UEA installed 4.3 kilometres of minor water mains for Shoalhaven Water, located in the Nowra and Culburra Beach Region and spread over nineteen sites of the Shoalhaven region, approximately two hours south of Sydney. The aim of these packages was to improve the water supply to a number of dairy farms, coastal towns and suburban areas.
Scope of Works
The principal’s intent was to replace various minor water mains throughout the region of existing mains – less than DN100 with appropriately sized mains. Work involved replacing existing 40mm and 50mm mains with 125mm PE, with internal diameters of 100mm.
UEA was able to offer a complete package by performing all works by internal HDD and civil crews, including:
- Temporary water supply
- Supply of pipe and fittings
- Installation of pipes
- All civil works
- Reconnect 105 house services to the new main
- Installation of fittings
- Testing and commissioning of the new main
The package was designed as an open trench contract but UEA proposed HDD to reduce the impact on the local community, limit disturbance to the natural surface and reduce restoration required. UEA used a combination of technologies to install the new mains – HDD, bed boring and conventional trenching techniques.
Challenges and Wins
UEA and the client worked together to overcome design issues before crews mobilised to site, in order to avoid site delays. UEA’s internal HDD and civil crews completed all components of the project, enabling a streamlined project with only one point of contact.
The greatest challenge was the different ground conditions, including soft water charged clay, beach sand, shale and hard rock. UEA’s experience, combined with the choice of drill – one of its two DitchWitch AT3020 HDD rigs capable of dealing with mixed ground conditions – allowed the team to overcome any foreseeable problems. UEA’s multi-skilled and qualified civil crew has been performing this type of work for a combined total of over 20 years.