In the world of construction and development, we are often taught to expect the unexpected.
But when it comes to waste, too often it’s the known risks, asbestos, underground petroleum tanks, and chemical residues that get overlooked until it’s too late. This pervasive attitude of “out of sight, out of mind” is a dangerous one, a relic of a time when environmental regulations were lax and public scrutiny was minimal. Today, this mindset is not only irresponsible but also a significant legal and financial liability. Waste does not simply disappear; it leaches, corrodes, contaminates, and sometimes, it kills.
My own experience has shown me this time and again. It started with a dump, found during a large greenfield project in regional New Zealand. The initial discovery was unassuming: a few rusted drums, plastic sheeting, and what looked like a decayed concrete slab. As we dug deeper, however, the picture became clearer and far more alarming. We uncovered broken pieces of asbestos cement, rusted fuel tanks, and pesticide containers. This was not an isolated incident. Over the course of my career, I’ve seen countless sites with hidden dangers: old farm pits filled with asbestos, disused diesel tanks buried under new carparks, and containers of mystery chemicals. The list of these buried hazards is extensive: asbestos, unexploded ordinances, coal tar, and more.
The critical lesson here is that what is buried doesn’t stay buried forever. With a changing climate and modern regulations, these hidden problems are resurfacing with significant consequences. The long-term costs of neglecting this responsibility, to human health, the environment, and your reputation, far outweigh the short-term savings of improper disposal.
Specific Legacy Hazards and Their Consequences
The types of buried waste we encounter on construction sites are varied and each poses a unique and serious risk. Understanding these risks is the first step toward effective management and mitigation.
Asbestos: The Slow Burn Killer
For decades, asbestos was the “miracle material”. From the 1920s to the 1980s, it was used extensively in everything from water pipes to roofing, fencing, and boiler lagging. On construction sites, it is most commonly found in the form of asbestos cement (AC) pipes, those notorious grey pipes buried beneath our feet as water mains and sewer lines. These pipes are still being dug up, and they often shatter under the teeth of a bucket or saw, releasing deadly fibres into the air.
Inhalation of asbestos fibres is the primary cause of diseases like mesothelioma, asbestosis, and lung cancer. The risk is particularly insidious because there is no safe level of exposure. The fibres are microscopic and airborne, and you don’t know you’ve breathed them in until decades later. This is not a theoretical problem. Last year in NSW, The Guardian reported on a regulatory failure that led to asbestos-contaminated fill being spread into parks, playgrounds, and schools, exposing children and families to a deadly risk. Even today, asbestos is still turning up on modern projects, particularly in rural and brownfield locations.
Managing this risk is not just good practice; it is a legal requirement.
In Victoria, the General Environmental Duty under the Environment Protection Act 2017 requires anyone conducting activities that pose a risk of harm to human health or the environment to eliminate or reduce those risks. Similarly, in NSW, asbestos management is embedded in the Protection of the Environment Operations Act 1997, and the EPA is actively pursuing offenders. All states in Australia have legislation regarding environmental duty and management.
Training is also a legal requirement, with asbestos awareness training mandatory for workers on sites where ACMs may be present. The potential for long-term health consequences and severe legal penalties makes proactive management of asbestos a non-negotiable part of any project.
Buried Petroleum Tanks: A Leaking Legacy
You might assume that removing old underground fuel tanks (USTs) would be a standard part of site redevelopment. Unfortunately, this is not always the case. I have encountered tanks that were not just left behind but actively buried without properly disestablishing it first. In one particularly memorable instance, a crew were putting drainage behind an old, long-disestablished mechanics workshop when they hit an unknown concrete pit. It was still full of old, disposed-of oil that no one remembered being there. Works ground to a halt, and a simple drainage trench turned into a full-site remediation project.
Burying these tanks does not solve the problem. Over time, the steel corrodes, and leaks occur. Hydrocarbons seep into the soil and groundwater, contaminating both the site and its surrounds. The vapours alone can pose explosion risks in confined areas, not to mention the toxic impact of compounds like benzene, toluene, and xylene.
Unknown Chemicals: The Wildcard
The most dangerous substance on a construction site is often the one you can’t name. These are the chemical ghosts of past activities, drums with no labels, containers half-filled with liquids that smell like paint thinner, or bags of powder that crumble when touched. They can be anything from pesticides to cyanide, posing a range of serious risks.
A common problem is the hazardous substances container that goes from project site to project site without being properly cleaned out. On one project, we were proactive at the end and decided to clean it out. We found unlabelled containers of “who knows what” and chemicals that were traced back to a project from many years ago. We didn’t want the next project to take on an unknown legacy or have it leak on the back of a transporter halfway across the country, which I’ve also seen happen.
Under Australia’s National Environment Protection (Assessment of Site Contamination) Measure (NEPM), all sites with known or suspected contamination must undergo investigation and risk assessment. The challenge is that many of these buried waste caches are simply not documented, especially in rural and semi-urban areas where historical practices included burning, burying, or “bulldozing it into the dam”.
A Proactive Approach: The Five Pillars of Contaminated Waste Management
Getting contaminated waste management right requires a fundamental shift in mindset from a reactive to a proactive approach. The guidance I follow and share with clients is built on five key pillars.
1. Start with the “Why”: A Mindset Shift
Understanding the “why” behind these regulations is crucial. It transforms the work from a mere box-ticking exercise into real risk management. When you truly understand the devastating impact of asbestos exposure on workers, the contamination of drinking water from diesel leaks, and the threat of chemical waste to local food chains, you treat waste with the seriousness it deserves. This understanding compels you to pause, investigate, and report any potential issues. It’s this ethical and practical understanding that drives effective and responsible waste management.
2. Know the Site History: Beyond the Desktop
A simple desktop assessment is no longer sufficient. Comprehensive due diligence is essential. This means going beyond looking at property records and engaging with the community. Ask long-term landholders about past uses of the site, as they often hold invaluable institutional knowledge. Look at old aerial imagery to spot historical changes in land use, such as the presence of old sheds or dumping areas. Pull previous development applications or council records that might contain clues. Finally, use test pits and targeted sampling in suspect areas to physically verify your findings. If the site was a former farm, specifically inquire about chemical sheds, dip sites, fuel tanks, and farm dumps.
3. Train Your Team: The Frontline of Defence
Your team on the ground is the first line of defence against hidden hazards. If your operators can’t identify an asbestos cement pipe or tell the difference between a harmless drum and a hazardous one, you are already exposed. Asbestos awareness training is mandatory for workers on sites where asbestos-containing materials may be present. Beyond legal requirements, training empowers your crew to recognise and report suspicious materials, ensuring that work stops and the right professionals, like a contaminated land expert or an environmental consultant are engaged before a problem escalates. This investment in training is a direct investment in the health and safety of your workers and the public.
4. Waste Tracking and Documentation: The Paper Trail of Accountability
Waste management is a chain of custody, and you are accountable from the moment waste is generated until it is safely disposed of. This means using a licensed transporter and demanding disposal certificates for every load. Use waste tracking spreadsheets or online tracking systems to document every step of the process. It is simply not worth the risk. Keeping all manifests, disposal receipts, and contamination clearance reports is essential for future reference and regulatory compliance.
5. Work With the Right Landfill: Matching Waste to the Facility
Not every site can accept every kind of waste, and they shouldn’t. Landfills are regulated by state EPAs, and sites that accept asbestos, contaminated soils, or chemical waste must be licensed for those specific materials. Their liners, leachate systems, and environmental monitoring programs are specifically engineered to isolate harmful substances. However, the ultimate responsibility falls on you to accurately declare what you are sending them. You must confirm the receiving site’s license conditions before arranging disposal. Misclassifying waste can lead to significant fines and environmental damage.
Practical Takeaways and a Call to Action
The responsibility for waste management is a shared one. We need to stop thinking about contaminated waste as someone else’s problem. It’s not just a site manager issue, a truck driver’s job, or the consultant’s role to take the fall. If you are on the job, you are part of the solution. And if you are a contractor, supplier, or client, you have clear responsibilities under the law.
Pre-works phase:
- Conduct Phase 1 environmental assessments on all greenfield or brownfield sites.
- Interview long-term landholders if records are thin.
During excavation:
- Monitor for suspect materials: AC pipes, strange smells, staining, unexpected rubble.
- Stop work and engage a consultant if something is found.
Waste handling:
- Classify waste in accordance with state EPA guidelines.
- Use trackable transport systems with documentation!
- Confirm receiving site’s license conditions before arranging disposal.
Post-removal:
- Keep all manifests, disposal receipts, and contamination clearance reports.
- Submit reports to the regulator if required.
I’ve worked on projects where we’ve had to manage everything from a buried “night soil” depository to drums of leaking solvents. It’s messy and stressful, and it can grind a site to a halt if you are not prepared. I’ve also worked on projects where, by identifying risks early, engaging the right people, and tracking every load, we got it right. No fines. No spills. No exposure. Just good work done properly.
So, next time you load a truck and wave goodbye to a pile of contaminated soil, ask yourself: do I know where it’s going? If you don’t, stop. Find out. Ignorance isn’t a defence; it’s a liability.
Protect human health. Protect the environment. Protect your reputation. These are not just slogans; they are the guiding principles of modern, responsible construction and development.
About Me
I’m an environmental professional with a background in construction and infrastructure projects across Australia and New Zealand. I’ve worked alongside contractors, regulators, and specialists on sites where contamination, from asbestos to buried fuel tanks and unknown farm dumps, was an unexpected reality.
While I’m not a contaminated land expert, I know enough to recognise when something doesn’t look right and I always refer onsite sampling, investigation, and reporting to qualified contaminated land consultants and site auditors. My role is about helping teams navigate the real-world application of environmental responsibilities on active sites, ensuring we get the process right from day one.
I write this to share what I’ve learned on the ground, lessons that help others protect human health, the environment, and their own professional reputations.
TIH Consulting 
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