Edinburgh Water Hardness & Quality Report (2026)

Scottish Water, the entity that took over from the Edinburgh Water Company, provides water to roughly 450,000 people throughout Edinburgh, Midlothian, and nearby districts. The main treatment plant, Glencorse Water Treatment Works, can process as much as 175 million litres each day. This supply originates from reservoirs nestled within the Pentland Hills watershed and other upland catchment areas. The Edinburgh supply region is situated in the Pentland Hills and adjacent Midlothian uplands, defined by Ordovician and Silurian metamorphic bedrock comprising schist, slate, and quartzite, with very little carbonate geology present.

This geological setting of hard rock, alongside moorland and peat soils, naturally results in soft water that contains very few dissolved minerals. Because there are no limestone or chalk aquifers, the water collects minimal calcium and magnesium as it travels from its sources to the treatment facility. The character of the bedrock, specifically the Ordovician and Silurian formations, is key to the water's softness.

Because Edinburgh's water is soft, it doesn't cause much scale buildup in appliances or pipes, which is generally good for household equipment and plumbing. You'll likely use less soap, and things like kettles and boilers won't get clogged with limescale, potentially making your appliances last longer. However, the softness means there's a need for careful pH management and corrosion control measures to safeguard metal pipes, especially in older homes, against leaching of copper and lead. Edinburgh's water is celebrated for its fresh taste and purity.