Abstract
Taste and odor issues occur in drinking water due to production of 1,2,7,7-tetramethyl-2- norborneol (geosmin), 2-methylisoborneol (2-MIB) and β-cyclocitral. Odor threshold concentrations for these compounds are very low, ~20 ng/L for geosmin and 2-MIB, and 19 μg/L for β-cyclocitral. Current chemical analysis methods have difficulty reaching detection limits below the odor thresholds, giving water suppliers little warning that a problem is developing. The Monitor of Non-Ionic Trace Organic Residues (MONITOR) is an autonomous analytical system that continuously extracts and concentrates organic compounds from water, measures absorbance and fluorescence of the extract and collects it as 24-hour composites for laboratory analysis. This system was applied for the first time to monitor for these compounds in drinking water. The 6-week averages (±σ, ng/L) in Syracuse tap water were: geosmin 3.8±2.6; β- cyclocitral 4.9±3.3. In Lake Ontario raw the 8-week averages were: geosmin 1.6±2.4; 2-MIB 0.15±0.29; β-cyclocitral 0.68±1.08.