Houston has so many tightly clustered chemical facilities, you can’t even see them all on a map.

After Hurricane Harvey slammed the Texas city with record-breaking rainfall, many of the 100 or so oil, gas, and chemical facilities in Houston were flooded or forced to shut down. In total, the storm caused the release of more than five million pounds of air pollution above usual amounts, according to official reports. As the Trump administration continues to rollback environmental regulations — many of which aimed to protect people from the risk of industrial pollution — future storms could have even worse effects.

Three regulations in particular — the Risk Management Plan; the Startup, Shutdown, and Maintenance requirement; and the New Source Performance Standards — all had amendments added to them under President Barack Obama, specifically designed to help reduce toxic air emissions and communities exposure to them. As with many other environmentally hazardous industries, the communities affected are disproportionately minorities.

But Environmental Protection Agency administrator Scott Pruitt, who’s come under fire for his coziness with the fossil fuel industry, has tried to demolish all three — and succeeded with two.

When the steadily rising waters from Harvey blew out the energy lines supplying power to the Arkema chemical plant’s cooling system, highly volatile organic peroxides at the plant started to warm. They eventually exploded, sending thick, black plumes of smoke into the sky.

Although people living within a 1.5 radius of the plant were evacuated, at least 15 first-responders were admitted to the hospital after inhaling the chemicals. But the public, including doctors, had no way of knowing exactly what chemicals they had been exposed to — or their potential effects. Under current laws, Arkema doesn’t have to reveal what chemicals they store and use.

Had amendments to the Risk Management Plan — enacted Obama in 2016 — been in place, Arkema would have had to monitor and report the chemicals in its facility to the neighboring communities and invest in safer storage methods. Then, both first-responders and the surrounding community would have known what regulated substances, if any, they were being exposed to, how to protect themselves, and if they needed to evacuate.

The current administration, however, overturned those amendments in June.

East of Houston, a Chevron chemical plant in Cedar Bayou was releasing 28,000 pounds of benzene, 56,000 pounds of acid-rain forming nitrogen oxide gases, and 40,000 pounds of various other chemicals from “miscellaneous” sources. Gas facilities, like the Chevron plant, can also emit large amounts of methane, a potent greenhouse gas with detrimental health effects, especially to children.

Another 2016 Obama-era rule, the New Source Performance Standards, capped the amount of methane that oil and gas facilities were allowed to emit. The rule, which also sought to reduce gas leaks of other environmental air pollutants, could have reduced methane emissions equivalent to 10.8 million tons of carbon dioxide.

Just days after the standards were supposed to go into effect in June, however, Pruitt implemented a 90-day stay of key provisions to the New Source Performance Standards and now seeks to pause the methane rule for two years to “look broadly” at regulations and review their impact.

He even gave the American Petroleum Institute — the lobbying arm of the oil, gas, and chemical industry, a head’s up.

A few miles down the road, refineries, such as those in the ExxonMobil Baytown Complex along with at least 24 other plants in the area, shutdown to avoid more damage. Soon afterward, many residents started complaining of strong chemical odors in the air.

When refineries shut down quickly, they often emit excess air pollutants. As a result of immediate shutdowns during Harvey, 2 million pounds of extra air pollution was released into the air. Many of the chemicals pose known threats to human health, such as benzene and acetaldehyde. Both can cause cancer and respiratory problems.

In emergency situations like Harvey, the Startup, Shutdown, and Malfunctions Emissions requirement, passed by Obama in 2015, would have mandated that industries must maintain and monitor their facilities so any event, planned or unplanned, wouldn’t cause excessive air pollution. The EPA estimated that implementing these rules would have reduced exposure to smog-causing volatile organic compounds by 50,000 tons per year.

But after the American Petroleum Institute made revoking the standard a priority, Pruitt tried to end it. The emissions requirement now hangs in limbo as a lengthy court battle plays out.

Harvey took 70 lives, displaced hundreds of thousands of people, and will cost at least $125 billion in recovery. And it won’t be the last disaster of its kind. Climate change, accelerated in large part by the carbon-emitting oil, gas, and chemical industries, only increases the frequency and severity of flooding and hurricanes.

Just days after Harvey, Hurricane Irma, the strongest storm to ever come out of the Atlantic, will soon hit Florida. Hurricanes Katia and Jose are trailing close behind.

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