Why New Zealand Needs a Contaminated Land QA/QC Practice Note – Now More Than Ever
By Simon Hunt, EHS Support New Zealand Ltd
While the country benefits from a “reasonably” robust legislative framework—including the National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health (NESCS) and the Ministry for the Environment’s Contaminated Land Management Guidelines (CLMGs)—there remains a clear gap: a consistent, industry-endorsed Quality Assurance and Quality Control (QA/QC) practice framework.
The development of a dedicated QA/QC Practice Note for contaminated land work in Aotearoa represents an important step forward. More than a technical manual, it is an opportunity to raise the quality, defensibility, and consistency of environmental investigations nationwide.
This need has not emerged in isolation. It is the result of extensive industry reflection, consultation, and collaboration, including discussions at the 2023 ALGA New Zealand Conference and subsequent workshops, where practitioners from councils, consultancies, laboratories, and industry groups reached a strong and recurring theme from participants: New Zealand needs a modern, sector-wide QA/QC reference that supports—not just regulates—the quality of contaminated land investigations.
Regulation Sets the Floor—But Best Practice Should Aim Higher
Current guidelines provide important direction, but their QA/QC detail is limited. For instance, CLMG No. 5 outlines key concepts and minimum expectations, yet practitioners often rely on internal procedures or international guidance. This has created variability between investigators, councils, and even regions. A national QA/QC practice note helps resolve this by:
Defining best-practice procedures, not just minimum standards.
Clarifying defensible QA/QC processes so that datasets are reliable, reproducible, and transparent.
Supporting consistency across soil, groundwater, surface water, vapour, and landfill gas investigations.
Ensuring data supports decision-making for human health, environmental protection, and regulatory compliance.
In other words, where regulation creates a threshold, best practice sets a benchmark.
There is growing momentum across the sector: The Time for Alignment Is Now
The initiative to create a QA/QC practice note emerged organically from industry demand. Practitioners observed that as project complexity increases—due to urban redevelopment pressures, climate-driven groundwater changes, or legacy contamination—the quality and consistency of data underpinning decisions must improve.
Workshops facilitated by ALGA revealed several shared challenges:
Highly variable QA/QC practices across organisations.
Gaps between international guidance and typical New Zealand field procedures.
The need for clearer expectations around sampling design, field measurements, laboratory QA, and PARCCS reporting (Precision, Accuracy, Representativeness, Completeness, Comparability, Sensitivity).
Growing pressure to produce defensible datasets for regulatory review, litigation, or redevelopment investment.
In response, a steering committee and contributing authors from across the country have begun drafting the first version of the Practice Note supported by councils, industry experts, and the WasteMINZ CLM Sector Group.
Building a Toolkit for Excellence
The Practice Note is being designed as a toolkit—practical, accessible, and applicable across a wide variety of project types and contamination media. It will cover essential QA/QC considerations, including:
Minimum QA/QC requirements for soil, groundwater, surface water, vapour, and landfill gas.
Development of Sampling and Analysis Plans (SAPs) and Data Quality Objectives (DQOs).
Standard equipment, calibration, and field-readiness protocols.
Expectations for IANZ-accredited laboratory use and interpreting lab QA/QC reports.
Guidance on meeting PARCCS criteria for defensible datasets.
These components ensure the practice note is not just theoretical—it will be actionable for consultants, regulators, and even laboratories.
Supporting a More Sustainable and Trustworthy Contaminated Land Sector
Environmental decision-making relies on trust. Communities, mana whenua, developers, and regulators need confidence that contaminated land investigations are both competent and credible.
A QA/QC Practice Note supports this vision by:
1. Improving Environmental and Human Health Outcomes
Better data leads to better risk assessments, which in turn protect people and ecosystems more effectively.
2. Supporting Regional and National Consistency
Whether you’re in Auckland, Canterbury, Otago, or Gisborne, stakeholders should be able to rely on comparable investigation practices.
3. Helping reduce avoidable rework and delays
Clear expectations mean fewer re-samples, fewer rejected reports, and fewer delays during regulatory review.
4. Enhancing Professional Capability
New graduates and early-career practitioners gain a reference that builds national capability and strengthens career development.
5. Future-Proofing the Industry
With updates planned as science and regulations evolve, the practice note remains a living document that grows with the sector.
Conclusion: A Small Document with Big Impact
A contaminated land QA/QC Practice Note may seem like a technical artefact—but its impact goes well beyond sampling protocols and checklists. It strengthens environmental stewardship, reduces uncertainty, builds trust, and raises the professional standard of the entire industry.
As New Zealand navigates new environmental challenges (including planned changes to the Resource Management Act), urban development pressures, and evolving regulatory expectations, this practice note represents a crucial investment in quality, consistency, and sustainability.
By uniting the sector around a shared QA/QC vision, we are building a safer, more resilient, and more transparent future for contaminated land management in Aotearoa.