In Canada our federal government also monitors wastewater for drug use and claims it's a practice from Europe. Though it doesn't carry a "war on drugs" tone.
https://www150.statcan.gc.ca/n1/pub/13-605-x/2018001/article...
https://www150.statcan.gc.ca/n1/pub/13-605-x/2018001/article...
They've been doing this for a while in some European countries, yeah.