Understanding Your Home’s Water Drainage System
Your home operates with two fundamental water systems: one that brings water in and another that takes water out. In previous blogs, I have discussed where water in Minneapolis and St. Paul originates. This blog will focus on where wastewater goes after it leaves your home.
How Wastewater Leaves Your Home
Every plumbing fixture in your home—whether it’s a bathtub, toilet, or sink—has a wastewater pipe that carries used water away. Smaller fixtures have smaller pipes, while larger fixtures have larger pipes. Eventually, all these pipes join together into a single system.
The Main Sewer Drain
Your house has a main sewer drain, typically located under the basement floor, which you usually cannot see. This main drain continues underground and connects to the city sewer main under the street. The city sewer main collects wastewater from all the houses on your street.
From Sewer to Treatment Facility
As the main sewer line grows larger, all the sewage eventually reaches a water treatment facility. Here, the water undergoes a multi-step treatment process:
- Trash and Debris Removal: Large trash and debris are removed and taken to landfills.
- Grit and Small Debris Removal: Smaller debris and grit are filtered out.
- Grease and Oil Skimming: Grease and oil are skimmed off the surface.
- Aeration and Disinfection: The water is aerated and disinfected using chlorine and ultraviolet light.
Discharging Treated Water
Once fully treated, the water is discharged into a local river or body of water. Wastewater treatment facilities are responsible for ensuring that the treated water is not harmful. While this water is not potable (drinkable), its purity often exceeds that of the body of water into which it is released.
Wastewater Sewers vs. Storm Sewers
There is a common misconception about wastewater sewers and storm sewers. Years ago, all water—whether from rain or household sewage—was combined and sent to the wastewater treatment plant. This single-system approach was inefficient and costly.
The Push for Separate Systems
In recent decades, towns have been mandated to separate stormwater from wastewater. This separation was necessary because stormwater does not require the same level of treatment as sewage, and treating it was becoming prohibitively expensive. The grates you see on the sides of roads are now exclusively for stormwater, which leads directly to a river or body of water without treatment. This efficient system not only saves costs but also benefits the environment.
Resources and Contact Information
For more information about water services in the St. Paul and Minneapolis area, you can visit the following websites:
If you have any questions about your water or need a quality plumber in the St. Paul and Minneapolis metro area, call St Paul Pipeworks today.
Yours Truly,
Matthew Dettwiler
Social Media Manager
FAQs
Q: Does toilet wastewater drain into a storm sewer?
A: No, toilet wastewater does not drain into a storm sewer. It is connected to a separate system called the sanitary sewer, which carries wastewater from toilets, sinks, showers, and other household drains to a treatment facility.
Q: What is the difference between a storm sewer and a sanitary sewer?
A: A storm sewer is a system designed to handle rainwater runoff from streets, parking lots, and other surfaces. It collects and carries this water directly to nearby bodies of water, such as rivers or lakes. On the other hand, a sanitary sewer is a separate system that carries wastewater from buildings to a treatment facility, where it is processed and treated before being discharged.
Q: Are storm sewers and sanitary sewers interconnected?
A: No, storm sewers and sanitary sewers are designed to be separate systems. Storm sewers are specifically meant to handle rainwater and prevent flooding, while sanitary sewers deal with wastewater from toilets, sinks, and other drains. The separation helps to ensure that stormwater does not mix with wastewater and overload the treatment facilities.
Q: What happens to toilet wastewater after it enters the sanitary sewer?
A: Once toilet wastewater enters the sanitary sewer system, it travels through a network of underground pipes and is directed to a wastewater treatment plant. At the treatment plant, the wastewater undergoes a series of processes to remove contaminants, such as solids, chemicals, and harmful bacteria, before being discharged into the environment or reused for various purposes.
Q: Is it important to maintain the sanitary sewer system in my home?
A: Yes, it is crucial to maintain the sanitary sewer system in your home. Regular maintenance, including proper disposal of waste, avoiding flushing non-biodegradable items down the toilet, and periodic inspections, can help prevent clogs, backups, and costly repairs. It is also essential to be mindful of what goes down your drains to ensure the proper functioning of the system and to protect the environment.
