Northumbrian Water and its partners Esh-MWH are carrying out the work to renew a large, aged water pipe in the Deepdale Aquaduct and Lartington Lane area of Barnard Castle.
The £900,000 project has seen the team encounter a number of unforeseen challenges, which have led to the completion of the work being delayed until the end of December.
The traffic management on Lartington Lane will remain in place, and Northumbrian Water continues to work closely with Durham County Council and Barnard Castle Town Council to keep disruption to a minimum.
The company is replacing 160 metres of water pipe, and the project includes a temporary pipe being laid across the aquaduct to ensure supplies are maintained for customers throughout the work.
Project Manager Gary Cassells said: "As well as delays earlier in the year, caused by safety concerns around harsh weather conditions, and the discovery that large parts of the century-old pipe are surrounded by concrete, the work has continued to prove challenging, but we are now making good progress towards completion.
"Most recently, delays were caused by issues surrounding the safe installation and operation of the temporary pipe, as the ground conditions have caused further unexpected difficulties. Our team discovered unexpected shallow bedrock, while volumes of water in the ground in the surrounding area caused difficulties with excavation and the shoring up of the work, and related health and safety concerns for our people and the public.
"We apologise to those affected for the inconvenience caused by the work, which is being carried out to help safeguard water supplies for future generations.
"For safety reasons, Deepdale Aquaduct, which people often use as a pedestrian footbridge, will remain closed. We would ask members of the public to continue to respect that closure and use the diversion that has been put in place.