A multi-million project will deliver better drinking water to people in Helston from this week.

Work at Wendron Water Treatment Works, which supplies nine per cent of Cornwall with water, is part of a £14.5 million upgrade to supply “even better drinking water”, according to South West Water.

Five new granular activated carbon (GAC) filters have been installed at the Wendron facility, and the existing rapid gravity filters have been refurbished.

Granular activated carbon is a porous material with a large internal surface area – just one teaspoon has the same surface area as a football pitch. Due to its large surface area and specific surface chemistry it can remove large quantities of natural and manmade organic matter sometimes present in rivers and reservoirs supplying water treatment works.

Chris Rockey, science and water quality manager, said: “We already have some of the best tap water in the country but this major investment will deliver even better drinking water to our customers in Cornwall.

“In the short term, the smell or taste of chlorine may become more noticeable to some customers. For this reason, we will bring the new filters online one at a time and blend the new and improved water with the water currently produced by the works to ensure a smooth transition.”

Customers supplied by the Wendron facility will notice the change this week, as water that has been through the GAC treatment process started to be introduced into supply from Tuesday.

Work is also being carried out at Restormel Water Treatment Works, near Lostwithiel, which supplies 67 per cent of the population of Cornwall with drinking water, including St Austell, Newquay, Truro, St Ives and parts of Bodmin, Redruth and Camborne.

At Restormel, six much larger GAC filters have been installed. A similar approach is being taken there and customers will start receiving a blend including the new water from late October 2014.

Work started on both sites last year and all the new filters will be in use by the end of December 2014.