The Minnesota Pollution Control Agency expects to take ownership of the Eden Prairie Flying Cloud landfill by the end of 2009, with plans to buy it a new $15 million cover in the next several years.

Closed in 1986, the 106-acre landfill on a bluff overlooking the Minnesota River was once a deep gravel pit. Owned over the years by BFI and Allied Waste, it is now in the hands of Republic Services.

The MPCA is in negotiations with Republic now and expects to have the property transferred to the state by the end of the year, said Peter Tiffany, engineer for the agency's closed landfill section.

MPCA Commissioner Paul Eger is expected to ask for money for the landfill's new cover in the agency's state bonding request, Tiffany said. The landfill must be owned by the state to be eligible for bond funding.

Overall, the landfill is in good shape, Tiffany told the Eden Prairie City Council last week. Monitoring wells show that volatile organic compound levels are dropping, which means the water inside the landfill is gradually getting cleaner, he said.

The cover is supposed to keep rainfall out of the landfill, allowing the garbage to dry up and preventing pollutants from leaching into the groundwater, Tiffany said.

But the landfill needs a new cover because the decomposing trash has settled, causing the existing clay-and-earth cover to crack and leaving places for water to pool instead of running off quickly, Tiffany said.

The current cover consists of 2 feet of compacted clay topped by a layer of sand, 18 inches of vegetative material and 6 inches of soil topped with growing grass. The MPCA would replace it with a synthetic liner topped by sand or a similar covering, vegetative material, soil and grass, Tiffany said.

When the new cover goes on, the state also will upgrade the landfill's gas recovery system, Tiffany said. A new cover will cost at least $15 million, he said.

The MPCA monitors 112 closed landfills around the state, using money from three sources: a solid-waste tax applied to individual garbage bills, general obligation state bonds and funds from insurance policies that landfill operators took out during the 1970s. Through legal action with the insurance companies, the agency has collected about $100 million, Tiffany said.

When the state takes over a landfill, it accepts responsibility for maintenance and monitoring but not for liability, he said.

The bottom of the Flying Cloud landfill is not lined, and some contaminants are leaking out to the Minnesota River nearby, Tiffany said. The MPCA is not concerned that any underground aquifer contamination could occur from the landfill, he said.

Asked by Eden Prairie City Council Member Ron Case if landfill leaks could be contributing to the destabilization of the bluff slope and riverbank below, Tiffany said he doubted it because the landfill is well west of the erosion point along the riverbank. A black substance oozing out of the bluff is decayed vegetation that is not related to the landfill, he said.

Tiffany said the landfill holds 8 million cubic yards of waste that can never be moved. The closest homeowners are 800 feet away from the landfill, and they have no reason to be concerned about it, Tiffany said.

The agency was approached by a developer who wanted to build a golf course on the landfill. But with 80 to 100 gas extraction wells on the site, the land is not likely ever to be used for other purposes, Tiffany said.

Laurie Blake • 612-673-1711