Faulty plumbing in your home
Illegal connections happen when appliances or plumbing in your home or business are connected to the wrong sewer, resulting in pollution.
Where does my wastewater go?
Until the 1960s, most houses were fitted with drains that mixed wastewater (showers, toilets etc) and surface water (rain runoff from roofs etc.) into one combined sewer system.
Many buildings still have a combined system, but more modern buildings have separate drains connecting to either a foul sewer or a surface sewer.
- Foul (wastewater) sewers take all flows from household appliances, including toilets, washing machines and kitchen sinks, to one of our treatment works. Here we treat the wastewater so that it can be safely returned to the environment.
- Surface water sewers take clean rainwater that has run off from roofs, driveways and pavements to local streams, rivers and the sea.
This separation helps relieve the pressure put on our wastewater treatment sites during heavy rain and as a result, prevents necessary storm overflows.
However, pipes to foul and surface sewers can be misconnected, having a negative impact on the environment.
What is an illegal connection?
Illegal connections 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. Pipes can be misconnected in two ways:
- If a waste pipe (for example, your dishwasher or toilet) is connected to a surface sewer this can contaminate clean surface water, polluting local waterways and impacting bathing water quality.
- If a surface water pipe (for example, a gutter collecting rain water) is connected to a foul sewer, this can overwhelm wastewater treatment sites during heavy rain as the system is unable to cope with the excessive water.
It's difficult to estimate the number of properties with illegal connections and many people don't ever know the pipes in their home have been wrongly connected.
A UK Water Industry report suggests around 140,000 properties have faulty plumbing, although in some areas up to one in five properties are illegally connected. The nationwide total could be more than 500,000.
How do they cause pollution?
If any of your plumbing or waste pipes drain 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 our wastewater treatment sites, leading to flooding.
Who is responsible?
The homeowner is responsible for pipework on their property up to where it joins the public sewer. This includes making sure that there are no illegal connections.
If you're unsure about what to do you can contact us for advice. Or, you can get help from an approved plumber.
If you're building a house extension, a new home or a commercial building, or simply making changes to your existing drainage, you may need a new connection to our sewer network.
What are we doing about illegal connections?
We're working together with local councils and the Environment Agency to identify illegal connections and put them right. Most of the time they're on private land, so we have to get permission from the home or land owner to rectify them.
You can help by making sure that your plumbing is connected properly. Water UK have a useful guide on how to check for illegal connections.
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