Image Credit

Description:

Chemistry Science fair project This map of the United States shows, by color, where water levels are hardest and softest. The red areas have the most dissolved calcium cations in the water and the hardest water, while the dark blue areas have the least dissolved calcium cations in the water, and therefore, the softest water. (USGS, 2005.)

Source:

United States Geological Survey, 2005

License:

US Government website

Source URL:

http://ga.water.usgs.gov/edu/characteristics.html#Hardness