Thames Water has announced a £21m ($27.60m) upgrade at the Cirencester sewage treatment works (STW) in the UK. 

This project aims to enhance the quality of effluent released and expand the site’s capacity to address climate change challenges and prepare for population growth. 

Currently, the STW treats up to 269 litres of wastewater per second.  

The upgrade will nearly double this capacity to 484 litres per second, including the construction of a new high infiltration reed bed (HIRB).  

Thames Water project manager Paul Parfrey said: “We are pleased to be working towards improving our Cirencester sewage treatment works for residents and businesses in the area. Our new 9,000 square metre HIRB will treat an extra 114 litres of waste per second, to help increase capacity of the site.  

“As custodians of this important infrastructure we need to ensure our sites are resilient to the pressures of climate change and population growth so we can continue to provide reliable services to our customers. This upgrade to our network will help protect customers and the health of the rivers and waterways.” 

This increase in capacity is expected to minimise storm overflow risk during heavy rainfall.

The upgrade is expected to be completed by early 2025.  

The initiative is part of Thames Water’s broader commitment to modernising its infrastructure and enhancing river and waterway health.  

Specifically, the latest upgrade is included in Thames Water’s plans to improve 250 wastewater sites across the region, including those in the Cotswolds such as Fairford, Cricklade, and Bourton-on-the-Water. 

In June this year, Thames Water appointed the Arup Binnies joint venture as its technical partner to lead the development of a proposed reservoir in Oxfordshire, England.