LA CROSSE, Wis. -

Clean up of contaminated soil at the La Crosse Oktoberfest grounds is slightly behind schedule.

Xcel Energy knocked down the Bier Hall and two other buildings as part of the project. It started last week.

The cold weather and deep frost is posing an added challenge to removing the soil that was contaminated by an old factory gas plant. "We're seeing some, a couple spots of what we expected to find, some purifier box waste from an old manufacturing gas plant and a little bit of tar," said Mike Herro from Xcel Energy.

Xcel still expects the project to be finished mid-June. They also believe this will be the last major clean up project in the area.