For those of you that are interested in Hamilton's water profile, here is the results from a test carried out in July 2010.
Total Alkalinity g/m3 as CaCO3 = 39
Total Hardness g/m3 as CaCO3 = 57
Chloride g/m3 = 22
Total Calcium g/m3 = 14.1
Total Magnesium g/m3 = 2.7
Sulphate g/m3 = 31
From my understanding, 1 gram per metre cubed = 1 part per million.