Sooooo, What Happens After You Flush?

TL;DR

After you flush, wastewater joins other household flows, travels through increasingly large sewer pipes, and reaches a treatment plant where screens, settling, filtration, and other processes remove debris and harmful substances. New York City’s plants handle 1.3 to 3 billion gallons per day, while improperly flushed wipes and similar objects can clog pipes and cause sewage backups. Read on to follow each treatment stage and see why only waste and toilet paper belong in toilets.

Transcript

If you're like most people, you probably assume that when you flush your toilet sanitation wizards simply cast the scourgify charm as your expulsions exit the main pipe coming from your house, thereby eliminating it with little effort or expense. While that would be an easy solution, it turns out for primarily historic reasons, a different, much mo... Read More

Key Insights

• 💦 Public sewer systems and septic systems are the two main methods of waste water treatment, with the former being used in urban areas and the latter in rural areas.
• 😳 Flushing non-flushable items like wet wipes can cause significant problems in sewer pipes and wastewater treatment plants.
• 🌱 Wastewater treatment plants process enormous amounts of wastewater daily, requiring careful design and maintenance of the sewer system.
• 💻 The treatment process involves multiple stages, including screening, grinding, settling, and filtration, to remove solids and harmful substances.
• 💦 The purified water is often reused for purposes like irrigation in dry regions.
• 🤽 Waste water treatment plants play a crucial role in maintaining public health and preventing sewage backups.
• 🫢 Waste water treatment plants also contribute to environmental sustainability by harnessing gases produced during the treatment process for bio-fuel production.

Questions & Answers

Q: What happens after you flush the toilet?

The contents enter your home’s pipes and join wastewater from sinks and other sources. They then mix with flows from neighboring properties and may also combine with rainwater from storm drains before traveling through larger pipes to a wastewater treatment plant.

Q: How does wastewater reach a treatment plant?

Wastewater moves through progressively larger sewer pipes with many connections along the route. Systems are designed around elevation changes, sometimes using pumping stations at low points, while treatment plants are usually placed below the areas they serve.

Q: What should and should not be flushed down a toilet?

Only human waste and toilet paper should be flushed. Wet wipes, baby wipes, facial wipes, tampons, condoms, diapers, and other debris belong in the trash because they can become trapped in screens or clog pipes and pumping equipment.

Q: What happens when wet wipes and other non-flushable objects enter the sewer system?

They can clog household or municipal pipes, obstruct pumping mechanisms, and contribute to sewage backing up into homes or overflowing into receiving waters. New York’s wastewater system spends over $7 million per year hauling away material caught in its screens.

Q: What is the first treatment step when sewage reaches the plant?

The plant first passes sewage through a series of screens that capture objects that cannot be broken down or might clog the system. Automated scrapers or workers periodically clear the screens, and the collected debris goes to landfills or incinerators.

Q: How are solids removed from wastewater after screening?

Screens remove large debris, while grit chambers and settling tanks allow additional solids to sink to the bottom. Those accumulated solids are periodically removed and transported to landfills or incinerators.

Q: What happens to the liquid after solids are removed?

Microbes help break down the organic matter remaining in the liquid. Further treatments may use UV light, chlorination, or ozonation to kill microbes before the treated water is released back into the environment.

Q: How much wastewater and screened debris do treatment systems handle?

New York City’s wastewater treatment plants process about 1.3 to 3 billion gallons per day. Tampa reports transporting roughly 5,000 cubic yards, or about 350 to 400 dump-truck loads, of screened garbage per year that should not have been flushed.

Summary & Key Takeaways

• Waste water from toilets and sinks joins together with other wastewater, including flushed objects and debris, in the pipes within your home.

• The combined wastewater from multiple households goes through a series of pipes and pumping stations, where it may be mixed with rainwater from storm drains.

• The waste water eventually reaches a wastewater treatment plant, where it undergoes various processes, including screening, grinding, settling, and filtration, to remove solids and harmful substances before being released back into the environment.