Stevenson Aggregates (Drury) – Water Treatment Upgrade.

Stevenson Aggregates provides a wide range of aggregate products for commercial, residential, and infrastructure projects across New Zealand. As part of a broader processing plant upgrade at their Drury operation, Stevenson required a higher-capacity water treatment solution to handle storm water, truck wash waste, and increased process water volumes.

To meet this need, Stevenson engaged MIMICO to replace the existing twin LT-100 Lamella clarifiers with a single high-capacity LT-500 unit. The LT-500 system is capable of processing up to 500m³/hour of wastewater, with additional capacity built in to allow for future plant expansions.

Given the size and complexity of the upgrade, careful design and planning were required to integrate the LT-500 into the existing site footprint. MIMICO supplied and installed the full system, including a new Metso VS200 L150 slurry pump to transfer waste slurry to the clarifier, as well as all associated pipework to ensure seamless transition from the old units to the new system.

A fully automated PLC control system was included to manage chemical dosing and provide real-time monitoring of solids content in the feed and turbidity levels of the treated water. Installation was completed on a tight timeline to align with the commissioning of Stevenson’s new process plant.

Project Highlights:

• LT-500 Lamella clarifier installed (500m³/hour capacity)

• Full PLC system for automated chemical dosing and water quality monitoring

• Metso VS200 L150 slurry pump supplied to feed the LT-500

• Complete new pipework system designed and installed

• Installation completed to coincide with process plant commissioning

By delivering an advanced, fully integrated water treatment system, MIMICO helped Stevenson Aggregates increase wastewater handling capacity, optimise plant performance, and future-proof their site for ongoing growth.