Feasibility study for a CCA vineyard post aggregation site

Abstract

This feasibility study evaluated the viability of establishing dedicated aggregation site/s in South Australia for discarded chromated copper arsenate (CCA)-treated vineyard posts. It examined environmental, health, safety, and economic risks posed by uncontrolled stockpiling or improper disposal, including contamination, fire hazards, and regulatory non-compliance. Over 500 potential sites in South Australia were assessed, with 15 high-potential locations shortlisted across five key wine regions, with a focus on the Riverland and Limestone Coast. Three operational models were considered, with the co-location of an aggregation site at an existing waste facility (Brownfield Site with Existing Operations) identified as the most cost-effective and feasible option due to its low capital cost, faster implementation, and existing infrastructure. The report proposes comprehensive risk mitigation strategies and provides a roadmap for establishing a sustainable and compliant solution for managing end-of-life CCA posts in the wine industry. 

Summary

This feasibility study, conducted by Rawtec Pty Ltd in collaboration with Waste and Management Services Pty Ltd, investigated the viability of establishing and operating aggregation site/s in South Australia for discarded chromated copper arsenate (CCA) vineyard posts. The study evaluated potential locations, operational requirements, and risk management strategies to suggest a suitable approach for implementation.

CCA-treated vineyard posts have been widely used in SA’s wine industry for over 50 years and have a lifespan of 30 to 40 years. Currently, there is no clear and responsible end-of-life management strategy apart from disposal at suitably engineered and licensed landfill sites.  It is estimated that 35 million CCA-treated posts are in use in South Australian vineyards, with up to 1.8 million posts removed annually due to breakage. Additionally, recent economic challenges in the wine industry have led to vineyard removals, further increasing stockpiles of obsolete CCA vineyard posts.

Key Findings

Environmental, Safety & Business Risks

A risk assessment was conducted to compare potential CCA aggregation sites with current uncontrolled private stockpiles. Key risks of aggregating and storing CCA vineyard posts include:

• Leaching of arsenic, chromium, and copper into soil and water.
• Dust and airborne contamination from handling CCA-treated timber.
• Fire hazards, requiring proper stockpile spacing, firebreaks, and emergency response measures.
• Reputational risks and long-term financial liabilities if stockpiles are abandoned.

The report outlines risk mitigation strategies, including proper site selection, hardstand storage, dust suppression, fire prevention measures, and strict operational controls.

Site Selection & Assessment

The study assessed over 500 sites in South Australia, narrowing it down to 15 high-potential locations across five key wine regions, with a focus on the Riverland and Limestone Coast. Sites were evaluated based on:

• Proximity to vineyards and transport infrastructure.
• Existing site infrastructure (e.g., landfills, transfer stations).
• Environmental impact and compliance requirements.
• Operational feasibility and long-term viability

Operational & Establishment Models

Three potential models were considered:

1. Greenfield Site: Requires full development; highest cost (~$2.62 per post, 21–42 months implementation time).
2. Brownfield Site (No Current Operations): Existing infrastructure but not operational; moderate cost (~$1.26 per post, 9–18 months implementation time).
3. Brownfield Site (Existing Operations): Co-located with an active waste facility; most cost-effective (~$0.68 per post, 8–15 months implementation time).

The Brownfield (Existing Operations) model is the preferred option, given its lower capital costs, faster implementation timeline (8–15 months), and existing infrastructure.

Key Recommendations & Next Steps

To proceed with establishing a CCA vineyard post aggregation site, the following steps are recommended:

• Confirm financial & technical feasibility – Assess the cost/technical feasibility of combined aggregation and processing or reusing stockpiled posts. This could include short term piloting or other trial recovery and processing program.
• Engage industry stakeholders – Determine the willingness of vineyard owners to cover transportation and disposal costs.
• Refine site selection – Prioritize brownfield sites with existing waste operations.
• Address financial liability – Develop a framework to manage stockpile risks if a reuse or recycling solution is not viable.

A CCA vineyard post aggregation site presents an important and necessary step for managing SA’s growing stockpile of end-of-life CCA vineyard posts. By establishing a controlled, regional storage site, it may be possible to:

• Reduce environmental and WHS risks associated with uncontrolled stockpiles.
• Improve disposal efficiency and cost-effectiveness for vineyard owners.
• Support future recycling and circular economy initiatives.

While operational and financial risks exist for a CCA vineyard post aggregation site, they are manageable and consistent with other waste and recycling operations. Brownfield sites with existing operations should be prioritized to ensure a cost-effective, low-risk, and sustainable approach to managing end-of-life CCA vineyard posts.

The project was commissioned by Wine Australia, with funding provided by the South Australian Government through Green Industries SA.