Oil refineries release billions of pounds of pollution annually into waterways, and that pollution disproportionately affects people of color, according to a new analysis of Environmental Protection Agency regulatory data.

The pollution includes heavy metals, nitrogen and other compounds that can kill aquatic animals, feed harmful algae and make waterways dangerous for humans to fish in, swim in or even touch. The pollution affects communities across the country, but is especially concentrated along the Gulf Coast, in California and near Chicago.

The new findings underscore health and environmental dangers across fossil fuel operations, from the wellhead to pipelines, refineries and consumer use.

The report was published by the Environmental Integrity Project, an independent watchdog group that routinely analyzes public data collected by the EPA.

"This is a highly polluting industry discharging large volumes of wastewater," says Eric Schaeffer, executive director the Environmental Integrity Project, and former director of the EPA's Office of Civil Enforcement.

The report authors examined EPA water pollution data from 2019 to 2021 for 81 major refineries across the country – about two thirds of all refineries operating in the U.S. Refineries are required to tell the government how much pollution they release into waterways.

Most refineries included in the analysis reported releasing extra pollution, beyond what they are legally permitted to. But less than a quarter of those with violations were penalized by the EPA, the data show.

"We have a chronic problem with enforcement of the [Clean] Water Act," Schaeffer says.

ExxonMobil, which operates some of the largest refineries in the country including multiple facilities that the report found are among the largest emitters of key pollutants, declined to comment specifically about its operations. Instead, the company referred NPR to a general environmental statement by the American Fuel & Petroleum Manufacturers trade group.

"We have preserved and protected land and water resources by implementing waste management programs and adhering to federal guidelines that govern effluent discharge, hazardous waste disposal and other priority areas," the AFPM statement reads. "We have made great progress in environmental stewardship under the Clean Air Act, the Clean Water Act and many other environmental regulations, and continue to innovate to evolve our operations and products."

Most of the pollution is happening near communities of color

In the U.S., people with less power have consistently been exposed to more pollution, whether it's excess air pollution from highways and factories, drinking water contamination, exposure to lead paint or polluted lakes and rivers.

That trend shows up clearly in the new report, which finds that the majority of the worst-polluting refineries are located near communities that have lower-than-average income and a higher-than-average proportion of non-White residents.

A further NPR analysis of the data finds even more stark inequities: some types of water pollution are concentrated overwhelmingly in communities where people of color live.

For example, about three-quarters of the nitrogen, selenium and dissolved solid pollution from oil refineries came from facilities that are surrounded by neighborhoods that are home to people of color.

The EPA declined to comment on the report or on NPR's findings.

The new pollution data reinforce what people who live in the shadows of refineries experience every day.

"I'm not surprised at all," says John Beard, a former city council member in Port Arthur, Texas and current director of the local environmental group the Port Arthur Community Action Network. The Gulf Coast city is crisscrossed by bayous and other waterways, and is home to multiple major refineries.

Beard says the pollution is obvious. "You can see the [oil] sheen on the water," he explains. Sometimes the water smells.

"This is affecting places where some people make their living fishing," he explains. Others fish recreationally or as a regular source of food, and Beard worries that some aquatic species may not be safe for human consumption if the water is contaminated with heavy metals and other pollutants.

Many waterways near petrochemical facilities have signs warning residents not to touch or fish in the water, but it can be unclear which areas are safe.

Beard worked for 38 years at petrochemical facilities in the area, and says the supposed economic benefits for local workers – especially Black people and other people of color who live next to the refineries – are outweighed by the costs to human health and the environment.

"They don't build these [refineries] in Beverly Hills, or River Oaks or Madison Avenue. They don't build them in communities of affluence." he says. Instead communities that have faced generations of systemic racism also live with polluted air and water. "We pay a severe price."

Federal rules about water pollution from oil refineries are outdated

The EPA's water pollution regulations for oil refineries were established in 1985 and don't cover many pollutants, Schaeffer says. In the nearly 40 years since then, there have been major advances in wastewater treatment methods, he argues, and the Clean Water Act requires the agency to update its pollution limits accordingly.

"Nobody thinks that a rotary phone is the best available technology for making a phone call in 2023," Schaeffer says. "That same thinking was applied in the Clean Water Act. As treatment methods improve, the standards are supposed to get tighter."

In December, Congress approved a modest increase in the EPA's budget for enforcement of existing environmental regulations. The EPA has not indicated any plans to update its limits on water pollution from oil refineries.