Taste and Odour Data Lake Ontario 1999 to 2010

Lake Ontario is the primary source of drinking water for millions of people. Undesirable taste and odour events may occur in late summer as a result of the release of two volatile organic compounds geosmin (trans-1,10-dimethyl-trans-9-decalol) and 2-Methylisoborneol(1,6,7,7-tetramethylbicyclo[2.2.1]heptan-6-ol) (MIB). These secondary metabolites are produced by actinomycetes and cyanobacteria and yield a musty or earthy taste and odour. These compounds can be detected at very low concentrations (~4 ng/L). Here we present Geosmin, MIB, nutrients and physical data collected between 1999 and 2010 to characterize taste and odour events in Lake Ontario. Spatial surveys of Lake Ontario consisting of approximately 60 stations were conducted yearly in late August and weekly surveys were conducted July to September near the Lorne Park drinking water Intake and Lakeview Park near Toronto, Ontario. Bay of Quinte surveys were conducted August to October 2004 to 2010.