When a six-inch water main burst last Friday, the main problem was the decades-old pipe did not have enough isolation valves for crews to fix the problem without shutting off all of the town's water.

Thousands of Fort Mill residents were without water Friday afternoon while town employees attempted to patch a leak in the water main running under Skipper Street.

The town realized the line was leaking about two days earlier, according to Public Works Director Davy Broom. The full extent of the problem became clear when water from the busted main filled the hole a work crew dug at the corner of Grier and Skipper streets to work on the line.

"We had to take off the main line into town [from Rock Hill] temporarily until we take enough pressure off this line to repair it," Broom said Friday at around 3:30 p.m. while a small, gas-powered pump sprayed gallons of water onto the street. Town workers also opened the valves on as many as seven fire hydrants to relieve the water pressure in the line.

He hoped to have the problem fixed by 4:30 p.m., but water wasn't restored until later that evening. After service was restored, residents were advised to boil tap water for two minutes as a precaution against bacteria. Tests completed over the weekend confirmed the water supply was safe.

With the main's incoming line shut down, residents and businesses east of downtown maintained water service, although they were drawing water from the town's Doby's Bridge Road water tower, Broom said.

"Most of what we do is trouble shooting," Broom said. "We get one this bad every couple of years."

Broom was unsure of the line's age.

"If I had to guess, I'd say it's at least 80 years old," he said.

Most of the water lines running beneath Fort Mill's older neighborhoods are about the same age, he added.

With aging infrastructure under the streets, Town manager David Hudspeth said addressing the potential problems is a major concern, but not one with any short-term fixes. The town is studying the old pipes to determine where isolation valves can be added. The new lines going in these days have plenty of the valves, but they are few and far between on the old lines.

"We repair the lines when needed, and we're constantly upgrading the system to provide enough flow," Hudspeth said. "We don't typically replace old lines with new ones. If we have constant issues with any one line we will replace it, but that doesn't happen often."

Figuring out where and how many valves to add could take as long as six months, Hudspeth said, and could get expensive, depending on the number of valves and the size of the lines in which they will be installed.

"It's a budgetary issue," he said.

Line breaks as severe as last Friday's don't come around often, he added.

"I don't ever remember as issue as severe as last Friday's," he said.