Ruins, concrete slabs, and abandoned tunnels and towers that line a large portion of UMore Park may be a common sight for drivers in Rosemount — they've been there since the end of World War II.

But what lies beneath them has raised the contentious question of who is responsible for cleaning it up.

"There's a very long, extensive history about it," said Bill Donohue, general counsel for the University of Minnesota, which has owned the land since 1947. "We've always wanted to utilize that land, and utilize it in a responsible way."

For years, the university has been trying to get the federal government to take responsibility for cleaning up contaminants in the soil and groundwater from when it operated a World War II gunpowder plant in 1945.

A 2012 report, almost 600 pages long, prepared by the university after a remedial investigation of 3,500 acres of the 5,000-acre park, says the soil contains arsenic, mercury, cadmium, lead, PAHs, PCBs and dinitrotoluene (DNT), which is an additive to the cannon powder that was produced at the plant, known as Gopher Ordnance Works.

The DNT is "not an explosive risk but a pollution risk," Donohue explained.

"There are no immediate harmful effects," Donohue said. "If you walk on the land you're not going to be harmed by the contaminants. You're more likely to step in a hole and hurt yourself. There are a lot of holes out there."

The university has been trying to address the contaminants as Rosemount plans to add large residential and commercial developments at the park property in phases over the next 30 years.

The impact of the contaminants depends on what the land will be used for. But the agency representing the federal government, the U.S. Army Corps of Engineers, denies responsibility, saying that since the government no longer owns the land, the university must clean it up.

"We've come to a point where we felt at the Corps that we had no further responsibility," said Stanley Tracey, assistant district counsel for the U.S. Army Corps of Engineers, Omaha District, which was assigned to the land.

The Corps since 2006 has helped with funding environmental studies on the land — until it took this position. But the language in the deeds at the time the property was transferred leaves the Corps with no liability or responsibility for the land, Tracey said.

The Minnesota Pollution Control Agency [MPCA] says under Minnesota superfund law, both should be held responsible."We think it's a mutual responsibility, and we think it's appropriate for the Corps to be part of that," Donohue said.

Besides the environmental pollutants, physical structures were left behind, scattering the area with crumbled concrete ruins. Although it's hard to tell what they were just by looking at them, the leftovers come from powder production lines that were constructed but never put into use. Demolition debris and remnants of navy firing and shooting ranges sit on the land. Rifle and cannon powder blending towers and packing houses also cover the property, along with abandoned sewer lines and tunnels, open manholes and pits containing up to eight feet of water.

"We think that it's obvious that there's DNT out there; there's heavy metals out there, things that are characteristic of the building and operation of a defense plant," Donohue said. "We're pretty comfortable that they have some responsibility, and we just want them to cooperate with us."

He added, "I have been surprised for several years that they have not taken responsibility. This isn't the first time. I'm just surprised that they don't step up and take responsibility for contamination which they helped create."

The Corps, for the first time in writing from a high-ranking official, denied responsibility after a recent letter from the MPCA suggested both parties enter an agreement to cooperatively clean up the site. The MPCA asked for a response by Aug. 1, and with the denial by the Corps, the university is working to develop alternative solutions.

"When you have a couple of responsible parties or more, we want to work out something where they share that responsibility," said Gary Krueger, supervisor of MPCA's remediation division.

"We would have to look at what we could do as far as any potential enforcement action under Superfund law," Krueger said. "Right now, we want to try and work cooperatively and voluntarily with both parties to move ahead."

Some cleanup done

The plant operated for nine months and never went into full production because of the war's end. A few years later, the government deeded the land to the university. The area of UMore containing the ruins is not currently used. The rest of the park is used for agricultural research and farming by tenants.

MPCA says the university also contributed to some contamination, and the university doesn't deny that. But officials say they have cleaned up most of it and want the U.S. government to clean up its portion of the pollution.

The university rented land to tenants who used it for industrial purposes, and the university had a burn pit where chemicals were burned. Donohue says that pollution came to everyone's attention in the 1980s through the Superfund law. The university discovered contaminants it was responsible for and in 1994, after securing funding from the state, the university cleaned up the land and it was taken off the Superfund national priority list in 2001, Donohue said.

The MPCA does not know what percentage of the land was contaminated by which party, but wants both to figure it out and take action, Krueger said. "They're related to both, from operations when the Gopher Ordnance operated and also from when the university has owned the property," he said.

The Corps says it is willing to meet with the university and the MPCA to discuss any claims against the Army. Donohue says the university recently invited the Corps to come to Minneapolis to discuss solutions, but the Corps declined.

In its last report, the university said it needs more information to come up with a plan to clean up the pollution.

"It kind of goes back to what the proposed land use is going to be," Krueger said. "And that will dictate how or what type of cleanup is done."

Liala Helal • 952-746-3286