The official, Robert LaMere, then the solid waste chief of the Michigan Department of Natural Resources, was speaking to residents and officials working on a regional solid waste management plan for northeast Lower Michigan. He asked them to think very carefully before burying anything harmful down in the big hole, known as “the world’s largest limestone quarry.”

“There are a lot of questions on a landfill in the quarry...at least my office has questions,” Mr. LaMere told the group.

That is because much of the quarry’s moonscaped bottom is below the Lake Huron waterline and is made of leaky limestone known as “karst geology” that constantly seeps lake water into the gigantic hole. In the wrong circumstances, the contents of  quarry landfill could quickly spread in unknown, subterranean directions.

Last month, however, almost two decades after the county took Mr. LaMere's advice and excluded quarry landfills from its part of a regional, state-mandated Solid Waste Management Plan, the Presque Isle County Board of Commissioners did an about-face. At the request of Wolverine Power Supply Cooperative, which wants to build a 600 MW coal-fired power plant in the quarry, the board endorsed putting a landfill for coal ash there, declaring it consistent with its solid waste plan.

The vote was unanimous, despite the fact that the large majority of citizens who spoke at board meetings about the issue strongly opposed the idea. Commissioners seemed reassured by Wolverine’s plan to put the landfill on a plateau well above Lake Huron’s water level and away from known karst geology.

The board’s sign-off was the necessary first step in Wolverine’s quest for a state permit for a landfill for its proposed plant. It is an urgent matter to the company: Without a landfill in the quarry, Wolverine would have to annually haul at least 500 thousand tons of ash—80 semi truckloads a day—laced with heavy metals to another, perhaps distant, location. The decision angered many opponents of the landfill, including a former member of the county's planning commission.

“In my opinion, the commissioners aren’t looking out for their citizenry anymore,” said Bud DeLong, who was ousted from the commission last year after repeatedly raising questions about the coal plant. “It’s beyond me. They’ve acted too quickly on all of this. It’s become, ‘Whatever it takes to get us that small number of jobs’ is okay, no matter what the long-term costs to the community are.”

Officials from Wolverine refused to respond to questions from the Great Lakes Bulletin News Service for this article. But, even as Wolverine sends its permit application to Lansing, events in Washington, D.C. could soon present a new hurdle to the utility.

The U.S. E.P.A., galvanized by a coal-ash landslide that ruined miles of the Clinch River near Kingston, Tenn. last December, and by the nation’s hundreds of leaky coal ash depositories, will soon announce the first federal regulations for storing ash. That could make it hard for Wolverine to place a landfill in many parts of karst-laced Presque Isle County, not just the quarry, and mean more expensive leakage protections.

Given the soaring cost of building new coal plants,  the increasingly skeptical eye that many investors now cast on them, and the decline in electricity demand that prompted state utility regulators to declare the Wolverine plant unneeded, such additional project costs could become a financial last straw for the $1.3 billion project. That may be why, although the plant is years away, the company pushed the county to act so quickly.

"The power companies know there are regulations coming," Lee Sprague, clean energy campaign manager for the Sierra Club in Michigan, told The Detroit News. "They are desperately trying to get their coal ash permits approved before new rules are in place."

Karst Collapse?
Bill Lewis, a county resident and member of the environmental group Citizens for Environmental Inquiry, which opposes the plant, has worked on water stewardship issues in the county for years. He sees the landfill “as a pretty risky” idea, given that the quarry operators must constantly pump out Lake Huron water that steadily leaks into the miles-long, manmade crater.

He said there are no guarantees that Wolverine could prevent the entire quarry from flooding if water pumps in the quarry were to fail.

“If it would develop a leak, or if weren’t covered and we had a period of heavy precipitation, which is not unusual, it seems to me it could flood,” Mr. Lewis said.

If that happened, any contamination would probably spread rapidly, and well beyond the quarry.

According to the local Soil Conservation District Office’s Karst Aquifer Protection Project, Presque Isle and adjacent Alpena County, which also hugs the Lake Huron coast, have more than 284,000 acres of karst within their borders. In fact, there is visible evidence of karst geology throughout the county. There are sinkholes developing near Leer and Posen, southwest of Rogers City, within a few miles of Sunken Lake and Fletcher County Park. According to Geology of Michigan, there are also sinkholes just east of Long Lake, in Bismarck and Case Townships.

One fear is that the ground underneath a landfill might collapse. Another is that significant contamination of the community’s water supply could spread through crevices in the limestone, even if a full sinkhole did not develop. Many county residents have their own water wells, and if toxics reached their aquifer it could spread rapidly and widely.

Chris Grobbel, a partner in Grobbel Environmental Planning & Associates, an environmental engineering firm in Traverse City, said that any landfill placed in limestone—particularly one containing coal ash—should be treated with extreme caution. He said water flows through limestone in very curious ways and water contamination can be very difficult to track and remedy once it occurs.

A manual published by E.P.A., entitled Groundwater Monitoring in Karst Terrains, backs up Mr. Grobbel’s statement.

“Waste-disposal facilities should not be located within a karst terrain unless one is willing to risk sacrificing the use of at least part of the subjacent karst aquifer as a source of potable water,” according to the manual. “This is a high risk, almost a certainty.”

Trucking Is Tricky, Too
The manual offers another warning, albeit wryly stated, that would apply if Wolverine were to truck its waste through the karst-laced county to another location: “Hydrologists are rarely consulted in the selection of a proper site for an accidental spill of hazardous material.”

That, coal plant opponents say, means trucking ash is risky, too.

A letter from Frank Krist, who worked for the Presque Isle County Health Department for more than 33 years, to Mr. Lewis, in response to his request for comments on the landfill, implies that an accident with a semi truckload of coal ash could harm drinking water. Mr. Krist described a test he and MDEQ groundwater experts conducted just outside of Rogers City, which placed dye markers in several “swallow holes” along one of Presque Isle’s two main highways.

“Within a few days,” he wrote to Mr. Lewis, “the dye showed up in the water supply of several homes. Again this showed the speed at which groundwater can travel in karst aquifers.”

Mr. Grobbel, the Traverse City engineer, believes that, if Wolverine gets permission to put a landfill in the quarry, it should used a “Type II” landfill, which can handle contaminated municipal waste. He would also require the company to continually observe adjacent and underlying groundwater via monitoring wells.

“You need to be very careful placing waste in a limestone quarry with or without karst formations,” he said. “If karst cavity-forming occurred, it could be a direct vector of waste into Lake Huron.”

However, John Orzaga, an MDEQ official who is helping Wolverine with its proposal and who seemed to support it at one of the board of commissioners meetings, indicated that Wolverine plans to build a less advanced, Type III landfill, which typically receives inert, safe material such as tree stumps, bricks, or other toxic-free rubble. Currently, coal ash is state-regulated, so rules vary widely. Like most other states, Michigan treats coal ash as non-toxic.

Some in Washington Listening
But that view of coal plant leftovers is changing. As Bruce Nilles, head of the Sierra Club’s national Beyond Coal Campaign explains, the ash typically contains lead, mercury, selenium, cadmium, arsenic, boron, aluminum and other heavy metals that have been linked to cancer, birth defects, and neurological disorders.

Some federal legislators are getting the message.

Whether spurred by the Tennessee coal pond collapse last December, the EPA’s follow up investigations of other pond storage sites, or the report on the matter aired by CBS’ 60 Minutes earlier this year, 60 U.S. Representatives sent EPA Director Lisa Jackson a letter last month urging her agency to quickly take strong action on coal ash storage.

“History shows us that far too many states have allowed dangerous conditions to persist, and the public has paid the price in health and economic terms,” the legislators wrote to Ms. Jackson.

The letter urged the director to, “at minimum, phase out dangerous coal combustion waste impoundments and establish federally enforceable regulators for the disposal of coal ash landfills.”

Rep. John Conyers was the only Michigan congressman to sign the letter. According to The Detroit News, in 2005, the most recent year with available data, the Energy Information Administration ranked Michigan 20th in the amount of coal ash placed into landfills: 2,129,700 tons. Most of the sites provide the equivalent of Type III protections, and many are located close to a Great Lake or a river that feeds them. 

Glenn Puit, a veteran investigative journalist, is a policy specialist with the Michigan Land Use Institute. Reach him at glenn@mlui.org.