National sewer overflow map to go live this Spring, Water UK pledges

River water quality data for the whole of England is set to be made publicly available for the first time within the coming months, Water UK has said.

The trade body is coordinating the creation of a map allowing access to information about the quality of water in rivers, beaches and waterways from event duration monitor (EDM) data.

Speaking at Utility Week WWT’s Wastewater 2024 Conference, Panos Achilleos, head of resilience at Water UK, said the aim was to publish the National Environment Hub in late May or early June.

Achilleos said it builds on the commitment in Water UK’s 2021 River Action Plan to use next generation monitoring to give customers and stakeholders more information about waterways.

“The aim of the National Environment Hub is to bring together all the data sets available from companies’ reactive maps,” Achilleos said. “We’re trying to expand the catchments to the whole of the nation. We’re aiming to publish data from England first, then add data from Wales, Scotland and Northern Ireland also.”

All wastewater companies were required to install EDMs to provide near-real time data for the first time on combined sewer overflows (CSOs) by the end of 2023. Information from these will be collated for the first time in the National Environment Hub.

The resource is the next step in the transparency journey to inform consumers about waterways and the impacts from CSOs. Thames Water created the first reactive map of each CSO point in its region with each EDM reporting on whether a CSO has spilled in the past 48 hours, if it is currently discharging, and what work Thames is undertaking in the area to minimise these.

Southern and South West have both created maps covering bathing water areas in their coastal regions, while Wessex is understood to be close to publishing a map for its own region.

Around 97% of all spills are legal, under the terms of wastewater companies’ discharge permits as issued by the Environment Agency. However, the publication of EDM data has brought sharp attention to these discharges from customers, politicians and media that showed public anger that these overflows have been permitted.

After the publication of the national map, the next step in Water UK’s work is to include more data sets.

This will include continuous water quality data from monitors upstream and downstream from CSOs, as well as final effluent from sewage treatment works. From 2025 companies will be required to start rolling out monitors at these points with a view to the work being completed by 2035.

Achilleos explained the intention is to move towards a whole catchment approach for monitoring sources of pollution. This would include stakeholders form other industries that could impact a waterway such as agriculture, highway runoff and manufacturing.