Tahuna Waste Water Treatment Plant

Naylor Love Dunedin carried out the civil work associated with Stage 2 of the $30m Tahuna Waste Water Treatment Plant upgrade as a subcontractor to UGL NZ Ltd. The work involved new concrete pumping stations, UV treatment building, dewatering building and conversion of the existing settling tanks to HRAS. The existing plant remained operational at all times during the project.

In all we placed around 5,000m³ of concrete over our two-year involvement in the project, installing large new concrete structures, as well as altering and repairing existing structures, including deep in-ground pumping stations, 8m high insitu concrete walls up to 2.5 metres thick, concrete channels and tanks, precast buildings and HRAS & screens tanks – all in a live environment, with work carefully planned to avoid peak flow times.

We worked on multiple fronts simultaneously, often carrying out concrete works in confined spaces, and achieving high-quality finishes. The hazardous working environment required detailed planning, controls and monitoring, and we implemented rigorous safety procedures to prevent waterborne and airborne diseases and infections.

Environmental management was key to the success of the project, with strict precautions to prevent silt and sediment contamination of surrounding ground water and much consideration given to the sensitive location, adjacent to the beach on one side and a residential area on the other.