Recycling C&D waste as best as we can

Post Date: 22 September 2025
Read Time: 7 minutes

Encouraging construction and demolition debris recycling

If you wanted the ideal conditions for encouraging construction and demolition (C&D) debris recycling, now is a promising time. Our landfills are running out of space, time, or both[1], and the cost to use them is going up.[2] Yet we continue quarrying, logging, milling, and mining tonnes of materials that could be replaced by recycled C&D debris[3], even as Aotearoa New Zealand sends about 6 million tonnes of waste to landfill each year.[4] There is a clear financial, social, and sustainability case for diverting as much C&D debris as possible into recycling.

The challenge of asbestos-containing material in C&D recycling

Asbestos-containing material (ACM) can find its way into the C&D waste recycling stream. When it does, it poses serious risks to health, reputation, and commerce. How are we attempting to minimise these impacts, and can we do better?

Historic Example: Sydney Asbestos Crisis

Last year’s Sydney Asbestos Crisis first came to light in January 2024 when a child brought home playground mulch contaminated with non-friable ACM.[5] By year’s end, mulch contaminated with non-friable and/or friable ACM was removed from 79 parks, schools, hospitals, supermarkets, industrial areas, aged care facilities, and other sites[6], many of which experienced shutdowns during the process.[7] Most of the mulch was traced back to a single C&D debris recycling facility, leading the New South Wales Environmental Protection Agency to lay over 100 charges against the owner.

The New Zealand experience: Taupō District Council case

In Aotearoa New Zealand, Taupō District Council’s Broadlands Road Landfill provided vital concrete recycling services to the local community for years. However, in August 2024, a suspected asbestos-contaminated load of recycled concrete triggered an investigation that eventually uncovered 10,000 tonnes of asbestos-contaminated concrete at the facility.[8]

The council responded by staffing a hotline for those who suspected contaminated concrete on their property and paid for testing.[9] The recycling facility’s operator subsequently closed the business, disheartened by the repercussions of bad-faith actors deliberately ignoring staff instructions.

By May 2025, cleanup efforts were estimated to cost approximately NZD 1.35 million.[10] In June, a truck transporting contaminated material offsite jack-knifed on the Waikato Expressway, closing the highway for 11 hours while crews cleaned up the contaminated concrete spilled across the road.[11]

Health, reputational, and financial risks

Both incidents highlight the health risks faced by end users, facility operators, and waste transporters exposed to contaminated C&D debris, as well as the reputational and financial damage suffered by facility operators and councils.

Preventing asbestos contamination in C&D recycling

What steps are being taken to prevent asbestos-contaminated C&D debris from being unknowingly handled by recycling facility staff or the public, and to stop contamination in the first place?

Currently, prevention relies heavily on compliance with laws, guidelines, and industry best practices. This high-trust model demands integrity and technical competency throughout the C&D “chain of custody,” which introduces multiple points of potential failure.

Recycling facility operators often provide written and verbal instructions to depositors about prohibiting asbestos-containing material. Some conduct periodic laboratory testing or visual assessments of loads. Others use near infrared (NIR) handheld analysers, despite their use being banned for asbestos analysis in some jurisdictions[12] and their high dependence on user skill. Unfortunately, most controls at the facility gate come too late, acting more as mitigation than true prevention.

The risk of future asbestos crises

This situation suggests the inevitability of future asbestos crises. For Aotearoa New Zealand, a significant asbestos contamination event could be catastrophic for C&D debris recyclers, especially smaller rural facilities where recycling services are most needed.

Reasons for optimism and industry initiatives

There is, however, cause for guarded optimism. WorkSafe’s recent update to Conducting Asbestos Surveys: Good Practice Guidelines for Asbestos Surveyors[13] and forthcoming updates for asbestos removalists and assessors[14] will improve the identification and removal of asbestos before demolished structures enter the C&D waste stream.

Additionally, the updated New Zealand Guidelines for Assessing and Managing Asbestos in Soil[15] and WasteMINZ’s Disposal of Low-Level Asbestos-Contaminated Soil at a Landfill[16], provide practical requirements for training and awareness for waste transporters and facility operators.

Leading change in the industry

Those of us in this industry must raise awareness and shift mindsets across disposal and recycling sectors. Recycling facility operators should regularly request evidence that demolition waste comes from structures built after 2000, or from buildings where asbestos was not identified (e.g., a survey report), or where asbestos was properly removed (e.g., a clearance certificate). Operators who insist on these documents should be applauded.

The health, reputational, and financial risks of accepting C&D debris from sources that cannot or will not provide these documents are simply too great. We can and should help lead change for the better.