Consol impoundment size, thickness doom early search attempts - Business, Government Legal News from throughout WV

Consol impoundment size, thickness doom early search attempts

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Updated with two recovery approaches explained by Consol at 2 p.m. Thursday

Two approaches that were rejected early in the search for the miner trapped Friday, Nov. 30, in Consol Energy's Robinson Run coal slurry impoundment give insight into the nature of the situation.

The miner, a bulldozer operator, was dragged into the impoundment when the section of dam he was working to expand collapsed.

Two recovery solutions came into place mid-week: short-term, to drop a very large pipe over the bulldozer, sitting 25 feet down or more, flush sediment out and dive in; long-term, if that doesn't work, to wall off the bulldozer and pump slurry out.

Those plans formed after pumping the impoundment down, one of the earliest approaches to rescue and recovery, was rejected.

The West Virginia Department of Environmental Protection started pumping fluid out of the impoundment Friday evening.

It abandoned that effort on Saturday.

"They were bringing a fourth pumping system in to try to accelerate it a little bit," said WVDEP spokesperson Kathy Cosco Saturday afternoon. "But then they stopped the pumps around 3 p.m. because they came to the conclusion that it's going to take an incredibly long time to make a difference in the water level."

At the targeted pumping rate of 1,600 gallons per minute, the impoundment's current working volume of about 6,000 acre-feet would have taken more than two years to drain. Any pumping that could have been completed during a recovery operation would have made very little difference in the depth of the slurry.

Another early search approach was to send divers into the slurry.

Divers were quickly on site on Friday and returned to the site on Saturday. But around 11 a.m. Sunday, federal Mine Safety and Health Administration spokeswoman Amy Louviere sent out an e-mail update to media covering the recovery: "The divers had no idea the material was this thick. Other options are being considered."

There is probably a range of consistencies throughout the 70-or-so-acre impoundment, as described by economic geologist Alan Stagg, president and CEO of Stagg Resource Consultants in Cross Lanes.

Slurry — a suspension in water of fine refuse from washing the coal — is piped in from the coal preparation plant, Stagg explained.

At the point where it enters the impoundment, it's "blackwater"; from there, it fans out as it settles.

"Basically you're creating a delta," Stagg said. "The farther away you get out from there, the less murky it will be."

The area where the collapse took place was at a far edge from the slurry inlet and may have been relatively clear water — before the collapse.

"Of course the minute you have a slip, where the whole slope gives way, now you've just created a whole plume of material," Stagg said. "It would be like a swimming pool with a foot of mud in the bottom sitting there all winter. Stir that up with a stick, it won't settle out right away."

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