What are utilities doing to control taste and odour?

The member utilities are committed to provide high quality, safe water at all times and to meeting aesthetic objectives for T&O. The levels of T&O during the events in 1998 and 1999 were about 10 times higher than historic levels. Utilities could not completely remove the T&O during those events with the control measures in place at that time.

Utilities are taking strong actions to manage any future event. The optimal short to medium term solution for most utilities is the use of activated carbon to trap the geosmin and MIB in the treatment plant. This carbon can be installed as a cap on the existing filters or it can be fed in powdered form and mixed with the water before the water is filtered at the plant. A combined investment of over $25 million has been made by the member utilities to remove T&O. Long-term solutions can be based on permanent carbon systems, use of ozone or another strong oxidant, or deeper intakes (where the access to deeper water is feasible). Each of these options must be considered in terms of costs and benefits.

Another element of the commitment of the utilities is their contribution to the research that is providing a deeper understanding of T&O in Lake Ontario. These findings will assist utilities in making decisions on long-term solutions and may also help predict future events.

Back to top