St. Paul Park's water hardness is 18 grains. This is very hard. While individual water softening is not necessary, many individuals choose to have private water softeners.
The calcium from limestone is the major contributor to the hardness of St. Paul Park's water. Hardness can appear as a nuisance when water is boiled or dried from a drip because it forms a white powder residue when all the water evaporates. It also interferes with soap and detergent use. People with very soft water can use smaller amounts of soap and detergent for washing.