Do levels of cannabis in wastewater in Australia vary by geographic location?
The amount of cannabis found in Australian wastewater varies substantially between Australian jurisdictions†.
The amount of cannabis found in Australian wastewater varies substantially across Australia. In general, cannabis consumption is higher in regional areas than in capital cities. In 2025, cannabis consumption in regional areas of the Northern Territory, South Australia and Western Australia was substantially higher than the national average, while Hobart recorded the highest cannabis consumption of the capital cities.
Estimated cannabis consumption for August 2025 in mass consumed per day (left axis)^
Estimated average cannabis consumption per jurisdiction, August 2023 to October 2025 in mg consumed per day per thousand people^
^ The number of collection days varied from 5-7 days
Source: Australian Criminal Intelligence Commission (2026). National Wastewater Drug Monitoring Program: Report 25. Canberra: ACIC.
Source: Australian Criminal Intelligence Commission (2026). National Wastewater Drug Monitoring Program: Report 25. Canberra: ACIC.
† This FAQ uses data from the National Wastewater Drug Monitoring Program. Tetrahydrocannabinol (THC) is the main psychoactive compound in cannabis. Cannabis consumption was measured by its urinary metabolite, 11-nor-9-carboxy-∆9-tetrahydrocannabinol (THC-COOH).