You’ve likely seen these small, sometimes larger, unassuming buildings, or sometimes just a fenced cabinet, near your home. There’ll be a discrete sign identifying them — pumping stations. They are part of Fairfax County’s wastewater collection and treatment system. Have you ever wondered exactly what’s inside and how the system works? Here is a look at this part of Fairfax County’s wastewater infrastructure.
The Wastewater System
The wastewater system, one of the largest in the country, serves over a quarter of a million customer accounts, protecting public health by treating wastewater to meet or exceed state and federal water quality standards, and once cleaned, releasing it back into the region’s waterways. What is wastewater? It’s the water used in households and businesses that comes from drains, sinks, bathtubs, showers and toilets. Since the earth’s water system is closed, meaning we have all the water on earth we will ever have, this wastewater is cleaned for continual reuse. Stormwater, from rain and snow, moves through a separate system, cleaned by soil’s natural filtration.
In order for wastewater to be cleaned, it must be collected. That’s what about 3,300 miles of sewer pipes and 63 pumping stations accomplish every day of every year, round the clock. About 100 million gallons is conveyed through the pipe network daily. The majority moves through use of gravity sewer, using the energy that results from a difference in elevation, to move the flow. Most sewers are gravity sewers because they offer dependable movement of the water with no energy costs wherever the grades are favorable. This is the reason one often sees sewage manholes along stream beds, as all water naturally moves to the low points of topography. The system uses pressure pipe meaning the water is always full and flowing, and at a speed that keeps solid waste moving without creating blockages. Wastewater moves under pressure, by gravity, to a low point where there’s a pumping station to move the wastewater to another high point. Eventually, the wastewater moves to one of five wastewater treatment plants. The Noman T. Cole Jr. Pollution Control Plant is owned and operated by Fairfax County. (For more on the Cole treatment plant, see “Local Naturalists Tour Cole Pollution Control Plant”, Mount Vernon Gazette, Oct 14-20, 2022.)
Crews from the pumping station branch of the county’s Wastewater Division visit the pumping stations weekly to perform inspections. There are 26 employees in the branch involved with the inspections, including mechanics, instrumentation technicians and electricians. They check to assure the pumps, located deep underground, 10 to 50 feet depending on location, are working and the wastewater is flowing without obstructions. They clean and sanitize the pipe entries into the main pipe system’s wet-well. They also check the operation of the above ground generators which are used to keep the pumps working in the event of a power outage. While one might expect unpleasant odors from the large wet-well access pipes, only a mild aroma of pine-sol cleaner is detectable from the regular cleaning regimen. Carbon filters scrub air at stations located close to backyards.
Two new pump stations are in the design phase, five pump stations are currently undergoing rehabilitation, and 15 are in various phases of design for rehabilitation. Customers pay for the sewer base system and service usage as part of their water bill received quarterly, not through taxes.
The Pipe System
The pipe system, too, is inspected regularly. Employees conducting inspections fall under a separate management branch under the Wastewater Division. With so many thousands of miles of piping, inspections can cover only about 250 to 300 miles of the 3,300 total each year. Six in-house crews, sometimes supplemented with contract help, use cameras, multi-sensors and lasers, to see below the flow line and assess pipe conditions to determine if upgrades are needed.
Making new sewer connections which are needed at a distance from existing county main piping, is no small task to accomplish. Consider the new rest room facility being built at Laurel Hill Park’s Central Green in Lorton. Contractors are working now to connect new pressure piping to the nearest sewer line connection point. They are using a boring method, accomplished using ditch witch machinery. This method avoids having to open a trench and disrupt Lorton Road to lay pipe to connect the new line to the nearest pressure piping and pumping station. The work is slow, requiring several test pits to assure that pipe is laid near, but without disturbing or damaging, existing gas lines. Work started near the Workhouse Road pumping station and has continued for more than two months with piping now approaching the new restroom facility. When the line connection and building construction is completed next year, the park will have full restroom facilities.
These unpretentious pumping sites, miles of pipeline, and the crews who maintain the system are parts of a huge, but little thought of complex, that makes life easy and pleasant. There are a few things each of us can do to help the 134 employees in the wastewater division to keep the system flowing smoothly, says director Shwan Fata. In addition to remembering what things should not be flushed or poured into drains, Fata asks if you see or smell anything abnormal happening with the system, call the 24 hour Trouble Response Center at 703 323-1211, where employees are dispatch ready to handle those issues that start at the curb connection.
For more on the county’s wastewater treatment system, see The Connection, “Down the Toilet. Down the Drain. Then What?”, Dec 22-28, 2022;