When spring arrives and the UMore Park gravel mine starts up after a dormant winter, it will be operating on a new schedule: 24 hours a day, seven days a week.

The Dakota Aggregates mine, located in Rosemount on land owned by the University of Minnesota, is one of a number of south metro gravel mines that feed construction across the metro. As construction picks up in the economic recovery, so too does the demand for gravel. Amid that demand — plus a trend toward nighttime construction to avoid daytime traffic congestion — a 24/7 operation isn’t unusual.

“We’ve seen the volumes and we understand that the business is sort of rebounding a little bit,” said Steven Lott, director of operations for UMore Development, LLC. “So we’re encouraged.”

The Rosemount City Council approved a permit in the fall allowing the mine at UMore Park to run 24/7, although Dakota Aggregates — which is composed of Cemstone and Ames Construction — won’t necessarily work around the clock every day.

“We may only run 18 hours, you know, 20 hours. And then there’ll be some hauling,” said Tim Becken, Cemstone’s senior vice president of operations. “There’ll be a job here or a job there.”

About 1,700 of UMore Park’s 5,000 acres are designated for mining, though only 80 acres can be mined at any given time. The gravel pit didn’t open until 2014, and it will be a couple more years before the mine is fully operational, Lott said. As Dakota Aggregates’ landlord, the university earns money from the mining operation that goes into a legacy fund created by its Board of Regents. And for every ton of gravel mined, 2 cents go into a scholarship fund for geology and civil engineering students in the university’s College of Science and Engineering.

“Really, the mining is a revenue source for a variety of things that include both how to help promote development on the site and the financial front-end costs, but also to help with any remediation that might need to occur on the property,” said Kim Lindquist, Rosemount’s community development director. “So it’s kind of a giant pot, so to speak.”

The university estimates the mine will produce $3 million to $5 million annually.

Initially, the mine operated between 6 a.m. and 10 p.m., and hauling was allowed between 7 a.m. and 7 p.m. on Saturdays. The 24/7 operation will occur throughout the mine, though the northern side will be limited to what’s needed for a select number of projects.

Ruth and Robert Pryor live in a townhouse development north of the mine, and wrote to the Rosemount Planning Commission in October to raise concerns about increased light and noise. They’re particularly worried about the summer months, when noise can travel through open windows.

“Who would like that?” Ruth Pryor said. “I don’t think the mayor or the council members would like it next to their homes.”

Unclear future

Aggregate mines fall under the jurisdiction of the cities they inhabit, and it’s up to those cities to sign off on hours of operation.

In Apple Valley, 24/7 mining is permitted on a limited basis, said community development director Bruce Nordquist. A recent airport runway project required nighttime construction hours, and so the mine supplying aggregate was allowed to run at night, too.

That particular mine is still in operation, though parts of Apple Valley — like many metro cities — are built on redeveloped mine sites.

The UMore Park mine is a new addition to a site that still carries the scars of a World War II-era ammunition plant, and that the university says it will one day turn into a sustainable community for up to 30,000 people.

“If you’ve already disturbed the land, why not build either residential or commercial on that space?” said Dennis Martin, section manager for the lands and minerals division at the Minnesota Department of Natural Resources. “This is a natural follow-up activity.”

The university has a 40-year lease agreement with Dakota Aggregates, but for now it’s unclear what even the next few years will bring. The mine could continue to run 24/7, or it could slow down again.

“It is cyclical,” Lott said. “So next year could be a great year and 2016 could be slow and 2017 and 2018 could be good.”