Fluoridation is still on hold at OWASA, but the utility’s staff will learn from and improve the distribution system connected to a February water-main break in northeastern Chapel Hill.
A 12-inch water main that was installed improperly, just inches above a storm water pipe, was determined to be the root cause of the break, a consultant told Orange Water and Sewer Authority officials. The break followed an overfeed of fluoride into the Jones Ferry Road water treatment system, caused by operator and mechanical errors.
The failures shut down water service to more than 80,000 customers for about 24 hours.
OWASA’s Board of Directors approved a plan largely focused on the area around the water main break at Foxcroft Drive and Summerfield Crossing. However, staff also could re-evaluate how water mains are replaced and consider using a newly installed metering system to improve break and leak detection, said Vishnu Gangadharan, capital projects engineering manager.
The board also heard about proposed improvements to OWASA’s fluoridation system but delayed a decision to get more information.
Customers again asked the board Thursday to reconsider adding fluoride to local drinking water. Customer William Young took issue with buying equipment that he said is unnecessary and still prone to failure.
“You are introducing a toxin, a poison into the water that is unnecessary and not beneficial, and however small the risk that your system does not work, there is that risk,” Young said.
“Systems fail, pipelines leak, power plants overheat and melt down, and there is no reason to believe that you can come up with a system that is 100 percent foolproof and guarantee that there will never be a situation where you poison the water here. You could guarantee that if you simply stop putting fluoride into the water,” he added.
The board decided earlier this month to resume fluoridation but has not decided when to restart the system.
OWASA can improve the system by replacing the metering pump that failed in February with two smaller ones that meet the maximum capacity needed, said Kenneth Loflin, water supply and treatment manager.
An operator still could adjust the pumps manually, however, they could be programmed to set maximum fluoride dosage and speed limits, avoiding erroneous keystrokes, he said. New valves could help keep excessive fluoride out of the water and protect the system from a clog or closed valve that could damage a pump or break a pipe, he said.
Fluoride could be monitored continuously by a magnetic flow meter that can automatically turn off the system and alert the operator to problems, he said, while a fluoride analyzer could identify overfluoridated water before it enters the pipes.
Loflin estimated the preliminary cost at $125,500 to $175,500. There is money in OWASA’s budget for the work, which could take several months, he said.
Board member Barbara Foushee sought more information about potential staff and training changes. It’s unlikely OWASA will hire more staff, executive director Ed Kerwin said, but existing staff will get more training and won’t be given more responsibility than they can handle.
“In light of the chain of events, it makes me uncomfortable that we would not consider additional staffing,” Foushee said. “That’s the kind of information that I’m looking for, and I really was hoping we were going to add additional staffing, but hearing that we’re not, I’m somewhat disappointed, because that’s one of the first things I thought about … after the water emergency and we were reviewing everything that happened.”
Kerwin responded to other concerns by noting risk assessments at the Jones Ferry and Mason Farm Road treatment plants could be in next year’s budget and staff will continue to review its response in case of future emergencies.
“Those answers aren’t easy – there are difficult decisions that need to be made – but I think addressing them ahead of any emergency and having some guidance in place would be extremely useful,” Kerwin said.