Danielle Bailey-Lash, a 40-year-old customer service representative from the sleepy lakeside community of Belews Creek, NC, never used to get sick.

Growing up in the foothills of the Blue Ridge Mountains, she got plenty of exercise, never smoked or drank, and took pride in looking after herself.

But in 2010, Bailey-Lash was rushed to hospital with agonizing headaches that radiated from her neck to the top of her head. Doctors conducted a scan, and found a tumor the size of a juice box growing on the right side of her brain. She was told she had just a few months to live.

Miraculously, Bailey-Lash beat the odds: after undergoing surgery, she is now in remission, with little to show for her brush with death besides an impressive scar above her right ear. But when she returned from the hospital, she got to thinking.

At least 10 of her friends in the neighborhood had recently fallen seriously ill with similar ailments - "breast cancers, strange tumors, a lot of problems with kidneys and livers" - that seemed to have come out of nowhere.

"It was just really strange - we were all so young and healthy, and at 35 or 40 we're all getting sick", she says.

Looking back, Bailey-Lash now thinks she knows what caused the rash of unexplained illnesses: the huge Belews Creek coal-ash impoundment, run by Duke Energy, that lay just a few hundred yards from her home.

The 342-acre pond, built four decades ago to serve a neighboring 2,240-megawatt power plant, contains more than four billion gallons of ash slurry - the waste from years of coal-fired energy generation, mixed with water to make it easier to pour into an unlined hole in the ground.

'Always on my mind'

Like many people who live near such ponds, Bailey-Lash fears that heavy metals and other toxins present in the coal ash are seeping out of the crude pit and entering the local groundwater. That's especially problematic in rural communities like Belews Creek, where many residents depend on wells rather than municipal pipelines for their drinking water.

Indeed, a recent inspection found elevated levels of radon - a major cause of various cancers, and one known to be present in coal ash - in Bailey-Lash's drinking water, and she was advised by local environmental officials to avoid cooking with, drinking or doing laundry with her tap water, and not to take showers for longer than a few minutes at a time.

The water problems make it impossible for Bailey-Lash to sell her house and move away, and have left her afraid for her own health and that of her daughter and husband. "It's always on my mind", she says.

And Bailey-Lash's plight is hardly uncommon. More than 1,700 people - of whom around a quarter are below the poverty line - live within a three-mile radius of the Belews Creek plant and ash-pond, according to EPA data. There has been no formal study of health problems in the community, but activists and residents say that anecdotal evidence makes it clear that something is wrong.

Caroline Armjio, a former neighbor of Bailey-Lash's, rattles off a long list of cousins, neighbors and family friends who've been afflicted by brain cancer, birth defects, leukemia and other mysterious ailments.

Armjio acknowledges that without proper scientific studies it's hard to conclusively blame such problems on pollution from the Duke plant, but she can't think of any other explanation. "There are so many people who're sick", she says. "There's just too many."

A quiet tragedy

America's coal plants produce 140 million tons of ash each year, making it the country's second-largest industrial waste stream. The vast majority of that ash is blended with water to make it easier to move, and then pumped into impoundments that are often little more than holes in the ground.

There are currently more than 1,100 such impoundments in the US, of which almost half lack any kind of lining to prevent seepage, and every state that has coal-ash impoundments has also had EPA-verified water contamination incidents linked to the sites.

That's troubling because coal ash contains toxic heavy metals such as arsenic, lead, selenium, and other agents that have been linked to cancer, learning disabilities, neurological disorders, birth defects, reproductive failure, asthma, and other illnesses.

According to an EPA risk assessment, people who live within a mile of an unlined coal-ash facility have a 1 in 50 risk of cancer due to arsenic exposure alone, without even considering the other toxins to which they're potentially exposed.

More than 1.5 million children live near coal ash storage sites in the US, and there's a growing body of evidence that those children suffer from increased rates of a range of health problems including sleep disorders and respiratory problems.

Catastrophic ash-pond failures, like the 2008 spill that saw 5.4 million cubic yards of coal ash choke 300 acres of the Tennessee countryside, or the 2014 disaster in which a Duke-operated facility spilled 39,000 tons into North Carolina's Dan River, just 35 miles downstream from Belews Creek, have brought coal ash into the public eye.

A hidden story

Yet ongoing but largely invisible ash-pond leaks remain "a quiet tragedy" of which most Americans remain unaware, says Mary Anne Hitt, head of the Sierra Club's national anti-coal campaign.

"It's a hidden story of the coal pollution problem in America. People don't realize this is going on", she says. "There are hundreds of slow-motion Dan River spills happening all around the country, where these ponds and dams are slowly leaking."

Last November, Will Scott, the Yadkin riverkeeper, was part of a team that surveyed High Rock Lake, an hour's drive south of Belews Creek, where Duke maintains three coal-ash ponds with a combined capacity of around five million tons of ash.

Extremely low water levels made it possible to see ugly orange streaks on the banks below the usual waterline, where Scott says waste from Duke's ‘50s-era ash ponds was literally oozing out of the ground. "The ash is pushing down on the water table and pushing the ash out in all directions", says Scott.

Duke insisted that the streaks were naturally occurring iron deposits, but Scott says subsequent testing of the orange streaks and the lake's water found elevated levels of metals including lead, arsenic, and chromium, in keeping with coal-ash pollution.

And while low water levels made the High Rock Lake seepage easy to spot, Scott says, similar leaks are taking place, albeit less visibly, at coal-ash sites across North Carolina: "At this point there are seeps at pretty much every site across the state."

Eat as much coal ash as you want

Duke Energy currently has around 150 million tons of coal waste stored in 4,500 acres of ash dumps, of which about 70% are in North Carolina. In the aftermath of the Dan River spill, the company admitted cutting corners and ignoring engineers' requests for better monitoring at the site, and agreed to pay $102 million in fines and environmental restitution fees.

Duke also says that it will spend upwards of $3 billion to improve its waste storage facilities in coming years. "We are accountable for what happened at Dan River and have learned from this event", said Duke CEO Lynn Good in a statement. "We are setting a new standard for coal ash management and implementing smart, sustainable solutions for all of our ash basins."

Like the rest of the industry, however, Duke still denies that its ponds are to blame for health problems in surrounding communities. Coal-industry supporters point out that the EPA considers ash a non-hazardous substance, and argue that the heavy metals and carcinogens found in water surrounding coal-ash sites are naturally occurring.

"Coal ash is basically soil", says Tom Robl, a University of Kentucky geoscientist who serves as a director of the American Coal Association. Not only is coal ash non-toxic, Robl says, it's so safe that you could eat a brimming bowlful for breakfast without adverse consequences. "Feel free to eat as much coal ash as you want - it's not toxic", he says.

The root of all evil

It's true that there's little direct evidence that coal ash is causing health problems in humans, says Dennis Lemly, a Forest Service biologist who's been studying coal ash's impact on fish and wildlife since 1975. Still, there's plenty of reason to believe that ash is bad for you.

While traces of many of the chemicals found in coal ash are naturally present in soil, the process of burning coal serves to concentrate them, Lemly explains. "The fact is coal ash is not dirt. Coal ash is a highly concentrated source, and concentration determines hazard."

There's no doubt in Lemly's mind that coal-ash ponds are causing significant harm, both to people and to the environment. In an analysis of 23 coal ash sites, Lemly found that since the 1960s the facilities had jointly caused almost $3 billion in economic damage.

Causes range from lost tourism revenues to poisoned fish stocks, with most of the costs directly attributable to leaks and spills from coal-ash impoundment ponds. "Surface impoundment disposal is the root of all evil when it comes to water pollution and impacts on fish and wildlife", he says.

There's also growing evidence that selenium from coal ash is bioaccumulating in the food chain, even in areas that have theoretically been cleaned up. Ash spills leave behind buried sediments that are ingested by insects and microorganisms, reintroducing the toxins back into the food chain, Lemly says:

"Coal ash is highly toxic, and it poisons fish and wildlife every day. We've got case after case of that ... the toxicity of coal ash isn't debatable."

Increased risks

Radiation is also a potential concern: in a study released this month, researchers found that coal ash contains ten times more radioactivity than regular coal, and warned that the tiny size of coal-ash particles means that any spills or leaks could lead to serious health impacts.

"People breathing this air may face increased risks, particularly since tiny particles tend to be more enriched in radioactivity", lead author Nancy Lauer of Duke University told reporters.

The US coal industry has sought to downplay the risks of ash-related radiation: in the aftermath of the Tennessee spill, TVA told consumers that the ash was less radioactive, gram for gram, than table salt. Researchers subsequently found that the coal ash released during the Tennessee spill was about half again as radioactive as typical coal ash.

The Tennessee ash, moreover, was laced with radium-228 and radium-226, which when ingested is between 15 and 42 times more carcinogenic, per pico-curie of exposure, than the potassium-40 radionuclides found in salt.

And when all's said and done, says Amy Adams of the Appalachian Voices non-profit group, the anecdotal evidence for patterns of health problems in communities abutting coal ash impoundments is overwhelming:

"The health issues around these ponds are similar from community to community. We can't say unequivocally that it's causing these illnesses. But it's highly consistent with what we see with heavy metal toxicity."

A parallel universe

But even as the evidence has grown for the health impact of coal-ash exposure, utilities have remained wedded to a "primitive and archaic" approach to dealing with their waste, says Frank Holleman, a senior attorney with the Southern Environmental Law Center.

That's especially problematic because more sophisticated air-pollution countermeasures have increased the amount of toxins present in coal ash, Holleman explains: "We're using 21st-century technology to remove the pollution from the air, and then we're using 13th-century technology to store the toxins that we've removed from the emissions."

Part of the problem, says Lisa Evans, an Earthjustice attorney specializing in hazardous waste law, is that coal ash impoundments were exempted from rules introduced in the 1970s to monitor and regulate coal slurry storage sites.

Coal slurry ponds now have tough structural safety rules and mandated quarterly inspections, and as a result there hasn't been a major collapse of a slurry impoundment since 1972. "But high hazard coal-ash ponds never have to be inspected, because there's no federal oversight", says Evans. "It's really a parallel universe. It's quite incredible."

'A good framework'

Recent disasters are finally leading to a rethink, at least in some jurisdictions, of the rules governing coal-ash storage. Last year's Dan River spill sparked a popular backlash against coal ash in North Carolina, says Adams, the Appalachian Voices activist.

Crucially, many of the most vocal protestors weren't the liberals clustered in the state's Research Triangle, far from the coal ash sites, but rather the more conservative, Republican-voting residents of rural areas bordering the ash ponds.

"It's become a joke in North Carolina", says Adams. "How do you turn a Republican into an environmentalist? You have a coal-ash spill in their back yard."

The prospect of losing the support of their conservative base drove the state's Republican lawmakers to take action: the Coal Ash Management Act, which was signed into law last September, banned the construction of new coal-ash impoundments, and created a commission to oversee the closure of existing sites.

"I think coming out of last year's legislation there's a good framework in place, and right now the big question is going to be how well it's implemented", says Robin Smith, a lawyer who served as North Carolina's assistant secretary for the environment between 1999 and 2012.

Ticking time-bombs

Still, concerns remain: many of the sites to be 'closed' will simply be covered up and abandoned, without any effort to address potential leaks from the ash still stored in the unlined pits, activists say. And while some monitoring and oversight programs are now in place, prior budget and staffing cuts have left the state environmental agency without the resources and expertise to adequately enforce the law.

Federal regulators have also weighed in, with the Environmental Protection Agency due to announce supplementary regulations this week placing the first federal limits on toxic metals in wastewater from power plants, much of which comes from coal ash.

The new rule builds on a prior federal coal-ash rule, introduced last year, which disappointed campaigners by failing to declare coal ash a hazardous substance, and by establishing a 'self-implementing' regulatory regime in which utilities are responsible for monitoring their own efforts, and can only be held accountable through citizen lawsuits.

"It's putting the fox in charge of the hen house", Adams explains. "Without a fleet of inspectors to go out and check, we're relying on industry's good graces. And they've not been shown to have good graces when it comes to being honest in reporting correctly."

Experts say the EPA's rules will raise the bar somewhat for states that have so far ignored the coal-ash issue, but won't drive the sweeping changes that are needed. There are also concerns that Republicans could try to roll back federal efforts, especially if they reclaim the White House: Jeb Bush, the establishment favorite for the Republican presidential nomination, has already pledged to repeal the EPA's "new and costly" coal-ash rules if he reaches the Oval Office.

But even assuming the EPA's standards remain in place, they're hardly tough enough to protect public health in the absence of strong state-level regulations, says Hitt, the Sierra Club campaigner. North Carolina's efforts in the aftermath of the Dan River spill are the exception rather than the rule, she warns:

"Most states don't have any real state standards whatsoever. Leaving this to the states means leaving lots of ticking time bombs on the shores of our rivers and lakes."

'All I want to do is leave'

Back in Stokes County, residents are waiting to hear how high a priority the new coal-ash commission will assign to closing down and cleaning up the Belews Creek ash-pond.

Belews Creek wasn't identified as a high-priority site in the board's first round of rulings, raising the prospect that it could ultimately receive a low-priority designation. That would allow Duke to 'clean up' the facility simply by capping the storage site, leaving the ash in place in its existing unlined pond, with no new measures taken to prevent coal-related toxins from entering the groundwater.

In the meantime, officials have been carrying out water testing mandated by the new regulations. So far officials have tested more than 200 wells located near coal-ash sites, including several in the Belews Creek area, and barely 10% have passed the state's water quality standards for chemical nasties such as lead, vanadium and hexavalent chromium.

Of the handful of wells that did pass muster, it recently emerged, many had improperly been given the all-clear by labs using testing protocols that weren't capable of detecting contaminants to the levels required by state water rules.

The state is in the process of retesting those wells, and Duke - which still denies its coal facilities are to blame for the contaminated water - has begun paying for bottled water to be delivered to homes around the state where residents have, like Bailey-Lash, been told their water is no longer considered safe for drinking or cooking.

It's unclear how long it will take for officials to determine the future of Belews Creek and North Carolina's other coal-ash ponds. While regulators weigh their decision, Bailey-Lash and her family remain stuck in their now-unsellable home, fearful for their health but unable to move out of the shadow of the coal plant.

"All I really want to do is leave, but I can't", she says. "I feel like a bad parent. But we don't have anywhere to go."

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Ben Whitford is The Ecologist's US correspondent. He tweets - occasionally - at @ben_whitford, and can be found online at BenWhitford.com.