EUSEME: Analysis of drugs in sewage water during the intelligent lockdown in the Netherlands

In the week after the announcement of the ‘intelligent’ lockdown in the Netherlands, KWR tested levels of illegal drugs in the sewage water of Amsterdam, Utrecht and the Eindhoven region. The use of various drugs in Amsterdam in March 2020 fell by comparison with measurements in 2019. In Utrecht and the Eindhoven region, however, drug use in 2020 was virtually unchanged from 2019.

Sewage water reflects society. By normalising the data for the population, it is possible to compare drug use in different regions.

The study

The world has been hit hard by the corona pandemic. On 15 March, the Dutch government announced in a press conference that all restaurants, cafés, gyms, saunas, sex clubs and coffee shops in the Netherlands had to close at six p.m. People’s conduct, daily routines and mobility have been severely affected by the Covid-19 measures. People are travelling less for their studies, work or pleasure, and they could not go to restaurants or bars, or visit events. The result was a society that was primarily home-based. ‘Have people used more drugs in these circumstances?’ wondered KWR researchers.

The study was conducted in the week of 18 to 24 March 2020, just after the announcement of the intelligent lockdown. This was a unique situation: we were able to measure drugs use in the absence of tourists and any active nightlife.

For the EU EUSEME project, KWR researchers analysed sewage water samples in the three cities for one week to determine levels of benzoylecgonine (a metabolite of cocaine), amphetamine (speed), MDMA (XTC), methamphetamine (crystal meth) and THC-COOH (a metabolite of cannabis products). As on previous occasions, the study was conducted in close collaboration with the three water authorities in question: Water cycle company Waternet (Amsterdam), the De Dommel water authority (Eindhoven), the Stichtse Rijnlanden water authority (Utrecht) and the EMCDDA (European Monitoring Centre for Drugs and Drug Addiction).


Cocaine use per thousand inhabitants in Utrecht and Eindhoven at the time of the lockdown was almost the same as in 2019. Cocaine use in Amsterdam, on the other hand, was down by a quarter in 2020 by comparison with 2019.

Amphetamine (speed)

The amphetamine load per thousand inhabitants (the total amount of a substance in the sewage water per day) was slightly higher in Utrecht at the time of the lockdown than in 2019: the increase seen in recent years is continuing. In Amsterdam, on the other hand, levels were a third lower in 2020 than in 2019. In the case of the Eindhoven region, it is difficult to compare loads because it has only been possible to measure amphetamine use three times in the last ten years without that measurement being affected by a discharge of waste from amphetamine production.


The MDMA load per thousand inhabitants in Amsterdam in 2020 is about half the level in 2019. In Utrecht and the Eindhoven region, use in 2020 was virtually the same as in 2019.

Methamphetamine (crystal meth)

Methamphetamine is not popular in the Netherlands. The load and related use per thousand inhabitants are considerably lower in Amsterdam, Utrecht and the Eindhoven region than in the case of other drugs. The use of methamphetamine is also limited by comparison with various other European cities. Because use is so limited, it is difficult to arrive at firm conclusions about the impact of the intelligent lockdown measures. A discharge of waste from the production of methamphetamine was observed for the first time in the Eindhoven region in 2019. A discharge was seen again in 2020.

Cannabis (marijuana and hashish)

THC-COOH is the metabolite of cannabis products (marijuana and hashish). The loads per thousand inhabitants in 2020 are very similar to previous years. Use has been stable for years and the intelligent lockdown measures have had no effect on total use.

Drug use during lockdown

The use of XTC in Amsterdam in March 2020 fell by half, speed use by a third and cocaine use by a quarter by comparison with measurements in March 2019. The use of cannabis products remained stable. In Utrecht and the Eindhoven region, there was no clear decline for any of these drugs. The absence of tourism and nightlife during the lockdown may have affected the use of XTC, speed and cocaine in Amsterdam but had no significant effect on Utrecht and the Eindhoven region.

To understand drug use better during the corona pandemic, it is useful to monitor trends in drug use before, during and after the relaxation of corona-related measures. It is also useful to conduct population research in order to establish a clearer picture of users/user groups and their behaviour during this period. Information of this kind can help government authorities to assess and improve their policies.