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Wednesday, July 09, 2008
©2008 The Connection
UOSA Gets Go-Ahead
Agency will replace sewer pipes in Chantilly and Centreville
By Bonnie Hobbs, Centre View
It’s something most residents pretty much take for granted — that the waste products emanating from their homes will somehow be disposed of properly and efficiently.
But to the Upper Occoquan Service Authority, whose job it is to keep things flowing smoothly in Centreville and Chantilly, it’s serious business. That’s why UOSA representatives told Fairfax County in April that, unless it replaces some of its deteriorating, 30-year-old pipes, "sewage overflows" could result.
They then explained the project to everyone from county officials, to Park Authority members to homeowners. The county Planning Commission had the final say and, on June 26, it approved the plan.
"All 10 commissioners were there," said Sully District Planning Commissioner John Litzenberger. "Nine voted yes and one abstained because she wasn’t there for the public hearing."
It’s a massive undertaking because UOSA’s responsible for wastewater management in the Occoquan Watershed, including western Fairfax County. And before the project could go forward, several agreements had to be reached between UOSA, the county and the Park Authority — whose land will be disturbed when the old pipes are dug up and the new ones go in.
WORK IS PLANNED on the 13-mile, Cub Run Gravity Delivery System, consisting of the Upper Cub Run, Middle Cub Run, Lower Cub Run, Flatlick and Rocky Run branches. Wastewater flows north to south through this system, and pipeline in all but the Rocky Run section needs replacing.
Project cost is $27 million, with funding coming from UOSA’s bond money, plus water-bill payments. The system was built in the 1970s and, according to UOSA’s project manager, Rick Zaepfel, since UOSA was considered "experimental" then, the pipe sizes were capped.
The existing pipe is just 27-42 inches in diameter, but the new pipe will range from 36-60 inches in size and is expected to last 50-100 years.
"The system was designed to take us to the 1990s and a population of 45,000," said Zaepfel. "Now it’s 2008 and the population is 100,000, so capacity is definitely driving this project."
The current pipe is reinforced concrete, but the new pipe will probably be crafted out of a corrosion-proof Fiberglas. The new section will be about five miles long and will be sized to convey peak flows through the year 2050.
Construction will proceed in phases from south to north. An area 80 feet wide will be temporarily cleared during the work, but UOSA will restore the disturbed area to the property owners’ satisfaction.
"The easement was originally to be 100 feet wide, and then they shrunk it to 80 feet to save some old, mature trees," said Litzenberger. "In exchange, the Park Authority will let them temporarily store their dirt on parkland."
CURRENTLY, between 2 million and 12 million gallons a day of raw sewage come to the Cub Run Pump Station. So sewage will have to be pumped around the work area to maintain continuous service during construction. But the pumps will be enclosed and silenced to minimize noise.
Design engineer Dave Wieller said the work will require temporary closures of Park Authority trails at Gate Post Estates near Compton Road, near Route 29, along Oakengate Way to the Chantilly National Golf Course.
Construction access will be at Route 29, Wetherburn Drive and Hidden Canyon Road in Virginia Run, Honsena Drive in Chalet Woods and Braddock Road near Cub Run Elementary.
"I was concerned about traffic, and we assured the residents that each entrance would be used equally," said Litzenberger. "Each one will be used by UOSA for about six months to bring in their equipment, and they won’t use Route 29 during rush hour."
He noted that At-Large Planning Commissioner Jim Hart "expressed concern about the wood turtles and freshwater mussels that were threatened by this project, so the Park Authority agreed to monitor how UOSA handles the environmentally sensitive plant and wildlife on the scene."
In addition, when parkland is disturbed, the Park Authority must be reimbursed, and agreement was also reached on this point. Besides restoring the land to its original state, said Litzenberger, "As part of the reimbursement, UOSA will build two footbridges over the Cub Run Stream — which will really enhance the park."
He also praised the contribution of Supervisor Michael R. Frey (R-Sully). "I want to credit Mike Frey - who walks in the park every day with his dog - for pushing for the footbridges," said Litzenberger. "He even told UOSA where in its budget it could find the funding for them."
Another condition, which Litzenberger pressed for, was a blasting agreement. David Marshall, of the county’s Department of Planning and Zoning, has arranged for the fire department to monitor any blasting, if required. And there’ll be a phone number that residents may call if they have any questions or complaints about it.
Wieller expects the project design to be finished late this year. For more information, see www.uosa-construction.org.
There’s also news about the construction schedule. "UOSA’s Deputy Executive Director Mike Reach told me they plan on breaking ground, the end of March/beginning of April 2009," said Litzenberger. "He said construction will last three to three-and-a-half years, depending on the weather."