Written question WQ84616

Natural Resources Wales (NRW) issue permits for water discharges, including treated discharges from clean and waste water treatment works. The permits require the discharge to meet specific regulatory criteria to make sure there’s no deterioration to the water environment. In 2020 Dŵr Cymru Welsh Water (DCWW) complied with 99.7% of their permits and had the lowest number of sewage pollution incidents for at least 10 years, and Hafren Dyfrdwy achieved almost 97% compliance.

Combined Storm Overflows (CSOs) located near coastal bathing waters are only permitted to discharge when the sewer network has reached capacity due to heavy rainfall and where there is a risk of sewage flooding in properties. NRW and DCWW have identified and reduced the spill frequency of storm overflows which could affect designated bathing water sites.

We have made sustainable drainage systems (SuDS) mandatory on almost all new building developments. This will help relieve pressure on the network by redirecting and slowing down the speed at which surface water enters the sewer system. It will help ensure storm overflows are only used as a last resort.

We have established a framework with NRW for water companies to develop effective and evidence based Drainage and Wastewater Management Plans (DWMPs). These will look at ways to address existing and future pressures on the sewer system, including population growth and climate change, to build a more resilient wastewater and drainage infrastructure. Water companies will be consulting on these plans later this year.

Between 2020 and 2025 DCWW are investing over £100 million to upgrade their wastewater management network to reduce discharges into waterways as part of a wider investment package of £765 million to protect the environment.

Hafren Dyfrdwy are investing £17million on wastewater and environmental improvements which includes over £3milion on wastewater management network and treatment works enhancements, including storm overflow improvements.