Welsh Water Publish 2021 CSO Data

Welsh Water have today published CSO data for 2021
  • The total number of spills in 2021 was 97955, compared to 108451 in 2020
  • The total duration of spills in 2021 was 889608 hr of spills, compared to 807512 hr of spills in 2020
  • Welsh Water now have 99.5% coverage of all assets monitored. This is the highest of all water companies in England and Wales. Welsh Water have also committed to finding a solution for the remaining 0.5% so that 100% coverage of monitoring can be achieved.
Event duration monitoring on CSOs only provides a count of the number of spills and the duration the CSOs operated for, therefore, we are unable to interpret the data in terms of when (during the year/ seasonally) the CSOs were operating and therefore the effects that the CSOs might have on the river water quality which is heavily weather dependent.
Defra Announcement and changes in England

Defra have also published this press release announcing a major overhaul of sewer systems in England. A consultation has been launched in England on the proposed targets and timelines, coupled with a new monitoring and reporting framework.   There is no similar announcement from Welsh Government.

The Rivers Trust will be updating their sewage map this week.

What next?
  • Afonydd Cymru are now technical advisors to the Welsh Government #Better River Water Quality Taskforce.
  • We expect Welsh Government and Welsh Water to provide a commitment, like Defra, to eliminating CSOs which cause environmental harm. We therefore need to implement improved monitoring across Wales to evidence not only the impact of CSOs but all contributors who cause poor water quality.
  • Action plans to deliver changes to the CSOs in Wales will be published in May 2022.
  • Afonydd Cymru have specifically requested a review of regulation of CSOs including a review of how CSO permits are written to ensure that they are unambiguous and enforceable.
  • Welsh Water have identified £120m investment for CSOs by 2025. This includes implementing screening. Welsh Water have stated that to completely remove all CSOs would require an investment of circa £9billion.  We need to understand how this figure has been determined, what would be required over what time and the implications this has for the customer water bill in Wales.
  • Unlike England, the Flood and Water Management Act 2010 (Schedule 3), came into effect in Wales on 7 January 2019 and all new developments have been required to include Sustainable Drainage Systems (SuDS) since then.
  • In March 2020, Welsh Government announced its intention to ban single use plastic in Wales. We urge that this ban is implemented and extended to include non-biodegradable wet wipes. 
Posted: March 31, 2022