CHAMPAIGN – The city council gave its verbal support Tuesday to AmerenIP's plan to clean up a former manufactured-gas plant site at Fifth and Hill streets, starting in mid-April.

But council members were less enthusiastic about an administration proposal under which city staff would work with AmerenIP to transfer ownership of the 2.4-acre site to the city once the cleanup is complete for future development.

"Frankly, I don't see why it's important we own the property," said council member Marci Dodds.

Council members put off a vote on the ownership question, but did appear to give their OK to having city planning staff work with residents in planning future uses for the site.

Meanwhile, neighborhood residents continued to express dissatisfaction with AmerenIP's cleanup plans, saying that the Illinois EPA-approved plan doesn't call for cleaning up contaminated groundwater that they allege could recontaminate the site over time.

"We do not believe for one second it is safe to leave that contaminated groundwater in place," said Claudia Lennhoff, an organizer with the Fifth & Hill Neighborhood Rights Campaign.

Lennhoff alleged that other sites across the country have had problems with dangerous vapors being released from the ground from contaminated groundwater beneath. She said AmerenIP needs to be doing indoor vapor intrusion testing of homes in the neighborhood to make sure that isn't happening now. And she alleged groundwater could eventually recontaminate the soil, even though Ameren plans to excavate the top 10 feet of soil on the north half of the site.

Residents, speaking during public participation, asked the city council to repeal a city groundwater ordinance that prohibits city residents from drilling private water wells, which AmerenIP has been able to use as a legal justification for leaving the groundwater in place.

"If this was Cherry Hills, it would be cleaned up," said Maggie Cook, 310 E. Hill St.

But council member Vic McIntosh said the city shouldn't repeal the groundwater ordinance.

"If we reverse this ordinance, the downside for us is everybody could go out and drill," he said.

AmerenIP's cleanup of the site should begin in mid-April and take about a year to complete, at a cost of up to $7 million, said Brian Martin, a consulting environmental scientist for Ameren. The utility plans to remove the top 10 feet of contaminated soil on the north half of the site and replace it with clean soil. The utility also would use a chemical oxidation process to clean soil and groundwater up to a depth of 20 to 28 feet, he said.

A large tent with air-handling units with carbon filters will be set up over the areas being excavated, and there will be perimeter air monitoring to ensure the neighborhood is safe, said Peter Sazama, project manager with PSC of Columbia, an Ameren consultant.

Martin said the soil excavation and chemical oxidation treatment "will contribute to an improvement of the groundwater over time."

"It's likely to be decades before everything is clean out there," Martin said. "But in the meantime, there's no potential for exposure."

Mayor Jerry Schweighart complimented AmerenIP for moving quickly to clean up the site after acquiring Illinois Power five years ago.

"I feel Ameren has been very cooperative with the city and the EPA," he said. "I'm sure you don't want to go through all this expense and do a half-baked job."

The Fifth and Hill site is contaminated with benzene and other compounds generated by the former coal gas plant, which operated there from the late 1800s until the early 1930s.