Risdon Brook Dam

Don't Flush This

Just because something can be flushed, doesn’t mean it should be. We find a lot of strange things in our sewerage network - things that belong in the bin, instead of the toilet.

Remember the three Ps - pee, poo and paper.


Wet Wipes

Wet wipes, baby wipes, moist towelettes, flushable wipe, whatever you call them, please do not to flush them down the toilet. No matter what it says on the pack, they don’t break down like toilet paper does and they often cause huge problems such as;

  • Blocking sewer pipes and pumps in the sewerage network
  • Overwhelming screening equipment at sewage treatment plants (STPs)
  • Blocking pipes and pumps at the STPs
  • Sticking to aerators at STPs, reducing treatment efficiency and increasing power demand which can cause failures.

To show you what we mean we tested various types of wipes in a side by side comparison with toilet paper. Toilet paper was the only one which started to break down. 

Other bathroom nasties

Wet wipes are not the only issue; many bathroom products also cause blockages in the sewer network and at our treatment plants because they don’t break down.

  • Tampons and sanitary items are a big contributor to blockages. They’re designed to absorb liquid and don’t break down in our pipes.
  • Hair from hairbrushes clumps together with all the other nasties in the sewer and can cause blockages
  • Cotton bud sticks are made of plastic and can sneak through tiny holes in our screens and filters and hold up the treatment process.
  • Cotton wool balls stay in wet clumps can add to blockages
  • Dental floss gets tangled in our equipment and can also tangle other items together leading to blockages.
  • Even facial tissues are designed to absorb moisture and stay intact, unlike toilet paper which is designed to break down in the sewerage network.

All of these items when they come together can form large tangled masses which lodge on any catch point in the network and cause blockages or treatment disruptions. 

Other items

  • Nappies are also commonly found in our sewer network and contribute to blockages. 
  • Cooking oils and fats can also cause blockages in the sewer pipes. Although they usually enter the network in liquid form, most oils and fats will turn to solids in cooler temperature and congeal in the network. They attach to other solid materials like hair, wet-wipes, floss etc and can form an impermeable barrier for water flow. They can also stick to the pipes creating a choke point which can block over time and act as a trap for any other foreign objects that might follow.[MA1] 
  • Needles are also occasionally found in the sewer network and pose a large health risk to our crew members, especially when they are clearing blockages. Needles should always be deposed of correctly and never flushed down you toilet.
  • Condoms are regularly seen at our sewer treatment plant screens, where they usually get trapped. It’s important to note that most condoms are not biodegradable, so it can take many years for them to break down.

We also come across less common items such as clothing, towels, tennis balls, shoes, lego, money, goldfish, door stops and even golf balls! All items which should have been placed into a bin. Also these fats and oils can cause gas build-up in the pipes that are noxious and dangerous for our staff.

What we find


Picture of Wynyard jet aerator with 800KG of wipes and sanitary items.jpg

Picture of Wynyard jet aerator with 800KG of wipes and sanitary items

This jet aerator located at the Wynyard STP stopped working in November 2018, after it was clogged with a combination of sanitary items and wipes weighing approximately 800kg. 


Carrick STP Screen.jpg

Carrick STP Screen

This is a screw screen located at our Carrick STP. It is constantly blocked by sanitary products and wipes, which have to be cleared by hand on a daily basis. 

Pardoe bin.jpg

Pardoe bin

This located at our Pardoe STP at East Devonport, consists of a large number of wipes, sanitary items such as pads and tampons, plastic items and even a doorstop. It is emptied and sent to landfill weekly.

Remember if it’s not pee, poo or (toilet) paper, don’t flush it!