Excavators digging deep in the yard of a home on South Eighth Street still haven't found the source of a sewer leak.

An emergency bidding process handled by Burlington Public Works staff ended over the weekend and digging began Monday. By Thursday, the area in question had turned into a pit of mud and sewer water.

In January, the city received a report of a small pond of murky water in a yard. Realizing a leak in the sewer line was to blame, Burlington staff contacted the Department of Natural Resources and set to work hiring an excavation company to do the work.

Two companies submitted bids for the job. Four Seasons Excavation won the project with a $90,000 bid. Fye Excavating bid about $150,000.

Public Works Director Nick MacGregor said he hopes the leak will be resolved by the end of next week. The old, likely collapsed pipe being sought probably is 30 to 40 feet below the surface, he said.

The site doesn't smell, which city staff presume is why it went unreported for so long. The leak is likely coming just from sewer water skim off the top of the pipe's contents. The stuff one wants to avoid tends to sink to the bottom.

"Make no mistake, it's still a biological hazard," MacGregor said. "It's sewer water. There just isn't much of a smell to indicate that."

While they're digging, crews are going to address a smaller problem with the pipe slightly further south than the leak. While they've dug a giant hole, MacGregor figures, they may as well make sure they won't have to again.

A large part of the Family Dollar and Kempker's True Value parking lot is consumed in excavation equipment for the dig. Much of the project's price tag comes from the eventual needed repairs to the lot where crews are digging through.

Money for the project comes out of miscellaneous cash on hand for similar sewer problems. MacGregor said it isn't a terrible financial problem, but it leaves less money for another sewer leak down the road.

"It's not fun, and we'd rather use the money on other projects," MacGregor said. "But it's just got to be fixed."

City Engineer Jesse Howe believes the age of the pipe is to blame. Sewer components found in the area date back to 1910.