An attorney for the Environmental Protection Agency says the EPA is supportive of Omaha's plans to build a downtown ballpark as long as precautions are taken.

Lead contamination has been found in the soil where the ballpark would sit.

A restrictive covenant between the Union Pacific Railroad and the city says no athletic field can be built on the site unless one foot of soil is replaced with clean fill dirt. The UP was previous owner.

The downtown site once was an industrial area contaminated by materials used in the old railroad maintenance shops and by the old Asarco lead refinery.

Debbie Kring is the EPA's regional community involvement coordinator. She says the mandate requiring 1 foot of clean soil is not arbitrary. She said lead contamination has not been found beneath that depth at the proposed ballpark site.

Former Omaha mayor Hal Daub is urging more studies be done on the site of the proposed downtown ballpark to make sure lead is the only contaminant in the soil.

Daub is a member of the Metropolitan Entertainment and Convention Authority, which would manage the ballpark.

He says he's concerned because he's witnessed oily gunk rising to the surface when landscaped areas of Qwest Center parking lots are watered in the summer. The proposed ballpark would sit in Lots C and E.

The Environmental Protection Agency says lead is the only known contaminant in the soil where the ballpark would sit. The city says it will take EPA-mandated steps to clean up the site before construction begins.