What are misconnections?
The foul system receives wastewater from your home/property and transports it to a sewage treatment works for treatment, while the surface water system receives rainwater from your roof discharging it directly into a watercourse. Combined sewage systems receive both rain and wastewater.
A misconnection occurs when the wastewater from your property is wrongly connected to the surface water system, or when the properties rainwater drainage is connected to the foul sewer.
Both of these types of misconnection cause pollutions.
Foul-to-surface water misconnection: This allows water from toilets, baths, and sinks to flow straight into rivers instead of being treated.
Surface-to-foul misconnection: Rainwater enters the foul sewer, increasing load on the system and the risk of flooding and sewage spills.
On average, we each use 153 litres of water a day for washing, cleaning, and flushing toilets. If your pipes are misconnected, this untreated water could be going straight into a river or bathing water, where it can harm wildlife, the environment and people.
Fact: DEFRA estimates 150,000–500,000 UK homes are misconnected.
What are we doing to stop misconnections?
We are working hard to identify and get misconnections fixed, but we need your help.
If you see a pipe discharging dirty water, toilet paper, or causing discolouration in a stream, please report it to us.
Here’s how we investigate:
Our team use CCTV and lift and look of manhole covers to trace the contamination up the surface water line to suspected properties.
If we suspect a misconnection, we carry out a safe dye test at the property.
The dye doesn’t stain, and the test takes 30–60 minutes.
Preventing misconnections
Misconnections often happen when homes are built, extended, or the plumbing is altered.
Misconnections are illegal and so must be fixed. In the majority of cases this rectification and its cost are the responsibility of the property owner.
To avoid having a misconnection:
When having work done that involves altering your plumbing or sewers it is vital you use a reputable tradesperson. Also consider asking the tradesperson:
- Have you double checked you are connecting to the correct sewer?
- Do you know who owns the sewer you are connecting to?
- Are you making a new direct or indirect connection into South West Waters sewer?
If so you need to request the right to connect, otherwise the connection will be illegal.
We support schemes that help you find trusted plumbing and heating professionals in your area. A quick check now can prevent costly repairs later and protect our rivers.
Misconnections and tradespeople
It’s important for tradespeople to consider the risk of misconnections. If they cause a misconnection at a property, the property owner could approach them for compensation for the cost of putting it right.
We want to help tradespeople so that misconnections become a thing of the past. Our asset mapping can help them make informed decisions when working on or near a property’s drainage to avoid mistakes.
The property owner can request free SWW asset plans for their property by emailing searches@southwestwater.co.uk.
Tradespeople can also request an asset plan, but there is a small cost for them:
https://www.sourceforsearches.co.uk/commercial/recommended/underground-asset-plan/.
If you're creating a new connection into to our network or altering an existing connection, don't forget, you need to request the right to connect, otherwise the connection will be illegal.
Need a plumber?
Check out our guide to choosing an industry approved plumber so that you can find one you can trust.
