Laying fibre in the Britain’s aging sewage system could provide users with speeds of at least 100 megabits per second and save the country around as much as £15bn, according to Wales-based H20 Networks.

The company is in discussions with councils in Dundee, Bournemouth and Northampton with a view to serving up ultra-fast broadband to city residents using residential sewerage systems.

According to H20 Networks managing director Elfed Thomas it would cost between £15m and £24m to connect to a small town or city, compared with up to £80m through new road cables. Using the sewage system instead should also prove much to the environment than digging up the roads.

H20 Networks is already providing a sewer-based broadband service to small, concentrated user communities, including Bath and Aberdeen University. The company hopes to supply an additional 10 to15 towns and cities using the sewage system over the next five years.

Similar schemes have proved a success in other parts of the world, including France and Japan.