Thousands of Scottish homes could soon get high-speed internet access through the sewerage system.
The system trial begins this week
Scottish Water has launched a pilot scheme in Rosyth and believes leasing sewage pipes to broadband providers could drive down internet costs.
It also avoids the problem of digging up streets to lay wires and could bring access to remote parts of Scotland.
Scottish Water said the first stretches of cables would be installed by the end of this week.
Commercial director Chris Banks said it is a project that has been in the pipeline for some time.
"Our partner Fibrelink is financing the network, the fibre that actually goes down the sewers, we are simply renting out the sewers to them," he said.
Information sewerage highway
"Fibrelink will then contract with various telecoms providers on a neutral carrier basis, that is we can facilitate anyone hooking up to this and they'll be making the charges.
"Where Scottish Water gains is we will take a percentage of the revenues that are generated through the fibre."
He added that with 24,000 miles of sewers there was the potential for the pilot scheme to be a widespread success.
Two miles of cable will be laid in Rosyth over the next 28 days for full testing to begin.
The concept and cable have been in use in Europe for six years and are said to have proved cost effective.
The starting point for the pilot will be Dunfermline waste water treatment works, where the cable will be fed in and floated down through the pipes.