SES Water is investing to upgrade Cheam Water Treatment Works
SES Water is investing £4.5m to add resilience and support high-quality drinking water for 100,000 customers
SES Water is investing £4.5m to upgrade Cheam Water Treatment Works to ensure the site is more resilient and continues to deliver high-quality drinking water for around 100,000 customers in Sutton, Cheam, Ewell, Belmont, Stoneleigh and parts of Epsom for years to come.
The investment follows an extensive review of the site’s performance after an unplanned shutdown in December 2024 nearly led to all of those customers losing their water supply.
The incident also highlighted that some ageing assets at Cheam needed to be upgraded. The review identified several opportunities for SES Water to strengthen the site’s resilience, and work has been ongoing this year to improve the treatment processes and operational practices.This work is set to continue for another two years.
The company has carried out a series of upgrades to strengthen the site’s resilience and reduce the risk of supply interruptions for customers, including:
- Improving the site’s water treatment process by replacing equipment in its filtration process.
- Replacing two treated-water pumps and chemical dosing equipment.
- Installing improved monitoring and alert systems.
- Updated emergency planning procedures to strengthen day-to-day resilience.
These upgrades mean the site will be more reliable, issues will be spotted earlier, and there are stronger safeguards in place if equipment fails.
Changes have also been made to SES Water’s emergency planning and response procedures based on customer feedback, ensuring it is better placed to keep customers informed and supported when incidents occur.
These improvements have already started to make a difference to the site’s performance and have reduced the likelihood of similar issues occurring in the future.
Planning for the future
And SES Water is not stopping there. The company is continuing to invest in improvements to boost the site’s resilience in 2026 including replacing key valves, refurbishing treated-water pumps, installing UV water treatment on site, and installing new pipework to support the water treatment process.
Together, these upgrades will reduce the likelihood of future disruption and support SES Water’s industry-leading water quality performance.
Pete Harris, Head of Production at SES Water, said: “The work we’ve completed at Cheam is making a real difference to the resilience of the site, and the further upgrades we have planned will strengthen it even more.
“We know how important a reliable supply of high-quality drinking water is to our customers, and these improvements mean we are better equipped to prevent issues in the future and respond quickly if they do occur.
“This investment is about ensuring the site continues to perform to the highest standards and I’m so proud of the work our teams are doing to make these changes for the future.”
Local recognition
SES Water recently welcomed Luke Taylor, MP for Sutton and Cheam, to the site so he could see the improvements first-hand after he raised questions about the site following the unplanned shutdown last year.
Mr Taylor was given a tour by Pete Harris and members of the operational team, who explained the upgrades and the further investment planned for the site.
Mr Taylor said: “The outage last year reminded us all just how important it is that our area can rely on stable, modern and effective infrastructure.
“In response to that outage - I requested a tour of the works SES have been doing at the Cheam Water Treatment Works, and was grateful to have that opportunity in November.
"It was great to find out more about the investment being made and to see for myself the work that is underway to bolster SES’ local water infrastructure - improving the resilience of our local water supply.”
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