A multi-million pound programme to improve Bury's sewer network has been announced to help it withstand heavy rainfall in a bid to reduce 'storm spills' leading to river pollution.

United Utilities has announced a £230M investment across the North West.

A total of £50M will be spent upgrading Bury wastewater treatment works so that it can treat more sewage during heavy rainfall.

The nearby sewer network will also be improved with additional storage capacity.

Together with the investment at the Stoneclough-based Bolton treatment works this will improve 40km of the River Irwell. Here additional storage capacity will be built into the wastewater treatment works which will reduce the need for storm spills

Storm overflows are designed to act as relief valves when the sewerage system is at risk of being overwhelmed, for example during heavy downpours when a lot of rainwater runs into drains and the sewerage system in a short space of time, according to watchdog Ofwat.

If the system does get overwhelmed it can cause flooding.

To prevent that happening water companies sometimes use storm overflows to release extra rainwater and wastewater into rivers or seas.

According to the government's environment agency, there is too much pollution, including from sewage pollution, from storm overflow discharges.

Water companies have come under intense pressure, including from the public, for allowing far too many sewage spills into rivers and coastal waters.

The investment was announced on the day that United Utilities has retained the top 4-star rating for its environmental performance in 2021.

Jo Harrison, Director of Environmental Planning and Innovation at United Utilities, said: “At United Utilities, our purpose is very clear – we don’t just supply water, we also want to make the North West greener, healthier and stronger. We work very hard to maintain a high level of environmental performance and we’re pleased that for the second year running we have been awarded the top 4-star rating by the Environment Agency.

“We know there is always more to do, and playing our part to improve the health of the region’s rivers is very important to our customers. This is already well underway and, by 2025, we will have invested £230m improving 184km of waterways and we will have developed our plans to progressively reduce the impact of storm overflows in the coming years.”