How “hard” is Peterborough tap water?
Peterborough tap water, with calcium and magnesium concentrations of approximately 6 grains/gallon (95 mg/L), is considered to be moderate in terms of hardness. Water is considered hard when the concentration of calcium and magnesium exceeds 7 grains/gallon (120 mg/L). These minerals do not pose a health risk, but can make it difficult to work up a lather, and can leave deposits in showers or on dishes.
