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

Here are some of our projects that we are currently undertaking that will help reduce phosphate levels from our waste network within the river Usk.

Usk SPS and Wastewater Treatment Works
Start date: June 2022
Expected completion date: December 2025
Investement: £10 million
What are we doing: Over the next three years, we’ll be upgrading our assets at both our Sewer Pumping Station and Wastewater Treatments Works in Usk. You can read more about this investment as dwrcymru.com/Usk

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.