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Saltire were awarded the project by the Water Corporation to address the recent customer complaints regarding odour issues associated with an existing pressure main and gravity sewer discharge point in Duncraig, WA. With Saltire’s assistance, the design had been altered to suit trenchless technology, the existing environment and infrastructure and suit the end project needs. The project involved extending the existing pressure main to an existing gravity section away from residential properties and providing a new discharge point that eliminated issues with odour control. The works consisted of installing a 288m long DN355 PN20 HSCR PE100 pipeline with associated concrete chambers.

Saltire were responsible for supply, construction, installation, and testing of the wastewater infrastructure assets for the project. The works consisted of setting out and surveying existing infrastructure and services, proposing levels for trenchless HDD Installation, excavation of HDD pits and for valve chambers, HDPE pipe welding and Fitting, Installation of pipework via Horizontal Directional Drilling (HDD), Installation of fittings, valves, and precast concrete chambers, backfilling and compacting, pressure testing, inter-connections with existing pressure mains and restoration works.


Due to the proposed works being on the front verge of residential properties, the impact of the works to the local area would be significant under conventional methods, requiring temporary blocking and removal of residential driveways access, road closures and deep excavations in the vicinity of members of the public. Proposing horizontal directional drilling reduced the amount of excavation significantly and by planning the location of access pits, all driveways and access roads were maintained during the works.

The program was completed within 25 working days, providing a fast, safe and efficient installation with minimal impact to the residents. The works resulted in very positive community feedback. The project outcome was also a success having removed the odour issue to the local area.


Providing an engineering solution to an existing design, Saltire were able to assist Water Corporation in improving customer experience and providing a positive project outcome in all aspects, with a fast project completion time with minimal disruption.