Our investment in the river Usk


We fully understand the importance of river water quality to our customers and we are committed to continuous improvement in this key area and take our environmental responsibilities very seriously.

In the decade to 2025, we will have invested approximately £1.5 billion in improving and maintaining our wastewater network and this has helped ensure that 44.5% of our rivers in Wales are in good ecological status compared to 14% in England.

On this page you will find some information on the challenges we face and the investment projects that we are currently undertaking to improve quality of the river Usk.

What’s the problem?

The quality of our main rivers is monitored by Natural Resources Wales. There is concern about the river water quality in parts of the Usk as they’re not achieving what’s called ‘good’ ecological status. This means that there are too many chemicals in the river such as ‘phosphorous’ which can cause algal blooms which can affect the amount of oxygen available in the water and harm wildlife.

What’s causing this?

There are a number of factors which can increase phosphate levels. This includes how we treat wastewater before it’s returned to the environment. Our modelling of the river Usk for example shows that our assets (i.e. our treatment works, Combined Storms Overflows or CSOs) are responsible for between 21% - 23% of the phosphates in the main water bodies, with CSOs only responsible for 1%. The remainder – over 75% - is caused by other factors such as agricultural run-off and animal faeces, urban surface water drainage, misconnected drains, as well as private septic tanks.

However, we understand that this is an important matter for our customers and we are committed to playing our part to doing what we can to reduce our impact on the river Usk.

Our investment

We know we have a significant amount of work to do which has taken time, but we are committed to making continuous improvement year on year. That’s why our work is being carried out between 2022 and the end of 2025 in the following phases:

Phase 1 — Work at Usk Sewer Pumping Station — Completed

We completed our work to upgrade the assets at the Sewerage Pumping Station. This included installing a screening chamber which will remove any heavy particles – such as rags, wet wipes and large objects – from the waste water that the station receives.

Phase 2 — Building new assets at Usk Wastewater Treatment Works — Starts April 2024

By transferring more waste to the wastewater treatment works, we need to ensure that it has the capacity to treat the waste. Using the latest technology, we’ll be installing brand new assets and storage tanks to do this. Between April 2024 and the end of 2025, construction work on phases 2 and 3 will be delivered within private land and the local wastewater treatment works located approximately 1km past the Athletic Club.

Phase 3 — Work to increase the networks capacity to transfer waste — Starts June 2024

Our waste network relies on gravity for waste to be taken away from homes and businesses. Where this is not possible, the Sewerage Pumping Station will help pump the waste to the local wastewater treatment works where it can be safely treated. The main scope of works includes installation on two new pumps and associated equipment.

Brecon Wastewater Treatment Works
Start date: November 2022
Expected completion date: July 2024
Investement: £9 million
What are we doing: We’re upgrading several of the assets at the wastewater treatment works. This includes building a brand new storm tank which will help contain any excess water from the sewage system in the event of heavy rain and stop it from overloading our wastewater treatment works. The water stored in the tank will eventually be released back in the sewage system when it has capacity, where it will be treated before being safely returned to the environment. We are also introducing a process which will remove phosphates from the treated wastewater before it is returned safely to the environment.

When additional investment projects get underway, we’ll share more information on this page.