In preparation for the upgrade of one of its key water treatment facilities at Huia (140 ML/day), Watercare engaged Hunter H2O to undertake an extensive pilot plant investigation. The focus of the study was to ascertain design criteria and test the robustness of the proposed upgrade option comprising dissolved air flotation, ozonation and biological filtration in order to achieve advanced organics removal. The upgrade is a key component for addressing water quality issues and securing supply during peak demand periods.