The Water Fittings Regulations and Scottish Water Byelaws are national requirements for the design, installation, operation and maintenance of plumbing systems, water fittings and water-using appliances. Their purpose is to prevent misuse, waste, undue consumption or erroneous measurement of water and, most importantly, to prevent contamination of drinking water. They replaced the former local Water Supply Byelaws, which each water supplier administered for similar purposes for many years and are designed to protect public health and promote the efficient use of water.