LOUISA, Va. (WVIR) - Tests are underway and a probable cause has been ruled out after reports of an unknown gas in the Town of Louisa's water system on November 28.

Since the "Do Not Use" water order was lifted, town officials have worked with several state and federal agencies to find out what kind of gas, if any, was in the water.

Restaurants are up and running, but business owners still want to know what happened that day.

Town officials say they are testing out a couple of different scenarios that may have led to the leak of an unknown gas in the water system.

Louisa Town Manager Thomas Filer says the most recent test of the sewer system ruled out at least one cause.

“We spent the day doing smoke testing in the sewer system investigating a theory of sewer gases that may have gotten into two of the buildings and caused elevated readings," Filer said. "So that's what we’re looking into right now, the actual gas has not been identified."

As of December 6, those smoke tests have not yielded any results.

The mayor of Louisa says more test results should be available as early as Friday, December 7.

The water in the town of Louisa was tested again on December 6 by the division of consolidated laboratory services in Richmond.