This post is part of a series about climate change and the increasing risk of floods releasing toxic chemicals from industrial facilities.
As Hurricane Harvey lingered over Texas in 2017, it created a wall of water that swallowed much of Houston. Catastrophic flooding over a wide swath of southern Texas left towns, cities, and the countryside under feet of water. The floodwaters sloshed toxic chemicals from the area's 10 oil and gas refineries, 500 chemical plants, and 12 Superfund sites around "like a wet mop," according to one resident who lives near the ExxonMobil refinery and chemical plant. The torrential rainwaters engulfed her home, and she was forced to swim with her four young children through a toxic soup that smelled like "a rotten sewer." Their exposure to contaminated floodwaters likely accounted for the skin and strep throat infections her children later developed. Rice University researchers also collected floodwater samples just a single block from her home and found levels of benzo[a]pyrene, a known carcinogen, above an acceptable EPA threshold for human cancer risk.
With climate change and increasingly frequent extreme weather events, we are at risk for more Houston-like "toxic soup" flooding events. We have tried to tame our rivers to keep ourselves dry while allowing industry to build in floodplains and closing our eyes to the risks of toxic releases during floods. Over time, we have seen parallel but uncoordinated efforts on flood control, emergency management, and industrial chemical regulation, often in response to some large flood event and/or industrial spill.
Over the last two centuries, officials at the local, state, and federal levels have struggled to balance their roles in flood control and regulation of toxins with budgetary constraints and their willingness (or reluctance) to confront industry interests in the service of flood control and environmental protection. Many state and local governments, in the desire to expand their economic base and boost employment, have promoted reckless economic growth by opening floodplains to industrial development. The toxic chemicals and hazardous waste many of these industries introduce into our waterways often pose dangers to our health that are both obvious and hidden.
While biological toxic flooding (from sewage and other organic waste) has occurred for centuries, the growth of the synthetic chemical industry increases the risk and amount of toxic substances that end up in our waterways during a flood. Indeed, routine toxic dumping produced dramatic visuals in the past (including the repeated Cuyahoga River fires of the 1950s and 1960s, which eventually helped galvanize determination to pass the Clean Water Act). However, the sources of danger that can lead to toxic flooding today are more often hidden in storage containers and underground pipelines.
Preventing toxic floodwaters requires coordination of both flood management and protection against toxic releases. As straightforward as that sounds, in practice it has been anything but simple. The federal government was initially cautious to play a role in flood control, viewing it as a state issue. Only in 1917, after significant repeated floods along major waterways that crossed state lines, did the federal government make its first flood control appropriations, continuing a post-Civil War strategy exclusively focused on levees. This levee-only strategy created a false sense of safety, boosting construction in floodplains and exacerbating flooding (such as the 1927 Great Mississippi Flood) rather than preventing or reducing ...