Water hardness

The hardness of water is due to the presence of calcium and magnesium minerals that are naturally present in the water. The usual signs of a hard water supply are scaling inside kettles, poor lathering of soaps, and scum.

The majority of raw water in the North West comes from upland surface water reservoirs which are soft or very soft. We do use water from a number of boreholes in the south of the region that are reasonably hard, but these tend to be blended with softer sources to meet demand.

If you are interested in hardness for your dishwasher or washing machine, visit our water quality page where you can get this information quickly and easily. The factsheet on water hardness, which you can access below, can be used get the conversion tables you might need for your appliance.

Hard water can be softened by the installation of a water softener or the use of ‘jug type’ filters. Medical experts recommend that a non-softened supply is maintained for drinking purposes because softened water may contain high levels of sodium. Softeners should be fitted after the drinking water tap and comply with the requirements of the Water Supply (Water Fittings) Regulations 1999. They should be maintained in accordance with manufacturers’ instructions. Further information and advice about water softeners can be found on the Water Regulations Advisory Service website.

For more information, please take a look at our factsheet on water hardness (PDF 99 KB opens in a new window)