CHARACTERIZATION OF DRINKING-WATER ODOR ARISING FROM SPRING THAW FOR AN ICE-COVERED UPLAND RIVER SOURCE

Recurring odour events during spring thaw in the North Saskatchewan River led to a program to characterize contributing odour agents. Raw and treated water samples were adsorbed on granular activated carbon which was then exhaustively solvent extracted. The solvent concentrates were subjected to a chromatographic sniffing procedure combined with gas chromatographic-mass spectral analyses. Geosmin and 2-methylisoborneol were identified by sensory and analytical means as likely major contributors to the raw water odour. Benzaldehyde, camphor and dihydroactinidiolide were other relevant compounds identified. Given the near freezing water conditions at the time of the odour event, the biogenic source of the odour agents remains a subject for investigation.