Burying waste was never a perfect solution, just the most convenient one we had. Decades later, aging or poorly sited landfills are resurfacing as environmental and community risks, especially under rising seas, extreme rainfall, and expanding urban footprints. In Season 2, Episode 2 of the Rethinking EHS podcast, we explore how regions are confronting legacy sites while raising the bar for modern landfill design and operations.
In this Q&A-style recap, two experts, Paul Walker, Technical Director from Tonkin + Taylor New Zealand, and Andrew Green, Senior Associate from Peter J. Ramsay & Associates in Australia, have a conversation with co-host Anqelique Dickson, President of Inogen Alliance and EVP at Antea Group USA, on what’s working, what’s changing, and where EHS leaders should focus next.
Listen to the full podcast episode here.
Q: What’s the biggest landfill risk in your region right now?
Paul Walker (NZ): Legacy sites are coming back to haunt us. A 2019 event on the Fox River exposed large volumes of waste along a pristine coast. This was an image that clashed with New Zealand’s “clean, green” identity. That moment triggered a national reckoning: how many legacy sites are vulnerable to climate-driven hazards, and which ones should we prioritize?
Andrew Green (AU): In Australia, especially around Melbourne, urban encroachment is the pressure point. Communities are expanding toward active and closed landfills, prompting stricter expectations across the full lifecycle: siting, engineered containment, daily operations, and rehabilitation. The bar is rising because neighbors are closer.
Q: How is New Zealand tackling legacy landfills?
Paul: The government commissioned a national mapping and risk tool to identify climate-vulnerable legacy sites (many coastal). We’re refining it with agencies and supporting councils, who legally own many sites, to plan and fund fixes. Two big lessons:
- Data equity matters. Some councils have robust inventories; others have almost none. A predictive tool is only as good as the inputs, so building consistent baseline data across regions is step one.
- Risk-based funding beats “whack-a-mole.” Visible problems (waste on a beach) attract attention but may not be the highest risk to ecosystems or public health. We need a portfolio view and to prioritize by risk and consequence, not just headlines.
To pay for this, New Zealand aligned policy with practice: diverting a portion of the national waste levy into a fund to investigate and remediate vulnerable landfills and contaminated sites. It’s a smart loop: today’s waste helps finance yesterday’s cleanup.
Q: Australia is known for stringent standards. What does “best practice” look like there?
Andrew: Victoria has one of the oldest environmental protection acts and some of the highest landfill standards in the country. Many other states, and even other countries, reference Victoria’s technical requirements. Key features:
- Specialist design & QA/QC: Geotechnical and geosynthetics expertise is mandatory, and construction is tightly prescribed and verified.
- Engineered containment systems: Composite liners, leachate collection, capping systems designed for centuries-scale performance, not decades.
- Operational discipline: Landfill gas capture, tipping face management, stormwater controls, bird/nuisance management—all with community proximity in mind.
Takeaway: High-quality outcomes require lead time, the right team, and meticulous execution. You don’t get a first-class facility without first-class preparation.
Q: How are climate extremes changing the engineering of landfills?
Paul (NZ): Modern landfills consider climate hazards in design. The challenge is the legacy stock: coastal erosion and sea-level rise will expose more sites over the next 100 years. Expect rising numbers of interventions and the need for hard protections in specific hotspots.
Andrew (AU): We’re seeing more high-intensity, short-duration storms during construction that exceed design assumptions. This can wash out capping before vegetation establishes, especially on steeper caps used to maximize airspace. Over-engineering everything isn’t feasible, so we combine geosynthetics with rapid revegetation and improve construction-phase water management to reduce erosion risk.
Q: What happens when communities grow toward landfills?
Andrew: Airspace gets tighter and operating costs rise to meet nuisance, odor, and gas controls at the urban edge. Profitability is still essential, but operators must prove environmental performance and social license every day.
Paul: Society needs landfills but prefers not to see them. Many legacy sites were once community dumps placed in locations we’d never permit today. As cities expand, reverse sensitivity kicks in and new neighbors face old decisions. That’s why planning, inventory, and proactive remediation matter.
Q: What are the most transferable lessons for EHS leaders?
From New Zealand (legacy focus):
- Inventory first. Know what you have, where it is, and what’s at stake.
- Prioritize by risk. Build a portfolio risk profile and fund the highest-consequence sites, not just the loudest.
- Fund sustainably. Tie waste levies or similar mechanisms to long-term cleanup needs.
- Multidisciplinary by default. Coastal processes, climate scenarios, engineering, ecology, public health—landfills sit at their intersection.
From Australia (forward design):
- Make best practice the default. Codify siting, containment, gas capture, and capping standards and audit them.
- Invest in expertise. Geotech + geosynthetics + construction QA/QC is non-negotiable.
- Plan for operations near people. Design for community proximity: gas, odors, stormwater, traffic, aesthetics.
- Stage for climate. Expect outlier storms during construction. Blend materials + vegetation to stabilize caps fast.
Q: Where do innovation and knowledge-sharing fit in to Landfills?
Paul: We’re importing proven adaptation frameworks such as risk tolerance, acceptable outcomes, and portfolio management, and applying them to landfill portfolios. It’s less about flashy new tech and more about structured decision-making under budget constraints.
Andrew: Australia borrows and contributes in a global loop. American and European guidance informs practice here, while Victorian standards and implementation experience feed back into the international community via networks like Inogen Alliance.
Q: If you had to explain this to a non-expert, what would you say?
Paul: Some older landfills were built in the wrong places. With rising seas and stronger storms, a few will fail if we don’t plan ahead. Our job is to find the riskiest ones first and fix them smartly.
Andrew: Modern landfills are engineered facilities, not holes in the ground. When designed and run well, they protect neighborhoods and nature, even as cities grow around them.
Conclusion & Key Takeaways
- Out of sight isn’t out of risk. Climate change and urban growth are exposing legacy sites in new ways and inventory, and risk ranking are foundational.
- Fund the future with today’s waste. Dedicated, ring-fenced mechanisms (e.g., waste levy allocations) create durable remediation budgets.
- Standards save money. Stringent, codified best practice in siting, containment, gas capture, and capping reduces long-run costs and complaints.
- Design for the construction phase. Extreme storms now happen during build, not just in service life, so stabilize caps quickly with geosynthetics + vegetation.
- Operate at the urban edge. Community encroachment demands tighter nuisance control, better monitoring, and day-to-day social license.
- Prevention still wins. Minimize landfill dependency through waste reduction, materials recovery, and energy-from-waste where appropriate.
- Think like a portfolio manager. Prioritize by risk and consequence, not visibility. Use multidisciplinary inputs and scenario planning to spend where it matters most.
Yesterday’s trash doesn’t have to be tomorrow’s crisis. With clear data, stable funding, proven engineering, and honest community engagement, EHS leaders can turn legacy liabilities into a managed, lower-risk future.
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