"clifto" wrote in message
...
Bob F wrote:

http://egov.cityofchicago.org/city/w...inCategoryOID=

Not a word about hardness in there. Daley said "hardly" once, though.

--
"A man's country is not a certain area of land, of mountains, rivers, and
woods, but it is a principle; and patriotism is loyalty to that
principle."
-- George William Curtis

OK. Google chacago water hardness.

Second choice is
http://www.dpwc.org/faqprint.htm.

Where does our water come from?
The DuPage Water Commission's water comes from Lake Michigan, the largest
freshwater lake in the United States and the fifth largest lake in the
world. The Commission purchases the water from the Chicago Water Department.

How hard is my water and should I use a water softener?
Dissolved minerals make water hard; as the amount of minerals in the water
increases, the water becomes harder. Two common minerals found dissolved in
drinking water are calcium carbonate and magnesium carbonate. There is
usually much more calcium carbonate than magnesium carbonate present in
water; therefore, water hardness is reported as the amount of calcium
carbonate (CaCO3) dissolved in the water. There are two units of measurement
for hardness commonly used in the United States, grains per gallon and
milligrams per liter calcium carbonate (mg/L as CaCO3). The conversion
factor is 17.1 mg/L as CaCO3 = 1 grain per gallon. Our water is about 8
grains per gallon or 137 mg/L as CaCO3. Average well water hardness is 55
grains per gallon or 941 mg/L as CaCO3.