Contenido

CERCLA fue promulgada por el Congreso en 1980 en respuesta a la amenaza de sitios de desechos peligrosos, tipificada por el desastre del Canal Love en Nueva York y Valley of the Drums en Kentucky.[12]​ Se reconoció que la financiación sería difícil, ya que no era fácil encontrar a las partes responsables, por lo que se estableció el Superfund para proporcionar financiación a través de un mecanismo impositivo a ciertas industrias y crear un marco integral de responsabilidad para poder responsabilizar a una gama más amplia de partes.[3]​ El fondo fiduciario inicial del Superfund para limpiar sitios donde no se pudo identificar a un contaminador, no pudo o no quiso pagar (quiebra o negativa), consistió en alrededor de $1.6 mil millones[13]​ y luego aumentó a 8 8.5 mil millones.[3]​ Inicialmente, el marco para implementar el programa provino del Plan Nacional de Contingencia de petróleo y sustancias peligrosas.

La EPA publicó el primer Sistema de Clasificación de Peligros en 1981 y la primera Lista de Prioridades Nacionales en 1983.[14]​ La implementación del programa en los primeros años, durante la administración Ronald Reagan, fue ineficaz, con solo 16 de los 799 sitios del Superfund limpiados y solo se recaudaron $40 millones de $700 millones en fondos recuperables de las partes responsables.[15]​ La mala gestión del programa bajo Anne Gorsuch Burford, la primera administradora elegida por Reagan de la agencia, llevó a una investigación del Congreso y a la reautorización del programa en 1986 a través de una ley que enmendaba CERCLA.[16]​.

1986 amendments

The Superfund Amendments and Reauthorization Act of 1986 (SARA) added minimum cleanup requirements in Section 121 and required most cleanup agreements with polluters to be filed in federal court as a consent decree subject to public comment (Section 122).[17] This was to address the "sweetheart deals" between industry and the Reagan-era EPA that Congress had uncovered.[18]​[19]​.

Environmental Justice Initiative

In 1994, President Bill Clinton issued Executive Order 12898, which called on federal agencies to make the achievement of environmental justice a requirement by addressing low-income populations and minority populations that have experienced disproportionate adverse health and environmental effects as a result of their programs, policies, and activities.[20] EPA regional offices had to apply the required guidelines for their Superfund managers to take into account the analysis of data, managed public participation, and economic opportunity when considering the geography of toxic waste site remediation.[21] Some environmentalists and industry lobbyists saw the Clinton administration's environmental justice policy as an improvement, but the order did not receive bipartisan support. The newly elected Republican Congress made numerous unsuccessful efforts to significantly weaken the program. The Clinton administration then adopted some industry-favored reforms as policy and blocked most major changes.[22]​.

Reduction of the selective consumption tax

Until the mid-1990s, most funding came from a special tax on the oil and chemical industries, reflecting the polluter pays principle.[23] Although by 1995 the Superfund balance had declined to around $4 billion, Congress decided not to reauthorize collection of the tax, and by 2003 the fund was empty.[24] Since 2001, most of the funding for the Cleanup of hazardous waste sites comes from taxpayers. State governments pay 10% of cleanup costs generally, and at least 50% of cleanup costs if the state operated the facility responsible for the contamination. By 2013, federal funding for the program had declined from US$2 billion in 1999 to less than US$1.1 billion (in constant dollars).[23]​.

In 2001, the EPA used Superfund funds to institute the anthrax cleanup on Capitol Hill after the 2001 anthrax attacks. It was the first time the agency dealt with a biological release rather than a chemical or oil spill.

From 2000 to 2015, Congress allocated about $1.26 billion in general revenue to the Superfund program each year. Consequently, less than half the number of sites were cleaned up from 2001 to 2008, compared to before. The decline continued during the Obama administration, and since then, under the direction of EPA Administrator Gina McCarthy, Superfund cleanups fell further from 20 in 2009 to just 8 in 2014.[13]​.

Reauthorization of the selective consumption tax

In November 2021, Congress reauthorized an excise tax on chemical manufacturers under the Infrastructure Investment and Jobs Act.[26]​ The new chemical excise tax takes effect on July 1, 2022 and doubles the rate of the previous Superfund tax. The 2021 law also authorized approximately $3.5 billion in emergency appropriations from the U.S. government's general fund for hazardous site cleanup in the immediate future.[27]​.

CERCLA authorizes two types of response actions:

1. • Elimination actions. These are typically short-term response actions, where steps can be taken to address releases or threatened releases that require an immediate response. Removal actions are classified as: (1) emergency; (2) critical time; and (3) non-critical time. Removal responses are typically used to address localized risks, such as abandoned drums containing hazardous substances and contaminated surface soils that pose serious risks to human health or the environment.[28]​.

Cleanup of the Housatonic River in Pittsfield, Massachusetts.

Corrective actions. These are usually long-term response actions. Corrective actions seek to permanently and significantly reduce the risks associated with releases or threatened releases of hazardous substances, and are generally larger and more costly actions. They may include measures such as the use of containment to prevent contaminants from migrating and combinations of removal, treatment or neutralization of toxic substances. These actions can be carried out with federal funds only at sites listed on EPA's National Priorities List (NPL) in the United States and the territories. Remedial actions by responsible parties under consent decrees or unilateral administrative orders with EPA oversight may be undertaken at both NPL and non-NPL sites, commonly referred to as Superfund Alternative Sites in EPA's published guidance and policy documents.[29]​.

A potentially responsible party (PRP) is a potential polluter who may eventually be held liable under CERCLA for the contamination or misuse of a particular property or resource. Four types of PRP may be responsible for contamination at a Superfund site:.

1. • the current owner or operator of the site;[30]​.

2. • the owner or operator of a site at the time the removal of a hazardous substance, pollutant or contaminant occurred;[31]​.

3. • a person who organized the removal of a hazardous substance, pollutant or contaminant at a site;[32]​ and.

4. • a person who transported a hazardous substance, pollutant, or pollutant to a site, who has also selected that site for the disposal of the hazardous substance, pollutant, or pollutant.[33]​.

The CERCLA liability scheme changed commercial and industrial real estate, holding sellers responsible for contamination from past activities, meaning they cannot pass the buck to unknown buyers without liability. Buyers should also be aware of future liabilities, including latent and ongoing contamination in the purchased property, as well as contamination of adjacent properties.[3]​.

CERCLA also required the revision of the National Petroleum and Hazardous Substances Pollution Contingency Plan 9605(a) (NCP).[34]​ The NCP guides how to respond to releases and threats of releases of hazardous substances, pollutants, or pollutants. The NCP established the National Priorities List, which appears as Appendix B of the NCP, and serves as EPA's information and management tool. The NPL is periodically updated through federal regulations.[35]​.

The identification of a site for the NPL is primarily intended to guide EPA in:.

• - Determine which sites warrant further investigation to assess the nature and extent of risks to human health and the environment.

• - Identify what CERCLA-funded corrective actions may be appropriate.

• - Notifying the public about the sites, EPA believes warrants further investigation.

• - Notify PRPs that EPA may initiate corrective action funded by CERCLA.[35]​.

Despite the name, the Superfund trust fund has lacked sufficient funds to clean up even a small number of the sites in the NPL. As a result, EPA generally negotiates consent orders with PRPs to study sites and develop cleanup alternatives, subject to EPA oversight and approval of all such activities. EPA then issues a Proposed Corrective Action Plan for a site where it receives public comments, after which it makes a cleanup decision in a Record of Decision (ROD). RODs are typically implemented under consent decrees by PRPs or under unilateral orders if consent cannot be achieved. If a party fails to comply with such an order, it may be fined up to $37,500 for each day the failure continues. A party that spends money to clean up a site can sue other PRPs in a contribution action under CERCLA.[36]​ CERCLA liability has generally been judicially established as joint and several among the PRPs to the government for the cleanup costs (i.e., each PRP is hypothetically liable for all costs subject to contribution), but CERCLA liability can be allocated among the contributing PRPs based on comparative fault. An "orphan share" is the share of costs at a Superfund site that is attributable to a PRP that is unidentifiable or insolvent.[37] EPA seeks to treat all PRPs equitably and fairly. Budget cuts and restrictions may hinder more equitable treatment of PPRs.[38]​.

Upon notification of a potentially hazardous waste site, EPA conducts a Preliminary Assessment/Site Inspection (PA/SI), which involves record reviews, interviews, visual inspections, and limited field sampling.[39] EPA uses the information from the PA/SI to develop a Hazard Rating System (HRS) score to determine the CERCLA status of the site. Sites that score high enough to be listed generally proceed to a Remedial Investigation/Feasibility Study (RI/FS).[40]​.

The RI includes an extensive sampling and risk assessment program that defines the nature and extent of contamination and site risks. The FS is used to develop and evaluate various remediation alternatives. The preferred alternative is presented in a Proposed Plan for public review and comment, followed by a selected alternative in a ROD. The site then enters a Corrective Design phase and then the Corrective Action phase. Many sites include long-term monitoring. Once Corrective Measures have been completed, reviews are required every five years, as long as hazardous substances are left on site above levels safe for unrestricted use.

• -

Superfund site evaluation process.

The CERCLA Information System (CERCLIS) is a database maintained by EPA and the states that lists sites where releases may have occurred, need to be addressed, or have been addressed. CERCLIS consists of three inventories: the CERCLIS Removal Inventory, the CERCLIS Corrective Inventory, and the CERCLIS Compliance Inventory.[37]​.

• - The Superfund Innovative Technology Assessment (SITE) program supports the development of technologies to evaluate and treat waste at Superfund sites. EPA evaluates the technology and provides an assessment of its potential for future use in Superfund remedial actions. The SITE program consists of four related components: the Demonstration Program, the Emerging Technologies Program, the Monitoring and Measurement Technologies Program, and Technology Transfer activities.[37]​.

• - A reportable quantity (RQ) is the minimum amount of a hazardous substance that, if released, must be reported.[37]​[41]​.

• - A source control action represents the construction or installation and implementation of those actions necessary to prevent the continued release of hazardous substances (primarily from a source above or within the ground, or in buildings or other structures) to the environment.[37]​[42]​.

• - A section 104(e) letter is a government request for information about a site. It may include a general notice to a potentially responsible party that CERCLA-related actions may be taken at a site for which the recipient may be responsible.[43]​ This section also authorizes EPA to enter facilities and obtain information related to PRPs, releases of hazardous substances, and liability, and to order access for CERCLA activities.[44]​ The collection of information in the 104(e) letter resembles written interrogatories in litigation. civilians.[44]​.

• - A section 106 order is a unilateral administrative order issued by EPA to PRPs to take corrective action at a Superfund site when EPA determines that there may be an imminent and substantial danger to the public health or welfare or the environment due to an actual or threatened release of a hazardous substance from a facility, subject to treble damages") and daily fines if the order is not obeyed.[37]​.

• - A corrective response is a long-term action that stops or substantially reduces the release of a hazardous substance that could affect public health or the environment. The term remediation, or cleanup, is sometimes used interchangeably with the terms corrective action, elimination action, response action, remedy, or corrective action.[37]​

• A non-binding assignment of responsibility (NBAR) is a device, established in the Superfund Amendments and Reauthorization Act, that allows EPA to make a non-binding estimate of the proportionate share that each of the various responsible parties at a Superfund site should pay for cleanup costs.[37]​.

• - Relevant and appropriate requirements are those United States federal or state cleanup requirements that, while not “applicable,” address issues similar enough to those found at the CERCLA site that their use is appropriate. Requirements may be relevant and appropriate if they were "applicable", except for jurisdictional restrictions associated with the requirement.[37]​[42]​.

Al 3 de julio de 2025, había 1.343 sitios incluidos en la Lista; se habían eliminado 459 adicionales y se habían propuesto 38 nuevos sitios en la NPL.[2]​.

Históricamente, alrededor del 70 por ciento de las actividades de limpieza del Superfund han sido pagadas por partes potencialmente responsables (PRP). Cuando no se puede encontrar a la parte o no puede pagar la limpieza, la ley del Superfund originalmente pagaba la limpieza del sitio a través de un impuesto especial sobre los fabricantes de petróleo y productos químicos.

El último año fiscal completo (AF) en el que el Departamento del Tesoro recaudó el impuesto especial fue 1995.[24]​ A fines del año fiscal 1996, el saldo del fondo fiduciario invertido era de USD 6.000 millones. Este fondo se agotó a fines del año fiscal 2003. Desde entonces, los sitios del Superfund por los que el PRPS no pudo pagar se han pagado con cargo al fondo general.[24]​ Según la autorización del Congreso de 2021, la recaudación de impuestos especiales de los fabricantes de productos químicos se reanudará en 2022.[27]​.

Hazard Classification System

The Hazard Rating System is a scoring system used to evaluate the potential relative risks to public health and the environment from releases or threats of releases of hazardous waste at uncontrolled waste sites. Under the Superfund program, EPA and state agencies use the HRS to calculate a site score (ranging from 0 to 100) based on the actual or potential release of hazardous substances from a site through air, surface water, or groundwater. A score of 28.5 places the site on the National Priorities List, making it eligible for long-term corrective actions (i.e. cleanup) under the Superfund program.[37]​.

Groundwater pollution

Groundwater is water that exists underground within saturated zones beneath the Earth's surface. Fills pores, fractures and cracks in underground geological materials such as sand, gravel and rock. Groundwater is a vital natural resource, representing available freshwater resources as it serves as the primary source of drinking water.[45] Contaminants once released into the soil generally move downward through the soil profile. The soil acts as a filter for larger particles, but many dissolved chemicals, fine particles, and various man-made substances can pass into the aquifer and descend to the ground.[46]​.

Groundwater contamination at Superfund sites is the result of the release of hazardous substances from various industrial activities and waste disposal practices. The characterization of Superfund sites means that it is a complex mixture of contaminants rather than a single contaminant.[47]​ These substances can be transported from the original source through the soil to underlying aquifers, which could create a persistent environment and cause potential health risks. Superfund sites generally originate from past industrial operations where hazardous substances were manufactured, used or disposed of, with practices that would be considered inadequate or illegal by modern environmental standards.[48] Many of these sites reflect a history of unregulated industrial practices, where waste disposal methods common at the time led to direct and often extensive contamination of soil and groundwater. This historical context means that contamination is widespread, involves mixtures of contaminants, and is deeply embedded in the soil, making cleanup inherently more complex and costly. The varied industrial histories of Superfund sites have resulted in a wide variety of contaminants contaminating groundwater.[49]​ The fact that these contaminants are persistent means that they do not break down in the environment as easily. Such mixtures can cause toxic effects on humans and ecosystems and make remediation considerably more difficult, as technologies effective for one contaminant may be ineffective or even counterproductive for another. Some of the most common contaminants include: Lead (43% of sites), trichlorethylene (42%), chromium (35%), benzene (34%), perchlorethylene (28%), arsenic (28%), and toluene (27%) (ATSDR, 1989).[50]​.

Key industrial activities and sources contributing to groundwater contamination at Superfund sites include:[51]​.

• - Chemical Manufacturing and Production: Facilities involved in the manufacturing of chemicals, pesticides, pharmaceuticals, plastics and other goods have often been sources of pollution through improper disposal of process waste, accidental spills or leaks of solvents, pesticides and various industrial chemicals. These pollutants often include persistent organic pollutants.

• - Mining and Metal Processing: Mining operations and metal processing facilities can release heavy metals such as lead, arsenic and mercury into the environment. Acid mine drainage, a highly acidic, metal-laden discharge from certain types of mines, is a particularly serious form of water pollution. Many legacy mining operations, which ceased activity before the advent of modern environmental regulations, have left extensive soil and water contamination.

• - Petroleum refining and storage: Leaks and spills of crude oil, gasoline, diesel fuel, and other petroleum products can contaminate soil and groundwater with hazardous substances such as benzene. Underground storage tanks (UST) used to store petroleum products at gas stations and industrial facilities are a common source of leaks.

• - Waste Management and Landfills: Landfills, particularly older ones built before strict design and operational regulations were implemented, are major sources of groundwater contamination. Hazardous waste discarded at these landfills can leach as rainwater percolates through the waste, forming a contaminated liquid called leachate. If the landfill lacks adequate liners and leachate collection systems, leachate can migrate into the underlying soil and groundwater.

• - Military and Defense-related Activities: Numerous military bases and defense-related facilities have become Superfund sites due to contamination from activities such as weapons testing and maintenance, aircraft and vehicle maintenance, and waste disposal. Common contaminants include explosives, solvents (such as TCE used for degreasing), fuels, and in some cases, radioactive materials.

• - Agricultural practices: Although less frequently the primary driver of a Superfund designation compared to industrial sites, agricultural activities can contribute to groundwater contamination through the widespread use of pesticides and fertilizers. Runoff from agricultural fields can carry these chemicals into surface waters and also allow them to leach into groundwater.

Contamination of groundwater resources by hazardous substances released from Superfund sites has consequences that affect human health. Humans can be exposed to contaminants present in groundwater through multiple pathways, not just through direct consumption of drinking water.[52]​ This multiplicity of exposure pathways means that simply providing an alternative source of drinking water may not eliminate all health risks if other pathways are not appropriately evaluated and managed. The specific health risks associated with exposure to contaminated groundwater depend on several factors, including the types and concentrations of contaminants present.[53] Toxicity is the most common concern regarding groundwater contaminants. Toxicity is classified as acute or chronic. Acute toxicity results from short-term exposure to relatively high doses of contaminants and chronic toxicity occurs as a result of drinking low concentrations of contaminants over a long period of time. Chronic toxicity is the most common toxicity in groundwater contamination that comes from improper disposal of hazardous chemicals.[50]​.

Common health effects related to contaminants frequently found at Superfund sites include:[54]​.

• - Microorganisms: They can cause gastrointestinal diseases and infections.

• - Nitrates and nitrites: High levels can cause methemoglobinemia ("blue baby syndrome") in babies, a serious condition that affects the blood's ability to carry oxygen.

• - Heavy metals (e.g., lead, arsenic, cadmium, mercury): They can cause a wide range of health problems, including acute and chronic toxicity, liver, kidney and intestinal damage, anemia, neurological damage, developmental problems and several types of cancer.

• - Organic chemicals (e.g., volatile organic compounds, pesticides): Associated with damage to the kidneys, liver, circulatory system, nervous system, and reproductive system. Many are known or suspected carcinogens.

Groundwater contamination from Superfund sites does not remain isolated beneath the ground. As groundwater moves, it can be discharged into surface water bodies such as rivers, lakes, streams, and wetlands.[55]​ Pollution is removed from the original source of pollution at the Superfund site and continues to other areas. Contaminated groundwater can play a factor in many environmental and ecological areas.[56]​.

Effects of the introduction of dangerous substances:[57]​.

• - Direct toxicity to aquatic life: Many contaminants are directly toxic to fish, amphibians and aquatic plants. Exposure can lead to mortality, reduced growth and reproductive success, physiological stress, or chronic health problems.

• - Bioaccumulation and biomagnification: Persistent contaminants, such as heavy metals and certain organic contaminants, can accumulate in your tissues over time. As these organisms are consumed by predators, the concentration of these toxins can increase at successively higher levels of the food chain, potentially reaching levels that are harmful to wildlife and humans who consume these contaminated fish.

• - Habitat Degradation: The influx of pollutants can alter the chemical composition of surface water, such as changing pH and sediment, making habitats unsuitable for many native aquatic species. This can lead to a decrease in species richness and abundance.

• - Loss of biodiversity: The overall biodiversity of the aquatic ecosystem can be reduced. This can upset the ecological balance and affect the ecosystem's ability to perform essential functions, such as nutrient cycling and water purification.

• - Eutrophication and Oxygen Depletion: Over-enrichment of nutrients that feeds the excessive growth of algae and aquatic plants (algal blooms). When these flowers die and decompose, bacteria consume large amounts of dissolved oxygen in the water, leading to dead zones that can suffocate fish and other oxygen-dependent aquatic life.

• - Soil Pollution: The accumulation of heavy metals, persistent organic pollutants or other toxins in soil can reduce soil fertility and damage soil microorganisms essential for nutrient cycling.

• - Vegetation Impacts: Plants can absorb contaminants from soil or water, resulting in reduced growth, visible injury, or death. Contaminants can also accumulate in plant tissues, potentially entering terrestrial food webs.

Las acciones federales para abordar las disparidades desproporcionadas en salud y medio ambiente que enfrentan las poblaciones minoritarias y de bajos ingresos a través de la Orden Ejecutiva 12898 requirieron que las agencias federales hicieran de la justicia ambiental un elemento central de sus programas y políticas.[58]​ Se ha demostrado que los sitios Superfund tienen el mayor impacto en las comunidades minoritarias.[59]​ A pesar de la legislación diseñada específicamente para garantizar la equidad en la inclusión en el Superfund, las poblaciones marginadas aún tienen menos posibilidades de inclusión y limpieza exitosas que las áreas con niveles de ingresos más altos. Después de que se implementó la orden ejecutiva, persistió una discrepancia entre la demografía de las comunidades que viven cerca de los sitios de desechos tóxicos y su inclusión en la lista de sitios Superfund, que de otro modo les otorgaría proyectos de limpieza financiados con fondos federales. Se descubrió que las comunidades con poblaciones minoritarias y de bajos ingresos aumentaron sus posibilidades de incluir sitios en la lista después de la orden ejecutiva, mientras que, por otro lado, los aumentos en los ingresos llevaron a mayores posibilidades de incluir sitios en la lista.[60]​ De las poblaciones que viven dentro de un radio de 1 milla de un sitio Superfund, el 44% de ellas son minorías a pesar de ser solo alrededor del 37% de la población del país.

A enero de 2021, más de 9,000 propiedades subsidiadas por el Gobierno federal, incluidas las que tienen cientos de viviendas, estaban a menos de una milla de un sitio Superfund.[61]​.

Case studies in African American communities

In 1978, residents of the rural black community of Triana, Alabama, were found to be contaminated with DDT and PCBs, some of which had the highest levels of DDT ever recorded in human history. DDT was found at high levels in Indian Creek, which many residents depended on for livelihood fishing. Although this major threat to the health of Triana residents was discovered in 1978, the federal government did not act until 5 years later, after the mayor of Triana filed a class action lawsuit in 1980.

In West Dallas, Texas, a largely African American and Latino community, a lead smelter poisoned the surrounding neighborhood, elementary school, and daycare centers for more than five decades. Dallas city officials were informed in 1972 that children near the smelter were exposed to lead contamination. The city sued the lead smelters in 1974, then reduced its lead regulations in 1976. It wasn't until 1981 that the EPA commissioned a study of lead contamination in this neighborhood and found the same results that had been found a decade earlier. In 1983, surrounding daycare centers had to close due to lead exposure while the lead smelter remained in operation. It was later revealed that EPA Deputy Administrator John Hernandez had deliberately stalled the cleanup of lead-contaminated hot spots. It wasn't until 1993 that the site was declared a Superfund site, and at that time it was one of the largest. However, it was not until 2004 that the EPA completed cleanup efforts and removed contaminating sources of lead from the site.

The Afton community of Warren County, North Carolina, is one of the most prominent cases of environmental injustice and is often pointed to as the roots of the environmental justice movement. The PCBs were illegally dumped in the community and then eventually became a PCB "Dump (Garbage)" landfill. Community leaders pressured the state to clean up the site for an entire decade until it was finally detoxified.[63] However, this decontamination did not return the site to its pre-1982 conditions. There has been a call for reparations to the community that has yet to be met.

Bayview-Hunters Point, San Francisco "San Francisco (California)"), a historically African American community, has faced persistent environmental discrimination due to poor remediation efforts at the San Francisco Naval Shipyard, a federal Superfund site. health than other regions of San Francisco.[65][66]​.

Case studies in Native American communities

An example is the Church Rock uranium mill spill on the Navajo Nation. It was the largest radioactive spill in the US, but received a long delay in government response and cleanup after being placed as a lower priority site. The United States Congress has implemented two sets of five-year cleanup plans, but contamination from the Church Rock incident has not yet been fully cleaned up. Today, uranium contamination from mining during the Cold War era remains throughout the Navajo Nation, posing health risks to the Navajo community.[67][68][69]​.

Superfund Program data is available to the public.

• - Search on the Superfund Site[70]​.

• - Superfund Policy, Reports and Other Documents[71]​.

• - TOXMAP was a Geographic Information System (GIS) of the Specialized Information Services Division[72]​ of the United States National Library of Medicine (NLM) that was deprecated on December 16, 2019. The application used maps of the United States to help users visually explore data from the EPA's Toxic Release Inventory (TRI) and Superfund programs. TOXMAP was a resource funded by the US Federal Government. TOXMAP chemical and environmental health information is taken from the NLM Toxicology Data Network (TOXNET),[73]​ PubMed and other authoritative sources.

While simple and relatively easy sites have been cleaned up, EPA is now addressing a residual number of difficult and massive sites, such as large-area mining and sediment sites, which is tying up a significant amount of funding. Additionally, although the federal government has set aside funds for cleanup of federal facility sites, this cleanup is proceeding much more slowly. The delay is due to a number of reasons, including the EPA's limited ability to enforce performance, the difficulty of dealing with the Department of Energy's radioactive waste, and the large number of federal facilities.[3]​.

• - Environmental restoration.

• - Environmental Assessment.

• - Common Chemicals found at Superfund Sites, August 1994.

• - Superfund Program – EPA.

• - Superfund sites by state – EPA.

• - Superfund: A Half Century of Progress, a report by the EPA Alumni Association.

• - Agency for Toxic Substances and Disease Registry.

• - National Priorities List of Hazardous Substances.

• - 42 U.S.C. chapter 103 (CERCLA) of the United States Code from the LII").

• - 42 U.S.C. chapter 103 (CERCLA) of the United States Code from the US House of Representatives.

• - CERCLA (PDF/details) as amended in the GPO") Statute Compilations collection.

• - Hazardous Substance Superfund account on USAspending.gov").

Contenido

CERCLA fue promulgada por el Congreso en 1980 en respuesta a la amenaza de sitios de desechos peligrosos, tipificada por el desastre del Canal Love en Nueva York y Valley of the Drums en Kentucky.[12]​ Se reconoció que la financiación sería difícil, ya que no era fácil encontrar a las partes responsables, por lo que se estableció el Superfund para proporcionar financiación a través de un mecanismo impositivo a ciertas industrias y crear un marco integral de responsabilidad para poder responsabilizar a una gama más amplia de partes.[3]​ El fondo fiduciario inicial del Superfund para limpiar sitios donde no se pudo identificar a un contaminador, no pudo o no quiso pagar (quiebra o negativa), consistió en alrededor de $1.6 mil millones[13]​ y luego aumentó a 8 8.5 mil millones.[3]​ Inicialmente, el marco para implementar el programa provino del Plan Nacional de Contingencia de petróleo y sustancias peligrosas.

La EPA publicó el primer Sistema de Clasificación de Peligros en 1981 y la primera Lista de Prioridades Nacionales en 1983.[14]​ La implementación del programa en los primeros años, durante la administración Ronald Reagan, fue ineficaz, con solo 16 de los 799 sitios del Superfund limpiados y solo se recaudaron $40 millones de $700 millones en fondos recuperables de las partes responsables.[15]​ La mala gestión del programa bajo Anne Gorsuch Burford, la primera administradora elegida por Reagan de la agencia, llevó a una investigación del Congreso y a la reautorización del programa en 1986 a través de una ley que enmendaba CERCLA.[16]​.

1986 amendments

The Superfund Amendments and Reauthorization Act of 1986 (SARA) added minimum cleanup requirements in Section 121 and required most cleanup agreements with polluters to be filed in federal court as a consent decree subject to public comment (Section 122).[17] This was to address the "sweetheart deals" between industry and the Reagan-era EPA that Congress had uncovered.[18]​[19]​.

Environmental Justice Initiative

In 1994, President Bill Clinton issued Executive Order 12898, which called on federal agencies to make the achievement of environmental justice a requirement by addressing low-income populations and minority populations that have experienced disproportionate adverse health and environmental effects as a result of their programs, policies, and activities.[20] EPA regional offices had to apply the required guidelines for their Superfund managers to take into account the analysis of data, managed public participation, and economic opportunity when considering the geography of toxic waste site remediation.[21] Some environmentalists and industry lobbyists saw the Clinton administration's environmental justice policy as an improvement, but the order did not receive bipartisan support. The newly elected Republican Congress made numerous unsuccessful efforts to significantly weaken the program. The Clinton administration then adopted some industry-favored reforms as policy and blocked most major changes.[22]​.

Reduction of the selective consumption tax

Until the mid-1990s, most funding came from a special tax on the oil and chemical industries, reflecting the polluter pays principle.[23] Although by 1995 the Superfund balance had declined to around $4 billion, Congress decided not to reauthorize collection of the tax, and by 2003 the fund was empty.[24] Since 2001, most of the funding for the Cleanup of hazardous waste sites comes from taxpayers. State governments pay 10% of cleanup costs generally, and at least 50% of cleanup costs if the state operated the facility responsible for the contamination. By 2013, federal funding for the program had declined from US$2 billion in 1999 to less than US$1.1 billion (in constant dollars).[23]​.

In 2001, the EPA used Superfund funds to institute the anthrax cleanup on Capitol Hill after the 2001 anthrax attacks. It was the first time the agency dealt with a biological release rather than a chemical or oil spill.

From 2000 to 2015, Congress allocated about $1.26 billion in general revenue to the Superfund program each year. Consequently, less than half the number of sites were cleaned up from 2001 to 2008, compared to before. The decline continued during the Obama administration, and since then, under the direction of EPA Administrator Gina McCarthy, Superfund cleanups fell further from 20 in 2009 to just 8 in 2014.[13]​.

Reauthorization of the selective consumption tax

In November 2021, Congress reauthorized an excise tax on chemical manufacturers under the Infrastructure Investment and Jobs Act.[26]​ The new chemical excise tax takes effect on July 1, 2022 and doubles the rate of the previous Superfund tax. The 2021 law also authorized approximately $3.5 billion in emergency appropriations from the U.S. government's general fund for hazardous site cleanup in the immediate future.[27]​.

CERCLA authorizes two types of response actions:

1. • Elimination actions. These are typically short-term response actions, where steps can be taken to address releases or threatened releases that require an immediate response. Removal actions are classified as: (1) emergency; (2) critical time; and (3) non-critical time. Removal responses are typically used to address localized risks, such as abandoned drums containing hazardous substances and contaminated surface soils that pose serious risks to human health or the environment.[28]​.

Cleanup of the Housatonic River in Pittsfield, Massachusetts.

Corrective actions. These are usually long-term response actions. Corrective actions seek to permanently and significantly reduce the risks associated with releases or threatened releases of hazardous substances, and are generally larger and more costly actions. They may include measures such as the use of containment to prevent contaminants from migrating and combinations of removal, treatment or neutralization of toxic substances. These actions can be carried out with federal funds only at sites listed on EPA's National Priorities List (NPL) in the United States and the territories. Remedial actions by responsible parties under consent decrees or unilateral administrative orders with EPA oversight may be undertaken at both NPL and non-NPL sites, commonly referred to as Superfund Alternative Sites in EPA's published guidance and policy documents.[29]​.

A potentially responsible party (PRP) is a potential polluter who may eventually be held liable under CERCLA for the contamination or misuse of a particular property or resource. Four types of PRP may be responsible for contamination at a Superfund site:.

1. • the current owner or operator of the site;[30]​.

2. • the owner or operator of a site at the time the removal of a hazardous substance, pollutant or contaminant occurred;[31]​.

3. • a person who organized the removal of a hazardous substance, pollutant or contaminant at a site;[32]​ and.

4. • a person who transported a hazardous substance, pollutant, or pollutant to a site, who has also selected that site for the disposal of the hazardous substance, pollutant, or pollutant.[33]​.

The CERCLA liability scheme changed commercial and industrial real estate, holding sellers responsible for contamination from past activities, meaning they cannot pass the buck to unknown buyers without liability. Buyers should also be aware of future liabilities, including latent and ongoing contamination in the purchased property, as well as contamination of adjacent properties.[3]​.

CERCLA also required the revision of the National Petroleum and Hazardous Substances Pollution Contingency Plan 9605(a) (NCP).[34]​ The NCP guides how to respond to releases and threats of releases of hazardous substances, pollutants, or pollutants. The NCP established the National Priorities List, which appears as Appendix B of the NCP, and serves as EPA's information and management tool. The NPL is periodically updated through federal regulations.[35]​.

The identification of a site for the NPL is primarily intended to guide EPA in:.

• - Determine which sites warrant further investigation to assess the nature and extent of risks to human health and the environment.

• - Identify what CERCLA-funded corrective actions may be appropriate.

• - Notifying the public about the sites, EPA believes warrants further investigation.

• - Notify PRPs that EPA may initiate corrective action funded by CERCLA.[35]​.

Despite the name, the Superfund trust fund has lacked sufficient funds to clean up even a small number of the sites in the NPL. As a result, EPA generally negotiates consent orders with PRPs to study sites and develop cleanup alternatives, subject to EPA oversight and approval of all such activities. EPA then issues a Proposed Corrective Action Plan for a site where it receives public comments, after which it makes a cleanup decision in a Record of Decision (ROD). RODs are typically implemented under consent decrees by PRPs or under unilateral orders if consent cannot be achieved. If a party fails to comply with such an order, it may be fined up to $37,500 for each day the failure continues. A party that spends money to clean up a site can sue other PRPs in a contribution action under CERCLA.[36]​ CERCLA liability has generally been judicially established as joint and several among the PRPs to the government for the cleanup costs (i.e., each PRP is hypothetically liable for all costs subject to contribution), but CERCLA liability can be allocated among the contributing PRPs based on comparative fault. An "orphan share" is the share of costs at a Superfund site that is attributable to a PRP that is unidentifiable or insolvent.[37] EPA seeks to treat all PRPs equitably and fairly. Budget cuts and restrictions may hinder more equitable treatment of PPRs.[38]​.

Upon notification of a potentially hazardous waste site, EPA conducts a Preliminary Assessment/Site Inspection (PA/SI), which involves record reviews, interviews, visual inspections, and limited field sampling.[39] EPA uses the information from the PA/SI to develop a Hazard Rating System (HRS) score to determine the CERCLA status of the site. Sites that score high enough to be listed generally proceed to a Remedial Investigation/Feasibility Study (RI/FS).[40]​.

The RI includes an extensive sampling and risk assessment program that defines the nature and extent of contamination and site risks. The FS is used to develop and evaluate various remediation alternatives. The preferred alternative is presented in a Proposed Plan for public review and comment, followed by a selected alternative in a ROD. The site then enters a Corrective Design phase and then the Corrective Action phase. Many sites include long-term monitoring. Once Corrective Measures have been completed, reviews are required every five years, as long as hazardous substances are left on site above levels safe for unrestricted use.

• -

Superfund site evaluation process.

The CERCLA Information System (CERCLIS) is a database maintained by EPA and the states that lists sites where releases may have occurred, need to be addressed, or have been addressed. CERCLIS consists of three inventories: the CERCLIS Removal Inventory, the CERCLIS Corrective Inventory, and the CERCLIS Compliance Inventory.[37]​.

• - The Superfund Innovative Technology Assessment (SITE) program supports the development of technologies to evaluate and treat waste at Superfund sites. EPA evaluates the technology and provides an assessment of its potential for future use in Superfund remedial actions. The SITE program consists of four related components: the Demonstration Program, the Emerging Technologies Program, the Monitoring and Measurement Technologies Program, and Technology Transfer activities.[37]​.

• - A reportable quantity (RQ) is the minimum amount of a hazardous substance that, if released, must be reported.[37]​[41]​.

• - A source control action represents the construction or installation and implementation of those actions necessary to prevent the continued release of hazardous substances (primarily from a source above or within the ground, or in buildings or other structures) to the environment.[37]​[42]​.

• - A section 104(e) letter is a government request for information about a site. It may include a general notice to a potentially responsible party that CERCLA-related actions may be taken at a site for which the recipient may be responsible.[43]​ This section also authorizes EPA to enter facilities and obtain information related to PRPs, releases of hazardous substances, and liability, and to order access for CERCLA activities.[44]​ The collection of information in the 104(e) letter resembles written interrogatories in litigation. civilians.[44]​.

• - A section 106 order is a unilateral administrative order issued by EPA to PRPs to take corrective action at a Superfund site when EPA determines that there may be an imminent and substantial danger to the public health or welfare or the environment due to an actual or threatened release of a hazardous substance from a facility, subject to treble damages") and daily fines if the order is not obeyed.[37]​.

• - A corrective response is a long-term action that stops or substantially reduces the release of a hazardous substance that could affect public health or the environment. The term remediation, or cleanup, is sometimes used interchangeably with the terms corrective action, elimination action, response action, remedy, or corrective action.[37]​

• A non-binding assignment of responsibility (NBAR) is a device, established in the Superfund Amendments and Reauthorization Act, that allows EPA to make a non-binding estimate of the proportionate share that each of the various responsible parties at a Superfund site should pay for cleanup costs.[37]​.

• - Relevant and appropriate requirements are those United States federal or state cleanup requirements that, while not “applicable,” address issues similar enough to those found at the CERCLA site that their use is appropriate. Requirements may be relevant and appropriate if they were "applicable", except for jurisdictional restrictions associated with the requirement.[37]​[42]​.

Al 3 de julio de 2025, había 1.343 sitios incluidos en la Lista; se habían eliminado 459 adicionales y se habían propuesto 38 nuevos sitios en la NPL.[2]​.

Históricamente, alrededor del 70 por ciento de las actividades de limpieza del Superfund han sido pagadas por partes potencialmente responsables (PRP). Cuando no se puede encontrar a la parte o no puede pagar la limpieza, la ley del Superfund originalmente pagaba la limpieza del sitio a través de un impuesto especial sobre los fabricantes de petróleo y productos químicos.

El último año fiscal completo (AF) en el que el Departamento del Tesoro recaudó el impuesto especial fue 1995.[24]​ A fines del año fiscal 1996, el saldo del fondo fiduciario invertido era de USD 6.000 millones. Este fondo se agotó a fines del año fiscal 2003. Desde entonces, los sitios del Superfund por los que el PRPS no pudo pagar se han pagado con cargo al fondo general.[24]​ Según la autorización del Congreso de 2021, la recaudación de impuestos especiales de los fabricantes de productos químicos se reanudará en 2022.[27]​.

Hazard Classification System

The Hazard Rating System is a scoring system used to evaluate the potential relative risks to public health and the environment from releases or threats of releases of hazardous waste at uncontrolled waste sites. Under the Superfund program, EPA and state agencies use the HRS to calculate a site score (ranging from 0 to 100) based on the actual or potential release of hazardous substances from a site through air, surface water, or groundwater. A score of 28.5 places the site on the National Priorities List, making it eligible for long-term corrective actions (i.e. cleanup) under the Superfund program.[37]​.

Groundwater pollution

Groundwater is water that exists underground within saturated zones beneath the Earth's surface. Fills pores, fractures and cracks in underground geological materials such as sand, gravel and rock. Groundwater is a vital natural resource, representing available freshwater resources as it serves as the primary source of drinking water.[45] Contaminants once released into the soil generally move downward through the soil profile. The soil acts as a filter for larger particles, but many dissolved chemicals, fine particles, and various man-made substances can pass into the aquifer and descend to the ground.[46]​.

Groundwater contamination at Superfund sites is the result of the release of hazardous substances from various industrial activities and waste disposal practices. The characterization of Superfund sites means that it is a complex mixture of contaminants rather than a single contaminant.[47]​ These substances can be transported from the original source through the soil to underlying aquifers, which could create a persistent environment and cause potential health risks. Superfund sites generally originate from past industrial operations where hazardous substances were manufactured, used or disposed of, with practices that would be considered inadequate or illegal by modern environmental standards.[48] Many of these sites reflect a history of unregulated industrial practices, where waste disposal methods common at the time led to direct and often extensive contamination of soil and groundwater. This historical context means that contamination is widespread, involves mixtures of contaminants, and is deeply embedded in the soil, making cleanup inherently more complex and costly. The varied industrial histories of Superfund sites have resulted in a wide variety of contaminants contaminating groundwater.[49]​ The fact that these contaminants are persistent means that they do not break down in the environment as easily. Such mixtures can cause toxic effects on humans and ecosystems and make remediation considerably more difficult, as technologies effective for one contaminant may be ineffective or even counterproductive for another. Some of the most common contaminants include: Lead (43% of sites), trichlorethylene (42%), chromium (35%), benzene (34%), perchlorethylene (28%), arsenic (28%), and toluene (27%) (ATSDR, 1989).[50]​.

Key industrial activities and sources contributing to groundwater contamination at Superfund sites include:[51]​.

• - Chemical Manufacturing and Production: Facilities involved in the manufacturing of chemicals, pesticides, pharmaceuticals, plastics and other goods have often been sources of pollution through improper disposal of process waste, accidental spills or leaks of solvents, pesticides and various industrial chemicals. These pollutants often include persistent organic pollutants.

• - Mining and Metal Processing: Mining operations and metal processing facilities can release heavy metals such as lead, arsenic and mercury into the environment. Acid mine drainage, a highly acidic, metal-laden discharge from certain types of mines, is a particularly serious form of water pollution. Many legacy mining operations, which ceased activity before the advent of modern environmental regulations, have left extensive soil and water contamination.

• - Petroleum refining and storage: Leaks and spills of crude oil, gasoline, diesel fuel, and other petroleum products can contaminate soil and groundwater with hazardous substances such as benzene. Underground storage tanks (UST) used to store petroleum products at gas stations and industrial facilities are a common source of leaks.

• - Waste Management and Landfills: Landfills, particularly older ones built before strict design and operational regulations were implemented, are major sources of groundwater contamination. Hazardous waste discarded at these landfills can leach as rainwater percolates through the waste, forming a contaminated liquid called leachate. If the landfill lacks adequate liners and leachate collection systems, leachate can migrate into the underlying soil and groundwater.

• - Military and Defense-related Activities: Numerous military bases and defense-related facilities have become Superfund sites due to contamination from activities such as weapons testing and maintenance, aircraft and vehicle maintenance, and waste disposal. Common contaminants include explosives, solvents (such as TCE used for degreasing), fuels, and in some cases, radioactive materials.

• - Agricultural practices: Although less frequently the primary driver of a Superfund designation compared to industrial sites, agricultural activities can contribute to groundwater contamination through the widespread use of pesticides and fertilizers. Runoff from agricultural fields can carry these chemicals into surface waters and also allow them to leach into groundwater.

Contamination of groundwater resources by hazardous substances released from Superfund sites has consequences that affect human health. Humans can be exposed to contaminants present in groundwater through multiple pathways, not just through direct consumption of drinking water.[52]​ This multiplicity of exposure pathways means that simply providing an alternative source of drinking water may not eliminate all health risks if other pathways are not appropriately evaluated and managed. The specific health risks associated with exposure to contaminated groundwater depend on several factors, including the types and concentrations of contaminants present.[53] Toxicity is the most common concern regarding groundwater contaminants. Toxicity is classified as acute or chronic. Acute toxicity results from short-term exposure to relatively high doses of contaminants and chronic toxicity occurs as a result of drinking low concentrations of contaminants over a long period of time. Chronic toxicity is the most common toxicity in groundwater contamination that comes from improper disposal of hazardous chemicals.[50]​.

Common health effects related to contaminants frequently found at Superfund sites include:[54]​.

• - Microorganisms: They can cause gastrointestinal diseases and infections.

• - Nitrates and nitrites: High levels can cause methemoglobinemia ("blue baby syndrome") in babies, a serious condition that affects the blood's ability to carry oxygen.

• - Heavy metals (e.g., lead, arsenic, cadmium, mercury): They can cause a wide range of health problems, including acute and chronic toxicity, liver, kidney and intestinal damage, anemia, neurological damage, developmental problems and several types of cancer.

• - Organic chemicals (e.g., volatile organic compounds, pesticides): Associated with damage to the kidneys, liver, circulatory system, nervous system, and reproductive system. Many are known or suspected carcinogens.

Groundwater contamination from Superfund sites does not remain isolated beneath the ground. As groundwater moves, it can be discharged into surface water bodies such as rivers, lakes, streams, and wetlands.[55]​ Pollution is removed from the original source of pollution at the Superfund site and continues to other areas. Contaminated groundwater can play a factor in many environmental and ecological areas.[56]​.

Effects of the introduction of dangerous substances:[57]​.

• - Direct toxicity to aquatic life: Many contaminants are directly toxic to fish, amphibians and aquatic plants. Exposure can lead to mortality, reduced growth and reproductive success, physiological stress, or chronic health problems.

• - Bioaccumulation and biomagnification: Persistent contaminants, such as heavy metals and certain organic contaminants, can accumulate in your tissues over time. As these organisms are consumed by predators, the concentration of these toxins can increase at successively higher levels of the food chain, potentially reaching levels that are harmful to wildlife and humans who consume these contaminated fish.

• - Habitat Degradation: The influx of pollutants can alter the chemical composition of surface water, such as changing pH and sediment, making habitats unsuitable for many native aquatic species. This can lead to a decrease in species richness and abundance.

• - Loss of biodiversity: The overall biodiversity of the aquatic ecosystem can be reduced. This can upset the ecological balance and affect the ecosystem's ability to perform essential functions, such as nutrient cycling and water purification.

• - Eutrophication and Oxygen Depletion: Over-enrichment of nutrients that feeds the excessive growth of algae and aquatic plants (algal blooms). When these flowers die and decompose, bacteria consume large amounts of dissolved oxygen in the water, leading to dead zones that can suffocate fish and other oxygen-dependent aquatic life.

• - Soil Pollution: The accumulation of heavy metals, persistent organic pollutants or other toxins in soil can reduce soil fertility and damage soil microorganisms essential for nutrient cycling.

• - Vegetation Impacts: Plants can absorb contaminants from soil or water, resulting in reduced growth, visible injury, or death. Contaminants can also accumulate in plant tissues, potentially entering terrestrial food webs.

Las acciones federales para abordar las disparidades desproporcionadas en salud y medio ambiente que enfrentan las poblaciones minoritarias y de bajos ingresos a través de la Orden Ejecutiva 12898 requirieron que las agencias federales hicieran de la justicia ambiental un elemento central de sus programas y políticas.[58]​ Se ha demostrado que los sitios Superfund tienen el mayor impacto en las comunidades minoritarias.[59]​ A pesar de la legislación diseñada específicamente para garantizar la equidad en la inclusión en el Superfund, las poblaciones marginadas aún tienen menos posibilidades de inclusión y limpieza exitosas que las áreas con niveles de ingresos más altos. Después de que se implementó la orden ejecutiva, persistió una discrepancia entre la demografía de las comunidades que viven cerca de los sitios de desechos tóxicos y su inclusión en la lista de sitios Superfund, que de otro modo les otorgaría proyectos de limpieza financiados con fondos federales. Se descubrió que las comunidades con poblaciones minoritarias y de bajos ingresos aumentaron sus posibilidades de incluir sitios en la lista después de la orden ejecutiva, mientras que, por otro lado, los aumentos en los ingresos llevaron a mayores posibilidades de incluir sitios en la lista.[60]​ De las poblaciones que viven dentro de un radio de 1 milla de un sitio Superfund, el 44% de ellas son minorías a pesar de ser solo alrededor del 37% de la población del país.

A enero de 2021, más de 9,000 propiedades subsidiadas por el Gobierno federal, incluidas las que tienen cientos de viviendas, estaban a menos de una milla de un sitio Superfund.[61]​.

Case studies in African American communities

In 1978, residents of the rural black community of Triana, Alabama, were found to be contaminated with DDT and PCBs, some of which had the highest levels of DDT ever recorded in human history. DDT was found at high levels in Indian Creek, which many residents depended on for livelihood fishing. Although this major threat to the health of Triana residents was discovered in 1978, the federal government did not act until 5 years later, after the mayor of Triana filed a class action lawsuit in 1980.

In West Dallas, Texas, a largely African American and Latino community, a lead smelter poisoned the surrounding neighborhood, elementary school, and daycare centers for more than five decades. Dallas city officials were informed in 1972 that children near the smelter were exposed to lead contamination. The city sued the lead smelters in 1974, then reduced its lead regulations in 1976. It wasn't until 1981 that the EPA commissioned a study of lead contamination in this neighborhood and found the same results that had been found a decade earlier. In 1983, surrounding daycare centers had to close due to lead exposure while the lead smelter remained in operation. It was later revealed that EPA Deputy Administrator John Hernandez had deliberately stalled the cleanup of lead-contaminated hot spots. It wasn't until 1993 that the site was declared a Superfund site, and at that time it was one of the largest. However, it was not until 2004 that the EPA completed cleanup efforts and removed contaminating sources of lead from the site.

The Afton community of Warren County, North Carolina, is one of the most prominent cases of environmental injustice and is often pointed to as the roots of the environmental justice movement. The PCBs were illegally dumped in the community and then eventually became a PCB "Dump (Garbage)" landfill. Community leaders pressured the state to clean up the site for an entire decade until it was finally detoxified.[63] However, this decontamination did not return the site to its pre-1982 conditions. There has been a call for reparations to the community that has yet to be met.

Bayview-Hunters Point, San Francisco "San Francisco (California)"), a historically African American community, has faced persistent environmental discrimination due to poor remediation efforts at the San Francisco Naval Shipyard, a federal Superfund site. health than other regions of San Francisco.[65][66]​.

Case studies in Native American communities

An example is the Church Rock uranium mill spill on the Navajo Nation. It was the largest radioactive spill in the US, but received a long delay in government response and cleanup after being placed as a lower priority site. The United States Congress has implemented two sets of five-year cleanup plans, but contamination from the Church Rock incident has not yet been fully cleaned up. Today, uranium contamination from mining during the Cold War era remains throughout the Navajo Nation, posing health risks to the Navajo community.[67][68][69]​.

Superfund Program data is available to the public.

• - Search on the Superfund Site[70]​.

• - Superfund Policy, Reports and Other Documents[71]​.

• - TOXMAP was a Geographic Information System (GIS) of the Specialized Information Services Division[72]​ of the United States National Library of Medicine (NLM) that was deprecated on December 16, 2019. The application used maps of the United States to help users visually explore data from the EPA's Toxic Release Inventory (TRI) and Superfund programs. TOXMAP was a resource funded by the US Federal Government. TOXMAP chemical and environmental health information is taken from the NLM Toxicology Data Network (TOXNET),[73]​ PubMed and other authoritative sources.

While simple and relatively easy sites have been cleaned up, EPA is now addressing a residual number of difficult and massive sites, such as large-area mining and sediment sites, which is tying up a significant amount of funding. Additionally, although the federal government has set aside funds for cleanup of federal facility sites, this cleanup is proceeding much more slowly. The delay is due to a number of reasons, including the EPA's limited ability to enforce performance, the difficulty of dealing with the Department of Energy's radioactive waste, and the large number of federal facilities.[3]​.

• - Environmental restoration.

• - Environmental Assessment.

• - Common Chemicals found at Superfund Sites, August 1994.

• - Superfund Program – EPA.

• - Superfund sites by state – EPA.

• - Superfund: A Half Century of Progress, a report by the EPA Alumni Association.

• - Agency for Toxic Substances and Disease Registry.

• - National Priorities List of Hazardous Substances.

• - 42 U.S.C. chapter 103 (CERCLA) of the United States Code from the LII").

• - 42 U.S.C. chapter 103 (CERCLA) of the United States Code from the US House of Representatives.

• - CERCLA (PDF/details) as amended in the GPO") Statute Compilations collection.

• - Hazardous Substance Superfund account on USAspending.gov").