260 MLD A Block Filtered Water UV Disinfection for Ardmore Water Treatment Plant.


MTL led the design of a 260 MLD UV Disinfection system retrofit of the A Block filtered water stream (~70% of maximum plant production) Three new 33% duty Wedeco K Series K143 reactors are located inside the existing Chemical Building obsolete ‘salt bay’. A combination of CFD and conventional hydraulic modelling has been utilised for UV reactor certification and to minimise head loss. An innovative nominated contractor NZS3916 design build approach has been utilised by WSL to expedite delivery of the project.


This system will provide a second protozoa barrier to improve water treatment plant resilience and security of the drinking water supply for Auckland during off normal conditions as follows:

  • Low raw water quality during storm events that compromise filtered water turbidity, and,
  • To enable increased production through A Block (260 MLD from 160 MLD) during major treated water upgrade works planned for Ardmore WTP over the next 2 - 3 years.


Brian Perry Civil, Neo Consulting.