The 50-mile-long Potomac Interceptor sewer system, which carries waste water from Dulles Airport to the Blue Plains Sewage Treatment Facility in Washington D.C., is in dire need of repair. Approximately 1 mile of the sewer line is severely deteriorated as a result of hydrogen sulfide corrosion, and unfortunately, that 1-mile section runs through Great Falls.
"The concrete inside the existing pipe is breaking down and big chunks are falling off," said John Ulfelder, chair of the Great Falls Citizens Association (GFCA) land use and zoning committee. "The gases are so high that they erode the concrete and eat away at it."
Representatives from the D.C. Water and Sewer Authority (DCWASA) will attend the Nov. 8 Great Falls Citizens Association (GFCA) general membership meeting to give an informational presentation on the organization's upcoming sewer repair and improvement project. Members of the GFCA hope that local residents attend the meeting since the DCWASA project will have a definite impact on the community.
"One of the concerns is that there is going to be significant truck traffic associated with this. We're talking about dump trucks because what they're going to have to do ... is dig a huge hole because they have to dig down to where the pipe is underground and there is not enough room to store the dirt at the site, so they are going to have to move the dirt out," said Ulfelder.
The Nov. 8 GFCA meeting is not a public hearing. The DCWASA repair project will take place next year regardless of the impact its construction will have on the community, but John Ulfelder and the rest of the GFCA Board prefer that residents be informed and prepared.
"I just don't want people to wake up one morning and see a bunch of trucks," said Ulfelder. "The project is necessary and it's going to take place, but there will be some issues while it's being done."
To handle the inner deterioration of the pipe, DCWASA plans to re-line the segment with new plastic.
"Then you will have a new pipe within the pipe, and the space between the two will be filled with grout, so it's basically as good as new," said Roger Gans, an engineer with DCWASA. "It's expensive but it repairs the pipe."
The pipe will be accessed from a site on Northern Virginia Regional Park Authority property in northern Great Falls through River Park Drive to the end of River Park Lane.
REPAIR OF THE EXISTING PIPE is only one part of the overall DCWASA project. The second phase will be the construction of an active odor control facility on the Northern Virginia Regional Park Authority site where the pipe is accessed.
According to Roger Gans, the same gases that cause the pipe erosion are also the same gases that produce unpleasant odor.
"This pipeline was built in the 1960's, and when there was nobody living up there it didn't bother anybody, but as the populations got closer to the pipe it became a nuisance," said Gans.
To battle the production of these odors, DCWASA plans to create a forced air system that will only allow the air inside the pipe to be sucked out through a carbon filter.
"The idea is that all the vents along the pipe are going to be one-way vents which won't let air out — they will only let air in," said Gans.
Unlike the pipe re-lining, this portion of the DCWASA project will be subject to a public hearing before the Fairfax County Planning Commission and the Fairfax County Board of Supervisors.
"Because they are building a structure, they have to file for a special exception," said Ulfelder.
Ulfelder says DCWASA designers and engineers have already engaged in talks with members of the Northern Virginia Regional Park Authority about the use of natural building materials to ensure that the facility blends in as best as possible with the surrounding parkland.
THE ENTIRE PROJECT IS EXPECTED TO TAKE approximately 1-2 years to complete, and is tentatively scheduled to start sometime in 2006. Gans says that the design phase is nearly complete and that the process of obtaining permits and approvals is currently underway.
"They [DCWASA] told us that this is one of the largest projects of its kind in the world," said Ulfelder.
Ulfelder is mainly concerned with making sure that the various traffic concerns are addressed.
"In talking to them, they've been agreeable. One of our concerns is that their trucks not be running on the roads during local school bus hours as they are narrow and curvy two-lane roads, and they seemed amenable to working that out," he said.
GFCA president David Olin says that he would also like to "keep an eye on what sort of future access issues" might arise as a result of the new odor control facility.
"But the immediate concern is the amount of truck traffic," said Olin.
*The public is encouraged to attend the GFCA general membership meeting on Tuesday, Nov. 8 at 7:30 p.m. at The Grange at 9818 Georgetown Pike.