Map of water hardness (as calcium carbonate) from the U.S. Geological Survey Total downloads 0 File size 64.13 KB Mime type image/jpeg Show contributors This page has been seen 2,353 times. Created by SiBurning on Jun 12, 2011
Map of water hardness (as calcium carbonate) from the U.S. Geological Survey Total downloads 0 File size 64.13 KB Mime type image/jpeg