Soil Sampling Methods in Australia: A Decline or a Recalibration of Standards?

Having worked in this industry 2 decades, I’ve noticed a shift in how contaminated soil sampling is approached in Australia. What was once considered fundamental best practice—ensuring accurate, uncontaminated soil and groundwater samples— appears to be de-evolving.

My question is: Are these changes a gradual erosion of standards due to competitive pressures, or a recalibration driven by evolving regulations and risk-based assessment?

Evolving Soil Sampling Practices

One noticeable shift is the increasing use of soil samples collected directly from solid auger cuttings, often without decontaminating augers between boreholes. This approach was dropped in the early 2000's with the introduction of proven direct push technologies. Geoprobe rigs with dual-tube sampling systems became the industry standard, offering continuous core samples in a cased borehole. This sampling methodology provided precise vertical contaminant distribution data with a high confidence level. Even older methods like hollow auger split-spoon sampling, while slower, provided intact cores for reliable analysis. Yet, these methods seem to be used less frequently today.

Geotechnical vs. Environmental Drilling and Sampling: A Shift in Priorities?

Another trend is the increasing number of combined geotechnical and environmental investigations, where geotechnical requirements often take precedence over environmental sampling best practices.
In many cases, environmental samples are collected from disturbed material within geotechnical boreholes rather than using dedicated environmental sampling techniques.
With more projects prioritizing geotechnical data environmental sampling is conducted within the constraints of those methodologies, rather than as a separate, contamination-focused process?

Are Consultants Adapting Scope to Their Own Equipment?

Another potential driver is the increasing number of consultants owning and operating their own drilling rigs. This may mean that investigation scopes are written with specific in-house equipment in mind, rather than selecting the most appropriate or detailed sampling approach. If this is the case, is the industry shifting toward methodologies that balance practicality at the expense of quality?

What’s Driving This Shift?

Are these changes temporary, or is this the new industry standard?
Have regulations evolved to allow for different approaches?
Have auditors and regulators adjusted their expectations?
Or is this a response to industry demand for faster, more cost-effective investigations?

Positioning for the Future

If these new approaches are here to stay and accepted by industry, does it make sense to invest in the latest contamination-focused sampling technologies, or should we focus on aligning with what is now considered standard practice? The answer will ultimately determine how businesses in this space adapt to meet evolving client expectations.