Archaeologists have been called in to make sure workers burying waste pipes do not disturb artefacts in Cumbria.
United Utilities is laying six kilometres of water pipes in Bowness on Solway near Hadrian's Wall, which runs from the River Solway to the Tyne.
If no Roman artefacts are found then work will go ahead on the £6m scheme.
Currently waste water goes into the Solway Firth untreated. The scheme will mean water from Port Carlisle and Bowness will be treated in Glasson.
If any artefacts are found during digging work on the final trench, the scheme will be delayed.
But, if nothing valuable is found the company behind the project, United Utilities will ask planners for the go-ahead to finish the work.