Redeveloping the former Lorton prison site may be thirsty work involving long hours of negotiation, design and planning, but thanks to a new water treatment plant, water won't be a scarce resource.
Although no date has been set for the plant to open, the Frederick P. Griffith Jr. Water Treatment Plant has been built, modeled in part on the prison across the street, and will replace three other facilities in the fast-growing, southern portion of Fairfax County.
Being built at a cost of $110 million, the plant was named after the second engineering director of Fairfax Water, who served for 32 years between 1959 and 1991, said Jeanne Bailey, public affairs officer for Fairfax Water.
The water treatment process begins with water being pumped up from the Occoquan River into a pumping station, designed to look like the Rock Ledge Mansion on the other side of the river in the Town of Occoquan, Bailey said.
"Our facilities have to be in people's neighborhoods, and the community here said they like the mansion, so we built a large scale model of the house, complete with windows and a front door," she said.
Water that pours into nearly every home in Fairfax County doesn't just come directly from the river, Bailey said. The county has two sources of water: a reservoir which holds 8 billion gallons of water located near the Occoquan River is one source and the Potomac River to the north is the other. While the water treatment plant near the Potomac River is currently undergoing some improvements, the Griffith plant in Lorton is replacing three older facilities.
"The old buildings will eventually be dealt with by the [Fairfax Water] Board, which has talked with the Town of Occoquan and Prince William County about what they might like to see happen with them," Bailey said.
In order to serve its 1.3 million customers, the facilities owned and operated by Fairfax Water run constantly, Bailey said. "We serve parts of Fairfax, Loudoun and Prince William counties, the Dulles airport, Fort Belvoir and have agreements with the Town of Herndon, the cities of Alexandria, Falls Church and Fairfax. There are 3,100 miles of pipe in the ground that we are responsible for," she said.
Over 120 million gallons of water will be purified each day, in addition to the 150 million gallons produced by the plant on the Potomac River, Bailey said.
THE RAPIDLY growing Lorton/Laurel Hill community has been involved with the evolution of the water plant, said Bailey. "We went to the newly budding Laurel Hill community at the time to see what they thought the Griffith plant should look like, and overwhelmingly people liked the brick look of the prison." The buildings are long and rectangular, with elevated flat brick panels on the ends of the buildings.
Inside the main administration building, a visitors center complete with information on the suffragettes who were incarcerated at the Occoquan Workhouse across the street will be installed, said Charles Murray, executive officer for Fairfax Water. The lobby will have information on the water process in addition to some history of the area.
Also in the lobby will be a window into the room where engineers sit at control panels and computer stations, monitoring water levels, filtration systems and can regulate how much water is processed in a day, Murray said.
After water is pumped up from the river, it is stored in large outdoor bins, where poly-aluminum chloride, a coagulant, is mixed in. Dirt and other pollutants in the water react with the chloride and clump together, forming large globs of sediment which eventually fall to the bottom of the water bins, Murray said. The sediment, called floc, is sifted into a large bin and eventually into a quarry, which it will eventually fill over several decades.
"The settled water is clear and looks clean, but then it is sent through a two-step filtration process where it goes through a sand and carbon filters so the remaining floc is filtered out," said Murray. Chlorine is added to disinfect the water, which is then collected in large tanks. Ozone gas is also added to kill any viruses in the water and removes any residual taste or odors.
"The water is contained in a clear well until it is needed," said Murray. "Water does eventually go stale, but we are constantly operating the distribution so that doesn't happen. We use the water we have in the well during the day and fill the tanks at night, when the demand is less."
IF THE WATER stands in the tank for a few weeks, the chlorine and ozone's impact will be lost and the water would have to be re-filtered, Murray said. "It's like putting water from your tap into a bottle in the refrigerator. You can only keep it for a few weeks before it needs to be refreshed."
Samples of the treated water are taken several times daily to monitor the quality, Bailey said.
Inside the monitoring room, engineers oversee the operations and monitor various feed levels, said Len Ponn, one of the engineers at the Griffith plant. "We set valve pressures, control and monitor pH levels, water temperature in the tanks and how much raw water is brought in for processing," he said.
Computer monitors also keep track of the amount of build up on the 14 sand and carbon filters, which are backwashed every few days to maintain their performance, said Bailey. The two filters are each about six feet deep, she said, but incredibly effective.
"If you took three tablespoons of carbon and spread it as flat as possible, it would cover the outside of an aircraft carrier," she said.
When the water has been fully processed, it is released into the water supply through a series of pumps, each one powered by a 500 horsepower engine that can deliver a maximum of 16,000 gallons of water per minute, or 16,384,000 eight-ounce glasses of water every minute. The plant will have a capacity to produce a potential total of 23,040,000 gallons each day.
"This is a remarkable plant," Murray said. "It will prove to be an asset for the area in terms of the reliability and quality of the water we provide to our customers."
The construction of the plant was part of the initial legislation handed down from the federal government when the county took over the prison land, said Supervisor Gerald "Gerry" Hyland (D-Mount Vernon). "The land was made available to Fairfax Water to replace three older facilities and has turned into a major opportunity for us to have this facility here in Lorton," he said.
Residents of Fairfax County have been "so fortunate with a more-than-adequate water supply" during droughts, Hyland said, adding he is "thrilled" the plant is a part of the "transformation of Lorton."