Glan Devon: What we have learned so far

When I started writing about the proposed Glan Devon biosolids project in June, I thought I was looking at a large planning application with some fairly obvious questions. Why was this particular rural site chosen? What exactly was the proposed technology? What would come out of the stack? How much traffic would it generate? How would biosolids become a saleable fertiliser?

Those questions are still there, but nearly four months of digging has changed the picture quite a bit. I have now worked through the development application, supporting studies, responses to regulators, the history of the technology, operating records, patents, comparable projects, process diagrams, environmental assessments, sampling questions and the various ways the proposed plant is supposed to operate as one system.

With BYV's next response to the State Assessment and Referral Agency (SARA) now imminent, this seems a useful point to look back at what the investigation has actually established.

The biggest change in my thinking is that I no longer see Glan Devon as a collection of separate technical questions. The individual reports encourage you to do that: traffic in one box, air quality in another, water somewhere else, noise somewhere else again. The actual plant cannot work that way.

Wet biosolids arrive by truck. They have to be received, stored and dried. Drying produces a very large water stream. Heat for that drying is supposed to come from burning prepared non-recyclable waste in a Xetrov incinerator. That creates gases and residues which require air-pollution control. The dried biosolids then have to be blended, pelletised and turned into something that is legally and practically a fertiliser rather than a waste. Every change in one part of that chain changes something elsewhere.

That is now the central problem with the proposal. We have a large amount of documentation about individual parts, but we still do not have a demonstrated, fully defined Glan Devon plant in which all those parts have been shown to work together within a clear operating envelope.

Starting with the obvious questions

The early DeeperInsight articles concentrated on questions that could be seen fairly readily in the application. Why Glan Devon? Why a High Impact Industry on rural land rather than an industrial site? What does calling the first stage a "trial" actually mean? How useful are average emissions when real feed materials vary? Can a consultant show that something can be built without showing that it should be built there?

Those were useful questions because they exposed the assumptions sitting underneath the application. They also led to a recurring problem: quite a few claims were true in a narrow sense but did not necessarily answer the larger question being asked.

A truck number can be correct while still not describing the complete transport task. A model can be mathematically correct while modelling the wrong plant or the wrong source term. A laboratory result can be perfectly valid while the sample sent to the laboratory is not representative of the truck or stockpile it supposedly describes. A pollutant concentration can fall in one output stream without showing that the pollutant has been destroyed.

That distinction between a correct answer and the correct question became increasingly important as the investigation went on.

What exactly is the development?

One of the largest problems I have found is surprisingly basic. The development being applied for, the development described in the business material, the Stage 1 trial, the later commercial plant and the versions assessed in the specialist reports do not fit neatly inside one clearly defined envelope.

That matters because environmental assessments only mean something if we know what they assess. If a traffic study assesses one business model, an air study uses another plant configuration, an environmental authority concentrates on a trial and the development approval permits something broader, there is no single line around the development for a decision-maker to assess.

I have also found evidence of the project evolving while older assessment material remained in the application. BYV has itself acknowledged that the original traffic assumptions came from an earlier business model. The dryer is another example: current material refers to an SMS thin-film dryer while other submitted process material retains an Andritz configuration.

Changing equipment during project development is not unusual. What is unusual, and much more important, is failing to clearly reconcile the change through all the studies that depend on it.

Air, noise, water, heat balance, safety and operating behaviour are all affected by the actual equipment selected. A report about the old version does not automatically remain valid for the new one.

There is also a fundamental question about the nature of the development. The Xetrov is a waste incinerator. Whether its operation is genuinely ancillary to the proposed fertiliser manufacturing activity, or constitutes a separate Special Industry use, matters to what has actually been applied for and what Council can approve. That distinction is not resolved simply by calling the entire development a bio-fertiliser facility.

The location question never went away

The first site question was simply: why Glan Devon?

After all the subsequent technical work, I think that question has become stronger rather than weaker. This is not merely a fertiliser operation that happens to use agricultural material. It is a substantial waste-receival, waste-processing, thermal-treatment, biosolids-drying and manufacturing operation proposed on rural land.

The application explains benefits associated with the project and its agricultural end product, but that is not the same thing as demonstrating why this particular industry needs this particular rural location. I have not found a convincing alternatives analysis showing why the activity could not reasonably be accommodated on suitable industrial land or closer to major sources of the materials it consumes.

The investigation has also confirmed that industrial land exists within the South Burnett, including land identified for high-impact industrial activities. That does not establish that every available parcel would be suitable, but it makes BYV's failure to demonstrate why reasonable alternatives cannot accommodate the development more significant.

The specific site also brings its own circumstances. Mondure Crossing Road passes through the property and connects to the Burnett Highway. There are local drainage, bushfire, water-supply, wastewater, amenity and receptor questions. None of those disappears because individual State agencies have narrower areas of responsibility.

The broader question of whether this whole development belongs at Glan Devon remains a Council planning question.

The Xetrov story became much thinner when I followed it

A substantial part of the work has involved tracking the history of the Xetrov technology itself.

I found real machines and real development work. Pollington existed. Daventry exists. A machine went to Brazil. There has been work associated with Tarmac. There are patents, test programs and continuing engineering activity.

What I did not find was a demonstrated commercial reference plant comparable with what is proposed at Glan Devon: the same type of prepared waste fuel, running the relevant thermal system continuously, supplying the dryer, operating with the proposed air-pollution controls and producing the complete set of outputs under sustained commercial conditions.

The distinction between "the technology exists" and "this plant has been demonstrated" has become important.

The operating records obtained directly from UK councils have been particularly revealing.

East Riding Council has confirmed that the Pollington installation spent much of 2023 undergoing commissioning, never became fully operational and was mothballed later that year. No operating reports were submitted to the Council during that period.

The Daventry evidence is more extensive and, in some respects, more revealing. I obtained operating reports spanning several years, showing intermittent operation, changing equipment configurations, continued experimentation with feedstocks and additives, and problems with the emissions-monitoring system.

The longest continuous run identified was approximately 100 hours in March 2024. The records show much shorter operating periods elsewhere, followed by no combustion operations after May 2025 for the remainder of that year. The first six months of 2026 recorded just six runs totalling less than 13 hours.

The reports also document continuing work to determine the necessary emissions controls. As late as the end of 2025, Xetrov was still working to resolve monitoring problems and determine whether a full abatement system would be required or whether additives to the feed could provide adequate control.

This is not the operating history of a demonstrated, continuously operating commercial energy-from-waste plant.

It does not mean the Xetrov cannot work. It means the evidence presently available does not demonstrate the sort of continuous, comparable commercial operation that would answer the reliability question for Glan Devon.

The fuel is not just "waste"

Another issue emerged from following the technology rather than simply accepting the project terminology.

The Xetrov cannot meaningfully be assessed against the word "NRW". Non-recyclable waste is a regulatory or descriptive category, not a fuel specification. A combustion system sees moisture, particle size, calorific value, chlorine, fluorine, metals, ash, plastics and all the other chemical and physical properties of whatever is actually fed into it.

Xetrov material itself points toward a prepared fuel with limits on properties such as moisture, energy content and particle size. Yet the complete Glan Devon fuel-production chain remains poorly defined. We still do not have a sufficiently tight description of what may be accepted, how it will be prepared, what will be rejected and how variable the resulting fuel can be.

That problem runs directly into the emissions evidence.

The important emissions testing used polyurethane dust, with the Xetrov operating at about 70 per cent load. Some results were then scaled by a factor of about 1.42 for the Glan Devon modelling. The proposed fuel at Glan Devon is prepared non-recyclable waste.

Those are not the same proposition. What remains missing is the demonstrated bridge between the test fuel, the proposed fuel, the tested machine, the proposed machine, the operating load, the air-pollution-control system and the operating states that may occur at Glan Devon.

The air-quality problem is now bigger than the stack test

The air-quality work originally looked like a fairly conventional question about modelled concentrations at nearby receptors. Once I followed the assumptions backwards, two separate problems emerged.

The first is the source term. The model depends on emissions derived substantially from testing that does not reproduce the complete proposed Glan Devon fuel, plant and air-pollution-control configuration. Important contaminant classes, including fluorine and PFAS-related questions, have not been closed through measured emissions from a representative system.

The second is the dispersion model itself. The Glan Devon modelling uses a meteorological field without local observations at the site. It relies on modelling supported by regional meteorological information, including Kingaroy observations. I have not found a convincing reconciliation showing that the resulting wind and atmospheric structure adequately represents the actual Glan Devon setting.

Either problem deserves examination on its own. Together they create a more fundamental representativeness problem: are BYV dispersing the correct emissions through a sufficiently representative atmosphere?

The air-pollution-control system adds another layer. It is frequently treated as something that will control whatever the thermal process produces, yet the final system and its demonstrated performance across the proposed fuel and operating envelope remain insufficiently defined. Air-pollution control can capture or transfer contaminants; it cannot simply make mass disappear.

Water turned out to be one of the largest process streams

The water problem emerged from doing a very simple mass balance.

Using the nominal case of 40,000 tonnes a year of biosolids at about 18 per cent dry solids, dried to about 90 per cent dry solids, roughly 32,000 tonnes of water has to leave the biosolids each year. That is not a minor side stream. It is one of the largest material movements inside the plant.

Some of that water may become vapour. Some may be condensed. Some may be reused. Some may enter cooling or treatment systems. Some amount may eventually require disposal or release.

The problem is that the complete balance still does not close. The storage volumes, treatment requirements, reuse rates, purge streams, contaminant loads and final destinations have not all been reconciled into one current plant-wide water system.

The same problem appears in stormwater and process-water management. Drawings, catchments, clean and contaminated water segregation, storage, freeboard, reuse and discharge arrangements have continued to evolve. Future detailed design may refine those systems, but it should not be the first point at which we discover whether the water balance actually works.

PFAS forced us to stop thinking in concentrations

PFAS has been one of the most useful examples because it exposed a weakness in the way the project is often discussed.

It is easy to ask what the PFAS concentration is in the incoming biosolids or the final fertiliser. That does not tell us what happens to PFAS through the process.

Drying can move PFAS compounds and precursors from solids into vapour and gas streams. Other compounds may remain in the dried solids or enter the condensate. The question is what happens to those materials after they leave the dryer.

BYV's May response proposed extracting the dryer steam and process off-gases and directing them into the Xetrov incinerator for thermal oxidation. That introduces a critical connection between two processes that have not been demonstrated together.

What PFAS compounds enter the dryer exhaust? How much remains in the condensate? What is present in the off-gas after condensation? What actually enters the Xetrov, and what happens to it there?

There is a further problem. The emissions data obtained from the UK councils do not report PFAS measurements from the Xetrov burning polyurethane dust. We therefore have no measured PFAS emissions evidence from that operation, let alone evidence showing what happens when PFAS-bearing dryer off-gas is introduced into the proposed Glan Devon system.

We are being asked to accept a proposed thermal treatment pathway without evidence demonstrating what enters it, what is destroyed, what is transformed and what emerges.

The proper question is therefore a mass-and-phase question: how much fluorine enters, in what forms, and where does it leave?

I have not found a complete fluorine balance demonstrating that outcome. Nor have I found evidence demonstrating PFAS mineralisation across a fixed and representative Glan Devon thermal and air-pollution-control operating envelope.

The same reasoning applies more broadly to metals and other contaminants. Matter moves. If it is not in the product, it must either have left in another stream, accumulated somewhere or been chemically transformed into something else.

Sampling became a project in its own right

I did not expect sampling to become one of the most significant issues in the investigation, but it has.

The proposal relies repeatedly on sampling to characterise incoming material, decide whether a load complies, monitor operation, analyse residues, release a fertiliser product and demonstrate compliance with conditions. Yet a laboratory result is only as useful as the sample on which it is based.

The missing pieces are surprisingly fundamental. What exactly is the population being sampled? Is a truck a lot? A stockpile? A day's production? Where are the increments taken? How many are collected? Are they combined? How is heterogeneity handled? What is the sampling frequency? What happens after a failed result? Who takes the sample, and how is bias controlled?

Long-haul transport creates another question that was barely visible in the normal development-application frame. Wet biosolids hauled for a considerable distance may undergo gravity-driven liquid migration and physical segregation. The material at one point in the truck may not be representative of the material that was originally loaded or of the truck as a whole.

That creates a very practical problem. A perfectly accurate laboratory analysis of a badly selected sample produces a very accurate answer to the wrong question.

The same issue flows through the entire proposal. If compliance depends on sampling, the sampling system is part of the control system. It cannot be left as an undefined detail to be worked out later.

The plant has to operate between the steady states

Another theme developed as I looked more closely at reliability and process integration.

Most engineering studies naturally describe a steady operating condition: this much biosolids enters, this much heat is supplied, this much water is removed and these emissions leave the stack. Real plants spend part of their lives getting into and out of that condition.

Biosolids moisture changes. Fuel quality changes. A dryer changes load. A fan trips. The Xetrov stops. A pump fails. A storage area fills. A batch of material is rejected. Power is lost and then restored.

Those are not exotic events. They are normal operating states that any industrial plant has to manage.

At Glan Devon the systems are tightly connected. Wet biosolids create a dryer duty. Dryer duty creates a heat demand. Heat demand controls fuel consumption. Fuel changes affect emissions and residue production. Air-pollution controls have their own operating limits. Product manufacture and storage have finite capacities.

The May staging proposal introduces another problem. The first phase involves operating the Xetrov without the biosolids dryer. If the incinerator is operating without its intended heat consumer, where does the heat go? What equipment absorbs or rejects it? How is that operating state represented in the environmental assessments?

When the dryer is added, another set of interactions appears. If the dryer stops, the heat demand changes. If the Xetrov stops, the dryer loses its heat source. If the Xetrov also provides thermal treatment for the dryer off-gas, what happens to that gas during shutdown, restart or a process upset?

These are questions about the physical operation of the proposed development, not simply the performance of individual pieces of equipment.

I still have not seen the complete source-and-sink capacities, buffer volumes, control logic and operating-state analysis that show how the proposed system stays within environmental and safety limits while those things change.

That is the difference between demonstrating that each piece is capable of operating and demonstrating that the plant is robust and reliable as a system.

The fertiliser does not become a product because it's called one

The final product story also became more complicated as I followed it.

The development is presented as producing a pelletised fertiliser. Yet the final recipe, variability, contaminant limits, product lots, release testing, off-specification rules and legal status still contain unresolved questions.

The pelletiser itself was initially remarkably difficult to find in the technical material despite being central to the claimed final product. More importantly, the transformation from biosolids and mineral additions into a pellet does not automatically answer the regulatory question of when a waste has become a lawful product.

The same applies to the other solids leaving the process. Thermal processing and air-pollution control inevitably produce residues of some kind. Their quantities, composition, leachability, classification, storage and final destination need to be known.

Every residue needs a demonstrated lawful destination, whether through an applicable resource-recovery pathway or disposal. If the proposed fertiliser does not consistently satisfy its required specification and legal pathway, the plant also needs somewhere for off-specification production to go.

Those are operating constraints, not just paperwork at the end of the process.

Conditions have limits

One recurring response to unresolved matters is that they can be dealt with by conditions.

Conditions are entirely appropriate where a development has been adequately demonstrated and a condition fixes a known boundary: a noise limit, an operating hour, a maximum throughput, an emission limit, a monitoring requirement or a defined piece of mitigation.

A condition becomes much less satisfactory when it is being asked to discover what the development actually is after approval.

If the fuel specification is unknown, the condition has to invent it. If representative sampling has not been designed, the condition has to invent the measurement system. If acceptable air-pollution-control performance has not been demonstrated, the condition has to establish it. If the current plant configuration has not been reconciled, conditions start becoming part of the engineering design.

That reverses the order of assessment. The evidence should establish that the development is acceptable, with conditions then holding it inside the demonstrated envelope.

There is a related governance question. A workable condition needs a measurable limit, a defined measurement method, a responsible legal entity, reporting requirements and a consequence if the limit is breached. I have found several proposed or implied controls where some of those pieces remain unresolved.

The trial creates a question nobody can avoid

Calling Stage 1 a trial does not reduce the need to understand failure. In some respects it increases it.

A successful trial may provide useful data and allow later decisions to be better informed. An unsuccessful trial leaves a site containing whatever plant, prepared fuel, biosolids, process liquids, residues and other materials were present when operation ceased. The exact inventory will depend on which phase of the proposed development has been undertaken.

I have not yet seen a complete failed-trial case showing who is responsible, how remaining materials are removed, how liquids and residues are dealt with, what plant is removed, how contamination is investigated and remediated, and how those obligations are funded if the operating company fails.

There is a statutory framework through which environmental financial assurance can be required in appropriate circumstances. Yet neither Council nor SARA has raised a project-specific financial-assurance requirement in the material I have examined. Nor have I seen an assessment of what it would cost to close and rehabilitate the site if the trial or business failed.

This is not an abstract possibility. The purpose of a trial is to establish whether something works. Failure is one of the possible outcomes, and commercial or financial failure can occur even when the technology itself performs satisfactorily.

A trial is an experiment conducted in the real world. Failure therefore belongs in the design basis, not in the footnotes.

What has changed since the first article

Looking back over the DeeperInsight articles, the early work was largely about individual claims. The later work has increasingly been about connections between them.

The site question led into logistics. Logistics led into fuel supply and biosolids transport. Fuel supply led into Xetrov capability and emissions. Emissions led into representativeness, variability and air-pollution control. Biosolids variability led into sampling. Sampling led into the whole measurement and compliance system. Drying led into water, PFAS partitioning and contaminant balances. The trial led into operating states, monitoring and failure.

What has emerged is not simply a growing collection of missing information. It is a pattern in which assumptions made within one part of the proposal affect the validity of assessments elsewhere.

None of that says that every nut, bolt and pipe must be designed before a development application can be decided. There is always detailed engineering after approval.

The distinction is between detail that refines an already demonstrated development and information needed to establish whether the development is acceptable in the first place.

The ten questions I think now have to be answered

After nearly four months of investigation, these are the ten questions I consider most important. They are not matters that can simply be passed into later engineering, commissioning or management plans. They concern the development that Council is being asked to approve.

1. What exactly is being approved?

The Stage 1 trial, later commercial development, maximum permitted throughput, feedstocks, plant configuration and environmental approvals need to be reconciled into one clear development envelope. The role and planning classification of the Xetrov incinerator also need to be resolved. Without that, we cannot know whether the specialist studies assess everything the approval would actually permit.

2. Why does this development need to be at Glan Devon?

The case for a major waste-processing and thermal industrial operation on this Rural Zone site has not been convincingly demonstrated against reasonable industrial or alternative locations. The existence of project benefits does not establish the necessity of this location, and the location question cannot be repaired by later equipment design.

3. What exactly can be fed into the Xetrov, and what makes it an acceptable fuel?

"Non-recyclable waste" is too broad to define combustion behaviour. The allowable composition, moisture, particle size, calorific value, contaminants, preparation system, acceptance limits and rejection rules need to be fixed because they control heat output, emissions, residues, fire risk and air-pollution-control performance. The fuel envelope cannot be broader than the evidence used to assess it.

4. What evidence demonstrates the actual Glan Devon system?

Evidence from individual Xetrov machines, polyurethane-dust testing, separate dryer systems and other components does not by itself demonstrate the combined Glan Devon plant. A credible engineering bridge is needed between the proposed fuel, current Xetrov configuration, dryer, heat-transfer system, air-pollution controls and operating states. Separate pieces of evidence do not automatically add up to evidence for the whole system.

5. Can the complete plant operate safely and within limits when conditions change?

The heat source, dryer, ventilation, cooling, water systems, storage, air-pollution controls and product plant all respond to changes and failures elsewhere in the process. The required capacities, buffers, control logic, startup and shutdown behaviour, trip responses and abnormal operating states need to be demonstrated. This includes the proposed Xetrov-only operating phase and the consequences of losing either the heat source or the dryer during integrated operation.

6. Does the air-quality assessment represent the plant and the place?

The current assessment needs a defensible source term for the actual proposed fuel and plant configuration, including the final air-pollution-control system and relevant pollutants. It also needs a defensible meteorological basis for Glan Devon. Both the emissions entering the model and the atmosphere dispersing them remain open representativeness questions.

7. Where do the water and contaminants actually go?

The project needs closed mass balances for water and important contaminants, including PFAS and fluorine, across biosolids, vapour, condensate, gases, residues, wastewater and final product. In particular, the proposed treatment of dryer off-gas in the Xetrov requires evidence of what enters the incinerator, what happens during thermal treatment and what emerges from the stack. Statements about destruction or low concentrations in one stream are not enough when material may simply have moved to another.

8. How will sampling and monitoring actually prove compliance?

Sampling populations, lot definitions, locations, increments, composites, frequency, QA/QC, analytical methods, accreditation, retesting, rejection rules and consequences need to be defined for the streams on which decisions depend. The design also needs to deal with heterogeneity and possible segregation of wet biosolids during transport. If future compliance depends on measurements, the measurement system itself must be demonstrated.

9. What happens to every product, residue and off-specification material?

The fertiliser needs a defined specification and lawful release pathway, while ash, air-pollution-control residues, rejected feed, contaminated liquids and off-specification product all need real destinations. These pathways affect storage capacity, environmental risk and whether the process can continue operating when something does not meet specification. Beneficial use or disposal pathways cannot simply be assumed to appear after approval.

10. What happens when the trial or the business fails?

A trial can fail technically, commercially or financially, and the development needs a bounded exit case for remaining biosolids, fuel, liquids, residues, product, contaminated soil and plant. Responsibility, rehabilitation and funding need to survive the failure of the operating venture itself. Until that is demonstrated, the community and landowner risk inheriting consequences that were created by the trial but never properly allocated.

Where that leaves me

I began this exercise expecting to find some strong arguments, some weak ones and probably a fair amount that could be cleared up by better information. That has happened, but the overall result is not simply a longer list of objections.

The deeper problem is that too many of the unanswered questions sit at the boundaries between disciplines. They determine what the plant is, what goes into it, how it behaves, what comes out of it and whether the evidence being used actually represents those things.

There may be satisfactory answers to all ten questions. If there are, they should be produced, reconciled and assessed before a decision is made.

What I do not think is reasonable is to approve the broad development first and use a trial, later engineering, management plans and conditions to discover whether those answers exist.

Postscript — the DeeperInsight trail so far

The list below records the DeeperInsight material in chronological order and the main idea each piece explored. An asterisk beside a date means I have not found an explicit publication date in the extracted article itself, so the date shown is the file date in the archive rather than a claimed publication date.

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