Gov. Mark Dayton wants a deeper review of the Minnesota Vikings' $1 billion stadium proposal for a former munitions site in Arden Hills and he wants it done fast, he wrote this week in a letter to two of his appointees.

In what could be a precursor to a fall special session, Dayton directed Metropolitan Council Chairwoman Susan Haigh and his stadium point man, Metropolitan Sports Facilities Commission Chairman Ted Mondale, to conduct a thorough analysis of the risks and costs associated with the site.

The goal is to remove "as many uncertainties as possible before a transaction is finalized," Dayton wrote in the letter, sent Wednesday.

Vikings Vice President Lester Bagley said the team appreciates the governor's move. "Once we get through this [review], we should be in a position to address the stadium issue this fall," Bagley said.

Mondale didn't discount that timetable, saying Dayton's review is an attempt to make the package stronger. "We're working to button up a deal as fast as possible," he said.

On Thursday, Bagley attended an open house at the proposed Arden Hills site and reiterated the team's commitment to the proposed deal for the former munitions plant. The team's lease at the Metrodome runs out after this season, and Bagley said the Vikings won't sign another lease at the Dome without a deal for a new stadium in place.

Ramsey County and the team last spring announced an agreement to build a stadium in Arden Hills, but the proposal was largely ignored by the Legislature and Dayton as they fought for months over the state's two-year budget.

When the budget was approved in a special session last month, the stadium wasn't considered. At that time, Dayton held open the possibility of a fall special session even as he called the Arden Hills proposal inadequate.

'Time is of the essence'

In the letter to Haigh and Mondale, Dayton wrote: "At a minimum, an analysis of potential risks should include, but not be limited to, an examination of the requirements of an Environmental Impact Statement and Alternative Urban Areawide Review, remediation needs, transportation needs, costs and cost-overrun exposures, scheduling issues, funding projections, and permitting and approval issues for each of the local, metropolitan, state and federal jurisdictions involved."

He told Haigh and Mondale that he wants the process to be an example of his administration's "commitment to a streamlined and speedy review and permitting process."

The governor called the Vikings a statewide asset and urged the two leaders to conduct their analysis with "all due speed" because "time is of the essence."

Mondale said he expects the review to take 30 to 40 days.

"There's a series of unknowns in the Arden Hills site that, given some time now, we can try to take the unknowns out," he said.

The biggest issue will be transportation and roads, he said, because design plans will require approvals from the federal government to the state, county and city.

Road costs have been a problematic component in the proposal because Dayton has said the state contribution is capped at $300 million, including roads. Highway upgrade estimates have varied by tens of millions of dollars.

The deal includes a $350 million contribution from Ramsey County, to be raised through a countywide half-cent sales tax increase.

Both the St. Paul City Council and Mayor Chris Coleman have denounced the sales tax proposal.

Pollution remediation is another key issue. Mondale said the team and the county believe they have a "good handle" on the issue, but the analysis will attempt to forestall surprises.

Other issues loom

Finally, Mondale said costs are an issue -- both for the county, in terms of buying the land from the federal government, and the Vikings as a "viable and profitable" business.

Dayton also has expressed concern that the revenue streams in the bill -- which include a tax on pro sports memorabilia, a Vikings lottery game and a player income-tax surcharge -- may not be adequate to fund the state's $300 million share.

Some Ramsey County insiders have privately groused about possible favoritism for Minneapolis as a stadium site.

But now Haigh, a former Ramsey County Board chair, will be a key part of the discussions.

Ramsey County Commissioner Tony Bennett had nothing but praise for Dayton's letter, calling it "very positive. He wants to make sure everything's a go, and we're going to work with him."

Haigh could not be reached for comment Friday.

Rochelle Olson • 651-735-9749 Twitter: @rochelleolson