60 tons of a chemical substance, 1,2,4-Triazole, have been found in Lake Geneva, a drinking water source for millions of people. The culprit: legal discharges into the Rhône River by agrochemical giant Syngenta during the production of pesticides. Health-risk thresholds have not been reached. Yet, red flags remain. Notably, the notorious cocktail effect and the face that water treatment plants are currently unable to detect and eliminate this pollutant."