UEA Trenchless Division awarded HDD project under Lake Conjola at NSW

Posted 10 June 2014

The UEA Trenchless Division has been awarded a significant  Horizontal Directional Drilling (HDD) job on the South Coast of NSW.

The overall project aims to replace the  existing submarine cable running under  Lake Conjola. Demand during the area’s peak tourist season has been identified by the local electrical authority as a major risk to services. The underwater cable will be replaced by UEA Trenchless using HDD technology.

Construction technique

Prior to the HDD works commencing, UEA Trenchless needs to locate a treated effluent main that lies underneath the lake that could potentially impact on the proposed new alignment.

UEA Trenchless will install a 180mm conduit of 880 metres in length through sand and sandstone, representing one of the longest HDD boring projects undertaken by the Authority.

Part of the process involves a 350mm steel casing to be used over the first 80 to 100 metres. This is to prevent frac out whilst drilling through the soft formation into the harder sandstone. Frac out refers to the problem of pressure building from obstruction to a borehole, causing drilling fluid to escape to the surface.

Further information

For details about the Lake Conjola project, or for information about UEA Trenchless’ accreditation status, phone 02 9851 3000 or email us for a quick response. To find out more about Trenchless Technology, visit our Technical Centre.