Bloomington city officials and residents are challenging a proposal that would make an existing landfill in Burnsville hundreds of feet taller, creating a massive butte made of garbage that would tower above the two tallest ski hills in the south metro.

Rising an estimated 362 feet above the Minnesota River, the Burnsville Sanitary Landfill would tower nearly 100 feet above the 272-foot-tall U.S. Bank Stadium.

Texas-based Waste Management, the nation’s largest trash firm, wants to expand the landfill with 6 million cubic yards of trash it would accept from two nearby trash sites: Freeway Landfill and Freeway Dump. It would also expand the landfill’s volume by 20 million cubic yards of future garbage while reducing its footprint from 216 to 204 acres.

On Monday night, the Burnsville Planning Commission unanimously recommended the City Council approve the concept-stage plan for the landfill’s expansion, saying it opens the door for more discussion.

It now goes before the City Council on March 5.

Several Bloomington residents showed up to the meeting while others wrote e-mails in advance in protest.

“They’re saying they want it to look nice … rolling into Burnsville but you’re going to have a mound of garbage,” said Bloomington resident Scott Peterson.

Opponents were spurred at least partly by a letter Bloomington’s city manager posted on the city’s website. The city manager’s letter also cited numerous worries — including possible noise, odor and water pollution — due to Bloomington’s proximity to the dump just across the river.

“We are concerned that the landfill mound will become the dominant and defining visual feature of this portion of the Minnesota River Valley,” wrote James Verbrugge, the city manager.

The mound would be higher than Bloomington’s Hyland Hills Ski Area and Buck Hill in Burnsville, and would appear even taller because the river valley is down so low, his letter said. It would be more than 268 feet higher than the height the city approved in 2006, documents said.

Verbrugge said that the city wants Burnsville to wait until an updated environmental impact statement is done before moving forward and to only allow the landfill to accept waste from the Freeway Landfill and Dump, rather than new garbage.

Julie Ketchum, spokeswoman for Waste Management, said the landfill needs more space for municipal solid waste, regardless of whether it takes on garbage from the Freeway Landfill and Dump.

The company planned to ask for more space “well before” the Great River Energy incinerator in Elk River planned to close. Its shuttering didn’t affect their request, she said.

Kirk Koudelka, assistant commissioner for the Minnesota Pollution Control Agency, said the loss of the burner “will be felt” in the Twin Cities, since it took in 300,000 tons of garbage annually.

If Burnsville officials approve the proposal, it still needs state approval, said Dave Benke, director of the prevention and assistance division of the MPCA. Acquiring a certificate of need and permit from the MPCA would take six months, while the required updates to the environmental impact statement could take two years. Landfilling is the MPCA’s least preferred way to dispose of waste, MPCA officials said.

The MPCA has said that the Freeway Landfill and Dump in Burnsville are contaminated by heavy metals and harmful chemicals, and could taint both groundwater and the nearby Minnesota River. Once the nearby quarry stops mining, groundwater will fill the empty space, creating a lake that could potentially be polluted by the landfill.

The MPCA considers cleaning up the Freeway Landfill one of its priorities among all closed landfills in Minnesota, Burnsville city documents said. How to do that has been the subject of debate.

The MPCA has proposed digging up garbage at the Freeway Landfill, moving it temporarily and then returning it to the same site on top of a protective liner, which the old landfill doesn’t have.

But that idea isn’t popular with some people. The resulting pyramid of trash would be an unattractive way to welcome visitors as they enter the city on Interstate 35, Burnsville officials have said.

“There’s not one single good reason to do any of the MPCA’s plan,” said Dan Kealey, a council member.

Kraemer Mining and Materials, the company that owns the nearby gravel mine, and Waste Management unveiled a different solution in October. That plan would move the Freeway Landfill and Dump garbage to the Burnsville Sanitary Landfill. Kraemer could then mine the rock under the Freeway Landfill, removing and remediating it if contaminated. City officials prefer that plan.

Burnsville officials said that protecting the city’s groundwater is their first concern. But the city’s 2040 Comprehensive Land Use Plan also includes plans to redevelop the area near the Minnesota River, turning the land atop the Freeway Landfill into a mixed-use development, Kealey said.

“That’s just a fantastic opportunity for developers,” Kealey said, adding that plans are decades away.

But as they envisioned the near future, some Bloomington residents said they found the proposal alarming.

Resident Kirk Juergens asked: “Why must it be so tall?”