Bad plumbing and pollution

Misconnected household appliances and plumbing can cause pollution.

Pollution happens when wastewater from your home drains into sewers that lead to streams and rivers. This wastewater comes from several places in your home, including:

  • Washing machines
  • Sinks
  • Dishwashers
  • Toilets
  • Baths
  • Showers.

Find out more about pollution reporting in your region. (West Sussex, East Sussex, Kent and Hampshire).

Where does my wastewater go?

There are two types of sewer that take water and wastewater away from your property:

  • Foul (wastewater) sewers where all flows from household appliances are taken to a treatment works. Here we treat the wastewater so that it can be safely returned to the environment
  • Surface water sewers where clean rainwater that has run off from roofs, driveways and pavements is taken to rivers and the sea.

If any of your plumbing drains to a surface water sewer, the wastewater will pollute local watercourses. Similarly if clean water drains are misconnected, they can overload the foul sewer and lead to flooding.

Misconnections can happen during work to extend or improve a house, when a new house is built or simply when a new appliance is plumbed in

In most houses built after 1920 wastewater drains into separate sewer systems (foul sewers and surface water sewers). This means that clean rainwater goes to a surface water sewer which drains straight into local rivers and streams.

A misconnection where the dishwasher waste pipe (orange and white) drains into the same sewer as the rainwater pipe (black).

It's difficult to estimate the number of properties with misconnections due to the difficulty in measuring new housing stock.

A UK Water Industry report suggests around 140,000 properties, although in some areas up to 1 in 5 properties are misconnected. The nationwide total could be more than 500,000.

Misconnected pipe

Connect drains


 Is my house connected properly?

The diagram above shows how your property should be connected. The ConnectRight website has further information on how to make sure you don't have misconnected drains.

We are working together with local councils and the Environment Agency to reduce water pollution in your local rivers and streams. We want you to help by checking that your plumbing is connected properly.

Use the ConnectRight checklist for your property


Who is responsible?

It's the homeowner's responsibility to ensure there are no misconnections at their property. If you're unsure what to do you can contact us directly, on 0330 303 0368 (calls charged at local rate). Alternatively, for a list of plumbers in your area, visit the WaterSafe website.

The homeowner is responsible for pipework on their property up to where it joins the public sewer. We've produced a series of films to show how this works.