FLOODSFlood Maps Show U.S. Vastly Underestimates Contamination Risk at Old Industrial Sites
Floodwaters are a growing risk for many American cities, threatening to displace not only people and housing but also the land-based pollution left behind by earlier industrial activities. For communities near these sites, the flooding of contaminated land is worrisome because it threatens to compromise common pollution containment methods, such as capping contaminated land with clean soil. It can also transport legacy contaminants into surrounding soils and waterways, putting the health and safety of urban ecosystems and residents at risk.
Climate science is clear: Floodwaters are a growing risk for many American cities, threatening to displace not only people and housing but also the land-based pollution left behind by earlier industrial activities.
In 2019, researchers at the U.S. Government Accountability Office investigated climate-related risks at the 1,571 most polluted properties in the country, also known as Superfund sites on the federal National Priorities List. They found an alarming 60% were in locations at risk of climate-related events, including wildfires and flooding.
As troubling as those numbers sound, our research shows that that’s just the proverbial tip of the iceberg.
Many times that number of potentially contaminated former industrial sites exist. Most were never documented by government agencies, which began collecting data on industrially contaminated lands only in the 1980s. Today, many of these sites have been redeveloped for other uses such as homes, buildings or parks.
For communities near these sites, the flooding of contaminated land is worrisome because it threatens to compromise common pollution containment methods, such as capping contaminated land with clean soil. It can also transport legacy contaminants into surrounding soils and waterways, putting the health and safety of urban ecosystems and residents at risk.
We study urban pollution and environmental change. In a recent study, we conducted a comprehensive assessment by combining historical manufacturing directories, which locate the majority of former industrial facilities, with flood risk projections from the First Street Foundation. The projections use climate models and historic data to assess future risk for each property.
The results show that the GAO’s 2019 report vastly underestimated the scale and scope of the risks many communities will face in the decades ahead.
Pollution Risks in 6 Cities
We started our study by collecting the location and flood risk for former industrial sites in six very different cities facing varying types of flood risk over the coming years: Houston; Minneapolis; New Orleans; Philadelphia; Portland, Oregon; and Providence, Rhode Island.
These former industrial sites have been called ghosts of polluters past. While the smokestacks and factories of these relics may no longer be visible, much of their legacy pollution likely remains.
In just these six cities, we found over 6,000 sites at risk of flooding in the next 30 years – far more than recognized by the EPA. Using census data, we estimate that nearly 200,000 residents live on blocks with at least one flood-prone relic industrial site and its legacy contaminants.
