MUNSTER | A second sample of Munster's water was taken Wednesday evening, but Town Manager Tom DeGiulio said the earliest a boil advisory can be lifted is tonight.

The first samples -- taken at eight locations throughout the town including The Community Hospital and near a water main break -- were dropped off at the lab at 9 p.m. Tuesday.

DeGiulio said the preliminary results came back clean and showed no bacteria in the water.

During a boil advisory, officials recommend cooking and drinking water be brought to a complete boil for five minutes before using. DeGiulio said the water is fine for domestic use, such as bathing.

A second round of samples were taken Wednesday afternoon, but officials results won't be known until later tonight.

Two successive safe samples are needed to lift the boil advisory.

DeGiulio said the advisory is not as extensive as a boil order, and said it was similar to the watch and warning system used by the National Weather Service.

The boil advisory, issued about 4 p.m. Tuesday, extended throughout the entire town to avoid confusion surrounding which areas experienced the problems that led to a loss of water pressure, DeGiulio said.

"There are a number of circumstances there, so that to be on the safe side, you should boil water or use bottled water," he said.

The town's pumping station at Calumet Avenue had lost power, and does not yet have a backup generator. The town's largest pumping station on River Bend Drive lost power, but its generator worked promptly.

But the computer system at the River Bend station -- which reads how much water is stored and controls the amount of water coming from Hammond -- provided inaccurate readings and was not operating valves properly or communicating properly between ground-level and elevated storage tanks.

So when the level of water ground-level tanks started dropping, no water was coming from Hammond to refill them. That, coupled with the break of a 16-inch water main at White Oak Avenue and Fran Lin Parkway -- unrelated to the storm -- caused the loss of more water.

Normally, a water main break on its own wouldn't require a boil advisory, said Mark Knesek, the town's water utility supervisor.

Town officials used the schools' telephone system in the database, which allows officials to make calls to those enrolled in class.

In addition to notifying the media, Munster contacted the Lake County Health Department, which contacted health care facilities and restaurants.