The Department of Environmental Quality will convene a panel of experts to study Michigan rules for dealing with such waste that have been in place since 1996. The standards have drawn recent attention as a Wayne County landfill prepared to receive a shipment of Pennsylvania radioactive material produced through the controversial process of oil and gas production known as hydraulic fracturing, or fracking.
"We believe the standard in Michigan remains protective of our people and our natural resources," Snyder said, "but this advisory group of diverse experts, similar to the assembly that developed our standards, can provide an important, science-based and current review to make sure that's still the case."
The panel will include experts in the fields of health, waste disposal, oil and gas production and other interests, he said.
The Republican governor's announcement didn't satisfy critics, including environmentalists and Democratic leaders, who called for a moratorium on shipments of such waste from elsewhere.
"The state's action in authorizing hazardous radioactive waste to be dumped here is utterly and completely incompatible with everything Pure Michigan should stand for," said Mark Schauer, Snyder's Democratic re-election opponent.
Mike Berkowitz, legislative director for the Sierra Club, said the study was "more about public relations than protecting Michigan's drinking water sources."
The Wayne Disposal landfill in suburban Detroit is one of 17 commercial hazardous waste disposal facilities nationwide and the only one in Michigan certified to dispose of "technologically enhanced normally occurring radioactive material," or TENORM. The term refers to rocks, soils and other substances with radiation levels that, because of human activities, are higher than levels occurring naturally in the environment.
Mining, sewage treatment, demolition and ceramics manufacturing are among activities that can produce TENORM. Another is fracking, in which water, chemicals and sand are injected deep underground to break apart rock formations and release trapped oil and gas.
Fracking TENORM can consist of drill cuttings, liquids that flow back to the surface, treatment sludge and sediments that form in tanks and storage ponds. Pennsylvania allows its landfills to accept certain amounts of such waste. But loads that exceed prescribed limits are sent to out-of-state facilities authorized to receive it, said Morgan Wagner of the state's Department of Environmental Protection.
Wayne Disposal has agreed to take 36 tons of the material from a Pennsylvania oil and gas company. The landfill is specially designed to contain such waste, DEQ spokesman Brad Wurfel said. It has a double liner with leak-detecting sensors and is built above 70 feet of clay, a natural barrier preventing contaminated liquids from seeping into groundwater.
"It's an ideal place to dispose of any materials that have low levels of radioactivity," said Dave Crumrine, spokesman for Environmental Quality Co., which owns the landfill. "We have rigorous, highly engineered containment and monitoring systems."
But he said the shipment has been put on hold until the review of Michigan's standards is completed, even though the landfill has taken comparable types of waste since receiving DEQ authorization to do so in 2006.
Out-of-state waste is a sore point in Michigan, where many complain about the state's landfills accepting garbage from Canada. But Crumrine noted that Michigan also sends some of its waste to other states, including radioactive medical refuse and material needing incineration.