Pollution from Minnesota’s largest dump and sewage plant has seeped into the sediment of Pig’s Eye Lake in St. Paul, state environmental officials say, and they want the Metropolitan Council to help clean it up.

The cleanup push comes amid separate efforts to restore habitats and attract park visitors to a remote corner of St. Paul alongside the Mississippi River, where the city once threw its garbage in a massive unprotected pit — an unlined landfill that’s the biggest of its kind in the state. Pig’s Eye is also where about a third of the state’s population still sends its wastewater to one of the nation’s largest treatment plants, operated by the Met Council, which historically disposed of ash from sludge incineration on nearby land.

The state covered the dump, removed toxic waste drums and installed a soil barrier to help hold back what one staff member calls “garbage juice” about 20 years ago. And the Met Council stopped dumping its ash on its property in 1985. But the Minnesota Pollution Control Agency says metals remaining in the sediment pose a risk to wormlike organisms there and the animals that eat them.

“We can’t go back in time and prevent this. We can try to manage some of it and do the cleanup,” said MPCA Assistant Commissioner Kirk Koudelka. “We’ve learned from our past. And we’re going to work to clean this up together with Met Council.”

Other plans for the lake, named after early St. Paul settler (and tavern-keeper) Pierre “Pig’s Eye” Parrant, are simultaneously taking shape.

The U.S. Army Corps of Engineers solicited public feedback last week for a project with Ramsey County to build islands in Pig’s Eye Lake using materials dredged from the Mississippi River, benefiting migrating birds and reducing erosion. The former dump is now a city park accessible only through a wood-chipping yard, but park planners highlighted long-term hopes to redevelop it in a major riverfront plan released last year.

MPCA’s lead Superfund official Hans Neve walked the former dump site, where barrels of toxic waste and leaking batteries once dotted the landscape.

“It truly is one of the most surreal urban landscapes,” said Mary deLaittre, manager of St. Paul’s Great River Passage Initiative. “You can see downtown. You can see all the heavy industry and the infrastructure. And then of course, overhead, you’re going to see ducks and geese … because it’s one of the major flyways in the United States.”

The Met Council wants to study the surrounding area further before committing to a cleanup, however. In a 2014 letter, it disputed MPCA’s assertions that its ash contributed to contamination and said a survey showed a low risk to the wildlife there. It is now planning to test its land to study what remains of the ash.

“We want to understand what our property presents in terms of a contributor or an ongoing risk, so that we can do the appropriate thing with that,” said Leisa Thompson, who leads the Met Council’s wastewater division. “In part because we can’t commit to clean up all of that sediment … when the dump we know is a part of the problem. And we don’t know how much of that is ours, so we weren’t ready to be able to say, ‘Well, we’re getting out our bankroll here.’”

“We are not disagreeing that something needs to be done,” she added.

Hans Neve, who supervises the MPCA’s Superfund program, said they believe both the old city dump and the ash are contributors to the contamination. Tests have found what the agency says are unacceptable levels of metals such as cadmium, copper, lead and zinc at a number of sites. It has proposed cleaning up two small sites to see if the contamination returns.

“The contamination came to be located there over a long period of time,” Neve said. “It may be true the worst of it happened in the past.”

The Metropolitan Plant is the workhorse of the region’s wastewater system, pumping through 170 million gallons of water a day. The purified water is cleaner than the Mississippi River where it is discharged, and the modern plant has a good environmental track record.

The solids that sink to the bottom of wastewater holding ponds are called sludge. The sludge is incinerated, producing about 40 tons of ash per day, which is now trucked to a properly lined landfill in Rosemount. Tighter regulations have reduced its metal content dramatically.

“What was going on with that ash, and how did the contamination get to be where it is?” Neve said. “Not completely clear. What is more clear is that there is some contamination there of the land and also extending out into Pig’s Eye Lake.”

‘Constantly on fire’

Once upon a time, Pig’s Eye was known mostly as a nuisance. Not only did trucks deliver enough garbage there to fill about two U.S. Bank Stadiums, but it was often on fire. Angry neighbors demanded answers at a City Council meeting in 1964, noting the fire had been burning since 1956 and littering their yards with ash.

“I’ve spoken with neighbors who lived here during that time. They said it was just constantly on fire. It stunk,” said Rep. Sheldon Johnson, DFL-St. Paul, who lives on a bluff overlooking the lake.

Pig’s Eye is largely cut off from the rest of the city, bordered by the river and a large Canadian Pacific rail yard. To the north are barge-reliant businesses supplying the region’s chemicals, cement, salt and other bulk goods.

Visitors drive past piles of wood and turn down an unmarked road, where a lone portable toilet signals the trailhead. Little is visible of the dump, which was active from 1956 to 1972, but the garbage remains underground because the MPCA says removing it would cost about $730 million. Battle Creek runs through it to the lake.

The only major signs of human activity there today are groundwater monitoring wells, a tree-planting experiment area, and a safe that someone busted open and abandoned near the creek. Eagles and Canada geese soar overhead, and beavers have gnawed away at trees to make creekside lodges.

“The remoteness has made it to some extent more ideal because it’s been kind of undisturbed since the ’70s, which is interesting,” Johnson said.

The sprawling 200-acre Pig's Eye Municipal Landfill on St. Paul's far south side in 1967.

He introduced a bill last year to allocate $500,000 to help make the area more accessible and add recreational amenities such as trails, boardwalks and better water access.

“My vision is as a large natural area that could be used by the public to view some of the fabulous wildlife we have there,” Johnson said. “The many eagles and waterfowl. The largest heron rookery in the region by far sits right there on the south end of the lake.”

Structures would have to be limited, however, because it’s hard to build foundations in garbage.

eric.roper@startribune.com 612-673-1732

Twitter: @StribRoper