SEW updates on Resilience Plan ahead of return to EFRA Committee tomorrow

(by Karma Loveday)

South East Water (SEW) and regulator leaders will return to the Environment, Food and Rural Affairs Committee tomorrow (Tuesday 12) to give further evidence to MPs about November/December 2025’s Pembury water treatment works outage, which left many customers in the Tunbridge Wells area off supply. A new session has been convened now that both the company’s own investigation into the incident, and the Drinking Water Inspectorate’s (DWI) investigation, have been completed.

The Committee said it will “examine the extent to which SEW was at fault for the outage”. This follows conflicting accounts from the company and the DWI at a 6 January evidence session about whether the incident was foreseeable and could have been avoided.

The Committee will also scrutinise: SEW’s handling of previous and subsequent outages that impacted large areas of Kent and Sussex this year; how the company engages with Ofwat and the DWI; and how it has taken forward previous recommendations on how to improve.

Last week, SEW published an update on the progress of its six-month Resilience Plan — upgrades to deliver additional capacity, water quality protection and network resilience, and accelerated operational changes to the way supply interruptions are managed. It said critical progress had been made in many areas including:

• Pembury Water Treatment Works: two new filters have been installed to improve treatment processes, reduce the risk of water quality issues and increase the capacity of water that can be provided into the Tunbridge Wells system. These filters will allow SEW to support the Pembury network from the Bewl Water Treatment Works, providing an additional source of water to the Tunbridge Wells system, if needed. Additional operational improvements include revised site maintenance schedules, updated testing guidance for operators, and a revised inventory of critical spare equipment.

• Tonbridge Water Treatment Works: three carbon filters have been installed and are operational. Bringing Tonbridge back into supply adds 1.5m litres per day of water to network. These filters will bolster the site’s filtration capacity and prevent contamination from nearby housing construction sites. 

• Bewl to Cottage Hill Transfer Main: engineering work to the 12km pipeline is complete, with final tests now being scheduled. When operational, Bewl will distribute to the Wadhurst area of Sussex for the first time. This will provide much needed additional resilience in this area of the network that suffered from supply interruptions in the summer of 2023.

• Increasing spare stock levels: a programme to increase and optimise the location of spare equipment is complete. This will reduce supply interruption risks and enable quicker repairs.