Make the right connection

Avoid a DIY disaster and make the right connection

It’s probably not something you think about every day, but if you’re planning some home improvements which include connecting waste pipes to the drains on your property, please take time to check that you’re making the right connection.

Down the drain… but which one?

There are three types of drain that take used or ‘waste’ water away from your home.

Waste or foul drain – this drain takes used, dirty wastewater from your toilet, sinks, washing machine and dishwasher to a wastewater treatment works where it is cleaned and treated so it can be safely returned to our rivers and the sea.

Rainwater or surface water drain – this drain usually takes rainwater to local watercourses, streams and rivers as it doesn’t need to be treated.

Combined drain – this drain tends to be found in older properties and is where the used or wastewater and rainwater both go into the same drain. This drain connects to the sewer pipes and all the water is taken to the wastewater treatment works.

How to check that you’re making the right connection

If you’re thinking about doing some home improvements, for example, moving your washing machine into a new location such as the garage or even building an extension to your home, it’s important to make sure any wastewater pipes are plumbed in to the correct drain.

You can check your drains are properly connected by visiting

If you’re using a plumber to carry out the work, it’s a good idea to choose one who is a member of an approved contractors’ scheme. You can go to and type in your postcode to find your nearest plumber.


We work jointly with the Environment Agency to combat the issue of misconnected household drains. Once a contaminated watercourse has been discovered, where the waste or foul water is going where it shouldn’t, the pollution can be traced back to the property where the waste pipes are misconnected. The owner of the property is responsible for making sure the misconnection is put right.

Making the right connection

It’s really important that toilets, sinks, baths, showers and water-using appliances, such as washing machines and dishwashers, are all connected to the waste or foul drain. This drain connects to the sewer pipes which takes the used or wastewater to be cleaned and treated at our treatment works.

If these appliances are connected to the rainwater or surface water drain, then the used or dirty water could go straight into local streams, rivers and eventually the sea. Unfortunately this can pollute the local environment and cause harm to marine and plant life in watercourses.