How Do Sewer Systems Function?

aerial view of sewage treatment plant in wroclaw city in Poland

While we all contribute to sewage waste on a daily basis, most people don’t understand how sewer systems function, including how sewage waste is treated, the types of sewers that exist, and what common sewer issues that they may face. In this article, we examine everything you need to know about how sewer systems work, and how to recognize when you’re in need of sewer replacement or repair.

Where does sewage water come from?

Sewage water comes from homes, where water is being used in kitchens and bathrooms, as well as from commercial and industrial buildings. This waste flows through pipes attached to sinks, toilets, and bathtubs, and runs underground into the sewer system.

How does sewage get to a treatment plant?

Sewage water travels through pipes that flush the water and waste towards local sewers that are operated and managed by the city or town. Most sewer systems rely on gravity to move the wastewater to where it needs to go.

Sewer Waste Processing

Sewer waste in processed through a variety of systems in the following steps:

  1. Sewage is pumped from buildings and homes through pipes that transfer the waste to filters that separate large objects from the sewage water. Large items can include plastic, logs, and other materials.
  2. Next, mud, sand, and smaller materials will settle in a grit chamber. These materials are retrieved over time and taken to a local landfill for proper disposal.
  3. Sewage then flows into tanks where solids in the wastewater will separate into sludge and water.
  4. The sewage water then transfers to a treatment plant where oxygen is added to the water to promote the growth of microorganisms. These microorganisms consume the leftover waste and settle into the bottom of the tank. At this point in the process, almost 90% of human waste, solids, and chemicals have been removed from wastewater.
  5. The remaining water is disinfected and filtered into local lakes or oceans.
  6. The remaining sludge is processed in sludge digesters that kill bacteria. The sludge is then transported to a plant where it is dewatered, dried, and converted into fertilizer.

Diagram of town water treatment

Types of Sewers

Most home and business owners are unaware that there are many different types of sewers that their waste and rainwater may be processed through. The most common sewers include:

  • Combined Sewers: Combined sewers carry domestic, industrial, and storm sewage.
  • Sanitary Sewers: Sanitary sewers deliver sewage wastewater to treatment plants.
  • Storm Flow Sewers: Storm flow sewers carry rainwater to drains and detention tanks.

Diagram of the types of sewers

Common Sewer Issues

Most sewer lines can function for years without any cause for concern. However, when a sewer problem does arise, the situation can be overwhelming, gross, and extremely inconvenient.

You may have a sewer issue if you notice:

  • Multiple fixtures in your home are not draining properly
  • There’s strange kickback in your bathtub, sink, or toilet
  • Your drains are slow, gurgle, or smell badly
  • You notice sewer backup in your basemen, lawn, or driveway

Causes of Sewer Issues

Root InvasionAs trees grow, roots can stretch to push and move pipes that connect your water system and the town’s sewer system. Once shifted, these pipes can become disconnected or break. To prevent this issue, it is important to monitor the placement of trees and pipes.

Broken, Crushed, or Disconnected PipesOver time, pipes can burst, corrode, break down, and disconnect as the ground shifts. This can cause sewage to begin surfacing through the ground and will require the immediate attention of certified sewage repair plumbers.

Improperly Discarded WasteSewer backup can be caused by flushing napkins, diapers, tampons, and other materials down the toilet. It is important never to flush any garbage that can be disposed of in another way. It is also important not to flush or pour any grease down your drain as grease and fat can build up and line your pipes, preventing proper water flow.

Call Harris Plumbing for Sewer Repair

Should you experience any issues with your sewer line, be sure to contact Harris Plumbing as soon as possible. We’re ‘The Plumbers You Can Count On,’ and we’ll be there as soon as possible to provide our service and support.

[maxbutton id=”1″ ]