The Australian Criminal Intelligence Commission says it is "disappointing" that the Northern Territory is not taking part in the latest instalment of the National Wastewater Drug Monitoring Program.
The commission this week released its second report on the program after analysing wastewater at 37 facilities around the country.
"Regrettably, during the period covered by this report the operators of wastewater facilities in Tasmania and the NT declined to participate in the collection of samples," chief executive Chris Dawson said.
"Hence there is no analysis of drug trends in those jurisdictions in this report.
"This is disappointing, as it limits our understanding of trends and emerging issues in those jurisdictions, and the ability to compare current findings with those published in the first report."
The first report, published earlier this year, included sampling from two sites in the NT, which revealed Darwin had the highest levels of alcohol, tobacco and ecstasy of any capital city in Australia.
The Territory's Power and Water Corporation was unable to explain why it did not participate in the latest sampling program.
"Power and Water is liaising with the relevant parties about assisting with the monitoring program," it said in a statement.
"Negotiations re sampling are still taking place."
The Australian Criminal Intelligence Commission said it is "vital" that all jurisdictions participate to understand drug use and demand across the country.
"The Commission will continue engaging with all jurisdictions to secure ongoing participation in sampling for future reports."
