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Illinois Water Hardness

5 cities · average 11.3 GPG

Average hardness

11.3 GPG

Hardest city

Joliet 13.2 GPG

Softest city

Chicago 8 GPG

Tier distribution

Very Hard3Hard2

Cities ranked by hardness

1Joliet13.2 GPGVery Hard2Aurora12.7 GPGVery Hard3Peoria11.9 GPGVery Hard4Springfield10.8 GPGHard5Chicago8 GPGHard