MORGANTOWN, W.Va. -- Regulators have ordered stability tests on a 7 billion-gallon coal slurry dam in Raleigh County in response to residents' fears of catastrophic failure but said Friday they're not convinced there's a problem with its construction.

Rather, officials with the state Department of Environmental Protection and the federal Office of Surface Mining and Reclamation Enforcement said mining laws require them to assume a citizen complaint has merit.

"We assume the allegation is true without verifying it," said OSM Director Roger Calhoun.

It's up to the state to determine if the threats of failure and flooding are real.

"If we had any reason at all to believe there was an unsafe condition, we would be taking action," said Lewis Halstead, deputy director of the DEP's Division of Mining and Reclamation. "We do not take it lightly in any manner."

Harold Ward, also of the DEP's mining division, said state inspectors who visit the Brushy Fork impoundment have found nothing to suggest a defect. Still, the DEP is working with engineers and Alpha Natural Resources to devise a testing plan to prove it's safe.

OSM cited Alpha subsidiary Marfork Coal Co. on May 26 "for failure to prevent liquification and provide safeguards against the development of this condition."

"Existing data does not show liquification potential exists," the notice said. Still, it orders DEP to submit a plan to prove safeguards are in place.

Residents, however, plan a news conference next week in Charleston to put pressure on OSM, DEP and Virginia-based Alpha, the new owner of the former Massey Energy property.

Joe Stanley, a retired coal miner from Pritchard who battled Massey over the impoundment for years, filed the complaint with OSM. He believes poor construction has created too little compaction of the material inside the dam and too much pressure.

Impoundments are used to contain both solid refuse and coal slurry, the wastewater produced when coal is washed to help it burn more cleanly. The problem, Stanley argues, is that an impoundment must be built precisely to the approved engineering plan or the material inside may never fully compress and dry out.

The increasing pressure creates a greater risk of failure.

"This is not dirt. This is not rock. This is what we call refuse. It's slate," he said. "The cohesive properties are not good."

Alpha said company officials and a consulting engineer met with the DEP and the OSM on Tuesday, presenting data to confirm the impoundment met all state and federal regulatory requirements.

"Our experts are confident that there is no danger of liquefaction" at Brushy Fork, the company said.

Ward and Halstead said impoundments are the most scrutinized facilities they handle.

Engineers -- typically consultants hired by the impoundment owners -- must inspect them weekly, and state inspectors visit at least monthly. The DEP also requires quarterly and annual reports. Two federal agencies, the Mine Safety and Health Administration and OSM, provide even more oversight.

MORGANTOWN, W.Va. -- Regulators have ordered stability tests on a 7 billion-gallon coal slurry dam in Raleigh County in response to residents' fears of catastrophic failure but said Friday they're not convinced there's a problem with its construction.

Rather, officials with the state Department of Environmental Protection and the federal Office of Surface Mining and Reclamation Enforcement said mining laws require them to assume a citizen complaint has merit.

"We assume the allegation is true without verifying it," said OSM Director Roger Calhoun.

It's up to the state to determine if the threats of failure and flooding are real.

"If we had any reason at all to believe there was an unsafe condition, we would be taking action," said Lewis Halstead, deputy director of the DEP's Division of Mining and Reclamation. "We do not take it lightly in any manner."

Harold Ward, also of the DEP's mining division, said state inspectors who visit the Brushy Fork impoundment have found nothing to suggest a defect. Still, the DEP is working with engineers and Alpha Natural Resources to devise a testing plan to prove it's safe.

OSM cited Alpha subsidiary Marfork Coal Co. on May 26 "for failure to prevent liquification and provide safeguards against the development of this condition."

"Existing data does not show liquification potential exists," the notice said. Still, it orders DEP to submit a plan to prove safeguards are in place.

Residents, however, plan a news conference next week in Charleston to put pressure on OSM, DEP and Virginia-based Alpha, the new owner of the former Massey Energy property.

Joe Stanley, a retired coal miner from Pritchard who battled Massey over the impoundment for years, filed the complaint with OSM. He believes poor construction has created too little compaction of the material inside the dam and too much pressure.

Impoundments are used to contain both solid refuse and coal slurry, the wastewater produced when coal is washed to help it burn more cleanly. The problem, Stanley argues, is that an impoundment must be built precisely to the approved engineering plan or the material inside may never fully compress and dry out.

The increasing pressure creates a greater risk of failure.

"This is not dirt. This is not rock. This is what we call refuse. It's slate," he said. "The cohesive properties are not good."

Alpha said company officials and a consulting engineer met with the DEP and the OSM on Tuesday, presenting data to confirm the impoundment met all state and federal regulatory requirements.

"Our experts are confident that there is no danger of liquefaction" at Brushy Fork, the company said.

Ward and Halstead said impoundments are the most scrutinized facilities they handle.

Engineers -- typically consultants hired by the impoundment owners -- must inspect them weekly, and state inspectors visit at least monthly. The DEP also requires quarterly and annual reports. Two federal agencies, the Mine Safety and Health Administration and OSM, provide even more oversight.

Stanley is unconvinced. He said Brushy Fork is a manmade disaster waiting to happen.

"Impoundments scare me to death because I've worked on them," he said.

The dam has a capacity of more than 8 billion gallons.

Emergency response documents say that if it failed, the resulting flood would hit Pettus in just 12 minutes and the communities of Whitesville, Seng Creek and Sylvester within 36 minutes. It would travel through Orgas and Coopertown in the first 90 minutes to Fosterville, Prenter, Comfort and Bloomingrose. In about three hours, it would hit Racine and Peytona.

Impoundments have failed before, but it's been nearly 40 years since it happened in West Virginia.

In 1972, an earthen dam in Logan County's Buffalo Creek collapsed after heavy rain, unleashing a flood that killed 125 people, injured 1,100 and left about 4,000 homeless.

In 2000, a Massey Energy coal waste dam in Martin County, Ky., failed and released some 300 million gallons of slurry, creating a flood as wide as a football field and 6 feet deep.

No one died when the slurry burst through the bottom of the Martin County Coal Corp.'s 68-acre impoundment, flooding an underground mine and polluting 100 miles of waterways. But Massey eventually paid $46 million for the cleanup.

"I don't think any of them are stable," Stanley said. "I think they're all at risk of failure. And the DEP is not taking this seriously."

Two groups worried about Brushy Fork say a failure there could kill 1,000 people. The dam, they note, was built by the same engineers behind the Martin County project.

Coal River Mountain Watch and the Sludge Safety Project will gather supporters Tuesday outside the OSM office in Charleston. Chief among their concerns is a planned permit renewal and proposed blasting for the Bee Tree Surface Mine, which they fear could destabilize the dam.

Calhoun, at OSM, said testing at Brushy Fork "is a good thing to do."

Though he downplayed concerns about that site, he acknowledged that OSM shares some of Stanley's concerns about impoundments in general and the liquefaction potential. OSM is doing a study it hopes to release this year.

Ward, meanwhile, said the DEP is reviewing construction designs and reports and meeting with engineers to finalize a testing plan for Brushy Fork. If any problems are found, the DEP would require remediation.

How any problem would be fixed is unclear.

"It would be very inappropriate for us to provide any hypothetical remediation plan at this time," he said. "If any conditions are found that raise concerns, they will most likely be very specific and will require specific remediation."

CORRECTION: An earlier version of this story incorrectly said the Brushy Fork dam was near Marsh Fork Elementary School.