AP Photo/Jason Dearen

Extreme Floods and Superfund Sites: A Pending Disaster for Underserved Communities

, Research scientist | July 28, 2020, 9:40 am EDT
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You know, they straightened out the Mississippi River in places to make room for houses & liveable acreage. Occasionally the river floods these places. ‘Floods’ is the word they use, but in fact it is not flooding; it is remembering. Remembering where it used to be. All water has a perfect memory and is forever trying to get back to where it was.

—Toni Morrison

In a new UCS report released today, A Toxic Relationship: Extreme Coastal Flooding and Superfund Sites, we demonstrate how the Trump administration’s sidelining of science would disproportionately put the health of communities of color and low-income communities at risk. More specifically, we model how sea level rise would contribute to extreme coastal flooding along the East and Gulf coasts and lay bare the risks faced by many vulnerable communities located near hazardous facilities. We investigate the risks posed to more than 1,000 Superfund sites—those listed on the National Priority List (NPL) currently, and also hazardous sites proposed or being assessed for NPL status or that have been withdrawn or deleted from the NPL—which often contain some of the most hazardous chemicals known to humankind and may take decades to remediate.

Accelerating sea level rise, driven by climate change, is contributing to increases in the frequency and intensity of extreme flooding on the US coastline. In a recent study published by Nature Scientific Reports, researchers determined that nearly three-quarters of coastal cities in the U.S. could experience an extreme flood (a 2-percent annual chance flood) every year within the next 50 years. These extreme floods will likely affect the thousands of Superfund sites located along the East and Gulf coasts in the U.S. Additionally, many coastal areas are already experiencing the effects of nuisance, or high-tide, flooding that damages homes, inundates roads, and poses risks to the safety of drinking water in these communities. A recent report published by the National Oceanic and Atmospheric Administration (NOAA) shows that the frequency of nuisance flooding is increasing and affecting coastal communities across the U.S.

The Environmental Protection Agency (EPA) recognized such threats to its Superfund program as early as 2011 in a climate change adaptation implementation plan (revised in 2014), and began providing information about resiliency measures and adaptation capacity Superfund sites can implement to protect them from climate change effects. The EPA was working on incorporating climate change into future flood risks under Executive Order 13690, but the Trump administration rescinded this science-based policy in 2017 10 days before the floods of Hurricane Harvey wreaked havoc on the state of Texas, flooding multiple Superfund sites.

To determine which Superfund sites would be at risk from extreme flooding in the future, we first estimated future flood heights by adding together values for the localized 1-percent annual chance flood event (data provided by Climate Central) and projected sea level rise (data provided by NOAA). This value, which represents the expected “extreme flooding” for an area, incorporates the local effects of tides, storms, seasonal shifts in water level, and projected sea level rise. The horizontal extent of the estimated flood height was then modeled over land areas across the East and Gulf Coasts. We then added the location of Superfund sites using publicly available data from the EPA to determine which sites along the East and Gulf coasts fell within this modeled flood area (i.e., sites at risk of future flooding). We modeled the extent of future extreme floods using multiple sea level rise scenarios from 2040-2100 to determine which sites currently listed under EPA’s Superfund Enterprise Management System (SEMS) could be at risk in the future. These projections do not account for Superfund sites that could be proposed in the future (i.e., unknown hazardous sites), and it assumes that sites currently listed in the SEMS may pose risks to human health in the future.

In our analysis, we find more than 800 Superfund sites would be at risk of extreme flooding under low rates of sea level rise within the next 20 years. These extreme floods could pose risks to ongoing remediation activities, lead to recontamination of areas considered clean, and affect the health of people living near these facilities in situations where contaminants are (or were) transported off site in flood waters.

Superfund sites such as the American Cyanamid Site and the San Jacinto Waste Pits have already been compromised during extreme floods. While contaminants were transported off site in these cases, no harm to humans was reported. But as floods intensify and become more frequent, it’s possible that risks to human health will increase.

Vulnerable communities have long been in the fight to demand justice when Superfund sites pose disproportionate risks to their health. In a recent report, the Shriver Center on Poverty Law highlighted that 70 percent of the Superfund sites listed on the NPL are located within one mile of government assisted housing, which is home to an estimated 77,000 people. The report recommends putting communities first in the decision-making process and highlights how this has already been done in some cases. For example, local Native American tribes had direct consultation with the EPA in the risk assessment process for the Lower Duramish Waterway Site (LDW) in Washington state. This is but one story—there are many examples where communities have fought and successfully used their voices to protect their communities from health risks posed by Superfund sites.

In our analysis, we find that communities of color and low-income communities would bear the brunt of any harm to people’s health if contaminants leached from a Superfund site during an extreme flood event. For vulnerable communities, this is another negative impact to add to those already present in the community, known as cumulative impacts. Below, we highlight potential impacts for three areas to illustrate the potential health risks to communities in states at risk from extreme flooding.

New Jersey

New Jersey is home to the land of the Leni Lenape. New Jersey is also home to the New Jersey Environmental Justice Alliance (NJEJA), which works to prevent and reduce pollution in EJ communities, provides technical expertise to communities in their fight against pollution, creates public policy initiatives, and conducts so much more work to bolster the New Jersey environmental justice movement. This work is important in New Jersey, which is home to more Superfund sites than any other state along the East or Gulf coasts.

All states along the East and Gulf Coasts have Superfund sites close to the coastline. Florida, New Jersey, and New York are hotspots regarding their number of coastal Superfund sites. Flooding of any of these sites could cause adverse health effects to surrounding communities.

Under high rates of sea level rise, 34 Superfund sites (six of which are listed on the NPL) would be at risk of extreme coastal flooding in the next 20 years in the city of Newark alone:

The above GIF shows modeled extreme coastal flooding under high rates of sea level rise for the New Jersey coast, and the location of Superfund sites in this area. Sites marked in red are currently listed on the NPL, while others shown are hazardous sites not on the NPL that have been proposed or are being assessed for NPL status, or have been withdrawn or deleted from the NPL but are likely being monitored.

Sites that would be at risk include the Riverside Industrial Park Superfund site, which was added to the NPL in 2013 after hazardous waste leached from the area into the Passaic River. The site’s soil and groundwater are polluted with a wide mix of volatile organic compounds (VOCs) and polychlorinated biphenyls (PCBs). The EPA’s public information page states that “Certain VOCs are probable human carcinogens and PCBs are potential cancer-causing chemicals that persist in the environment and can affect the immune, reproductive, nervous, and endocrine systems of people and animals.” The proposed plan for EPA’s preferred alternative for cleanup was released earlier this month, but no finalized cleanup plan has been published.


Everything is bigger in Texas, including its concentration of refineries and petrochemical plants. As of January 2019, Texas accounted for over almost half of the nation’s crude oil production. Unfortunately, that also means there is a lot of potential for hazardous wastes generated from these operations to affect public health and the environment. The Texas Environmental Justice Advocacy Service (t.e.j.a.s) has been working to combat pollution in communities through providing community members tools, education, and community-based participatory research. The work of t.e.j.a.s will be ever more important in the future as under high rates of sea level rise, 15 sites would be at risk of extreme coastal flooding by 2040 in Houston alone:

The above GIF shows modeled extreme coastal flooding under high rates of sea level rise for the Gulf Coast region of Texas, and the location of Superfund sites in this area. Sites marked in red are currently listed on the National Priority List (NPL), while others shown are hazardous sites not on the NPL that have been proposed or are being assessed for NPL status, or have been withdrawn or deleted from the NPL but are likely being monitored.

One of the Superfund sites that is currently listed on the NPL that would be at risk under high rates of sea level rise in the next 20 years is the Patrick Bayou Superfund site. The site is a small bayou that is located within the lower portion of the San Jacinto River Basin. The EPA states that “Pesticides, Polynuclear Aromatic Hydrocarbons (PAHs), metals, and polychlorinated biphenyls (PCBs) have been detected in sediments in the Bayou since the early to mid-1990s.” In March, 2017 the EPA published a feasibility report on potential cleanup methods for the site, but no finalized cleanup agreement has been published to date. The 4,411-page document does not mention “climate change” nor its potential impacts to this site. This stands in stark contrast to a similar report released for a nearby Superfund site, the San Jacinto Waste Pits, published in 2016 that acknowledges the potential impacts of climate change and more extreme future floods, which may pose challenges to containment of hazardous materials.


The state of Delaware is home to former vice president Joe Biden. It is also where a group of folks built the world’s tallest LEGO tower. Unfortunately, it is also home to many polluting industries that disproportionately impact communities of color and low-income communities. A report compiled by the Environmental Justice Health Alliance, Coming Clean, Delaware Concerned Residents for Environmental Justice, Community Housing and Empowerment Connections, and the Union of Concerned Scientists brought attention to these issues. Seven Superfund sites would be at risk of extreme coastal flooding under high rates of sea level rise even within the next 20 years just in Wilmington, DE:

The above GIF shows modeled extreme coastal flooding under high rates of sea level rise for the coast of Delaware, and the location of Superfund sites in this area. Sites marked in red are currently listed on the National Priority List (NPL), while others shown are hazardous sites not on the NPL that have been proposed or are being assessed for NPL status, or have been withdrawn or deleted from the NPL but are likely being monitored.

One of those sites at risk and listed on the NPL is the Halby Chemical Co. Superfund site, a chemical manufacturing plant that operated in the past and discharged waste in an unlined lagoon in the area, contaminating sediment, soil, surface water and groundwater. In a 1997 proposed cleanup plan for the site, the EPA noted multiple contaminants posing risks to human health in the area including: ammonia, cadmium, manganese, trichloroethene, and carbon disulfide, which pose risks such as lung damage, blindness, nerve damage, and in some cases death. The EPA considered construction complete as of 2002, but the agency notes that continued monitoring is needed at the site with the last five year review published in 2017.


Communities of color and low-income communities are already exposed to disproportionately higher levels of environmental pollution than White people or those not living in poverty. This is a long-standing issue that is intertwined with racism and White supremacy, poor zoning laws, and bad policy choices. These decisions have resulted in communities of color and low-income communities living near chemicals that we know can have lasting damage to people’s lungs, heart, nerves, and brain, and exposure to some contaminants at these sites could result in cancer or even death. There is no single culprit nor any one government action that can explain the long-term injustices that underserved communities have faced. Rather, marginalized communities have experienced and continue to experience such inequities as a result of multiple factors and many interwoven policies and ideas. It has been known for decades that race is a significant predictor of the location of hazardous facilities, yet these inequities continue to exist—even as EPA administrator Wheeler has stated that “All Americans deserve timely action on Superfund site cleanups in their communities—not delays.”

The effects of climate change and the risks it poses to Superfund sites adds additional stress on already overburdened communities. Under high rates of sea-level rise, we find that multiple Superfund sites in Texas, Delaware, and New Jersey would be at risk of flooding, even in the next 20 years. When analyzing the demographic makeup of communities within five miles of these at-risk sites for coastal communities along the East and Gulf Coasts, we find significant disproportionate impacts:

To better understand the significance of the demographics of people living within 5-miles from an at-risk Superfund site, we estimated the number of people of color as well as low-income households that we would expect to be living in these at-risk areas based on the proportion of communities of color and low-income households within the total population of coastal counties across the East and Gulf Coasts. We could then determine if communities of color and low-income communities were overrepresented (more observed than expected) or underrepresented (more expected than observed) in at-risk areas by multiplying the expected proportion with the total population and total number of households within 5-miles of an at-risk Superfund site (the “expected at-risk communities”). Then we compared “the expected at-risk communities” value to observed data available via the US Census Bureau. If this expected value was less than the observed value, we considered this representative of a disproportionate risk of being affected by future extreme coastal flooding of a Superfund site. We find disproportionate impacts for people of color in a) New Jersey and Delaware, but not Texas, and for b) low-income households across all three states analyzed.

A 2019 report from the Government Accountability Office (GAO) found that 60 percent of Superfund sites are at risk of being affected by climate change. We find similar expected impacts for flooding alone on the East and Gulf Coasts. Yet Administrator Wheeler’s response to the GAO’s recommendation for the agency to incorporate climate change information into Superfund risk response decisions was, “The EPA strongly believes the Superfund program’s existing processes and resources adequately ensure that risks and any effects of severe weather events are woven into risk assessments.” Yet sites have already been compromised by extreme floods, and flooding is expected to increase in frequency and intensity, with evidence that some cleanup plans do not incorporate expected risks from extreme weather events. This begs the question, is the status quo working?

This year will likely be a significant test for the agency as an active hurricane season is projected during a global pandemic.

The Trump administration is no stranger to attacking science. Without any action to this issue during a pandemic, however, I am afraid that the administration’s disdain for science could truly prove to be deadly.

Thank you to Casey Kalman for helping to inform this post and developing all featured maps.

AP Photo/Jason Dearen

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