The $63 million St. Paul Saints ballpark project is moving into a new phase that includes removal of massive quantities of polluted soil from the former manufacturing site at Fifth and Broadway streets where the 7,000-seat stadium will rise up.
“That’s going to be a big process,” said Mark Maghrak, construction team leader for Minneapolis-based Ryan Cos. US Inc., the project’s design-builder. “There is a lot of contaminated soil on this site, and it’s not just concentrated on one area or another. It’s spread across the entire site.”
At the site in St. Paul’s Lowertown area, demolition crews have taken down the former 650,000-square-foot Diamond Products building, where products such as Dippity Do, White Rain hair spray and correction fluid were once produced.
Workers are clearing the site of crushed concrete and installing temporary shoring for the foundation wall along Broadway Street, Maghrak said.
An even bigger excavation job is taking place across the river where the new Minnesota Vikings stadium is now under construction in downtown Minneapolis. About 850,000 cubic yards of dirt will be moved for that project, Dave Mansell, a general superintendent for Golden Valley-based Mortenson Construction, said after the project team broke ground on the stadium last week.
Based on estimates from Bloomington-based Braun Intertec, roughly 200,000 cubic yards of the soil for the Vikings stadium project may be deemed “regulated,” which means it requires special handling.
Burnsville-based Ames Construction is in charge of the Vikings excavation. Regulated soil will be trucked to one of two destinations: a Dem-Con facility in Shakopee or SKB’s demolition landfill in Inver Grove Heights, according to Jenn Hathaway, director of communications for the Minnesota Sports Facilities Authority.
At the Saints location, it has long been known that the site was polluted, but last spring the city and the project team found out it was even more contaminated than expected, as first reported by Finance & Commerce in June.
The pollution was a big reason why the project’s cost rose by nearly $9 million to the current $63 million.
Former uses at the 11-acre Diamond Products property include coal gas manufacturing, a shoe factory, cold storage, meat packing, plumbing wholesales, and manufacturing of correction fluid and personal care products.
The soil work is affected by the weather, but the ground is only frozen about 42 inches down, and “once we get past that, it’s smooth sailing,” Maghrak said.
How much dirt and debris has to be dealt with?
Maghrak said it won’t be known for sure until the job is finished. But based on from Rogers-based Veit Cos., a project subcontractor, about 28 percent of the estimated 97,700 cubic yards of material to be dug up will require special handling or removal.
About 6,400 cubic yards is “environmentally restricted,” which means it may be reusable on site but only under certain conditions or in certain locations, Maghrak noted in an email.
Another 11,300 cubic yards have buried debris with asbestos-containing material, and 10,000 cubic yards have pollutants that include lead and coal tar. About 70,000 cubic yards are clean material that can be reused onsite without restrictions.
Veit came up with the estimates based on geotechnical reports and a plan prepared by Braun Intertec, a city consultant on the project.
“These quantities are subject to change as the work is completed,” Maghrak said in an email. “Some may go up; some may go down.”
The contaminated stuff will be trucked to SKB’s landfill in Rosemount, an approved final destination for that kind of material.
Andrew Nichols, project leader for the Minnesota Pollution Control Agency, said landfills are permitted to accept materials up to certain concentration levels of pollution. Anything that exceeds those levels has to be hauled elsewhere.
In some cases that could mean taking it to another state, he said.
“Asbestos would be treated a little differently from contaminated soil,” Nichols added. “You want to make sure it doesn’t get airborne, so you do things like keep it wet and double-bag it.”
At the Saints ballpark site, an environmental technician from Braun Intertec will be on site full time to analyze the soil as it’s dug up and classify it as clean or contaminated, Maghrak noted.
“With some of the contaminated material, they have to do what is called a burrito,” he added. “They will take a big dump truck and line it with poly and put all that contaminated material inside that. And that has to be wrapped so when it’s transported none of that material is flying around.”
Maghrak said the ballpark remains on schedule to open in time for the 2015 baseball season.