Reporoa Organics Processing Facility - Ecogas

The Project  

The Ecogas Reporoa Organics Processing Facility is New Zealand's first large-scale food waste-to-bioenergy facility. The 2-hectare site comprises large and heavy digester tanks, processing building with office block and gas upgrading facility. The extensive development, tight operational deadlines and geologically young and challenging soils created high pressure and complex project.

Check out the project website here: Reporoa Organics Processing Facility — Ecogas

Our Role

Pioneer Energy engaged us as the geotechnical experts to deliver a consent ready package. Our detailed site investigation and subsequent assessment highlighted complex geotechnical challenges, including a very high risk of liquefaction within the upper sand soils and deep settlement within a thick layer of peat within the pumice rich volcanic soils. We calibrated our liquefaction assessment to account for the pumiceous soils that were overestimating the vertical settlements.

The Solution

After working with our client and project partners, the final solution involved the design and verification of 21-metre deep driven timber piles below an embankment reinforced with high tensile geotextiles. This solution provided long-term stability while remaining cost-effective and practical to construct. During the trial filling of the tanks, settlement was completely uniform and within the structural tolerances, confirming the system was working as intended.

By leveraging our geotechnical expertise and smart thinking, we helped ensure the successful delivery of a key piece of infrastructure supporting New Zealand’s sustainable waste solutions.