The misery of misconnections


In Plumbing, Environment

Those extending or remodelling their properties are being warned to make sure they connect kitchen appliances and plumbing from bathrooms and kitchens into the right drainage systems, or risk a £50,000 fine or up to 12-months imprisonment.

Hundreds of thousands of UK properties have misconnections in the plumbing system, causing pollution to streams, rivers and on local beaches. This is when drains intended for rainwater, are mixed up with drains intended for wastewater. In properties that have been connected properly the wastewater from toilets, basins, baths, bidets, showers, sinks, washing machines and dishwashers all runs into the foul water sewer. This water is then taken to a water treatment plant to be cleaned up before discharge to a river or stream. However, if this water ends up in the surface water sewer, it is discharged straight into rivers and streams without treatment. This pollutes the local environment, killing wildlife and creating a public health hazard.

The Department for Environment, Food & Rural Affairs (DEFRA), estimates that somewhere between 150,000 and 500,000 properties are misconnected, although tests have shown that in some areas this number could be as high as 1-in-5 properties. Homeowners must be aware that they are liable for misconnections and that it is their responsibility to resolve any within their home. Water Companies are generally only responsible for misconnections in below ground shared drainage. The most common misconnections in the home are washing machines (35%), dishwashers (15%) sinks (10-15%), and toilets (5%).

The risk is especially high for those undertaking home improvement works and the Chartered Institute of Plumbing and Heating Engineering (CIPHE) is warning homeowners to be extra careful when it comes to moving drainage systems, plumbing in new appliances or installing new bathrooms, en-suites, kitchens and utility areas.

The CIPHE’s Technical Manager Jerry Whiteley said, “Half of UK homes are on separate foul and surface water sewers which makes misconnections possible. This is a very common problem, which is not understood by many. Action can be taken by the authorities, so apart from the moral implications of polluting your local environment, its wise to fix any misconnections as soon as you find them.”

There are a number of factors that make misconnections more likely. The more boxes your property ticks, the more likely you are to have a misconnection:

  • The property was built after 1920
  • You have more than one manhole inspection cover
  • Pipes, other than rainwater pipes, are connect to or discharge into the same gully as a rainwater pipe
  • Your property has had an extension, remodel or new bathroom, en-suite, kitchen or utility installed.

If you are concerned that you may have a misconnection, you can find help and guidance on the Connect Right website at which also includes information on how you can check your home.

If you find a misconnection, you’ll need the help of a professional plumber to put it right. Find trusted and vetted engineers in your area at