MUNSTER | Workers have capped off what they believe is the source of a leak that may have seeped up to 10 gallons of crude oil through a storm sewer system in Munster's Somerset subdivision.

An excavation crew discovered the hole, reportedly about the size of a pin, while unearthing a massive area Tuesday near abandoned BP pipelines along St. James Place at the intersection of Somerset Drive.

Nurten Ural raised her living room curtains Tuesday to reveal nearly a dozen workers and excavation equipment in her backyard.

"This morning I woke up, and saw all the digging," Ural said.

Investigators from the Indiana Department of Environmental Management and BP oversaw hours of excavation, which took place steps from the community's park and swimming pool.

BP spokesman Ron Rybarczyk said the company estimates that "a few gallons" leaked into the storm sewers. IDEM spokesman Steve Polston said his on-site representative had reported workers removing 5 to 10 gallons of oil from the storm sewer system.

Investigators say oil seeped into the storm sewer leading to a retention pond that spills into Hart Ditch. Workers capped off the pond's flow into the ditch, which leads into the Little Calumet River.

Two inactive BP lines run through the area of the subdivision, both out of service for at least five years.

Pipes are flushed when taken out of service, Rybarczyk said, "but it's probably typical for there to be residual crude oil in the line."

Rybarczyk said the company will conduct more research on the line, including X-rays, and investigate whether the recent rains contributed to the leak.

BP contracted Indianapolis-based Heritage Environmental Services to clean up the mess Tuesday. Workers from the firm used tools, including booms and sorbents, to sop up and halt the spread of the oil from the retention pond.

Polston said IDEM's responsibility with the leak is "to have oversight over containment and cleanup."

The Heritage crew vacuumed oil and water from the pond behind Sandra Gilmore's house. Gilmore, one of many residents who suffered through the stench, likened its lasting effects to cologne.

"You come outside, and you smell it," she said. After about 10 minutes, she said, "you can't smell it anymore."

"But it stinks, there's no doubt about it," she said.

Neither Munster Town Manager Tom DeGuilio nor BP's Rybarczyk could confirm whether any oil made it to Hart Ditch.

"If it made it to the ditch, it was very little," DeGuilio said.