Kaikoura Sewer Replacement

With a very old and depleted sewer system the main streets of Kaikoura needeed to be upgraded. Council tendered the jobs and Donaldson Civil won based upon the tender to use trenchless technology by way of pipe bursting in a new main line.

The job involved bursting 1100m of existing 225mm dia reinforced concrete pipe and pulling through 250mm dia SDR 17 Polyethylene pipe. This length was burst in many shots between 35 and 110m in distance. The depth of the pipe was 1.3 – 4.2m with ground conditions varying from lime stone to pea shingle. With the pipe bursting pulling through a solid line laterals were connected to the many shops along these streets, 42 connections were made by excavating holes at the existing junction and fusion welding on new saddles.

With buisness still open there were very high flow rates through the line, large pumps were used to over pump the lines during the bursting and testing operation.