Where Does Our Wastewater Really Go, Mate?

Think it just disappears? Discover the real journey of your wastewater and how flushing the wrong stuff could cost Aussie homes big.

Ever Wonder What Happens After You Flush?

Let’s be honest — most of us hit the flush and never think twice. But what really happens to all the stuff we send down the loo, kitchen sink, and laundry drains? As a kid, I imagined it all flowing into some enormous, foul-smelling underground pool — gross, right?
But truth is, the journey your wastewater takes is way more complex — and a bit fascinating too!

What Is Wastewater Anyway?

Every time you flush the toilet, rinse your dishes, or do a load of washing, wastewater is created. That includes everything from human waste and food scraps to detergents, oils, and dirty water.

Here in Australia, all that muck flows into our sewer systems — a network of pipes that run from your home to your local sewage treatment plant.

💡 Did You Know?
Sewage is actually 99% water and just 1% solids, fats, and chemicals.

Don’t Flush This

🧻 What NOT to Flush (and Why It Matters)

Despite what labels might say, “flushable” wipes aren’t your mate. Neither are these other usual suspects:

  • Wet wipes (yep, even “flushable” ones)
  • Cooking oils and fats
  • Food scraps
  • Sanitary items or nappies

Flushing this stuff doesn’t just clog your own pipes — it wreaks havoc on our treatment plants and waterways. Stick to flushing only toilet paper and human waste.

As a child, I often wondered where everything flushed down the toilet ended up. In my vivid imagination, I pictured it all going to a giant, foul-smelling pool—a nightmare scenario that no child would want to see. Surprisingly, many adults still don't know the journey wastewater takes after leaving their homes. We assume it disappears down the pipes, but wastewater disposal is far more complex. It involves a delicate and intricate process to ensure it is safely treated before returning to the environment. All the waste from toilets, kitchen sinks, laundry, and other drains flows into our sewer system, forming what we call sewage. Technically, sewage should only contain human waste, water, and toilet paper. Items like diapers, solid food scraps, and wet wipes—even those labeled "flushable"—should never go down the drain. Disposing of only appropriate materials makes it easier to clean and treat sewage properly. Did you know that sewage is 99% water, with the remaining 1% consisting of chemicals, fats, solids, and other pollutants? Untreated sewage poses risks to our natural water sources, making treatment essential. When sewage leaves your home, it travels through pipes called sewers, which connect to main sewer lines shared by other properties. These main sewers use gravity to transport wastewater to Sewage Treatment Plants—facilities vital for cleaning sewage before safe disposal.

🌊 The Journey of Your Wastewater

Once it leaves your house, your wastewater flows through:

  1. Property pipes – Connected to your home.
  2. Main sewer lines – Shared with neighbours.
  3. Gravity-fed pipes – Guiding flow downhill to…
  4. Treatment facilities – Like Sydney Water or Hunter Water plants.

At these plants, your wastewater is treated in three major stages:

The Journey of Your Wastewater

1. Screening

Removes large objects like toys, grease clumps (“fatbergs”), and rubbish.

2. Aeration & Sedimentation

Tiny microorganisms break down the gunk — fats, food, and waste.

3. Disinfection

Water’s treated using UV light, chlorine, or ozone to kill bacteria and viruses.

💧The result? Clean, safe reclaimed water that can go back into rivers, oceans, or be reused for irrigation.
How to Avoid Plumbing Disasters 3

🚫 What Happens If You Flush the Wrong Stuff?

  • Blocked drains in your house
  • Overflowing sewers in your street
  • Expensive plumbing repairs
  • Environmental damage to rivers and oceans

And if you’re in a unit or townhouse, your whole building can be affected by one person flushing the wrong things.

Man Using Water Jetter

🛠️ What To Do If You’ve Got a Blocked Drain

If your drains are slow, smell funky, or you hear strange gurgling noises — don’t wait. It could be a sign of serious blockage. ✅ Try This First:
  • Pour boiling water down the drain
  • Use a plunger
  • Mix baking soda + vinegar, let it fizz, then flush with hot water
Still blocked? Give The Plumbing and Electrical Doctor a buzz — we’ve got CCTV drain cameras, jet blasters, and the know-how to sort it fast.

💡 Why This Matters for Aussie Homes

When we treat wastewater right, we:

  • Protect our local waterways
  • Reduce stress on treatment plants
  • Avoid costly repairs at home
  • Keep communities clean and safe

So do your bit — know what goes down the drain, and what should never.

☎️ Need a Drain Expert?

Call The Plumbing and Electrical Doctor on 13 10 91 — your local pros in blocked drains, sewer inspections, and plumbing emergencies.

Want to learn more?
Check out our helpful reads:

Or download this article as a PDF for easy sharing with your neighbours.

✍️ Final Thoughts

So next time you flush, give a thought to the journey your wastewater takes. It’s not magic — it’s a clever system that depends on us doing the right thing.

And if things back up or smell a bit off? Call your trusted plumber and let the pros handle it.

THE DOCTOR GETS IT DONE

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