From Waste Stream to Value Chain: Why Biosolids Outcomes Depend on End Users
Australia’s water sector is facing increasing pressure to reduce waste, recover resources and demonstrate circular economy outcomes. As a result, biosolids are beginning to move from a disposal challenge to a strategic resource stream.
But unlocking value from biosolids is not simply a matter of adopting the latest treatment technology. The long-term success of biosolids programs depends on whether the final product creates value for the people and industries expected to use it.
This is one of the critical questions that will shape discussions at Ozwater'26 – particularly the workshop on the biosolids value chain, where our own Dr Glenn Dale will discuss this issue with industry representatives from utilities, agriculture, research and environmental management - examining how treatment decisions influence downstream adoption, economic value and long-term sustainability outcomes.
For Verterra, the conversation highlights a broader shift occurring across environmental management systems: success is increasingly determined not by whether waste is processed, but whether systems are designed to deliver measurable functional outcomes across the entire value chain.
Building consideration of functional outcomes into the waste treatment process can increase success of nutrient reuse programs.
Treatment Technology Does More Than Reduce Volume
Biosolids treatment is often discussed in operational terms - stabilisation, dewatering, transport efficiency, pathogen and odour reduction or regulatory compliance. But treatment decisions also fundamentally shape the value and usability of the end-product.
Different treatment pathways influence:
nutrient availability and release rates
carbon stability and soil functionality
odour and handling characteristics
moisture content and spreading practicality
transport economics
perceived contamination risk
compatibility with agricultural or rehabilitation systems
long-term regulatory and social licence outcomes
In practice, treatment technology determines whether biosolids behave primarily as a short-term nutrient source, a slow-release soil amendment, a soil-conditioning product, a stabilised carbon material, or a resource capable of supporting broader ecosystem restoration outcomes. These distinctions matter because different end users require different functional outcomes. A grazing enterprise focused on pasture productivity has different priorities to a forestry project, a mine rehabilitation program, or a degraded landscape restoration project.
The most technically advanced treatment pathway is not always the pathway that creates the greatest downstream value.
The Biosolids Value Chain Often Breaks at the End User Interface
One of the persistent challenges in biosolids management is that utilities and end users frequently optimise for different outcomes.
Utilities are understandably focused on:
plant operations
risk management
compliance
procurement structures
disposal certainty
reducing cost pressure on ratepayers
End users, however, evaluate biosolids through an entirely different lens. Farmers, forestry managers and rehabilitation practitioners typically focus on:
nutrient predictability
logistics and spreading practicality
compatibility with operational systems
flexibility around timing and application
confidence in long-term soil outcomes
regulatory certainty
and whether the product creates measurable value rather than management burden
This creates a critical systems-design problem.
A treatment pathway that improves dewatering efficiency or lowers transport cost for a utility may simultaneously reduce downstream adoption if it produces a product form, nutrient profile or risk perception that does not align with end-user needs. In these cases, the utility may achieve an internal operational benefit while unintentionally weakening the overall value proposition of the biosolids program itself.
That is why end users cannot simply be consulted after treatment systems are designed. They need to be integrated into system design from the beginning.
Biosolids Are Not Just About Nutrients
Historically, biosolids conversations have centred heavily on nutrient replacement - particularly nitrogen and phosphorus.
That remains important, but at a time of rising fertiliser costs and growing concern around global fertiliser security, biosolids represent an opportunity to recover and recycle nutrients that would otherwise be lost from productive systems. As a result, the potential value of biosolids extends well beyond nutrient substitution.
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Biosolids can partially replace synthetic fertilisers while supplying organic matter that improves broader soil condition. Importantly, beneficial use outcomes are highly site-specific.
The objective is not simply to apply waste to land, but to match nutrient delivery, soil condition and landscape requirements to the intended agricultural or environmental outcome.
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Biosolids also contain substantial organic carbon.
Depending on the treatment pathway, application method and project setting, this carbon may contribute to improved soil structure, water retention, biological activity and long-term soil functionality.
In some contexts, biosolids may also support measurable soil carbon outcomes or contribute to eligible activities within formal environmental market frameworks - although these opportunities depend heavily on methodology requirements, evidence standards, permanence obligations and project design.
More broadly, improving soil function creates value far beyond carbon accounting alone. Healthy soils support productivity, resilience and ecosystem stability across agricultural and rehabilitation systems.
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Biosolids also contain embedded energy potential.
Treatment pathways such as anaerobic digestion can recover biogas for renewable energy generation, helping utilities reduce operational energy demand while contributing to broader decarbonisation objectives.
Emerging technologies are also exploring opportunities to convert biosolids into bioenergy, biochar and other value-added products capable of supporting both resource recovery and carbon management objectives.
As energy costs rise and utilities face increasing pressure to reduce emissions, the ability to recover energy from biosolids is likely to become an increasingly important part of future treatment system design.
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Perhaps the most under-recognised opportunity lies in ecosystem restoration and landscape functionality.
Biosolids can play an important role in:
rebuilding degraded soils
supporting vegetation establishment
improving water retention
reducing erosion risk
stabilising disturbed landforms
and accelerating ecological recovery in degraded landscapes
This is particularly relevant in sectors such as mine rehabilitation, forestry establishment and large-scale landscape restoration, where soil function is often the limiting factor to long-term success.
From an ecological engineering perspective, the objective is not simply to dispose of material beneficially. It is to design systems where nutrient cycling, soil function, vegetation establishment and landscape stability work together to create durable environmental and economic outcomes.
Moving Beyond Disposal Thinking
The future of biosolids management will likely depend on whether the industry continues to frame biosolids as a waste problem - or begins treating them as part of a broader resource and ecosystem performance system.
That shift requires more than new technology. It requires utilities, regulators, researchers, farmers, environmental practitioners and end users to collaboratively define what “value” actually looks like across the full biosolids value chain.
Because ultimately, the success of a biosolids program is not determined by what leaves the treatment plant. It is determined by what the product enables once it reaches the landscape.
Join us for a discussion on this topic at OzWater’26:
PANEL 17 - BIOSOLIDS VALUE CHAIN
CONNECTING TREATMENT INNOVATION TO END USERS FOR A SUSTAINABLE FUTURE