Phase 1 in tunnels
Mercer (New Zealand)

Mercer Mushrooms, one of New Zealand's largest mushroom farms., faced with the challenge of complying with New Zealand's ban on compost importation, sought to establish an in-house composting solution. The primary goal was to avoid causing any odour nuisance to the surrounding community, as any odour issues could result in the closure of the composting facility.

Solution Proposal

To address the challenge of creating an odour-free composting system, Christiaens Group proposed Phase 1 composting in tunnels. This innovative approach offered the advantage of more compact construction, allowing for better control and management of potential odour concerns. The decision to opt for an unconventional solution, demonstrated Christiaens Group's commitment to meeting the specific needs of Mercer, ensuring the success of Phase 1.

Case details

3 aerated floors
5 phase 1 tunnels
7 phase 2/3 tunnels
Completed: end 2021

Seismic Considerations

Complicating matters further was the seismic vulnerability of the location for the composting facility. Due to the earthquake-prone nature of the area, the construction required 2 to 3 times more steel and concrete to efficiently dissipate forces without compromising the functionality of the system. Complex calculations were performed to design an ideal structure, balancing stability with operational requirements.

Global Construction during COVID-19 pandemic

The construction took place during the pandemic, with travel restrictions preventing entry into New Zealand. Christiaens Group overcame this challenge by leveraging a dedicated supervisor in Australia, forming a "bubble" with New Zealand to allow for onsite monitoring and continuous work.

Independent Validation

Mercer enlisted an independent advisor to assess the process and technology, initially sceptical but later becoming an advocate. Notable improvements, such as enhanced bio-efficiency, were observed and acknowledged.

Conclusion

The composting facility operates to Mercer's full satisfaction, with an independent advisor turned advocate, highlighting the success of the Phase 1 in tunnels approach and solidifying Christiaens Group's reputation as a reliable and innovative partner in complex projects.

The project showcases Christiaens Group's commitment to deploying proven concepts with innovative technologies, even in the face of global challenges like the COVID-19 pandemic and seismic vulnerability.

Phase 1 in tunnels Mercer (New Zealand)

Phase 1 in tunnels
Mercer (New Zealand)