Melanie L Harris

Australia’s electricity distribution networks rely heavily on timber utility poles, predominantly manufactured from durable hardwood species and treated to achieve long service lives. For the last 20 years, the treated softwood poles have become more common. While these poles provide strong environmental and economic performance during use, their end-of-life (EOL) management remains largely linear, with most treated poles disposed of in licensed landfills. This study quantifies the national scale of EOL timber utility poles in Australia and evaluates current management practices, regulatory constraints, and circular-economy opportunities. Using utility company surveys, sustainability reports, and industry consultations, we estimate that approximately 5.45 million timber poles are currently in service nationally. Between 70,000 and 85,000 poles are removed from service annually, equating to an average of 77,000 poles or approximately 69,000 m³ (54,000 t) of mainly hardwood entering the waste stream each year. Despite the high material quality and residual structural integrity of many poles, reuse and recycling remain limited due to preservative treatments, embedded metal contamination, transport distances, and regulatory barriers. This paper provides the first consolidated national assessment of EOL timber utility poles in Australia and demonstrates that even partial diversion from landfill could deliver substantial environmental and economic benefits. The findings support the development of targeted circular pathways, including resawing, encapsulated products, engineered wood applications, and decentralised processing, aligned with Australia’s national circular economy objectives.

Timber is an ideal resource for the circular bioeconomy with the potential to aid the transition towards a

net positive future. Preservative treated timber (PTT) and engineered wood products (EWP) can allow greater high value use of wood resources, can increase timber strength and durability, and store carbon. Adhesives and treatments however are problematic when re-circulating or recycling resources into new applications. With the Australian Government calling for a circular economy (CE) by 2030, all resources will have to be reused and recycled rather than moving linearly from use to landfill. Despite growing awareness of the benefits of a CE there has been little adoption of this approach within the timber supply chain. A clear understanding of available resources is vital for determining potential solutions for end-of-life (EOL) timber.

The Timber Circularity Project is a three-year national project spearheaded by The National Centre for Timber Durability and Design Life (NCTDDL) which aims to understand EOL resources available and potential solutions that will meet regulatory and logistics challenges. The aim of the project is to delineate circular pathways for PTT and EWP and aid the transition of the timber supply chain to a CE. The volume and condition of unused resources, logistics, regulations, and solutions are being geospatially mapped.

This paper presents an overview of a solutions matrix designed to evaluate potential pathways for enabling a timber CE. Rather than following a linear cascade from reuse to energy recovery, timber should be assessed within a broader framework that considers factors such as scalability, ecological impact, and establishment costs. Organizing solutions within a structured hierarchy allows for a more comprehensive evaluation against these key considerations. The matrix has been applied to identify the most viable options for a pilot demonstration of CCA PTT vineyard posts, set to commence in mid-2025. As new solutions emerge, the matrix will continue to evolve, supporting the advancement of a sustainable timber CE.