The wastewater network is a collection of pipes and infrastructure that take waste from the sinks, toilets and drains in our homes. This waste travels along sewers to treatment sites before being thoroughly treated and safely released into the environment.
It is important that the contents of the network can flow to keep this process moving. When blockages occur in the network, this can cause waste to stop flowing. With nowhere to go, this waste can then back up into homes or seep out into the environment.
We need to keep our networks performing to the highest standard to deliver the service our customers deserve. This is why we’re investing in innovative new technology for our networks to make them resilient for future generations.
Testing new technology across our region
Sewer blockages are extremely costly and time consuming for water companies to tackle, especially when caused by items that are not suitable for flushing. In 2018, it was estimated that sewer blockages from wet wipes alone cost UK water companies £100m a year to deal with, forming blockages and causing floods which can also impact the environment.
As part of our wastewater network transformation, we're piloting the use of sewer level sensor technology in our region. These sensors monitor the levels of liquid in the sewer. When they show the levels rising unexpectedly, this could indicate a blockage is forming. This could help us alert our teams to intercept and clear the issue before it becomes more serious.
We are trialling over 100 sewer level sensors in a six-month period across our region. Digitising our network in this way enables us to approach the management of our sewers proactively.
This will play an important part in helping us minimise flooding and pollution events.
Over the coming year, we hope to roll out up to 30,000 sensors across our region at no extra cost to Southern Water customers, in specific high-risk areas to target challenges we’ve experienced on our networks.
March 21: Pilot project begins.
April 21: Key worker operational crews head out to install the sensors in pilot areas.
September 21: We review how well the sensors have performed in the pilot and prepare to expand the new digital sensor network across our region.
October 21: Our crews begin to install sensors in key areas across our region.
March 22: Sensors are installed and functioning in key areas, helping us to provide a better service for our customers.
How you can help
It is estimated that around 75% of blockages occur due to the wrong things entering our sewers. Our sewers are only around 200mm in size and should only carry the three Ps – that’s pee, poo and paper.
The main items that end up in our sewers when they shouldn’t are:
- Unflushables such as wet wipes, sanitary items, nappies and cotton buds. Wet wipes are a serious problem for our sewer network. Even wipes labelled as ‘flushable’ do not break down in the sewer network. They are the main culprits for blockages.
- Fat, oil and grease from cooking poured into sinks when hot, which then solidify in sewers as they cool. Instead, you can simply pour used fat, oil and grease into a 'GunkPot' and transfer them to a waste bin when cool. If you don't have a GunkPot, then you can use other recyclable, heat-resistant items to contain these liquids, such as empty cans, heat-safe glass jars or microwave-safe bowls.
- When fats, oils and greases mix with wet wipes, it can form powerful solid blockages that have become known as 'fatbergs'. These disgusting blockages have been found weighing upwards of 130 tonnes and over 250 metres in length, requiring extensive work and disruption to remove safely.
We're asking customers to help us by only flushing the three Ps and disposing of all other items into waste bins. Along with our new network of sensors, you’ll be playing your part in helping to keep our sewers flowing freely.
Frequently asked questions
Get in touch
If you’d like to know more or have any questions about the pilot scheme and future roll-out, please get in touch with us using our contact us form.