Sanitary Sewer

The sanitary sewer system is a key piece of infrastructure consisting of approximately 465 miles of sewer pipes and 13 lift stations. This intricate network exists to make sure that the wastewater that gets flushed every day from homes and businesses makes its way to the Water Pollution Control Plant (WPCP) where it’s properly cleaned and treated before being recycled back into the environment.

How does it work?

The majority of the sanitary sewer system works on gravity. The wastewater flows into underground pipes at an elevated level from the private sanitary laterals that connect properties to the sewer, then it follows the downward direction of the pipe to its final destination at the WPCP.

What is a lift station?

Due to Arlington’s varied geographic area, it’s impossible to have a single pipe that flows continuously from the northeastern portions of Arlington all the way to the WPCP. So instead of having one pipe, the sewage flows into a deep pit with pumps that “lift” the sewage to a higher elevation where it can start flowing downward again. These lift stations are a key component in keeping the sanitary sewer system in working order. If a lift station were to fail, sewage could fill the pump pit and overflow onto the ground, causing a potential environmental hazard.

What causes a sewer to “back up”?

Sewers are designed to have enough difference in level from beginning to end to keep sewage moving quickly. However, sometimes material gets caught in the pipe and blocks water flow.

Some typical blockages are:

  • Tree roots, which work their way into the sewer through joints where pipes connect.
  • Grease from cooking oils and foods. In the cooler sewer water, grease coagulates and forms large masses that stick to pipe walls that can easily cause a blockage.
  • Debris like rags and toys from homes and businesses. Once a single piece gets stuck in the system, other pieces tend to pile up.
  • Broken lines caused by construction crews working near the line or by heavy equipment moving over it.

All these things can cause a sewer line to plug. Know how to prevent sanitary sewer backups

Warning Signs

Early blockage signs include weak-flushing toilets and lagging kitchen and bathroom drains.

Who should I call if I’m having a sewer problem?

If you’re experiencing a sewer backup, before you contact a plumber call 703-228-6555. We’ll dispatch our personnel to make sure that our sewer main is clear and flowing normally. If the blockage is in the County’s sewer main, we’ll clear it at no charge. If the sewer main is clear and flowing normally, we’ll inform you that the problem is in your private line and that you might need to contact a plumber to help you fix the problem.

Home laterals
Sewer backups in the private sanitary lateral are the homeowner’s responsibility to fix. Issues in the main sewer line are the County’s responsibility.

Storm Sewer

The storm sewer system consists of approximately 365 miles of pipe that range in size from eight to 144 inches in diameter. The system transmits rainwater runoff from streets, sidewalks and buildings to our local streams, preventing flooding during heavy rains. Water flows into “catch basins” (storm drains) located along the street, through storm sewer pipes and local streams. This water is not treated at the Water Pollution Control Plant, so it’s important not to dump chemicals or throw trash in the street or storm drains. Learn more about preventing stream pollution.

The County has a permit from the state of Virginia to operate the municipal separate storm sewer system (MS4). Find out more about the County’s MS4 permit.

In 1996, the County completed a Stormwater Master Plan to document the County’s policies and goals for stormwater management.