In May 2019 researchers from the UK published the results of their study which described a new method for the simulatenous identification of pharmaceutical products and drugs of substance abuse in drinking water. This newly developed simultaneous detection method was applied to drinking water collected from the East Anglia region of the UK. Results showed that the drinking water was found to contain citalopram, cocaine, fluoxetine, ketamine, mephedrone, methamphetamine and methylone at levels between the range of 0.14 and 2.81 ng/L.
Peng Y et al. The detection of drugs of abuse and pharmaceuticals in drinking water using solid-phase extraction and liquid chromatography-mass spectrometry. Chemosphere. 2019 May;223:438-447.