Scott Morrison’s plan to test wastewater to identify welfare recipients on drugs will only highlight the high levels of drug use among professionals working in “the finer leafy suburbs of Melbourne and Sydney”, an expert on the Victorian government’s ice action taskforce, John Ryan, has said.

Ryan, who is also chief executive of the not-for-profit drug research organisation the Penington Institute, also accused the treasurer of implementing “a new regime of big brother”.

Ryan was responding to Morrison’s comments during an interview with BuzzFeed on Thursday morning that areas of high drug use were “the best place to start” trials of drug testing for 5,000 Newstart and Youth Allowance recipients. Those welfare recipients with positive drug test results will be forced on to cashless welfare cards restricting cash withdrawals and barring the purchase of certain products.

Sewage testing of chemical compounds in raw wastewater is used by scientists and researchers to estimate the consumption and prevalence of drug use in cities and towns. This chemical analysis can also point to a population’s health and lifestyle habits, and can indicate changing drug trends over time of the population connected to the sewer system.

But Ryan said what the testing could not accurately pinpoint was how many people were using.

“It is not laser accurate when it comes to how many people are using as there are too many assumptions in the model,” Ryan said.

“It is not yet developed to the stage where you can identify a high number of users in a community. You can more likely predict how many standard doses of a drug have been taken, which is very different to how many people and which people are using. Some drug users might use once every four hours, some might use once every four months.”

He said a high number of working professionals used drugs.

“It might misfire if the government think they can rely on some chemical test of wastewater as we know drug use is expensive and more common drugs such as cannabis are consumed by people in the workforce,” he said.

“Using the wastewater approach, they will find high amounts in the wastewater of the finer leafy suburbs of Melbourne and Sydney.”

The Penington Institute has warned the government that targeting welfare recipients with drug testing will see an increase in crime and homelessness among Australia’s most vulnerable people.

People on welfare who were using drugs had complex mental health needs and to risk their welfare because they were using drugs of dependence was not an appropriate response, Ryan said.

“We don’t need wastewater analysis to identify what everyone in the drug treatment sector knows,” Ryan said.

“The treasurer could talk to doctors, he could look at drug and mental health treatment waiting lists, it shouldn’t be hard to identify where people are desperate and in need.”

University of Melbourne pharmacologist and drug and alcohol policy expert, Associate Prof John Fitzgerald, said the drug-testing program was unlikely to help welfare recipients become more responsible.

“Rather, experience from the US suggests these are costly programs with a low rate of positive test results,” he said.

“Also likely is that this trial is expanded and will produce a cost shift from the federal welfare budget to state crime budgets through net widening and displacement of drug crime. This may well increase the participation rate, not into legal work, but into a different kind of illegal activity.”



He said outlaw motorcycle gangs sometimes targeted regional areas, bringing drugs into those communities. But it wasn’t necessarily welfare recipients buying them.

He agreed sewage testing was the wrong tool to use to identify welfare recipients using drugs.