In Orlando, a mountain of coal ash evades EPA rules. It's not the only one.

Tucked among scattered pine and cypress trees near Orlando, Fla., a 175-foot-tall mountain of coal ash looms as a stark representation of this booming region's reliance on fossil fuels.

The mound is what's left over from the decades of coal burned at the Stanton Energy Center, a sprawling power-generation complex nearby whose cylindrical cooling towers send curls of steam into the clouds.

Piper Vargas thinks a lot about the coal ash landfill. Vargas fears the dust particles from the landfill carried by the wind to her tidy blue lakeside home six miles away, and what inhaling them might do to her family, especially her two young sons. She worries that toxic elements in the coal ash might seep into the area's vital groundwater.

"My mind starts to go to those places like, 'Why do we still live here?,' " says Vargas, 38, a stay-at-home mom who homeschools her kids. "They're not cleaning that up. Or they're still burning [coal] right now. They still have years left of burning it."

Like many electric utilities, the Orlando Utilities Commission (OUC), which operates the energy center, is moving away from burning coal. It plans to stop coal-fired power generation by 2027 and transition to net-zero carbon emissions by mid-century, mostly through solar energy. But nearly all utilities that burned coal, including OUC, face questions about the potential risks from years of buried coal ash, one of the nation's largest industrial waste streams.

For generations, the residue from combusting coal for electricity was dumped into pits, many without adequate liners to protect nearby groundwater. Coal ash contains toxic contaminants like mercury, cadmium and arsenic that can pollute the air and seep into groundwater, and that are associated with cancer and other illnesses.

In 2015, the Environmental Protection Agency adopted the first national regulations for coal ash. They applied to existing and new coal ash sites, but exempted landfills that had already closed. As a result, the rule may have left as much as half of all coal combustion waste ever produced in the United States unregulated by EPA, including most of what's buried on the OUC property, environmental groups estimate.

Now, environmental activists want the EPA to close loopholes they say were left by the 2015 rule. They want utilities to clean up contamination caused by ash dumping that occurred before the rule went into effect. They also want the agency to enforce the 2015 rule more aggressively and to deny utilities' requests for cleanup exemptions.

"We are in danger of leaving half the ash unremediated," says Lisa Evans, a senior attorney specializing in hazardous waste law at Earthjustice, a national environmental law organization. "It's not being monitored and therefore, it's not triggering corrective action requirements of the rule. So you're going to have this poisonous legacy, which could last permanently at many, many sites."

EPA officials say they are aware of ongoing concerns about the coal waste. And Tuesday, the Biden administration initiated its first steps toward enforcing its ash disposal regulations.

"I've seen firsthand how coal ash contamination can hurt people and communities," said EPA Administrator Michael Regan, who oversaw the regulation of coal ash as North Carolina's top environmental regulator before coming to the EPA last year. "Coal ash surface impoundments and landfills must operate and close in a manner that protects public health and the environment. Today's actions will help us protect communities and hold facilities accountable."

EPA's proposed actions, however, do not address the problem of ash that was dumped and buried before the 2015 regulations went into effect, environmentalists said.

When waste isn't considered waste

Over the last century, as the U.S increasingly relied on coal to power its economy, hundreds of power plants produced billions of tons of ash and other combustion wastes. All that coal burning waste had to go somewhere.

Utilities dumped it into watery, unlined pits called coal-ash ponds, and piled it office-tower high in landfills. They sent it to public works departments to spread on icy winter roads, used it as a dirt alternative at construction sites for embankment or structural fill, and disposed of it at old coal mines. The industry found commercial uses for some power plant waste products, including putting the ash into cement or concrete, or converting sludge from smokestack scrubbers into a form of gypsum used to make drywall.

For 28 years, OUC dumped much of its coal ash into its main landfill, covering about 90 acres. That dumping stopped on Aug. 28, 2015, just 52 days before the Obama-era national regulations went into effect. The maneuver exempted the landfill from the new requirements for environmental monitoring and, if contamination were found, a requirement to take corrective actions. Those standards only apply to new dumping areas at the Stanton Energy Center, next to the closed landfill.

OUC isn't unique, according to environmental watchdogs. They say OUC took advantage of a widely used loophole written into EPA's Coal Combustion Residuals Rule, passed in 2015, near the end of the Obama administration after decades of battles between environmentalists, industry and the EPA.

Coal ash disasters spurred the 2015 rules

EPA's 2015 coal ash regulations were spurred by major disasters. One was near Knoxville, Tenn., on Dec. 22, 2008, when a levee along a mountain of sodden ash suddenly broke loose from the Tennessee Valley Authority's Kingston power plant. Some 300 acres were smothered. The ash spilled into two rivers. Three homes were destroyed, dozens more were damaged. In the years since, hundreds of cleanup workers fell ill, and many have died.

Then in 2014, tens of thousands of tons of coal ash spilled from a Duke Energy power plant into the Dan River at Eden, N.C., causing damage for 70 miles downstream.

For decades, EPA had exempted coal ash from its "hazardous waste" definition under the nation's main law for regulating hazardous and solid waste, a result of an amendment in 1980 by the late U.S. Rep. Tom Bevill, D-Ala. Bevill was a 15-term congressman known as the "King of Pork" for his ability to draw federal dollars to his home state. He also delivered for the fossil fuel industry.

In congressional testimony at the time, Bevill said his amendment sought to curb EPA rules on fossil fuel wastes in order to protect the coal and electric utility industries from "unnecessary burdens" and high costs, and to "encourage coal as a primary source of domestic energy." Fossil fuel wastes, he argued, were not a "substantial hazard" to human health or the environment.

Thirty-five years later, despite having found dozens of examples across the country where coal ash had or likely contaminated groundwater, polluted lakes or caused fish deformities, the EPA in 2015 sided with the coal and electric utilities industry, and again declined to deem coal-burning wastes as hazardous.

EPA officials concluded that regulating coal ash as a solid waste — a less rigorous category — would be enough to prevent ash pile collapses, blowing ash dust and groundwater contamination. EPA officials also said their preferred strategy would give utilities "a practical approach" to managing its massive collection of coal burning wastes.

States' regulation of coal ash is "a mixed bag"

The EPA has effectively left enforcement of its coal ash regulations to citizens or states, resulting in a hodgepodge of contradictory and confusing activity.

In some states, like North Carolina and South Carolina, essentially all ash ponds are being drained and dug out, after the Southern Environmental Law Center sued. The toxic sludge is sent to modern landfills with protective liners. SELC and its partners have won other victories for ash pond cleanups in Virginia and Tennessee.

In other states, it's been a mixed bag, with utilities being allowed to merely drain and cover their ash ponds, a practice known as "cap-in-place."

The level of cleanup seems to depend on how much noise residents near coal plants make, and whether environmental lawyers like South Carolina's Frank Holleman, a senior attorney with SELC, get involved.

"The only way this becomes a public controversy is either a local community group gets concerned and brings it to the attention of some environmental legal advocacy group, or the legal advocacy and environmental group learns about the problem and checks around and sees a local community that has a vague notion but isn't quite sure what's going on," he says. "Or you have a catastrophe."

Sometimes the catastrophe is sudden, like what happened to the Kingston TVA power plant, but often, the damage is so slow that it escapes notice until it's too late, Holleman says.

If you burn coal, its ash will get airborne

Ash blowing into neighborhoods goes away when plants shut down, and ash piles are covered and capped. But coal still provides about 20% of the nation's electricity, and that means ongoing production and storage of coal-burning wastes.

Kristina Zierold, associate professor of environmental health sciences at the University of Alabama at Birmingham, found that children living near coal ash storage sites in Kentucky have a greater incidence of health issues such as asthma and neurobehavioral problems, compared to children living in areas without such sites.

"Dust does come off these landfills and surface impoundments," Zierold says. "You can see it. And it does affect the community surrounding them."

All eyes are on the Biden EPA

The Obama coal ash rule required utilities to monitor and report on groundwater conditions. As a result, a better understanding of the scale of coal ash contamination across the country has emerged.

In a 2019 report, the Environmental Integrity Project and other advocacy groups analyzed monitoring data utilities had posted on their websites. The report found unsafe levels of toxic contaminants in groundwater linked to more than nine out of every 10 coal-fired power plants with monitoring data.

In all, unsafe levels of contamination were reported in groundwater at sites in 39 states and Puerto Rico. Illinois has the most power plants with polluted ash storage sites with 16, followed by Texas, Indiana, Kentucky, Michigan, North Carolina and Missouri, all with more than 10.

Florida had nine power plants with polluted ash storage sites, including at the Stanton Energy Center, the report found.

Industry and environmentalists sued EPA after the agency adopted its 2015 rule, which is still in court. The industry has opposed what it calls a "one size fits all" approach and petitioned the EPA for changes the Trump administration made, such as extending compliance deadlines and allowing utilities to request exemptions.

The Edison Electric Institute, a trade group that represents investor-owned utilities, maintains that electric companies are managing coal ash "in ways that put safety first, protect the environment, minimize impacts to the community, and manage costs for customers."

Institute spokesman Brian Reil deferred questions about coal ash to Jim Roewer, the executive director of the Utility Solid Waste Activities Group, an association of more than 131 utilities, and the industry's primary spokesman on coal-burning wastes. Roewer did not return repeated requests for comment.

Lawyers from the utilities' solid waste group, in writing to the Trump administration in 2017, argued the 2015 EPA rule was too costly and was forcing premature closure of coal-fired power plants. The group asked for "a more balanced" rule that would still prevent adverse effects on health or the environment. Trump's EPA extended compliance deadlines and allowed utilities to request certain exemptions.

With a new administration in 2021 and utilities soon making final decisions on coal ash because of power plant shutdowns and cleanup deadlines, environmental advocates are looking for a much more aggressive stance from the Biden EPA. Environmental groups also want EPA to adequately address a 2018 court ruling they won against the agency that required the closure and cleanup of some 100 additional so-called coal ash ponds left out of the 2015 rule.

For its part, the Biden administration promises to revisit coal ash management in future rule-making, including a proposed rule dealing with legacy ash ponds.

This week, EPA began proposing determinations on 57 requests for deadline extensions for the closing down of unlined coal ash disposal pits. The agency said it was also putting several power plants on notice regarding their obligations to comply with its 2015 regulations.

In announcing its determinations, the agency said it was affirming its view that ash disposal pits or landfills cannot be closed with ash in contact with groundwater. The EPA also said limiting contact between coal ash and groundwater after closure is critical to minimizing releases of contaminants into the environment and will help ensure communities near these facilities have access to safe water for drinking and recreation.

"I wanted them to do better"

OUC, Florida's second-largest municipal utility with 250,000 customers in Orange and Osceola counties, prides itself on having progressively green energy policies. Last year, it announced it would stop burning coal by 2027 and use fossil gas as a bridge to net-zero carbon emissions by 2050, while ramping up solar power and energy storage. It has also constructed a 13-megawatt solar array on the older portion of its coal ash landfill that will generate enough electricity to power 2,100 homes.

Its clean energy plan makes the municipal utility a leader in a state that is uniquely vulnerable to the hotter temperatures, rising seas and other consequences of burning fossil fuels, but that lacks any statewide strategy for transitioning to cleaner energy sources.

But OUC has found ways to limit their cleanup obligations that are commonplace in industry, says Abel Russ, a senior attorney with Environmental Integrity Project, and the lead author of the 2019 national report on coal ash contamination.

Russ says utilities find wiggle room in their interpretations of regulations that require engineering assessments, environmental monitoring, closure plans, and potentially corrective action if groundwater pollution limits are exceeded.

At the Stanton Energy Center, for example, Russ observed that wells used to detect whether the new landfill area is polluting groundwater are more than a half-mile away, and utility consultants have said it would take groundwater "several hundred years" to reach them.

"If that's true, if it takes hundreds of years for the groundwater to get there, they're useless wells," Russ says. OUC spokesman Tim Trudell declined to comment on any of Abel's specific criticisms of how the company has managed its coal ash.

"It's a well-run site," he says of the Stanton Energy Center. "It definitely is, and we still have responsibility with coal. We are going to take that responsibility seriously and continue to do so."

And he adds, "We will continue to monitor that site for as long as it takes."

Yet Vargas still has her fears and she hasn't been alone. A lawsuit filed in 2018 on behalf of the area's approximately 30,000 residents alleged that air and groundwater pollution from the landfill were responsible for a cancer cluster, including pediatric cancers of the brain, blood and central nervous system. Named as defendants were OUC and three home builders that the lawsuit contended had built and marketed the neighborhoods without addressing the risks.

OUC argued that the claims were unsupported by science. The home builders said the plaintiffs lacked grounds to sue. Then the plaintiffs dropped the suit late last year for unspecified reasons.

Vargas was not part of the lawsuit. She became aware of the coal ash landfill about five years ago, near the same time her father died of cancer. The trauma prompted a new interest in health and wellness. Vargas also got involved in an environmental group called Moms Clean Air Force.

"That's when I met another mom here ... who told me about the cancer cases and about the coal ash," she says. And it's when she says she grew more worried about her local utility, OUC.

"I wanted them to do better, right?," she says.

This story is a collaboration between Inside Climate News and WMFE Orlando, a member of ICN's National Reporting Network-Southeast.