Telscombe Residents Association is calling for Southern Water to reinstate a public footpath which was lost in the 1970s.
Campaigners were hoping the coastal footpath just off the A259, in Telscombe, might return, now the Waste Water Treatment Works is complete.
Southern Water said the footpath could not be reinstated along its original route, because some of it was in mid air, but said it would continue talks with East Sussex County Council to find a solution.
Secretary of Telscombe Residents Association, Christine Bowman said: “Since Southern Water successfully obtained planning permission to create a new Waste Water Treatment Works in Peacehaven, it was naturally hoped that Southern Water had planned to restore the public footpath to its original position, thus contributing to the need for a coastal footpath all around the country.
“However, instead, Southern Water appears to be resolute in making an application for the Telscombe 12a Public Path Diversion Order 2009 to be made permanent.”
A spokesperson for Southern Water said: “Southern Water is committed to resolving this longstanding matter and is continuing its discussions with East Sussex County Council, as well as recently meeting with Telscombe Town Council.
“The footpath cannot be reinstated along the original alignment, as a section of it is in mid-air due to the essential cliff excavation work carried out by the water authority in the 1970s when the works was constructed, which was prior to Southern Water taking over the operation of the site. We will continue our discussions with the county council to secure a resolution.”
Mrs Bowman added: “There was a loss to the community of a valuable asset when the original path was blocked in the 1970s, and it is high time the path was restored, perhaps by installing a bridge or steps at the site.
“We believe we have a wonderful natural heritage in our coastal route in our area, and think the public have a right to enjoy the path in its original location, rather than merely walking alongside the main A259 with its inherent dangers and pollution.”
The residents association also pointed out it would be illegal for a public footpath to run along a highway and said Telscombe and Saltdean, residents, Telscombe Town Council and The Ramblers Association have been campaigning to have the footpath restored.
Public Footpath 12a ran along the coast, north of Portobello Sea Outfall Pumping Station, and south of the A259. Early in the 1970s, the footpath and therefore the Right of Way, was closed temporarily due to excavations associated with the waste water treatment works.