The Tennessee Valley Authority has invested nearly $100 million over the last year to shore up coal waste disposal facilities at its powerplant sites, and will spend up to $2 billion more to convert wet coal-ash storage sites to dry ash storage. But it’s not likely other utilities will follow suit until federal requirements become clearer.

In the wake of the 2008 coal-ash spill at TVA’s Kingston, Tenn., plant site—the biggest environmental disaster of its kind in U.S. history—most utilities have inspected their coal- ash waste ponds to make sure they are not a hazard to life or property.

But major changes to the coal stacks, ponds and disposal facilities at powerplant sites likely will wait until the U.S. Environmental Protection Agency issues its final ruling on the disposal of coal ash, says Jim Roewer, executive director of the Utility Solid Waste Activities Group. EPA’s final hearing on the ruling is set for Oct. 27 in Knoxville, near the site of the Kingston disaster. The agency likely won’t issue a ruling until late next year, at the earliest, he says.

Given the amount of money at stake for coal waste remediation, Roewer says the utilities won’t take action without knowing how EPA will regulate coal ash. The agency could require waste ponds to be shut down or continue to allow them to be used if they were built to higher standards. Utilities guessing wrong on which path EPA will take could leave them “holding the bag and not getting credit for sizable investments,” he notes.

As owner of the Kingston facility that failed, TVA is under greater pressure to take action. As a quasi-federal agency, it also has more certainty in recovering its costs, observers say. After the Kingston accident, the agency hired Edmonton, Alberta-based Stantec Inc. to complete a $20-million, four-phase examination of its 11 coal plants and 24 associated coal- waste facilities.

“We never want another Kingston to happen,” says Bob Dearcy, TVA vice president.

The results of Stantec’s examination, presented on Oct. 20 after 781 borings and 168,000 engineering work-hours, reveal that no TVA facility poses an imminent threat of failure or has a stability factor below 1. Stantec recommends dozens of projects at the coal plants to improve stability to greater than 1.5. By next July, all 24 sites will meet or exceed that standard.

Currently, TVA has 76 ongoing capital projects to improve coal-waste facilities, including spillway replacement, improved slope stability and upgrades to drainage, storage and seepage systems. The $100 million spent to shore up the coal-waste facilities includes Kingston, says Dearcy. By 2011, the utility will have completed 86 engineering and construction projects to improve its overall coal-waste disposal process. A spokeswoman did not return calls seeking specific contract information.

“Every recommendation that we have made to TVA is being picked up and acted upon,” says John Montgomery, Stantec senior principal engineer.

In addition to the remediation efforts, TVA is moving to store all coal ash in dry form, rather than wet, a process that will cost between $1.5 billion and $2 billion over eight to 10 years.