News article created on 17 November 2017

Game of thrones – boat toilet waste disposal

'Pump out or cassette' is one of the perennial debates amongst boaters, with most of us having strong feelings in one direction or other. Whatever we use - pump-out, cassette or composting - we all need to dispose of our toilet waste responsibly and without harm to the environment.

A man using a pump out A pump out


Cassette toilet users, a.k.a 'bucket and chuck-it' fans, will need to dispose of the contents of their cassette using an Elsan sanitary facility. The waste holding tanks or 'cassettes' vary in size but they are generally easily portable making them a convenient choice for many liveaboard boaters. They are ideal for when a boat is iced in during the winter and unable to cruise.

It’s a big job but somebody has to do it…

We provide around 220 sanitary facilities across our network, with many more provided by third parties such as marinas and boat yards. Using them requires more care than using a standard mains-plumbed sewage system. Sadly these facilities are frequently abused by people throwing inappropriate items into them, from nappies to black bags of domestic waste, used engine oil and more. The result is a blocked, revolting mess that not only poses a pollution threat to the environment but can cost us up to £6,000 a time to sort out.


Boaters who have a holding tank for toilet waste will need to use a pump out facility to empty the tank. Once again we provide some facilities, as do many marinas and boat yards. There is a charge for using pump-out facilities, it’s not included in the boat licence fee.

Many of our facilities don’t drain into the main sewage system so it’s a constant job for us to service all these septic tanks. What you must never do is use a free-standing pump to pump out your tank into an Elsan disposal point – these simply don’t have the capacity and there’s a high risk of the waste backing up and overflowing. Pollution of the canalside with raw sewage would be a very serious offence as well as a health hazard.


Composting toilets are increasing in popularity, particularly in areas with few facilities or very busy areas that suffer from frequently malfunctioning pump-out machines or Elsan units. Composting can be a great solution.  The main thing to consider with compost toilets on boats is having sufficient space to compost solids correctly. Solids can take anything from three months to twelve months to break down into harmless compost. And as anyone who has ever lived on a boat for any length of time will tell you, space is always at a premium. You can never have enough space on a boat! 

It ain’t what you poo it’s the way that you dispose of it

As the waste from a composting toilet may not have enough time to decompose sufficiently on board the boat before it needs emptying, this waste will still need to be disposed at an Elsan/sanitary station. With the increasing popularity of composting toilets, we are hoping to pilot a facility for solid waste from composting loos as part of the London Mooring Strategy but in the meantime liquids go into the Elsan unit and solids should be bagged in a nappy bag and placed in the domestic waste bins. Please don’t dump liquid and solid waste on the towpath or into the water, knowing that it hasn’t composted properly. 

Here’s a few simple dos and don’ts for everyone using onboard toilet facilities. To avoid blockages and problems, no matter what type of toilet system you use, you need to remember just a couple of simple rules.

  • If you haven’t eaten it or drunk it, it doesn’t go into the toilet.
  • Only use a small quantity of toilet paper, not half a rainforest!
  • Only use smallest amount of chemical recommended, try and use a 'green' chemical if you can.  (In pump out/cassette toilets)
  • The longer the better! Solid waste can take up to 12 months to compost. If you can’t store it for long enough, bin it!
  • Never pour urine into the canal nor at other random locations along the canal!

You can find out more about our boating services and search for non-Trust operated Elsans and pump-outs here.

Whatever type of throne you sit on, please use our waste facilities responsibly, not only to keep them available for your fellow boaters to use but to protect the environment from harm, and allow us to spend precious resources on maintaining the canal, not unblocking the Elsan/sanitary station again, and again, and again.

Please don’t be a loo-ny or urine touble!

Instructions on how to use an Elsan facility 

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