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Most people associate Walters Consulting Corporation and its Environmental Services Division with compliance audits, environmental site assessments and Phase III remediations of spills. However, from time-to-time, a client asks for work in other areas such as drinking water, which brings us to the blue-green algae problem otherwise known as the musty taste in the tap water from Lake Ontario. Although the must odour has been associated with algae for 50 years or more, it was only recently that the true culprits, geosmin and methyl isoborneol (MIB) were identified. These two compounds are produced when algae are killed by chlorination. The odour is often described as "gassy", "septic", "musty", "earthy", "spicy" or "camphorous". These odours have been identified with the brake up of a class of organisms called cyano-bacterium. To get much further than this brief description requires a chemistry course in microbiology.

The cyano-bacterium which produce the smelly geosmin grow particularly well in the early fall, late August through September. In 1994, the whole western end of Lake Ontario from Rochester around to Kingston had a musty water problem for a few weeks.

The discovery of the source of this taste/odour would not have been possible without aided analytical equipment, so knowledge of it is only a generation or so old and it was not in the curriculum of comparatively recent graduates. The text books are still being rewritten. This means that many people in the water business do not appreciate the significance of geosmin or MIB or how to measure it. As recently as 1993, the Ontario Clean Water Agency carried out its first survey to measure the level of these compounds. Unfortunately, the team neglected to refrigerate the water samples. The result was that the geosmin detection levels were underreported. These materials oxidize fairly readily unless carefully preserved.

Walters Consulting Corporation became involved in the problem when we assisted a client to identify the source of the musty odour in bottled drinks. There had been significant loss of potential drink business involved and a large insurance claim. After identifying the source of the problem, Walters Consulting Corporation carried out some further research to find a solution to the problem and this was suggested to the bottler.

The information contained in this web site is intended for marketing purposes only. It is not all-inclusive, and does not fully describe the many and varied services that the company provides, nor does it completely describe the education, training, skills, or expertise of our staff.


Walters Forensic Engineering | 277 Wellington Street West, Suite 800 | Toronto, ON M5V 3H2
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