Sewer tests flush out P use

Researchers find high drug levels in Auckland wastewater treatment plants

Drug sampling of Auckland’s sewers — which has revealed high levels of methamphetamine — could be extended to other New Zealand centres.

Methamphetamine was the most commonly detected of 17 drugs targeted — cannabis was excluded — in new research examining two wastewater treatment plants servicing 1.3 million people living in our largest city.

The lead researcher behind the Massey University-led pilot study, released yesterday, said the concerning results confirmed meth use was a “serious problem” facing Auckland.

Associate Professor Chris Wilkins said he now hoped to apply the same approach to treatment plants in other towns and cities to gain an accurate snapshot of drug use in New Zealand.

In the just-published Auckland study, daily tests carried out between May and July 2014 revealed high levels of methamphetamine, codeine, morphine and methadone in both facilities.

The results showed methamphetamine, codeine, morphine and methadone were detected in between 80 to 100 per cent of days over the sampling period — followed by amphetamine, MDMA and methylone.

Researchers estimated an overall average of 360mg of methamphetamine and 60mg of MDMA, better known as ecstasy, was being consumed a day per 1000 people.

While methamphetamine consumption was found at similar levels in both catchments — 377 and 351mg per day, per 1000 people — cocaine was detected in only one catchment, and on only eight occasions.

Methamphetamine, codeine and other opioids were detected at a consistent level throughout weekdays, while ecstasy and methylone, a common ecstasy substitute, were detected only during the weekends.

Wilkins said this suggested they were used primarily as party drugs.

“I think methamphetamine use is a concern and this is confirming that this is a serious problem,” he said.

The low level of cocaine consumption was meanwhile consistent with the very low use and availability of the drug, as reported in annual monitoring surveys.

Cannabis was not among the drugs sampled as it tended to bind to solids and required extra testing which was expensive and outside the pilot study’s budget.

Wilkins expected the data would be useful to police, but noted that testing for illegal drugs wasn’t the only way the approach could be used.

“It’s actually a really excellent way to gain data on a whole lot of health measures for a population: it could be used to include anything from diet to alcohol and tobacco use.

“But I think the real strength of this is it can be done in a whole lot of small towns and cities throughout New Zealand and for the first time, you can actually get some really accurate data about what’s happening in those places.”