Mains water in Buckinghamshire (England) is supplied by Thames Water (predominant); Affinity Water in the Chilterns; Anglian Water in far north; typical hardness: Hard, ~285 mg/l CaCO3. Water quality is regulated by the Environment Agency · Ofwat · Drinking Water Inspectorate.
Sources: Thames Water (predominant); Affinity Water in the Chilterns; Anglian Water in far north