The Whangarei District Council commissioned this work following frequent overflow of sewage into the Whangārei Harbour during heavy rain events.
The pump station upgrade and new one million litre underground emergency storage tank were designed to reduce these overflows – providing primary treatment and disinfection capability in the event of an overflow.
Our main challenges on this project were:
- constructing the wet well plus tanks at depths of up to six metres below existing ground level, beside a stream and in very poor soil conditions
- casting the storage tank floor insitu, together with pre-cast wall panels and a reinforced concrete slab that formed the tank.