Lake Hugh Muntz Sep 2024

PET was commissioned by City of Gold Coast to supply and apply 50.4 metric tonnes of Phoslock to Lake Hugh Muntz on QLD’s Gold Coast. Surrounded by residential housing, the lake has an area of 17 hectares and an average depth of 4.1m.

Phoslock was nominated as a suitable phosphate reduction agent to address internal P loads in the water column and the sediments to reduce the frequency of associated nuisance algae blooms. The aim of the application was to reduce and manage the internal phosphorus load in the lake and to provide an active layer of Phoslock to the water column/sediment interface.

An application of Phoslock on the lake was last conducted in 2021 but over the last year or so P levels had risen again because of the incoming stormwater loading and the lake was once again plagued by cyanobacteria blooms.

The Phoslock application was undertaken using a slurry mixing unit mounted on a pontoon boat. This system converts granular Phoslock into slurry using the lake water before dispersing the slurry onto the surface of the water body through a spray boom. Prior to the application the lake had been treated by Gold Coast Council with an algicide to kill the cyanobacteria and thus release P so that it could be removed by combining with the lanthanum in the Phoslock.