Skip to main content

Horsley Water Treatment Works Upgrade

Project Overview

Our £46 million investment to improve Horsley Water Treatment Works is continuing to make good progress, with our delivery partner, Mott MacDonald Bentley (MMB), carrying out the construction work.

Since our last update, significant progress has been made across the site. The new water treatment infrastructure is now taking shape, with major concrete structures completed and work continuing key treatment and pumping facilities.

Throughout the work, protecting water quality and maintaining a reliable service for customers remains our top priority.

Thank you for your continued patience and support while these improvements are carried out. We'll continue to share updates as the project progresses.

📅 Start Date: March 2026

📅 Estimated End Date: July 2027

🤝 Partner: Mott MacDonald Bentley (MMB)

🚧 Investment Value: £46 million

Phases

Phases overview

Phase 1: Project Updates

Project Updates

Project Updates

14 March 2025 00:00 - No end date

Keep up to date with the latest news, progress and upcoming work on our project.

13 posts

Community Hub Admin Team 1 week ago Hi all,With summer drawing to a close and the kids heading back to school, we wanted to share a quick update on the improvement works taking place at Horsley Treatment Works.✅ Good progress continuesIt's been another busy week on the Horsley Chlorine Contact Tank project, with good progress made on the main tank structure.🏗️ The first section of the roof has now been completed.🧱 There is just one remaining wall to build before the tank structure is fully enclosed.🔧 Work is also continuing on the new pipework and supporting infrastructure needed for the project.Behind the scenes, design work is continuing to support the next stages of construction and help keep the project moving forward.📅 Looking aheadOver the coming week, the team will continue work on the tank structure, install additional precast components and progress pipework activities across the site.💧 BHPS project updateWork is also continuing on the Horsley BHPS project, with recent activity including:✅ Pressure testing🔧 Pipework installation📋 Ongoing design work to support future construction and commissioning activitiesWe would like to thank you for your continued patience and support while we carry out these important improvements at the treatment works.If you have any questions, please leave a comment below and a member of the project team will be happy to help.🔔 Don't forget to click the Follow button at the top of the page to receive notifications about future project updates.Thank you,Julie & The Project Team

Community Hub Admin Team 5 months ago Hello everyone,Following our last update in January, we wanted to share how construction at Horsley Water Treatment Works has continued to progress as part of the ongoing upgrade works.Since January, work on the new chlorine contact tank has moved through several key stages.Inside the tank, all of the pre‑cast concrete baffle walls that form the internal layout are now fully installed. Securing and sealing works are continuing, alongside the installation of reinforcement and formwork in readiness for the next phases of concrete construction.Significant progress has also been made on the main tank structure itself. The first major concrete base pours have now been successfully completed, providing a key foundation for the tank walls. Preparation works for the remaining wall pours are ongoing, and the overall shape and scale of the new tank are now clearly visible within the site.Alongside the tank construction, work associated with the Granular Activated Carbon (GAC) filters and pumping infrastructure has continued as part of the wider upgrade.Pipework installation for the current phase has now been completed, with associated concrete support structures progressing beneath pipework and valves. These works are being carefully managed and coordinated to ensure water quality is protected at all times while construction continues.Construction of the new outlet flowmeter chamber has also begun in recent weeks. Excavation works have been completed, and a blinding layer has been installed at the base of the excavation to prepare the ground for the next stage of construction.Thank you for your continued patience and understanding while work progresses. We’ll continue to share updates here as the project moves forward.The Project Team

Community Hub Admin Team 7 months ago Hello everyone,We hope you’re well.Following our last update in November 2025, we wanted to share how the upgrade at Horsley Water Treatment Works is progressing and what you may notice around the site over the coming months.Back in November, the main excavation for the new chlorine contact tank had been completed, and we were building the reinforced concrete levelling slab that helps supports the ground around it. Most of the slab will remain in place beneath the new tank, with only a small section removed at the end of construction so the leased land can be returned to its owner. We also completed modifications to the GAC building roof drainage associated with the construction of the temporary crane running pad. Since then, work on the new tank has made good progress. Installation of the pre‑cast concrete baffle walls is now underway, with 25 of the 116 units already in place as the internal structure begins to take shape. These baffle walls are internal walls that help control how water moves through the tank during treatment. The 135‑ton crawler crane positioned on the southern side of the site continues to support the heavy lifting required for this stage of construction.Preparations for connecting to the existing GAC filters have also progressed, with excavation works safely exposing the required pipework and services. Work on the new de‑chlorination chamber is advancing well, with the excavation and base now complete and the chamber due to arrive on site shortly for installation.Works on the Chemical Storage tanks have progressed well with tanks and Bund now installed. Works are now progressing with the connecting pipework, pumps and controls with works expected to be complete in April this year.As we move into the next phase of the project, you may notice an increase in activity around the site. Over the next few months there will be more deliveries, including the remaining concrete wall units, materials for the main tank build beginning in February, and large‑diameter pipework expected in April. Work will also begin on the new Break Head and Contact Tank chambers during this period. All drivers and subcontractors have been reminded to use the agreed access route into the site and to avoid travelling through Horsley village.You may also notice temporary task lighting during darker periods to allow work to continue safely. This lighting will be positioned carefully and directed only where needed, helping to minimise its visibility outside the site.Thank you for your continued patience while this essential upgrade progresses. We’ll keep you updated as work moves forward.

Go Vocal Admin10 months ago Hi everyone,We’ve made great progress on site this month: The main excavation for the cofferdam is now complete. We’ve started building a temporary reinforced concrete slab (called a propping or levelling slab). This slab will support the ground and provide a flat base for the new chlorine contact tank. It also helps strengthen the excavation so a large 135-ton crane can safely operate close to the edge. Most of this slab will stay in place and the tank will be built on top of it. However, a small 2-metre strip on one side will be removed after the tank is built, so we can return the leased land to the owner clear of materials. We’ve also finished modifying the drainage pipework under the roof of the GAC building. What is GAC? GAC stands for Granular Activated Carbon. It’s a type of filter used in water treatment to remove things like chlorine, bad tastes, and odours. The GAC filters are located in the building opposite where we’re constructing the new tank.At Birny Hill Pumping Station, pipework replacement is currently on hold while we wait for refurbished valves to return to site. Work is expected to restart at the end of October.We’ve attached some progress photos and a timelapse of the excavation for you to view.If you have any questions or comments, feel free to leave them below and someone from the team will get back to you.

Go Vocal Admin1 year ago Hello everyone, here is this months update on our work at Horsley, The excavation of the cofferdam is progressing well, and we are on track to complete this element of works required to enable the build of the new Chlorine Contact Tank by early October. Once the excavation is completed, we will be able to start the temporary reinforced concrete propping slab. Work on BHPS pipework replacement is also progressing as planned, no all the old pipework is removed we have commenced installation of the new pipework.If you have any questions you’d like to ask us regarding the work, please don’t hesitate to reach out by adding a comment in the box below.

Go Vocal Admin1 year ago Hello everyone,We hope you’re all enjoying the summer we are having!Just thought I would provide you with your monthly update on the project at Horsley. The work on the new contact tank is moving along really well, the recent dry weather has helped us speed up the excavation work, prepare the ground, and get the foundations in place.We are also replacing the pipework at Burny Hill pumping station (BHPS), with much of the old pipework now exposed and ready for the next stage.We would like to thank you for your continued patience while this work is carried out, it’s an important step in improving our service for the whole community. If you have any questions or notice any issues during the work, please get in touch with us on the contact details provided and one of the project team we will be happy to helpThank youJulie

Go Vocal Admin1 year ago Hi Everyone,With the summer break just around the corner, we wanted to keep you in the loop with what’s been happening on the upgrading of the treatment works on the Horsley site.Good progress continues to be made on the construction of the new Contact Tank. The installation of the temporary piles has been completed, and we have started the cofferdam excavation. The cofferdam is required to create an enclosure that retains the surrounding ground and keeps water out of the work area. The excavation will take several months to complete. Work on Burny Hill Pumping Station (BHPS) pipework replacement continues on programme. Good progress is being made on the excavation to expose the existing pipework to be replaced.Once again, we thank you for your continued patience and cooperation while the works progress, if you need to contact us or have any queries, please use the contact details provided and one of the team will gladly help.ThanksJulie

Go Vocal Admin1 year ago Good afternoon, I hope everyone has been enjoying the lovely weather we have been having lately,I would like to provide an update to the works we are carrying out at Horsley treatment works as it has been a while since we have published anything. The work to build the new chlorine contact tank continues at pace. We commenced installing the temporary piles at the end of April which will support the excavation (Cofferdam) required to build the new buried tank. With the piling works progressing ahead of schedule, we are planning to start the main excavation of the cofferdam later this month.Work has also commenced on the Burny Hill Pumping Station (BHPS) pipework replacement contract. We have completed clearing services above the pipework. Excavation to expose the pipework has started this week.We once again would like to thank you all for your patience and continued support while the works continue. If you have any questions or issues relating to the project, feel free to get in touchThank youJulie

Go Vocal Admin1 year ago Good afternoon all,We are here with our latest update. Work to build the new Chlorine Contact Tank has commenced.To date we have carried out the enabling works for the scheme including the temporary alignment of the Southern fence line. This was to provide working room for our construction of the chlorine tank. This is still within the water treatment works boundary and will be relocated to its original position after construction is finished.We have also permanently diverted the surface water sewer and carried out a temporary diversion of the Granular Activated Carbon (GAC) backwash main which removes contaminants like chlorine, taste and odour by absorbing them.The backwash drainpipe was obstructing the construction of the new chlorine contact tank so it has been temporary relocated until the construction works are complete.These works have enabled us to construct a temporary stone piling mat which allows piling works to start WC 21st April, mobilising on site on the 22nd. This work may cause an increase in noise and vibration on site however we will continue to try and minimise any disruption where possible.If there are any issues or queries please leave a comment or contact a member of the project team.Thank you all again for your patience and cooperation throughout this project.

Go Vocal Admin1 year ago We are making good progress on site and have now completed the RGF’s (Rapid Gravity Filters) which are now operational and fully automatic. This has allowed us to fully remove the temporary syphon pipe including the permanent reinstatement of the road crossing on Water Lane. Other highlights has been the substantial completion of the lifting monorail in the Chemical building, significant progress with the final reinstatement works across site and completing the majority of training with operational personnel.We will keep you updated as best we can on a monthly basis but in the meantime if you have any questions, queries or issues please leave a comment below or use the details provided to contact us and one of the team will get back to you.Thanks again for all your patience and co-operation whilst the works are ongoing.

Go Vocal Admin1 year ago Work on site is going well. We're almost done setting up the new filters, so temporary equipment can be removed soon. We've started working on the pre-dosing system, with only a few tasks left to complete. Preparation for the new chlorine contact tank has also started, which includes checking underground pipes, moving lights, and doing a trial to help finalize the design.We would like to thank you for all your continued co-operation and patience while the works are ongoing, if you have any questions or issues please leave a comment below or use the contact details provided and one of the team will get back to you.

Go Vocal Admin1 year ago I am pleased to say that great progress continues to be made at Horsley with the commissioning of six new rapid gravity filters (see the image below), this is the 2nd stage of the water treatment process, where water is filtered through a layer of anthracite, sand and gravel. The rapid gravity filters (RGF) are expected to be fully operational within the coming weeks. Works substantially completed this month have included the diversion of a gas main and the site wide reinstatement including footpaths. We would like to thank you all for your continued support and patience while the works continue and that I hope we are not causing too much disruption in the village with the on going traffic. If you have any questions or queries please leave a comment below or contact us on the details provided and one of the team will get back to you.

Go Vocal Admin1 year ago Good progress continues to be made on site at Horsley Water Treatment Works. The new run to waste pipeline has been fully installed and brought into use. Final reinstatement of the pipeline at the treatment Works, through the fields and down near our pumping station are now underway. A key output for the project is to commission six new rapid gravity filters, of which four are now complete and in service. Our construction team continue with the site wide reinstatement, which includes the construction of a new retaining wall, roadways, and concrete footpaths, We are also carrying out investigation works to confirm our designs for the next stages of work within the site. This investigation work is expected to complete in the next 2 weeks or so.If you have any enquiries or issues, please contact us by either leaving a message below or use the contact details provided.

Filters

Total posts: 13

There are 13 projects available.

No values available.

Selected zero tag filters.