HAMMOND | The U.S. Environmental Protection Agency said it likely will take at least two days and possibly weeks to pinpoint a BP pipeline leak that sent gasoline and diesel fuel into sewers near 175th Street and White Oak Avenue.
EPA spokesman Sam Borries said the leak in Hammond is fairly common and manageable. He says there's no indication any of the leaked material reached any waterways. He said it's too early to determine the extent of soil and groundwater pollution.
Borries said the leak is small, and the pipeline is encased in concrete.
EPA Regional Administrator Susan Hedman says BP has been ordered to pay all the costs for stopping the leak and cleaning up the site.
The leaking substance is a gasoline/diesel fuel mixture, said Ron Novak, director of the Hammond Department of Environmental Management.
EPA's Borries said workers would be uncovering the suspected pipeline and removing its concrete casing through today.
Laid in 1947 and predating nearby homes, the pipeline runs south along White Oak Avenue from BP's Whiting Refinery, then curves westward at 175th Street before turning south at Walnut Avenue on its way to a terminal in Manhattan, Ill., said Thomas Keilman, BP's local director of government and public affairs.
A large excavator pulled soil from beneath the 175th Street intersection through Wednesday afternoon, depositing the oily material into a plastic-lined Dumpster for removal.
Complicating the procedure is an adjacent 30-inch water main that serves the south side of Hammond and customer communities Griffith, Highland and Munster, Hammond Mayor Thomas McDermott Jr. said.
"We're being very careful with the water line," McDermott said. "This is a pretty tough situation, but things are going as well as expected."
"The safety of residents is most important," BP's Keilman said. "If the leak is ours, we'll repair it and then restore the neighborhood so people can get on with their lives."
BP has a crude oil pipeline and a finished product pipeline that carries gasoline and diesel fuel in the area, Novak said.
Neighbors first reported a petroleum odor Aug. 8, according to an event chronology compiled by EPA. Fumes from a basement drain were suspected of involvement in an Aug. 13 residential fire. And on Tuesday, fire inspectors identified petroleum in the city's sewer system.
The contamination was removed from the sewers at the nearby Walnut Avenue pumping station, said City Engineer Stanley Dostatni, and absorbent booms placed around the station so none of the material would enter the adjacent Little Calumet River.
When Hammond officials dipped into the sewer Tuesday, they pulled out a solid black substance that looked like oil, Police Chief Brian Miller said.
EPA, along with the Hammond Department of Environmental Management and Indiana Department of Environmental Management, are directing operations at the site, EPA's Hedman said, and "BP has been very responsive."
The company has rented motel rooms for members of the four households most affected by the round-the-clock excavation work, McDermott said.
"This is a real inconvenience to residents," McDermott said. "It's not a very sleepy neighborhood right now."
Times staff and the Associated Press contributed to this report.