Contaminated land is rarely a contained technical problem. A site may have a defined boundary on a map, but its risks can change as groundwater moves, land use shifts, climate conditions become less predictable, and surrounding land uses change over time. Regulators, landowners, communities, and developers may also have different expectations and different ideas of what a successful outcome is.
That is why remediation success cannot be measured only by whether a selected technology works. The more important test is whether the remedy can work in the setting where it is placed, over the period for which it is needed, and under the practical, regulatory, environmental, and stakeholder conditions that will shape the site long after the project team has left.
In my experience, some of the most useful lessons in contaminated land management come from projects that did not behave exactly as expected. A remedy may fail because the technical assumptions were incomplete. Still, it may also fail because the site was poorly understood, future land use was unclear, the maintenance burden was underestimated, or the solution lacked sufficient resilience to changing environmental conditions.
The lesson is not that remediation is becoming impossible, but that we need to be more honest about what success requires.
Success has to be designed for context
Around the world, contaminated land professionals are dealing with a more complex operating environment. Water scarcity, extreme weather events, temperature fluctuations, and emerging contaminants such as PFAS and microplastics are changing the way we think about remediation and long-term site management.
These issues are not separate from the remedy. They shape whether the remedy will remain effective. In an African context, that point is especially important. The challenges around contamination and remediation are shaped by local site conditions, water constraints, regulatory expectations, available technical capacity, and the practical need to return land to safe and useful purpose.
The best remedy is not always the most complex or technology-heavy option. It is the option that reduces risk in a way that can be implemented, monitored, maintained, and understood.
Through my work with the Network for Industrially Contaminated Land in Africa (NICOLA), I see the value of bringing industry, academia, service providers, and regulators into the same conversation. NICOLA supports science-based, sustainable best practices in contaminated land management across the continent. That kind of cooperation matters because a single party rarely makes remediation decisions.
Sustainable remediation is not a slogan
Sustainable remediation should mean more than choosing a greener technology. It should reduce unacceptable risk while taking account of water use, resource demands, implementation practicality, and what the site must support afterwards. In essence, we need to always ask ourselves what the Net Environmental Benefit (NEB) of a remediation plan is.
Nature-based and low-carbon solutions have an important place in this conversation, but they are not automatically suitable in every case. Technology should not be selected because it sounds more advanced. It should be selected because it fits the contamination risk profile, groundwater conditions, exposure pathways, the people affected by the site, and the site’s future.
The same applies to engineered interventions. Containment, removal, treatment, monitoring, or managed risk reduction may each be appropriate. The critical question is which option is most likely to keep protecting people and the environment over time. Again, it boils down to the solution with the best NEB.
This is where lessons from both remedy failures and successes become useful. Failures show us where assumptions were too optimistic. Successes show us where technical design, implementation, governance, and long-term land-use thinking came together.
From cleanup to productive land use
The Delta E.M.D site in Mbombela is a useful example. The former electrolytic manganese dioxide manufacturing facility required decommissioning, demolition, remediation, and redevelopment. In projects of this nature, the value of remediation is not only in addressing contamination. It is also making it possible to repurpose land safely and productively.
That is a more demanding way to think about contaminated land. It requires a broad technical team to understand the contamination, regulatory expectations, stakeholder confidence, and what the site must be able to support afterwards.
This is where remediation success becomes visible beyond the specialist community. A well-managed project can reduce environmental risk, unlock constrained land, and support redevelopment. A poorly matched remedy can leave a site technically “managed” but practically limited.
The questions that matter before a remedy is chosen
Before deciding on a remedy, we should be asking harder questions.
What does success look like after five, ten, or twenty years? Who will be responsible for monitoring and maintenance? What happens if rainfall patterns change, water becomes scarcer, or the site is used differently from what was originally intended? Are emerging contaminants part of the risk profile? Does the remedy reduce long-term liability, or does it simply move the burden into the future? Can we prove NEB?
Remediation will always require science, data, modelling, engineering, and professional judgement. But technical competence alone is not enough if the remedy cannot remain effective in the real world.
The real test of a remedy is not whether it looks elegant in a design report. It is whether it continues to protect people, water, ecosystems, and future land use after the obvious work is done.
Dr Heidi Snyman is a Strategic Technical Advisor, WSP in Africa and NICOLA representative
