HydroVac was recently contracted by Downer to perform a full service on a sand-filter stormwater treatment system at Mt Eden Prison. It was a project that required precision, planning, and the right mix of old-fashioned hard work and smart methodology.

After months of planning, we determined the best approach was to combine manual labour, some craftily placed conveyors and our gantry skip-bin system. Due to the sensitive and highly secure location, the work had to be completed with minimal disruption to prison operations – meaning every movement had to be coordinated and carefully managed.

Over five days, our team removed 76 tonnes of contaminated filter media, loading it onto conveyors that fed into our gantry bin system. Once full, the bins were taken offsite to an approved disposal facility.

We also replaced the underdrainage system before reinstating the sand-filter over three days with 56m³ of new filter media. This stage was made more efficient with the help of a specialist trailer, alongside the reversal of the conveyors to return the media to the filter.

This was the first time HydroVac had used this particular combination of methods and it proved highly effective. The sand-filter is now in perfect working order.

The project was completed ahead of schedule and within budget, earning positive feedback from our client and stakeholders.

A big thank you to Downer, Corrections, and our other suppliers for their collaboration on a challenging but rewarding job.