In October, the EPA announced that it would not be revising federal water-pollution standards for slaughterhouses that discharge processed wastewater directly into waterways. Furthermore, the agency said that it would not create standards for facilities that send their wastewater to sewage-treatment plants before discharging into waterways.

The decision came even though the EPA has identified the country’s 5,000-plus slaughterhouses—which kill billions of animals every year—as one of the largest industrial sources of nitrogen water pollution.

According to non-profit Center for Biological Diversity—one of the organizations involved in the lawsuit—the EPA’s decision to not update standards means that thousands of slaughterhouses will continue using outdated pollution-control technology, causing widespread environmental damage to the country’s waterways.

“The Center for Biological Diversity and our partners believe this lawsuit is necessary for a number of reasons,” spokesperson Hannah Connor told Newsweek.

“The first is because meat and poultry slaughterhouses are currently one of the largest point source dischargers of nutrient pollution into waterways,” she said. “According to a report from one of our partners, the Environmental Integrity Project, the average slaughterhouse discharged over 330 pounds of nitrogen per day in 2017 alone, which is equivalent to the amount of pollution from untreated sewage from a town of 14,000 people.”

This pollution can lead to harmful algal blooms that may cause harm to humans and marine species, while also damaging fisheries and local economies.

“In addition to nitrogen pollution, which decreases oxygen levels in waterways and can cause incredible harm to aquatic species, these plants can also discharge a variety of pretty problematic pollutants such as biological materials—blood, hair, fats and fecal matter, for example—as well as standard industrial pollutants such as oil and grease,” Connor said.

The last time that the EPA revised standards for slaughterhouses that discharge polluted water directly into waterways was 15 years ago. In fact, more than a third of these facilities are still operating under guidelines dating back to the mid-1970s.

In addition, the agency has never set standards for slaughterhouses that send their wastewater to sewage treatment plants, despite the fact that this is common practice for many of these facilities.

“Many of these standards have not been updated since disco was the music of the day and people still listed to music on 8-track tapes,” Connor said. “Technology has advanced since then, and those advances should be reflected in the technological standards that these plants are required to employ. The Clean Water Act demands no less.”

“Slaughterhouses still seem to be violating the Clean Water Act with impunity, as was recorded further in the Environmental Integrity Projects 2018 report,” she said.

Many of the country’s slaughterhouses are found in rural areas such as eastern North Carolina and portions of Arkansas, Delaware, Georgia, Illinois, Indiana, Iowa, Mississippi and Pennsylvania. The risks of not reducing slaughterhouse pollution are “profound” for people living in these communities, according to Connor.

“Most wildlife, including endangered and threatened species, rely on clean water in some way to survive, for example through consumption, for habitat, and for breeding. The same is true for people and communities that rely on water resources, including around slaughterhouse, for drinking water, recreation, and sometimes subsistence,” she said.

“Taking away and impairing vital clean water resources cuts to the quick of the ability of species, including our own species, to survive and thrive. That is why revisiting and approving these slaughterhouse standards is so important.”

According to the Center for Biological Diversity, updating pollution standards can make a significant difference. Those slaughterhouses that incorporate advanced pollution-control technology release far less harmful waste than the dirtiest facilities, according to the non-profit.

“We have seen quite a robust set of environmental roll-backs from this administration, while at the same time seeing a sharp decline in the number of environmental enforcements brought by the administration against polluters,” Connor said. “For the environment and wildlife, that is a caustic and dangerous combination.”

In a statement provided to Newsweek, the EPA said that it does not comment on pending litigation.

This article was updated to include a statement from the EPA.