Situation 

While NI Water has many examples of using reed beds at the end of a conventional (mechanical) wastewater treatment system to ‘polish’ or ‘purify’ the water, Clabby is the first site in Northern Ireland to use reed bed technology for the full treatment of wastewater. 

Action

Known as Phragmifiltre®, this innovative system is the first reed bed technology in the UK that provides complete treatment of wastewater in one wetland system, with no pre-settlement and using little to no power. This signifies a major change in thinking towards a natural and sustainable alternative for wastewater treatment in the UK where reed beds have been traditionally used as a secondary treatment after settlement and as tertiary treatment to purify effluent prior to discharge. 

Because of the unique way the Phragmifiltre® process stores and composts sludge on site, there is no need for tankers to visit the site to desludge - a major difference to the previous treatment works. This natural system also provides wildlife habitats - another important element that a conventional treatment works doesn’t have. 

Results

The reed bed system at Clabby is an example of how NI Water and its project partners are working to promote ‘greener’ engineering solutions that have a smaller carbon footprint, require less power and ultimately have reduced impact on the environment. This has been recognised internationally, having been awarded a prestigious Green Apple Award to be presented in London in November 2021.

Clabby WwTW: February 2019 - Courtesy of BSG Civil Engineering Ltd

Clabby WwTW: September 2020 - Courtesy of BSG Civil Engineering Ltd