Actually Zeev, turbidity is a term that hydraulic engineers use to describe water that has a great deal of sediment in it, for example after a rainstorm, when rivers swell and scour dirt and debris from their banks, creating a cloudy brew. Therefore, one can speak of turbid water but not turbid mud, since it is the turbidity itself which turns the water into mud.
Then again, this may be nit-picking of the first water. <gg>
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