Australia’s wastewater network is doing more than carrying what we flush away. It has become one of the nation’s most potent and least intrusive tools for monitoring illicit drug consumption. For the Australian Criminal Intelligence Commission (ACIC) and its scientific partners at the University of Queensland (UQ), analysing what communities excrete offers a real-time window into drug trends that cannot be captured through traditional surveys or user-reported data alone.
What began as a small research initiative has matured into a national program that shapes law enforcement, public health responses and policymaking.
The technical processes outlined by ACIC specialists Amber Migus and Shane Neilson, strengthened by the analytical insights of UQ’s Professor Kevin Thomas, show how this program turns wastewater into a national intelligence resource.
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A blind spot becomes a dataset
The ACIC first turned to wastewater analysis more than a decade ago after noticing inconsistencies between user surveys and frontline agency observations, particularly in rural Australia.
“There were several occasions where the existing drug data did not reflect what was being experienced on the ground,” Neilson said. “We needed another source of data that could sample large sections of the population reliably and consistently.”
At that time, Australian universities were in the early stages of exploring wastewater-based epidemiology. UQ and the University of South Australia (now Adelaide University) were running small programs, but the potential for national-scale monitoring was clear. When the National Ice Taskforce highlighted the urgent need for better methamphetamine data, wastewater analysis was adopted as part of the official response.
A year-long national pilot followed. The results were compelling, and the program’s funding was incorporated into ACIC’s base operations. Today, it is one of the largest and longest-running wastewater drug monitoring systems in the world. It is regularly referenced in international scientific forums and early warning networks.
Inside the sample bottle
Although it may seem simple to test wastewater for drugs, the scientific process behind the program is anything but.
Migus explained that the journey begins at wastewater treatment plants, where operators collect composite samples using auto samplers.
“These are collected by the wonderful people at the wastewater treatment plants,” she said. “Without them, we would not have a program.”
Samples are frozen and transported to UQ or the University of South Australia, where they undergo laboratory preparation, extraction and analysis.
Professor Thomas described the technical backbone of the process. Drugs consumed by users are metabolised by the body and excreted in urine or faeces. Those metabolites are chemically stable enough to survive their path through the sewer network. Using liquid chromatography in tandem with mass spectrometry, the laboratory team detects and quantifies these compounds at extremely low concentrations.
“From there, it becomes an exercise in back calculation,” Thomas said.
The team must account for population estimates, flow rates provided by the treatment plant, the proportion of the drug excreted as each metabolite, and the limits of detection for each analytical method. Each drug has a specific excretion factor, a dose conversion value, and a quantification threshold. All are documented in program appendices and reviewed regularly.
While this mathematical work is invisible to most readers of the public reports, it ensures the final estimates reflect per capita consumption rather than raw chemical loads.
“It is a process with a lot of scientific rigour,” Migus said.
Strength in consistency
One of the program’s most powerful attributes is its regularity. Samples are collected every two months in capital cities and every four months in regional areas. This consistency has produced a seven-year longitudinal dataset that reveals seasonal patterns, long-term shifts, and the impacts of major disruptions such as COVID-19.
“During COVID, many traditional data collection methods were disrupted,” Migus said. “But we were still able to collect wastewater samples throughout that period.”
That continuity provided insights into how lockdowns affected the consumption of methamphetamine, cocaine, MDMA and cannabis. These insights would have been difficult to obtain through surveys or police data alone.
The breadth of the sampling network is equally important. Each sampling round covers more than half the Australian population, with participation from every state and territory. As a result, the program has become a key tool for understanding regional trends, an area that was previously underrepresented in national drug datasets.
What the data reveals
An ACIC report from 2024 noted record highs or concerning increases in methylamphetamine, cocaine and MDMA in several jurisdictions. It also noted long-term stability in cannabis and modest fluctuations in heroin. These trends mirror global shifts in production and supply, including record levels of cocaine cultivation in the Americas and sophisticated methamphetamine manufacture across Asia.
Australia’s data also contributes to international comparisons. The program participates in SCORE, a global collaboration that assesses drug metabolites using consistent methodologies.
“Using the same processes means we can see how our drug use compares to other countries,” Migus said.
Beyond law enforcement
For the ACIC, wastewater data complements rather than replaces traditional intelligence. It helps validate seizure data, detect discrepancies in reporting, and measure the short-term impact of major law enforcement disruptions.
“No single data set has all the answers,” Migus said. “Wastewater is part of a broader triangulation.”
The data is also increasingly valuable for health agencies, which can see shifts in drug consumption earlier than through hospital presentations or surveys. The COVID period demonstrated how wastewater-based epidemiology can serve as an early warning tool during public health emergencies.
Emerging tools and future applications
Professor Thomas sees wastewater-based epidemiology entering a new phase, driven by advances in analytical chemistry, automation, and portable sampling. Emerging methods allow detection of new psychoactive substances, synthetic opioids and pharmaceutical markers earlier than traditional systems. Scientific papers published over the past two years have demonstrated the ability to detect nitazene analogues, xylazine and related compounds in wastewater. These developments have significant implications for national preparedness.
“That is where we are heading,” Thomas said. “Faster detection, broader panels, more sensitive methods and the ability to deploy sampling wherever it is needed.”
That includes bespoke sampling, where investigators can monitor specific locations, such as festival sites, precincts or targeted catchments, without influencing citywide results.
A national resource with global implications
What began as a technical solution to a data gap now sits at the heart of Australia’s understanding of illicit drug markets. It is a program built on local operators, national partnerships, and world-class science. For utilities and water professionals, it highlights the unseen contributions treatment plant operators make to national health and security.
“We always say they are the unsung heroes,” Neilson said.
Their routine sampling has generated one of the most comprehensive longitudinal drug datasets in the world. It is a dataset that continues to grow more sophisticated each year.