Across the USA, there are thousands of contaminated sites where hazardous materials have been dumped in inadequate locations. The EPA is responsible for cleaning those sites up and making them usable again. When the EPA identifies a site that needs to be cleaned up, it’s referred to as a Superfund site.

What does Superfund mean?

Superfund sites are sites the EPA is cleaning up under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), which empowers the agency to investigate, identify and clean up polluted sites. Superfund refers to the trust fund the EPA used until 2003 to pay for site cleanup.

The EPA and state agencies use a Hazard Ranking Score (HRS) to calculate the actual or likely release of hazardous materials from a site. An HRS of 28.5 or higher qualifies a site for cleanup.

There are two purposes of Superfund sites: the first is to reduce health risks, usually by cleanups, engineered controls like caps and site restrictions like groundwater use restrictions. The second is to return the site to use as a place of business or recreation, or as a natural ecosystem.

CERCLA Responses

When a site is identified as a Superfund site, CERCLA allows two types of response:

1. Removal actions

Removal actions are usually short-term responses to a situation where the known or likely release of hazardous materials requires prompt action. They are classified as:

  • Emergency
  • Time-critical
  • Non-time critical

They’re usually used to deal with acute, localized risks like abandoned drums of hazardous waste or contaminated surface soils posing acute risks to humans and the environment.

The factors EPA and state and tribal agencies must consider when determining removal action are laid out in Title 40 of the CFR, § 300.415:

(i) Actual or potential exposure to nearby human populations, animals, or the food chain from hazardous substances or pollutants or contaminants;

(ii) Actual or potential contamination of drinking water supplies or sensitive ecosystems;

(iii) Hazardous substances or pollutants or contaminants in drums, barrels, tanks, or other bulk storage containers, that may pose a threat of release;

(iv) High levels of hazardous substances or pollutants or contaminants in soils largely at or near the surface, that may migrate;

(v) Weather conditions that may cause hazardous substances or pollutants or contaminants to migrate or be released;

(vi) Threat of fire or explosion;

(vii) The availability of other appropriate federal or state response mechanisms to respond to the release; and

(viii) Other situations or factors that may pose threats to public health or welfare of the United States or the environment.

2. Remedial actions

Remedial actions are usually longer-term responses, larger and more complex and expensive than removal actions. They seek to rehabilitate a site rather than just to remove acutely hazardous materials. They include containment to prevent hazardous material migration and leaching, and combinations of treatment, containment and removal of hazardous materials. Under CFR Title 40, §300.430, the EPA must consider ‘general principles of program management during the remedial process,’ including ‘site-specific data needs, the evaluation of alternatives’ and ‘use a combination of methods, as appropriate, to achieve protection of human health and the environment.’

The Hazard Ranking System

The EPA uses a structured approach to hazard ranking, assigning numerical scores in three categories:

  1. The likelihood that a site has or could release hazardous substances into the environment
  2. Waste characteristics, like quantity and toxicity
  3. People and environments affected by the release

Four key pathways are scored for HRS:

  1. Groundwater migration into drinking water
  2. Surface water migration into drinking water, human food chains, or sensitive environments
  3. Soil exposure and subsurface intrusion, with regard to local or affected populations and environments
  4. Air migration as dust, fumes, or other airborne contaminants, with regard to affected populations and environments

After all these have been scored, the EPA uses a root-mean-square equation, in which the separate scores are all squared, the mean is identified, and its square root used, to assign an HRS.

Higher HRS doesn’t mean the EPA will treat a site as a higher priority; priority is assigned by feasibility studies, evidence regarding urgency, and on the basis of available resources.

What is a Superfund NPL site?

Superfund Site Aerial View

The Superfund NPL is the National Priority List, a list that mainly exists to guide the EPA in identifying sites to investigate. It’s a list of the sites that are known or suspected to be releasing hazardous substances, pollutants or toxins, and which the EPA regards as national priorities. You can view the NPL here.

Who pays for a Superfund site?

Under CERCLA, entities that caused or are likely to have caused the pollution being cleaned up are obliged to pay for cleanup wherever possible. These are designated Potentially Responsible Parties (PRPs), and about 70% of Superfund cleanup activity is paid for directly by PRPs.

The rest comes from a fund which, despite the name, is depleted. The Superfund is a trust fund which was set up to handle cleanup in cases where the responsible party could not or would not pay — through bankruptcy or refusal — or could not be identified. It was set up in 1980, initially with $1.6 billion, rising to $8.5 billion at its peak.

It was paid into by a federal tax on industrial purchases of petroleum and chemical products, which was intended to both disincentivize industrial use of these chemicals and fund their cleanup, until 1995, when Congress chose not to renew the tax. By 2003, the Superfund trust fund was completely depleted and new funding for Superfund cleanups now comes from Congress.

Funding is a major issue for the EPA, and one reason why the number of site cleanups funded by the Superfund has fallen drastically. States are also required to contribute 10% of the cleanup cost of a Superfund site inside their borders.

What is an example of a Superfund site?

A relatively simple Superfund site is Robins Air Force Base, near Macon in Georgia. A large base with barracks for 1,400 servicemembers, Robins operated its own landfill — including an unlined landfill that was used to dispose of oils and solvents used in aircraft maintenance and operation. These leached into local groundwater, and are known to cause neurological problems and cancers.

Use of the unlined landfill was discontinued in 1978 and cleanup on the pit started in 1991 and was finished in 1998. Groundwater cleanup around the site was completed in 1999.

More complicated is the Brunswick Wood Preserving site in Glynn, Georgia: here, contaminated soil had to be capped with layers of gravel, clay and soil, and contained with subsurface barriers to prevent rainfall from leaching contaminants into the environment. Although this was successful, nearby groundwater remains contaminated.

The Independence Grove Forest Preserve site, formerly Petersen Sand and Gravel, is located in the Des Plaines River Valley in Illinois. It was used as an illegal dumping ground in the late 1960s and early 1970s, including debris from paint and oil storage. Drums containing lead and cadmium paint were buried and rusted through. When cleanup efforts by local agencies began in 1980, there was a contaminated site with no topsoil and 45-foot-deep pits with vertical walls.

The Illinois EPA and other agencies scanned the site and began the cleanup process — digging up and removing barrels of toxic waste, monitoring groundwater, containing contaminated areas. In 1986 the US EPA stepped in to take over from the IEPA, and cleanup continued. By 1988 the site was closed out, with some contaminants still detectable but none at dangerous levels, and the site is now a forest preserve, with the mining pits reconfigured into habitat for fish and wildlife.

Superfund sites can be safe

Are Superfund sites safe?

Superfund sites can be safe. Some are still in the process of cleanup, while others are on the NPL but have not yet been addressed. Superfund sites are worked on by the EPA until monitoring establishes that hazardous materials at the site no longer pose a threat to human health and the environment. At that point a No Further Action plan is proposed to stakeholders including local communities; if it is approved the EPA issues a Site Close Out Report, and deletes the site from the NPL; a record of deleted sites is also kept.

How close is too close to a Superfund site?

Each Superfund site is different. As we have seen, a highly-dangerous waste site became a forest preserve in Illinois. In the Navajo Nation, the Church Rock uranium spill was the largest radioactive spill in the USA. Despite more than 10 years of cleanup efforts, it remains seriously contaminated and dangerous to the health of local residents. Even now the tailings site for the uranium mine is on the NPL because ‘groundwater migration [of toxic and radioactive waste] is not under control.’ To decide whether a site is safe, or how close to get to it, you should see the EPA’s information on that specific site.

Top 10 Superfund sites

The EPA maintains an ‘Administrator's Emphasis List’ of the Superfund sites around the USA that require immediate and intense attention. It’s intended to be dynamic and reflect the situation at the different sites and any new sites that come to the EPA’s attention, meaning sites move on and off it faster than the NPL.

This list is complete and correct at the time of writing (March 2021), but the live list and accompanying details can be viewed here.

The top ten most serious Superfund sites in the USA are:

1. Sauer Dump, Dundalk, Maryland

An unpermitted dump and landfill backing onto the Back River, with contaminated soil and sediment. The EPA is currently carrying out feasibility studies. On the NPL since 2012.

2. LA Clarke and Son, Spotsylvania, Virginia

44 acres near Fredericksburg in Virginia, formerly the site of a railroad and telephone timber processing plant using creosote and tar at high temperatures and pressures. Polycyclic aromatic hydrocarbons and benzene contaminate the soil and sediments at the site. The EPA is performing remedial actions and monitoring. On the NPL since 1986.

3. DePue/New Jersey Zinc/Mobile Chemical Corp., Depue, Illinois

A zinc smelting facility and phosphate fertilizer plant in DePue village, 950 acres of toxic and heavy metal contamination. The Illinois EPA called in the federal agency to accelerate PRP-funded cleanup. Currently in its final stages.

4. Riverfront, New Haven, Missouri

Industrial pollution including perchloroethene in deep city wells near New Haven, with concentrations steadily rising since they were first detected. On the NPL since 2000.

5. Armour Road, North Kansas City, Missouri

A former herbicide mixing facility, and its contaminant plume in the alluvial Missouri River aquifer. Contaminated buildings and soil have been demolished and removed from the site, and it is currently under remedial investigation. On the NPL since 1999.

6. Bonita Peak Mining District, San Juan County, Colorado

A network of 48 historic mines and associated facilities, releasing heavy metals-contaminated water into surrounding creeks. Concrete bulkheads have been installed and a site management plan is under final development. The EPA agreed to postpone its addition to the NPL.

7. Anaconda & Co. Smelter, Anaconda, Montana

An old copper processing plant from the turn of the 20th century, with soil, groundwater and surface water contaminated with toxic and heavy metals. Properties onsite have been cleaned up and water protected, and over three million cubic yards of waste removed. On the NPL since 1983.

8. Abandoned Uranium Mines contamination on Navajo Nation

Part of a multiagency cleanup program involving the Navajo Nation and five federal agencies, the EPA is handling cleanup of mine sites.

9. Portland Harbor, Portland, Oregon

Industrial contamination from industrial use of the Willamette River, including Poly-Chlorinated Biphenols (PCPs), dioxin, pesticides and heavy metals. On the NPL since 2000.

10. Proposed NPL Sites

The EPA leaves the final spot open for sites on the NPL proposed list that turn out to be deserving of special attention or urgency.

Where is Superfund waste disposed of?

Superfund waste is disposed of in approved facilities for the waste type. When the EPA carries out removal actions, it transports the waste securely to appropriate landfills, incineration or other disposal.

Not all wastes from Superfund sites are designated hazardous, of course; Superfund wastes are regulated under the Resource Conservation and Recovery Act (RCRA), and only those wastes deemed hazardous under the RCRA’s Subtitle C need to be disposed of in hazardous waste landfills. Much Superfund waste is disposed of in municipal landfills — and much of it is disposed of by PRPs or their contractors rather than directly by the EPA. To find the nearest waste experts in your area, you can use our site locator.

Finding information on specific Superfund sites

The EPA offers information on Superfund sites. There are maps and you can search by state, site name, or the date the site was added, to find Superfund sites in your target area.

  1. You can see all 48 proposed NPL Superfund sites here.
  2. The active NPL, containing 1,327, is here.
  3. The 438 deleted NPL sites are here.
  4. You can also use this tool to search for Superfund sites near where you live.

The future of Superfund sites

The future of Superfund sites depends on Congress who now supply all Superfund funding. As the EPA has lost its funding source its job has also got more expensive; simpler more discrete sites with acute hazards like the Robins Air Force Base or the Petersen Gravel site have now mostly been cleaned up. But major, widespread contamination like the Church Rock spill will require many years of expensive, complex work; the EPA is already working on many such sites, tying up funding for years and limiting its capacity to respond to new acute sites.

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