Challenging Dewatering on contaminated grounds, Balcatta WA

We were engaged by BOS Civil, which required prompt dewatering in troublesome ground conditions throughout their 2 x extensive basin excavation works in Balcatta, WA.

The following morning, NPE mobilised all plant and technician specialists to start the wellpoint installation. The ground’s existing building materials, including rubble, bricks, steel, car diffs, and other obstructions, became apparent during wellpoint attempts, and this caused us to rethink and change our installation approach.

To ensure we could achieve the required invert depth, NPE provided an alternative wellpoint installation solution allowing the wells to stay open for the installation of each spear, maintaining absolute screen coverage of the gravel pack.

NPE also provided a localised sump pumping method staged across the areas as needed, which was sent into the dewatering discharge lines and all boosted approximately 200m away from the designated on-site infiltration basin. This was done because the actual ground soils also contained peat layers that were about 4-5 metres deep.

This job was a great success and provided a fantastic opportunity to utilise NPE’s specialist knowledge when up against unforeseen challenges.