Just like water, the 50 employees who operate the Fairfax County Water Authority’s (FCWA) 122-acre Corbalis water treatment plant in Herndon seek the lowest level of public awareness.
On a hot summer day, their customers consume as much as 220 million gallons of clean water without thinking about its source, said Tom Bonacquisiti, a chemical and environmental engineer who directs the plant’s operations.
The employees want their customers to take water for granted and know that “It’s there, and it’s good, and it’s safe,” he said.
Before Hurricane Isabel arrived in Fairfax County on Sept. 18, Bonacquisiti said, the biggest event in his 20-year career was the 400,000-gallon Colonial Oil fuel oil spill in Sugarland Run in March, 1993.
Corbalis, which pumps about 50 million gallons of water daily to customers in Fairfax, Loudoun, and Prince William Counties, two cities, and two large government installations, was shut down for 17 days.
Corbalis is the only one of Fairfax County’s four water treatment plants that takes its water from the Potomac River, where the fuel oil was flowing.
Three smaller water plants -- Lorton, “old Lorton,” and River Station -- that process a total of 110 million gallons a day among them, all get water from the Occoquan River, said Bonacquisiti.
Because the county’s water sources are interchangeable, he said, in 1993, no one in Fairfax County lost their water supply. “If one [plant] goes down, water can be shifted anywhere in the county,” he said.
But for more than 48 hours after Hurricane Isabel knocked out the power supply to all four Fairfax County water treatment plants, customers were warned they could drink, brush their teeth, and cook only in water that had been boiled.
“It’s a tough feeling when all your treatment plants are down,” Bonacquisiti said. “We’ve never experienced anything like that before. You just don’t like to have your customers without water.”
“We never lose power at Lorton. That is such a trustworthy plant,” he said. The cause of the power outage was simple: “just limbs on power lines,” Bonacquisiti said.
THE CORBALIS PLANT stores 14 million gallons of water in an underground “clearwell,” almost enough to outlast a 14-hour lapse in power to seven huge pumps that normally thrum with the power of liquid flowing through their 48” pipes.
Within the plant itself, “We have a wonderful cross-connection control program” that won’t let water flow back into the system, Bonacquisiti said.
But losing power from 11 p.m. on Sept. 18 until about 12:30 p.m. on Sept. 19 meant that impure water could have “backflowed” into the system from outside distribution points.
The length of the power loss mandated that two samples be tested, at least 24 hours apart, said Bonacquisiti.
The lab couldn’t rush the time it takes bacteria to grow, he said. It was 7 p.m. on Sunday, Sept. 21, before the tests confirmed that the water supply had been safe all along.
By Sept. 29, a week later, the Fairfax County Board of Supervisors wanted answers.
“It is unacceptable to have no back up,” said Dranesville District Supervisor Stuart Mendelsohn, whose district includes the Corbalis plant near Wiehle Avenue and the Fairfax County Parkway.
After meeting with the FCWA board and staff on Monday, the supervisors voted to analyze the FCWA’s response to the hurricane. “They will have to come back and see what they need, and look at the cost,” Mendelsohn said.
Building a backup power station for the whole system would be expensive, he said, but “Most of us were skeptical it would take $50 million. They don’t need to do the whole thing.
“Because they have great redundancy, they don’t have to have a super power plant at every facility. It may be that putting some of the backup power into the new station in the south,could be enough,” he said, referring to the new Griffith plant that will open next spring on the Lorton site of a former federal prison.
“In the end, there was never any risk to the water, [but] we all said [the FCWA] could have done a better job on communications. We didn’t think it was very good, especially telling people to boil water when they didn’t have power.”
“It is pretty much an issue of power,” said Pamela Beck Danner, the McLean attorney who serves as Dranesville District’s representative to the FCWA.
“The Water Authority did as much as they could, but when you have all four [water treatment] plants’ power source go out, there’s not much you can do.”