Cause of intermittent red coloring in cooling water discharge

["GLIN-Announce List Manager" <glinpost@great-lakes.net>]

Posted on behalf of Paul Kidd <c9526162@alinga.newcastle.edu.au>

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Hope you can help me.  I'm investigating an intermittent red
colouring (haematite from initial analysis) in cooling water
discharge from a local steel plant.  Most likely, the precurser is
ferrihydrite, and haematite is then formed by heat.  This reaction
may, or may not be catalysed by bacteria. I cant work out why
the problem is intermittent (about 4 times in 2 years) when iron
seems to be in excess at most times. The cooling waters are
discharged into a canal that passes through a residental area.
Although haematite & the associated bacteria are harmless and
are of no concern to biota or the ecosystem, the red colouring is
alarming to local residents.

Have you heard of a similar problem (in the Great Lakes region
or elsewhere)?  Can you shed any light on this?

Thank you for your time. I hope to hear from you soon.

Paul Kidd
Newcastle University Australia
c9526162@alinga.newcastle.edu.au