Excerpt
For cities across the Global South, where wastewater infrastructure is often inadequate, underfunded, or simply absent, this reframing carries significant implications. The argument for investment changes. A wastewater system that recovers energy and nutrients is not purely a cost centre requiring subsidy — it is economic infrastructure with potential revenue streams. That changes how it can be financed, who has an interest in building it, and what the business model looks like over time.
From Disposal Problem to Production System
There is a facility outside Amsterdam that no longer thinks of itself as a wastewater treatment plant. It thinks of itself as a biorefinery. The sewage that flows into it leaves as energy, recovered phosphorus, and cellulose fibre used in road construction and asphalt. What was once a disposal problem has become a production system.
This is not a pilot project or a proof of concept. It is where the sector is heading. For Henock Belete Asfaw, a biogas and wastewater engineer who has spent his career tracking this transition, the shift is already well underway in the countries where policy and economics have aligned to make it inevitable.
The traditional model of wastewater management was built around a single question: how do we safely remove this from human contact? Treatment plants were designed to neutralise, contain, and discharge. The benchmark was harm reduction. Success meant nothing dangerous left the facility.
That framing is becoming obsolete.
The emerging question is fundamentally different: what value is in this waste stream, and how do we recover it? Wastewater contains organic matter that can generate biogas for energy. It contains nutrients like nitrogen and phosphorus that can be extracted and returned to agriculture. It contains materials that, with the right processing, become inputs for manufacturing. Increasingly, researchers are identifying pathways to recover bioplastics and other circular economy products from waste streams that were previously considered spent.
Why Policy Moves Faster Than Technology
Henock describes this transition not as a technological revolution but as an evolution. Good technologies rarely disappear — they develop as policy, economics, and societal priorities shift around them. Biogas has been understood for decades. Anaerobic digestion is not new. What has changed is the policy environment in countries with serious circular economy ambitions, and the economic logic that follows: when incineration is restricted, when landfill costs rise, when carbon accounting makes energy recovery financially attractive, the business case for resource recovery from wastewater becomes compelling in ways it previously was not.
The Netherlands illustrates where this leads when policy and ambition align. Energy-neutral wastewater treatment is no longer aspirational — it is an operational target that facilities are actively working toward. The infrastructure does not just manage waste. It generates revenue, reduces energy costs, and produces materials that re-enter the economy.
What This Means for Cities in the Global South
For cities across the Global South, where wastewater infrastructure is often inadequate, underfunded, or simply absent, this reframing carries significant implications. The argument for investment changes. A wastewater system that recovers energy and nutrients is not purely a cost centre requiring subsidy — it is economic infrastructure with potential revenue streams. That changes how it can be financed, who has an interest in building it, and what the business model looks like over time.
The sector has not fully caught up with this logic. Investment strategies, donor frameworks, and project designs still largely treat wastewater as a problem to be managed rather than a resource to be recovered.
The facilities that understand what flows through their pipes are already building something different. The question is how quickly the rest of the sector follows.
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