sewage systems.

The slippery feeling associated with washing in soft water is caused by the weaker attraction of the soap to the water ions when the water has been stripped of its mineral content. The surface of human skin has a light charge that the soap tends to bind with, requiring more effort and a greater volume of water to remove. Calcium and magnesium ions in hard water reacts with soap, forming insoluble stearates, commonly called soap scum or soap curd.