The ageing asbestos concrete (AC) sewer, operated by Wessex Water, had suffered a number of fractures and was relined using CIPP to safeguard it for the future.

A CCTV investigation of the 650 m long sewer revealed that it had lost structural strength and sections exposed to the elements had caused exfoliation of the outside surface leading to a number of ring fractures – a common problem for AC sewers.

Wessex Water Engineer Barry Burtenshaw said repairing the 375 mm diameter sewer in Corsham, Wiltshire, using Trenchless Technology had many advantages.

Mr Burtenshaw said “Without the use of this technology it would have been impossible to repair the sewer without closing this busy section of railway line which would have been extremely disruptive and costly.

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“In addition, it meant that we could safely make improvements to support the pipe’s structure without the risk of compromising the asbestos cement pipe’s integrity.”

Before the relining work took place, the sewer was cleaned using a Weirdermann 1000 Recycler, which has over 400 m of reach and is a very quiet machine.

Once the cleaning was complete, the sewer was relined in two shots using liners measuring 325 m and 323 m.

With its new liner installed the sewer is now expected to continue providing a safe, reliable service for more than 50 years.