CANADYS -- People living in the shadows of the South Carolina Electric & Gas coal plant here have wondered for years about the black specks in their drinking water. When they turn on their faucets, water sometimes pours out in a gray gush. When they do laundry, their clothes get stained.

Worse, they worry that those black particles might be harming their health. It reminds them of the dust that settles on their cars after a still night. But their water comes from wells drilled deep into the area's limestone. How could dust particles get into their wells? Is there some other explanation?

Raymond Lewis is a retired shipyard worker who lives near the plant. He once asked the state Department of Health and Environmental Control to test his water.

"They sent me back a letter saying there was nothing wrong. That's bull," he said. "I have to buy water because I can't drink the stuff. I sent the power company a letter and never heard from them."

To find out what's in their wells, Post and Courier Watchdog examined hundreds of documents about the plant's operations and teamed up with researchers from the College of Charleston. To identify the black specks, these researchers used an electron microscope, X-rays and equipment that breaks down and measures materials with a torch as hot as the sun.

The search for an answer leads to a broader tale, a story that stretches back decades and comes as coal plants face intense scrutiny over their effects on everything from mercury in fish to global warming.

It begins in the 1970s when SCE&G quietly settled lawsuits by nearby residents who were fed up with coal dust coating their homes. The story continues through the 1990s, when the power company struck deals with state regulators over its groundwater pollution and bought up property next to the plant when the contamination spread.

And the black stuff in residents' water?

After extensive tests, College of Charleston researchers said they're "fairly confident" that the particles are fine grains of coal. So far, the newspaper's investigation has identified a half-dozen residential wells around the plant that have been affected.

An official with SCE&G questioned the validity of the tests. He said the power company hasn't heard about any problems with residents' water but would be happy to test their water.

Officials with DHEC also weren't aware of residents' complaints but immediately began making plans to investigate the matter.

"We have a lot of questions right now, more questions than answers," said Thom Berry, director of DHEC's media relations department. "We're going to follow up with the individuals and see what we find out."

Raw coal typically contains trace amounts of arsenic, cadmium and other toxic heavy metals. But it's unclear whether the particles are harmful if ingested. Researchers working with Watchdog said more tests are needed to answer that question.

Meanwhile, residents said they're sure of one thing: "That stuff shouldn't be in our water in the first place," Lewis said.

'Gray clouds'

Canadys is a cluster of homes and farms near the Edisto River, about an hour's drive north of Charleston. Though far inland, the sea has claimed this land from time to time over the eons, eventually creating wedges of sand and limestone that piled up like a layer cake. Ancient earthquakes pushed these layers upward south of Canadys, enough to divert the Edisto toward the ACE Basin and away from the Ashley River.

In the 1950s, SCE&G bought land along the Edisto for its third coal-fired power plant.

"There was a lot of opposition to it at first," said Henry Chambers, 72, who helped build and maintain the first unit and lives a few hundred yards away in a neatly kept brick ranch-style house. "My brother was so mad he even tried to call the president of the United States." He pointed to a concrete slab behind his house where black dust sometimes collects after a hard rain. "After a while, I guess we got accustomed to it."

Chambers drilled his drinking well more than 475 feet into the ground and hasn't noticed any particles in his water. But a few homes away, residents with more shallow wells tell different stories.

Danny Coe moved to the area in the 1970s and says his well is 389 feet deep. He said black flecks sometimes fill their bathtub. "Over the years, it came out pure black for a bit and then cleared up." He said the substance in the water looked similar to the particles they see floating in the air.

"We used to have gray clouds of the stuff coming down on the cars, especially in the late seventies and early eighties." Coe said he sometimes wondered about the pollution's effects; his father died of emphysema, and he remembers when an uncle, Madison Bailey, now deceased, sued SCE&G in 1970.

Bailey lived across a road from the plant at the time. His lawsuit said "a dense smoke has been given off containing cinders, fine dust and various other waste products." He also complained that "great clouds of coal dust from huge piles of raw coal" had made his family cough and sneeze incessantly and coated the inside and outside of their house.

Bailey demanded $100,000. Several other relatives filed nearly identical lawsuits, and according to court documents, SCE&G paid $7,250 to settle one of the claims. There's no court record of what happened to Bailey's lawsuit, though Coe said his uncle settled it for a large sum. "I remember the lawyer asking my dad if he wanted to partake in the lawsuit, and he said he didn't. It really stuck with me."

Connie Dille lives closer to the coal plant and has a well that's just 25 feet deep. "The water comes out gray at first, and the more water you use, the less you see," she said. "It's not quite as bad as it used to be, but it's kind of scary to be drinking water like that."

Across the road, Brandy and Marcus Koth said they have the same problem.

"My husband got stomach problems whenever he drank the water, and when we started buying bottled water, they went away," Brandy said. She's particularly cautious about the water because her two young daughters have severe health problems.

"We've called DHEC and given them samples and done all that, and every time they come back and say the water is safe." She said DHEC did a basic water test and told them more extensive testing would be costly. "We're a low-income family, and our daughters have health problems, so we can't do that."

On a morning last spring, Raymond Lewis opened the lid to his washing machine and turned it on. Water with black particles poured into the washer's tub, and a reporter and photographer for The Post and Courier collected samples. The particles were ink black and quickly settled to the bottom of a plastic container. "I remember one time we cut open the (holding) tank for my well," Lewis said, "It was filled with this black oily stuff."

Is it coal ash?

It's fairly common for people with wells to find sediment and particles in their drinking water. Sometimes the culprit is mold; other times it's manganese, iron and other naturally occurring substances.

The Post and Courier analyzed the water for manganese using commercially available chemical strips and found levels were slightly elevated. Other water samples were sent to a lab at the University of North Carolina-Asheville to test for mercury and arsenic. The lab found no measurable levels of either contaminant.

Meanwhile, Vijay Vulava, an assistant professor at the College of Charleston, agreed to test the particles as part of a student project.

Vulava is a native of India who studied civil engineering at the University of Maryland and received his doctorate in environmental sciences from the Swiss Federal Institute of Technology in Zurich, Switzerland. He specializes in environmental geochemistry and two years ago published a paper about the movement of coal tar contamination in groundwater under an industrial plant in Tennessee.

When Vulava first looked at the sample from Lewis' well, his first thought was that it might be coal. If it was, it certainly wasn't naturally occurring; coal isn't found in the area's geology.

After talking about the issue with his colleagues, he came across a 1984 report about a 375-foot well drilled at the Canadys plant. The driller logged the kinds of rocks he encountered as he went deeper, from clay and sand near the surface to clay-like marl to limestone and then layers of sand and clay drillers call "gumbo," which sometimes means you've hit an aquifer.

Vulava thought the log was an interesting vertical snapshot of the area's geology and was especially intrigued by the driller's notes about the limestone. Limestone can fracture and create pathways into aquifers.

Vulava also was interested in the plant's giant coal ash ponds, which were built on these layers of clay and limestone.

Coal-fired power plants produce millions of tons of ash that are typically dumped into nearby ponds or landfills. When exposed to water, arsenic, selenium and other toxic substances in the ash can migrate into groundwater.

This has been happening at the Canadys Station since 1982, when scientists first identified arsenic and nickel in groundwater below the ash ponds. The contamination eventually spread beyond SCE&G's land, and DHEC gave the utility two options: Clean up the contamination or buy the property. The company bought the property, an Environmental Protection Agency report on the site says.

Under federal law, industries also can deal with groundwater contamination by asking state regulators to create "mixing zones" -- designated areas under their properties where pollutants can mix with clean water. At Canadys, SCE&G asked DHEC for permission to create a mixing zone below its leaking ash pond, and DHEC gave the utility a green light.

Later, the power company built a second ash pond, and arsenic from this new pond also made it into groundwater. SCE&G sought DHEC's approval to expand the mixing zone, and DHEC agreed. The utility has spent about $11 million to shore up the ash pond's berms and says this fix should cause arsenic levels to decline.

Still, the EPA in 2007 classified the site as one of 24 "proven cases" nationwide of damage to the environment.

Was ash getting into the residents' drinking water?

Vulava didn't rule it out -- at first.

Mystery solved

This summer, Vulava filtered some of the sediments and gave them to Robert Nusbaum, a College of Charleston geology professor who specializes in mineralogy. Together, they studied a particle under the school's electron microscope, magnifying it 1,200 times its actual size.

At this level, ash typically looks like Swiss cheese -- similar to volcanic rocks that have been heated at super high temperatures.

But these particles were smooth and layered.

"It definitely wasn't ash," Vulava said.

As they peered at the speck, they noticed how it was made of tightly packed sedimentary rock. Coal is sedimentary, but so are many deposits in the area.

To do more tests, Vulava needed more particles. Along with a reporter and three students, Caroline Broderick, Jordan Goff and Wes Schneider, Vulava returned to Canadys to collect additional water samples.

During one visit, they stopped at a railroad crossing next to the power plant and picked up chunks of coal that presumably had fallen off a railcar. From the tracks, they could see towering black piles of coal waiting to be fed into the plant's boiler.

Like any coal plant, the Canadys Station burns huge amounts of coal, about a rail car every hour. It also generates a large amount of electricity -- 470 megawatts, or enough to power 235,000 homes.

When Vulava returned to the college's lab, he crushed the "railroad" coal and compared it to the sediment found in the drinking water.

To the naked eye, the particles from both samples looked identical.

This set the stage for a more extensive test using the "inductively coupled plasma mass spectrometer," or ICPMS.

The machine uses argon gas to create a plasma torch that's as hot as the sun and breaks materials down to the atomic level.

Vulava stressed that his college lab isn't certified by the EPA. "So our results couldn't be used in court, but we do follow established standards."

He filtered the black particles from the water and collected enough to fill a small pepper shaker. Two students, Kalen McNabb and Guinn Garrett, helped prepare the samples, and Vulava sent them through the ICPMS.

Then he did the same tests on the "railroad" coal.

The findings: The railroad coal and the black particles in residents' drinking water had remarkably similar levels of vanadium, strontium, barium, manganese, cadmium and other elements typically found in coal. In other words, Vulava said, "The filtered coal (in the drinking water samples) has very similar characteristics to the coal found on the railroad tracks."

There was one notable difference: The drinking water particles had higher levels of copper. Vulava wondered whether that might be coming from a residents' copper plumbing. (Lewis and Coe later said they had copper piping in their houses.)

Vulava said he couldn't say with 100 percent certainty that the black particles were coal, "but we had multiple lines of evidence" to conclude that it was "very likely that it is coal."

Vulava said his lab tests also wouldn't show whether the particles are harmful. Public health experts would need to do more tests.

"But this is a significant finding," he said. "Because if we find coal in their water samples, any kind of other liquid contaminant could be transported into the aquifer and their wells."

Results questioned

The Post and Courier supplied the results of the tests to SCE&G. Eric Boomhower, SCE&G's manager of public affairs, questioned the findings. "We can't make sense of the data to show what you're calling coal is really coal."

He said the power company would be "happy to come out and take a look at their water, and if there's an issue we'll address it."

He added that over the years, SCE&G has spent large sums of money to install pollution control equipment at the Canadys plant.

In 1992, it built a cooling system so it wouldn't have to dump heated water into the Edisto. In the late 1990s, it installed equipment to reduce fly ash and emissions that cause acid rain. In 2007 and 2008, it installed systems to collect coal ash so it could be sent to cement makers, who use it to strengthen concrete.

The newspaper also supplied the results to DHEC.

"We're intrigued by this," said Berry, DHEC's media relations director, adding that staffers have begun contacting residents to test their water.

Berry said DHEC officials were unaware of drinking water problems in the area, and that generally speaking, when people ask DHEC to test their water, the agency tests for bacteria and refers people to private labs for more extensive tests. But after being informed of the College of Charleston tests, DHEC plans to do a full chemical scan of residents' water next to the Canadys plant.

Berry said the situation is unusual because the plant sits on a layer of clay-like marl, which is virtually impervious. DHEC investigators may look at whether an abandoned well or some other pathway is sending particles through the marl into the area's aquifers.

'In our drinking water'

On a recent afternoon, a heavy storm moved through the area. Outside the gates of the Canadys Station and within a few hundred feet of the plant's coal piles, pitch black particles collected near a stop sign and in a road ditch leading toward a tributary of the Edisto River.

Down the road, Lewis and other residents said they're fed up with the particles and glad DHEC is looking into the matter.

"We've got all this mercury in the water," Lewis said. "You can't hardly eat any of the fish anymore. You go in the Edisto and find all the black stuff sprinkled like black pepper in the sand. Now, we've got it in our drinking water. It's not right."

Reach Tony Bartelme at tbartelme@postandcourier.com or 937-5554.