Mayflower Water Treatment Works

The future of water treatment 

South West Water’s Mayflower Water Treatment Works at Roborough, just north of Plymouth, is the first of its kind in the world.

It uses cutting-edge treatment processes, designed to produce impeccable drinking water and to be more sustainable than a traditional water treatment works.

In November 2020, Mayflower took over from the old treatment works at Crownhill in Plymouth, which has been serving the city since the 1950s.

The innovative treatment processes at Mayflower were designed and developed by Dutch water technology company PWNT, and tested at a prototype facility at Crownhill from June 2013 until June 2015.

Suspended ion exchange, inline coagulation and ceramic membrane microfiltration are used to produce more water, more efficiently and at a lower cost than traditional technology. It is the first time that these combined technologies have been used to produce high quality drinking water anywhere in the world.


But what does this mean for customers?

  • Keeping bills down in the long term – the plant will cost less to maintain, use less raw materials and require fewer staff to operate it.
  • Compact process therefore lower construction costs.
  • Requires less chemicals than traditional water treatment processes, reducing the environmental impact.
  • Ion exchange process captures hard to remove pesticides, colour and taste providing consistent high quality water.
  • The ceramic filters provide an absolute barrier to cryptosporidium and harmful viruses.
  • Located on a hill away from the city – reduces congestion from company vehicles and is safe from flooding.