More than half of super toxic sites in the US are at risk of spilling due to climate change; pose substantial risk to life

The analysis by the US Government Accountability Office says 945 of 1,571 sites could face storm surges, wildfires, and sea-level rise.


                            More than half of super toxic sites in the US are at risk of spilling due to climate change; pose substantial risk to life

Nearly 60% of the most hazardous waste sites in the US are at risk from intense flooding, wildfires, and sea-level rise - fuelled by climate change - which could damage them and potentially release contaminants. This could pose a substantial risk to human health and the environment, warns a new analysis. 

The report on these toxic sites - referred to as Superfund sites - has been released by the United States Government Accountability Office (GAO). 

The report says that available federal data on flooding, storm surge, wildfires, and sea-level rise suggests that about 60% - 945 of 1,571 - of these nonfederal National Priorities List (NPL) sites are located in areas that may be impacted by one or more of these potential climate change effects.

The data came from the Environmental Protection Agency (EPA), Federal Emergency Management Agency (FEMA), National Oceanic and Atmospheric Administration (NOAA), and US Forest Service.

Since most Superfund sites (about 90%) are located on nonfederal land, the report identified nonfederal Superfund sites and the natural hazards that might impact them. The sites, says the analysis, are located in areas that may be impacted by “selected climate change” effects - that is, 0.2% or higher annual chance of flooding or other flood hazards, storm surge from Category 4 or 5 hurricanes, high- and very-high wildfire hazard potential, and sea-level rise of up to three feet.

Superfund sites located in areas that could be adversely impacted by climate change. (US GAO report)

“Administered by the EPA, Superfund is the principal federal program for addressing sites containing hazardous substances. EPA lists some of the most seriously contaminated sites - most of which are nonfederal - on the National Priorities List and has recorded over 500 contaminants, including arsenic and lead, at those sites. Climate change may make some natural disasters more frequent or more intense, which may damage NPL sites and potentially release contaminants, according to the Fourth National Climate Assessment”, says the report. The audit was conducted from April 2018 to October 2019.

The Superfund program - the federal government’s principal program to address sites with hazardous substances - was established by the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). The EPA is responsible for administering the program.

Superfund sites in the US. (US GAO report)

According to the Agency for Toxic Substances and Disease Registry, the highest-priority contaminants, based on a combination of their prevalence, toxicity, and potential for human exposure, are arsenic, lead, mercury, vinyl chloride, and polychlorinated biphenyls.

Contaminants may be found in different media at nonfederal NPL sites, says the report. In 2017, EPA reported that groundwater and soil were the most common contaminated media, including at the nonfederal NPL sites it analyzed.

The EPA lists some of the most seriously contaminated sites - most of which are nonfederal - on the National Priorities List and has recorded over 500 contaminants, including arsenic and lead, at those sites.(Getty Images)

The analysis

As far as the impact of flooding is concerned, the researchers identified 783 nonfederal NPL sites, approximately 50%, in areas that FEMA had identified as having 0.2% or higher annual chance of flooding - which FEMA considers moderate flood hazard, or other flood hazards, as of October 2018. 

“Of these 783 sites, our analysis shows that 713 or approximately 45% of all sites are currently located in areas with 1% or higher annual chance of flooding, FEMA’s highest flood hazard category”, the team warns.

For example, there are a number of these sites in “EPA Region 7,” where states experienced record flooding in early 2019. Specifically, 51 sites are located in areas with 0.2% or higher annual chance of flooding or other identified flood hazards, of which 42 are located in areas with 1% or higher annual chance of flooding.

The team further identified 187 sites or 12% in areas that could be inundated by storm surge corresponding to Category 4 or 5 hurricanes, the highest possible category, based on NOAA’s storm surge model, as of November 2018. Of these sites, 102 are located in areas that may be inundated by a storm surge corresponding to Category 1 hurricanes. 

For analyzing the impact of wildfires, the report identified 234 sites - 15% - located in areas that have high or very high wildfire hazard potential. This, says the team, implies that they are more likely to burn with a higher intensity, based on a US Forest Service model, as of July 2018. “There are 22 nonfederal NPL sites in areas with high or very high wildfire hazard potential in EPA Region 9, a region that experienced wildfires in 2018, including the highly destructive Carr Fire,” the report adds.

The analysis identified 234 Superfund sites located in areas that have high or very high wildfire hazard potential - those more likely to burn with a higher intensity. (Getty Images)

Sea level rise of up to three feet could impact 110 sites or 7%. The analysis shows that if sea level in these areas rose by 1 foot, 97 sites would be inundated. If sea level in these areas rose by 8 feet, 158 sites would be flooded. 

“We also identified 84 nonfederal NPL sites that are located in areas that may already be inundated at high tide,” says the analysis.

The report says that EPA has taken some actions to manage risks from the potential impacts of climate change at the sites. However, says the analysis, EPA does not have quality information on the boundaries of the nonfederal NPL sites, which could affect its ability to identify the number of sites that may be impacted by one or more of these potential climate change effects.

The agency has taken initial steps to develop this information but does not have a schedule in place for completing this effort, says the report. 

The GAO has recommended EPA provide direction on integrating climate information into site-level decision making to ensure long-term protection of human health and the environment.

The extent to which EPA’s actions to manage risks to human health and the environment from the potential impacts of climate change effects at nonfederal National Priorities List sites aligned with GAO’s essential elements of enterprise risk management. (US GAO report)

“EPA has not clarified how its actions to manage risks from these effects at nonfederal NPL sites align with current agency goals and objectives, which could limit its senior officials’ ability to manage these risks. Further, EPA officials do not always have the direction to ensure that they consistently integrate climate change information into site-level risk assessments and risk response decisions, according to EPA documents and officials,” says the analysis.

The researchers warn without providing such direction for remedial project managers, EPA cannot ensure that remedies at the sites will protect human health and the environment in the long term.

“GAO is making four recommendations to EPA, including that it clarify how its actions to manage risks at nonfederal NPL sites from potential impacts of climate change align with current goals and objectives. EPA agreed with one recommendation and disagreed with the other three. GAO continues to believe that all four are warranted,” says the report. 


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