Water that is hard contains dissolved salts of calcium and magnesium. Rain water may pick up these minerals as it seeps through soil and rocks. Chalk or limestone rocks contain the greatest amount of these minerals, but they are not common in Scotland, so most water supplies are classified as soft.
Having hard water means that it will take more soap to form a lather. Limescale may form in kettles and on sanitary fittings and occasionally hardness can cause a slight scum to appear on hot drinks such as tea. This is completely harmless. Tap water in Scotland is perfectly safe to drink regardless of whether it is hard or soft. You can obtain a typical value for the hardness of your supply by contacting Scottish Water on Tel: 0800 077 8778 or by email to email@example.com.