WATERVILLE — About 15 businesses in the Elm Plaza were ordered to boil their drinking water Thursday by the Kennebec Water District, whose officials expressed concern about possible bacterial contamination during repairs to a water main break Wednesday.

Tests for contamination from coliform bacteria, including fecal coliform, are being done as a precaution. The tests are a standard practice whenever there is a pipe breach, said Jeff Lacasse, the water district’s general manager.

“When they shut down a pipe to make a repair, there is a capacity for stuff to get into the main,” he said. “You never know what’s going to be on the ground or underground. There’s potential for bacteria and we don’t want that in our water.”

Lacasse said it is unusual for the water district to impose an order on a privately owned water main, because the district is rarely aware of breaches on those pipes.

In this case, however, the problem at the Main Street shopping center was apparent and many customers also contacted the water district about it, Lacasse said.

Businesses at the plaza include a Hannaford supermarket, a Subway restaurant, Kmart and Champions Fitness Club.

Lacasse said some business owners, who faced a flooded parking lot and no water service at all when the pipe cracked Wednesday, were unhappy to hear that the water needed to be boiled but ultimately recognized the need for safety.

The boil order remains in effect until tests show the water is safe, Lacasse said.

Andy Rosenthal, who owns the plaza, said the water service was restored on Wednesday afternoon and that the system was flushed continuously overnight and into Thursday morning.

He said the affected portion of the parking lot would have to be repaved, and he was unsure of what the total cost would be.

Lacasse said four water samples were taken from throughout the system and that they were being tested to see whether bacteria cultures would grow in the samples, a process that takes about 24 hours.

Coliform bacteria typically don’t cause disease, but they can be an indicator of other disease-causing organisms, according to the Maine Center for Disease Control and Prevention.

Fecal coliform is a specific type of coliform bacteria that commonly is found in animal and human waste and also generally does not cause disease, according to the center.

This is the sixth boil-water order issued in the state this year. Of those six, two — at the Lakes Region Mobile Village in Winthrop on October 9, and at the Heslins Motel in Calais on July 22 — were issued because tests indicated the presence of E. coli.

Most of the 15 businesses in the plaza remained open during the period of no water service Wednesday, although several took steps to inform their customers of the problems they were facing.

Champions and Hannaford each brought in portable toilets for the day for their customers.

Verizon Wireless, the Subway restaurant, and Garden Island Dry Cleaners and Laundromat all closed their doors for the day Wednesday.

On Thursday, the laundry remained closed, but Verizon and Subway reopened, with Subway reporting steady business throughout the morning.

Laurie Stanhope, the assistant manager, said the store was offering only bottled beverages to its employees and customers, and it shut down the soda fountain for the day.

Matt Hongoltz-Hetling — 861-9287 [email protected] Twitter: @hh_matt