New EPA rule compels San Juan, Four Corners coal plants to clean up ash waste

May 3—Two coal-fired power plants have towered for decades on opposite sides of the San Juan River in northwestern New Mexico — twin engines generating immense energy for several Western states and untold pollution that's fouled the air, ground and water.

One of the behemoths, the San Juan Generating Station, shut down in 2022 after operating for a half-century south of the river. The Four Corners Power Plant, built on the river's north side in the early 1960s, was scheduled to close in 2031, but a proposed carbon sequestration system might extend its life.

Both plants represent an era that's being referred to more often in the past tense.

Coal is increasingly viewed as a dirty fuel with smokestacks spewing particulates and climate-warming carbon dioxide, while the boilers that burn the coal create heaps of toxic ash waste.

The ash, laced with toxins, has proved troublesome at these plants located just 9 miles apart near Farmington and the Navajo Nation.

Most of the waste was funneled into slurry ponds or buried in pits on site or at nearby mines. At least half of the ash disposal areas are unlined, posing a threat to groundwater and the river.

Utilities have made little effort to address the leaking ash dumps and make them less harmful to the environment.

But that's changing.

The U.S. Environmental Protection Agency has issued a new rule that requires companies to do a thorough inventory of on-site ash pits and remediate every one that might leach contaminants into groundwater, no matter how old it is.

Conservationists and community advocates hailed the new rule, saying it's way overdue in making utilities clean up a hazardous mess that's contaminating valuable waters in a state growing more arid with climate change.

"The San Juan River is still an important lifeblood for the region," said Robyn Jackson, executive director of the nonprofit advocacy group Diné CARE. "Any way the river is impacted very much affects that region."

About 19 Navajo communities rely on the river for farming and traditional practices related to water and food, Jackson said, so the ash pollution imperils their health and livelihoods.

Coal ash contains arsenic, lead, sulfide, selenium, nitrate and other heavy metals. Long-term exposure to this waste can cause kidney and liver damage, heart problems and cancer.

An estimated 50 million tons of ash were disposed of at the San Juan site and 33.5 million tons at Four Corners.

Public Service Company of New Mexico is the majority owner of the defunct San Juan plant, and Arizona Public Service is the primary owner of the Four Corners facility. These two utilities will be tasked with identifying and remediating their on-site ash waste under the rule.

A PNM representative gave a brief reply to a list of emailed questions about how the utility will respond to the new requirements.

"We appreciate the EPA's focus on our clean energy transition," PNM spokeswoman Kelly-Renae Huber wrote. "We will continue to manage to EPAs regulations."

APS spokesman Mike Philipsen also gave a short answer on how the company will address the rule's cleanup guidelines for Four Corners.

"APS is reviewing the Environmental Protection Agency's package of final rules for power plants ... to understand the full impact on the generation sources that APS uses to reliably power Arizona," Philipsen wrote in an email.

An important regulatory step

Conservationists say the rule has one glaring flaw: It doesn't require utilities to address millions of tons of ash used to fill mining excavation pits, many of which are unlined near the aquifer and river.

Although the EPA has the authority to regulate the waste at mining sites, the agency chose not to, despite the hazards of leaving ash in unsealed pits near the San Juan and Four Corners' plants, said attorney Lisa Evans with the nonprofit Earthjustice.

"Both of those places are problems and have documented contamination," Evans said.

It will be up to the federal Office of Surface Mining, Reclamation and Enforcement to issue a rule for dealing with ash waste at mines, and so far it has been slow to do so, she said.

Still, the new regulations requiring 100% cleanup of the on-site ash are significant progress, she added, even compared to the Obama administration's 2015 coal ash rule.

The 2015 rule only applied to places that still took waste or were at plants that still produced electricity after the rule went into effect — essentially grandfathering in legacy ash ponds.

Its limited scope was problematic because the older ash ponds and lagoons have some of the worst pollution, Evans said.

Earthjustice challenged the Obama rule, and in 2018 the federal appeals court in Washington, D.C., ruled the EPA had erred in excluding the legacy ponds from regulation, given these older dumping areas posed as much risk, if not greater risk, than the newer ponds.

The Trump administration didn't comply with the court order, but President Joe Biden's EPA has, Evans said.

As a basic measure, ash must be removed from unlined pits and ponds, Evans said. From there, it can go back into lined disposal areas or be recycled into construction materials such as cement, sheetrock or roadway filler.

In some cases, if the ground where the waste is contained is dry enough, it can be capped or covered, she said.

Still, the energy and coal industries have fought efforts to make them manage their coal waste better and redress pollution, Evans said. They often have prevailed through strong lobbying and well-funded campaigns.

But the transition to natural gas and now renewable energy is gradually phasing out coal-fired electricity, making it less of a sacred cow, she said. "And the [Biden] administration's explicit commitment to environmental justice is an important driver for finally cleaning up these toxic sites."

Jackson, of Diné CARE, agreed. After Navajos took the brunt of the area's ash pollution for many years — both in their water and in the air with what's known as "fugitive dust" — the government is taking the first important steps to protect them.

"Unfortunately, the new rules won't apply to all of those disposal areas," Jackson said, referring to the mining sites. "The ones where it does apply, it's going to be very beneficial."

Ash waste a 'big deal'

Ash waste became fodder for another legal battle at the San Juan plant.

The Sierra Club filed a complaint in 2010, alleging ash deposited underground near the San Juan coal mine caused pollutants to flow down an arroyo into the river.

The defendants — which included PNM and the mine operator — disputed this contention but ultimately agreed in a 2012 settlement to install a slurry wall across the arroyo to block the runoff, Sierra Club attorney Peter Morgan wrote in an email.

"We've always seen the slurry wall as a temporary solution," Morgan wrote. "We fully support additional investigations and efforts to clean up both the power plant site and the coal mine."

The slurry wall should be reexamined as part of the plant's inventorying to ensure it's working as well as PNM officials say it is, said Mike Eisenfeld, energy and climate program manager for the San Juan Citizens Alliance, an environmental advocacy organization.

The two plants both were built near coal mines that could conveniently feed them, creating a waste loop for ash to fill pits where coal was extracted, Eisenfeld said.

Energy and mining executives have said repeatedly they don't believe the enormous amount of toxic ash the plants generated is a big deal because New Mexico doesn't have the rainfall to wash it into the waterways, he said.

But, he added, research shows the waste still can seep into groundwater.

"We think it's a big deal," he said.

It's important that the EPA rule compels remediation of ash dumps not only in active coal-fired plants like Four Corners, but decommissioned ones like San Juan, Eisenfeld said. Otherwise, the companies can walk away and leave the mess for taxpayers to clean up.

"The federal government finally decided it's an issue," Eisenfeld said. "I think that there's more of a recognition of what the potential problem is."