Upgrading West Ham Water Treatment Works

We’re planning to invest around £10 million in upgrading our West Ham Water Treatment Works in Basingstoke.

The work is vital to ensure we continue to meet our statutory requirements with the Drinking Water Inspectorate (DWI) and maintain the high standard of drinking water provided for customers.

This project is part of our ongoing investment programme to improve water supply infrastructure across our area and this work is key to future proofing the top-quality drinking water we already provide to customers in Basingstoke.

At South East Water, we carry out more than half a million tests on our drinking water each year to ensure that the water we supply customers is of the highest quality.

We’re independently assessed by the water quality regulator, the Drinking Water Inspectorate, to ensure we continue to maintain these exceptionally high standards.

There is a regulatory requirement to ensure that all drinking water in England contains less than 50 milligrams of nitrate per litre. We meet these requirements and are committed to ensuring our drinking water quality is maintained and enhanced.

Nitrates can occur from natural sources, but the main source of nitrate in raw water supplies is from inorganic fertilisers from agricultural runoff. Our routine monitoring of the Basingstoke catchment area has identified increasing concentrations of nitrate in the groundwater.

We currently blend the water at West Ham to reduce nitrate concentrations to a safe level, however given the increasing concentrations of nitrate within the catchment, we plan to install specialist equipment at the treatment works to reduce nitrate concentrations.

Although this is not yet impacting drinking water supplies, we’re looking to implement measures to reduce this risk further.

We have designed an ion exchange plant as an additional water treatment solution to reduce any risk. This will be subject to the planning application submitted to the Basingstoke and Deane Borough Council.

Work is already underway, with nitrate monitoring taking place to assess and track the level of nitrates in the area.

We’re currently blending water from different sources to reduce the nitrate concentrations increases in the short term and to ensure that the final water remains below the safe regulatory limit set by the DWI.

If required, we’re designing an alternative water solution to reduce the risk further.

Our regulator, the Drinking Water Inspectorate, needs us to have installed permanent monitors for nitrate levels by October 2025. To meet this deadline, we have already started work, with monitoring trials taking place last year.

We intend to plan and design any water treatment solution required to reduce the risk by October 31, 2025 and our commitment is to meet the deadline of March 31, 2027 for completion of the project.

We’re committed to using the most up-to-date technology to make sure we provide you with the highest quality drinking water.

As a provider of drinking water in England, we must make sure we have wholesome water to supply 24/7.

If approved, the work would mainly be taking place within the water treatment works site, although there may be some work needed nearby.

During the work, there would be extra traffic delivering construction materials to the site. All traffic movements would be controlled by our team.

We‘ll work as hard as possible to keep disruption to a minimum, however there may be temporary noise from time to time and additional vehicle movements to and from the site.

We know that during any work, there may be extra noise above what you normally hear. We’re sorry about this, but we’re confident the impact would be temporary and we would do our best to minimise this.

Our teams would mainly be working during normal office hours (8am – 6pm) although there may be some activity on Saturdays.

During winter months, there would be some extra lighting needed to keep our workers safe and to allow work to continue during the days with less daylight. These would be temporary and lights would be switched off when we’re not using them. We would also make sure the lights are placed where they’ll not impact local residents.

During the course of our work, there would be some heavy goods vehicles travelling to and from the site with materials. We would do all we can to limit the impact on you.

This would include keeping additional vehicle movements to a minimum and within our site, although there may be some times when our workers would need to park their vehicles off-site, complying with parking restrictions on nearby roads.

We have a dedicated web page for the project on our South East Water website, with regular updates posted.

We also plan to keep local stakeholders and residents updated with a regular newsletter. To receive this, we need your consent.

You can sign up to this by sending an email to: community@southeastwater.co.uk

Our West Ham Water Treatment Works is a key site for us, with up to 26 million litres of water treated and distributed each day into the Basingstoke area.

The site is 9,857 square metres in size.

At South East Water, our water is abstracted from a range of sources, including rivers, reservoirs and underground aquifers.

We have operational ground water boreholes in the underground aquifer at West Ham and nearby in the local area. We pump water from these to the site so it can be treated and piped locally to Basingstoke and the surrounding areas.

Once our planning application has been submitted and validated, all documents related to the application will be published on the Basingstoke and Deane Borough council website.

There will then be the opportunity for you to comment on the application, before a decision is made on the proposals.

We would anticipate that a decision will be made on the application later this year in the autumn.

If you have any queries during the work our team on site will be happy to help, alternatively if you would like to speak to us directly please call our Customer Technical Centre on 0333 000 0002.