An environmental group and the Ho-Chunk Nation are suing the Wisconsin Department of Natural Resources over the agency’s handling of a permit for a Georgia timber company that wants to build a frac sand operation in southwestern Wisconsin.

Clean Wisconsin argues DNR Secretary Dan Meyer overstepped his authority when he agreed to review an administrative law judge’s ruling that had invalidated a permit issued to Meteor Timber for a proposed $75 million processing and loading facility in the Monroe County town of Grant. Complaints filed Monday in both Dane and Monroe County Circuit Courts seek to block the ongoing review while a judge considers whether the DNR’s rules allow the agency to potentially reverse a judge’s order.

Evan Feinauer, an attorney representing Clean Wisconsin, told the La Crosse Tribune the DNR does not have the authority to act as a judge of its own case. Judges, Feinauer said, must decide whether DNR permits comply with the law.

Administrative law Judge Eric Defort in May ruled that the DNR didn’t have information required by state law when it issued a permit allowing Meteor to fill 16.25 acres of wetlands near Millston. His decision followed a five-day hearing during which several former DNR employees said the agency granted the permit in spite of its own staff findings.

Supporters say the project will bring valuable jobs to the state and will give the economy a boost. But opponents of the project are concerned that the new sand facility would destroy more than 16 acres of forested wetlands

The project, if approved, would destroy wetlands that provide critical ecosystem services to the county as well as a rare habitat for a number of threatened and endangered species, including the Eastern Massasauga Rattlesnake, according to the nonprofit environmental law center Midwest Environmental Advocates.

In January, Midwest Environmental Advocates joined the Ho-Chunk Nation in asking the Army Corps of Engineers to deny permission for the plan to fill wetlands. The Wisconsin Democracy Campaign also raised their concerns about complex conflicts of interests for a law firm that serves as Meteor Timber’s attorneys and Jackson County’s corporation counsel.

Acting on a request from the investment company, Meyer last month appointed staff attorney Mark Herman to review Defort’s ruling. The agency has not determined a timeline for the review process.