Flushing the toilet takes little thought but managing the 3,200 miles of sanitary sewer pipes where Fairfax County's 100 million gallons of raw sewage flow every day requires maps, trucks and computers.
"It's a very extensive operation. We have one of the largest sewer systems in the country," said Iftekhar Khan, director of the Fairfax County wastewater collection division (WCD) on Freds Oak Road in Burke.
There are combined sanitary sewers, with storm drains mixing with household sewers, and separate sanitary sewers, with different pipes for each.
The county is separated into five different areas, each going to a separate water treatment facility. The Norman M. Cole Jr. Pollution Control plant in Lorton is the only plant specifically owned by Fairfax County. Then some is shipped off to the Blue Plains plant in Washington D.C., the Alexandria Sanitation Authority Plant in Alexandria, the Upper Occoquan Sewage Authority in Centreville, the Arlington County Plant and the H.L. Mooney Plant in Woodbridge. Arlington and Woodbridge handle small amounts by comparison.
Distribution of the sewage is based on the topographical landscape and everything is gravity-dependent. The northern region of the county goes to Blue Plains, Centreville and western Fairfax goes to Centreville, and Springfield goes to the Cole plant.
KHAN STOOD by the map, color coded according to treatment plant.
"If you flush the toilet here in Herndon, that will go to Washington. Sewer lines are laid to the existing topography. The only time it will go uphill is when we have a pumping station," he said. There are 61 pumping stations in this 24-hour operation.
On Sunday, Nov. 30, Frank Wilkes and Mohammed Abdoulle manned the Victor 2100 Series multi-use truck in the Newington area. The county has six Victor 2100 trucks which are armed with a vacuum device as well as a snake-like apparatus to clear sewer lines.
"From that manhole to the next manhole, there's something clogging it," Abdoulle said.
The sewer apparatus is put in the pipe, and forced down to the blockage where it chews its way through. It's similar to a snake that a plumber uses in a house to unclog a pipe.
"That's exactly what it is," said Wilkes.
"It busts through anything that's clogging the line," Abdoulle added. That may include household grease or tree roots that have made their way into the pipes.
"The worst problem we have is the shopping centers; we tell them to trap their grease but they don't do that," Abdoulle said.
Khan confirmed that restaurants were a major culprit in the grease situation but their office can only fix the problem, not enforce the required grease catching devices.
"All food establishments are required to have a grease trap. The problem occurs when their [traps] aren't properly maintained," Khan said.
IN THE 1950s and 1960s, the pipes were made of clay or concrete which became weak and porous after years of use. It wasn't until the 1970s that plastic pipes were widely used and Khan can see the amount of repairs reflects that difference. Inside the beltway, dominated by older houses, they find the clay and concrete pipes more than in the Centreville area for example.
"We have better material now," Khan said.
Then there is the occurrence of the "Orangeburg Pipes," which are pipes made of a composite material, leading from the house to the sewer under the street. Building codes prevent the use of Orangeburg Pipes now but it was common in the 1960s. This is a homeowner problem though, because the homeowner is responsible for the pipes from the house to the sewer line. Nine out of 10 calls into Khan's office are homeowner issues.
"Over time it will just disintegrate," Khan said.
When the calls come in, they have to send an inspector who checks the manholes on either side of the problem area to see if water is running freely through the pipes. If water is running at regular volume than the problem is in the homeowner's pipes. If the problem is in the county pipes, the snake line runs through the pipes. They run it upstream when possible because it eliminates the clog more efficiently, according to Khan.
"So you can clean, trap and remove it," Khan said.
The cities of Fairfax and Falls Church, along with the towns of Herndon and Vienna are customers of the Fairfax County WCD as well. The water from Herndon, for instance, goes into Fairfax County pipes, and then to the Blue Plains facility in Washington D.C. Fairfax County measures the Herndon flow and charges Herndon just as Washington D.C. charges Fairfax County for the waste treatment at Blue Plains.
"We have to measure that flow because we have to bill them," Khan said.
There are some areas in the county, like Great Falls, that do not have sewers, according to Khan.
The Wastewater Collection Division is a county facility but not dependent on taxes, according to Khan. The service is paid for by the homeowners as part of their water bill. Almost half of the water bill goes to the WCD.
Being in the Chesapeake Bay Watershed dictates many of the standards WCD adheres to. The water coming out of the treatment plants is one of the cleanest in the nation.
"Standards for discharging in the Chesapeake Bay area are the highest in the country," Khan said.