelman Sciences site in particular represents one of the most extensive groundwater contamination cases in the country.
The contamination began between the 1960s and 1980s when the company manufactured medical filters and disposed of wastewater containing 1,4-Dioxane into onsite ponds and soils.
Over time, the chemical seeped into underground aquifers that supply drinking water to Ann Arbor and nearby Scio Township.
Contamination was first detected in residential wells in the mid-'80s, triggering decades of investigation and remediation efforts.
Eventually, the plume spread beneath western Ann Arbor, forcing the city to shut down at least one municipal drinking water well after traces of the chemical were detected.
Dioxane is considered likely to be carcinogenic to humans, and exposure has been linked to liver and kidney damage, raising concerns for residents living above the expanding plume.
EPA Regional Administrator Anne Vogel said in a statement that the designation gives federal officials expanded authority to force faster action.
In 1979, the to-be Tar Creek Superfund site turned bright orange as acidic water poured out of abandoned mines
'With this Superfund designation, EPA will use its statutory authorities to hold the company responsible for near- and long-term actions to more expeditiously address possible risks to human health and the environment,' Vogel said.
One of the biggest challenges facing regulators is deciding which contaminated areas qualify for federal intervention.
Sites must meet a minimum score under the Hazard Ranking System (HRS), a federal method used to evaluate potential risks to human health and the environment.
Only locations scoring 28.5 or higher out of 100 are eligible for inclusion on the National Priorities List, meaning some sites may never receive full federal cleanup funding.
'The cutoff is ultimately an arbitrary threshold,' Vahedifard said.
'Potentially concerning sites may not always receive NPL designation, even if contamination is present.'
Also worrisome is that public awareness remains uneven across the country.
While residents near high-profile Superfund locations often receive extensive media coverage and regulatory outreach, people living near lesser-known sites may not realize the risks.
Environmental disclosures are commonly included during home sales, but experts warn many buyers may not fully understand what those notices mean.
Some states have taken additional steps to address this issue, like in Maryland, where residential sellers of property located within one mile of an NPL site are required to disclose that information directly to buyers.
But this is not a nationwide mandate.
Federal tools such as the EPA's Cleanups in My Community database allow residents to search nearby contamination sites, but studies suggest public awareness of these resources remains limited.
Despite the dangers, federal cleanup efforts have produced measurable benefits.
But experts warn that the long timelines involved in cleanup - often stretching decades - mean communities may live with contamination risks for years before full remediation is complete.
And as new sites continue to be identified, the number of Americans living near hazardous waste locations may remain a persistent public health concern for decades to come.