Assessing illicit drug use through the analysis of wastewater is progressively being integrated into existing methods used to monitor the epidemiology of drug use. However, the approach's potential to deliver pertinent information for law enforcement has been discussed only limitedly. Thus, this work focuses on evaluating the added value of the approach from the perspective of law enforcement. Results from wastewater analysis carried out in two cities in Switzerland were scrutinised, taking into account intelligence derived from the work of drug enforcement in the area. Focus was set on three substances, namely cocaine, heroin and methamphetamine. Findings show that results from wastewater analysis can be used by law enforcement to assess the market share held by criminal groups. Combined with intelligence resulting from police work (e.g., investigations and informants), wastewater analysis can contribute to deciphering the structure of drug markets, as well as the local organisation of trafficking networks. The results presented here constitute valuable pieces of information, which can be used by law enforcement to guide decisions at strategic and/or operational levels. Furthermore, intelligence gathered through investigations and surveillance constitutes an alternative viewpoint to evaluate results of wastewater analysis.

Highlights:
Wastewater-based epidemiology is increasingly used to monitor illicit drug use.
Use of gathered data for law enforcement has barely been contemplated.
Interpret results from the perspective of law enforcement intelligence.
Valuable information to guide strategic and operational decisions.