Northumbrian Water is starting work on a £3 million programme to clean 9 kilometres of pipes at 18 different locations in and around Newcastle, Gateshead and North Tyneside.

The work, which will improve tap water quality to around 500,000 customers, builds upon a £66 million cleaning programme, which began in 2010 and has seen more than 221 kilometres of mains cleaned to date.

Innovative methods trialled in that programme will be used again to make the cleaning process faster and more effective.

Supply partners, Fastflow Pipeline Services and Mott MacDonald Bentley (MMB), will be carrying out the work on behalf of Northumbrian Water and will spend short periods of time in a number of different locations as part of the year-long project. All the mains will cleaned by the end of March 2019, followed by additional work required after March when all the work will be finished in the summer of 2019.

Northumbrian Water will be using different methods to clean the sections of pipe, including high pressure water jetting and an innovative technique called ice pigging, which helps to speed up the cleaning process.

Ice pigging involves isolating a section of pipe by turning off valves at each end. Water is then emptied to make room for slushy ice to be injected. Valves are re-opened and, as the water flows, pressure compacts the ice and it scrapes the pipe clean. The ice is then flushed from the main and the water is sampled before being put back into supply.