Water company clears pipes with ice

United Utilities is using ice in its battle to clean pipes and improve drinking water quality in the north-west of England.

This pioneering technique was developed by Bristol University and trialled by United Utilities in a £1.6 million mains clearing scheme.

A mixture of slushy ice is passed through the pipes, cleaning as it goes. It picks up naturally occurring sediment such as iron and manganese inside the pipes and is expelled into a tanker for safe disposal.

It has the advantage over traditional methods of clearing such as clean water flushing using swabs, as no digging is required.

United Utilities project co-ordinator, Ray Melia, said: “The problem with swabs is that we need to dig up the road to put them inside the main and this can take a few days.

“In some streets this is impossible, for instance Preston Old Road in Blackpool which is a major diversion route at the moment.

“We can pump the ice slush in and out using hydrants in the roadway. The whole procedure takes just a few hours and the results are great.”

The procedure was tested on two pipes near Blackpool’s Promenade and in Lytham St Anne’s. Engineers will now carry out a full evaluation of the ice technique to see whether it can be used for other mains across the region.

United Utilities is due to complete its year-long scheme to clean the mains system as is part of a ten-year project to improve drinking water.

Alison Brown

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