Hard water is caused by calcium and magnesium compounds; rain water is naturally soft as it has had no chance to pick up any minerals from the ground. When water passes through the ground through soft rocks like chalk or limestone, it picks up these minerals. If the water passes through rocks such as granite or through peaty soil calcium and magnesium are picked up and so the water remains soft.
Hard water can create 2 main issues within a building: Issues Relating to Scale Heat causes the calcium and magnesium to precipitate out of the water and stick to things causing "scale" to form on the inside of pipes, water boilers, tea kettles and so on. The scale doesn't conduct heat well and reduces the flow through the pipes which can ultimately become completely blocked potentially leading to expensive repair bills. Reducing the Effectiveness of Soap Hard Water reacts with soap to form a scum and (in extreme cases) reduces soap's ability to lather, this impacts on cleaning throughout the house including washing, bathing and general cleaning. Hard and Soft Water Regions in the UK The list below is a good indication of the general hard and soft water areas in the UK although it is an indicator only as all areas can contain pockets of completely different water types. To find out more you can contact your local water company (see list at base of article). Regions with soft to moderately soft water in EnglandConwynCumbria DevonFlintshireGwyneddIsle of AngleseyMerseyside North West YorkshirePembrokeshireWest YorkshireRegions with soft to slightly hard water in EnglandCarmarthenshireCeredigionDurhamGlamorganshireMonmouthshireRegions with slightly hard to moderately hard water in EnglandCheshireDenbighshireDerbyshireHerefordshireLancashireLeicestershireNorthumberlandPowysShropshireWorcestershireWrexhamRegions with slightly hard to very hard water in EnglandNorth YorkshireSomersetSouth YorkshireSurreyWarwickshireRegions with hard to very hard water in EnglandBedfordshireBerkshireBuchinghamshireCambridgeshireDorsetEast Riding of YorkshireEast Riding of YorkshireEast SussexEssexGloucestershireGreater LondonHampshireHampshireHertfordshireIsle of WhiteKentLincolnshireLincolnshireNorfolkNorth East YorkshireNottinghamshireNottinghamshire OxfordshireRutlandStaffordshireSuffolkScotlandMost regions in Scotland range from soft through to various levels of hardness with the majority not exceeding moderately soft water. Ireland RegionsIreland maybe broken down as follows: Northern Division soft to moderately softEastern Division soft to moderately hardSouthern Division soft to moderately hardWestern Division soft to moderately hard Local UK Water CompaniesAnglian Water Services LtdPhone: +44 (0)1480 323 000http://www.anglianwater.co.uk Dwr Cymru Cyfyngedig (Welsh Water)Phone: +44(0)1443 452 300http://www.dwrcymru.co.uk Independent Water Networks LtdPhone: +44 (0)845 051 1650 Northumbrian Water LtdPhone: +44(0)8706 084820http://www.nwl.co.uk Severn Trent Water LtdPhone: +44(0)121 722 4000http://www.stwater.co.uk South West Water LtdPhone: +44(0)1392 446 688http://www.southwestwater.co.uk Southern ElectricPhone: +44 (0)118 958 0100http://www.southern-electric.co.uk Southern Water Services LtdPhone: +44(0)1903 264 444http://www.southernwater.co.uk Thames Water Utilities LtdPhone: 0845 9200 888http://www.thameswater.co.uk United Utilities Water PlcPhone: +44(0)1925 237 000http://www.unitedutilities.com Wessex Water Services LtdPhone: +44(0)1225 526 000http://www.wessexwater.co.uk Yorkshire Water Services LtdPhone: +44(0)1274 691 111http://www.yorkshirewater.com Albion Water LtdPhone: +44(0)20 8977 3055http://www.albionwater.co.uk Bournemouth & West Hampshire Water PlcPhone: +44(0)1202 591 111 http://www.bwhwater.co.uk Bristol Water PlcPhone: +44(0)117 966 5881http://www.bristolwater.co.uk Cambridge Water Company PlcPhone: +44(0) 1223 403 000http://www.cambridge-water.co.uk Cholderton & District Water Company LtdPhone: +44(0)1980 629 203http://www.choldertonwater.co.uk Dee Valley Water PlcPhone: +44(0)1978 846 946http://www.deevalleygroup.com/DVW/DVW.htm Essex & Suffolk Water (now part of Northumbrian Water Ltd)Phone: +4 (0)1245 491 234http://www.eswater.co.uk Folkestone & Dover Water Services LtdPhone: +44(0)1303 298 800http://www.fdws.co.uk Hartlepool Water Plc (now part of Anglian Water Services Ltd)Phone: +44(0)1429 858 050http://www.hartlepoolwater.co.uk Mid Kent Water PlcPhone: +44(0)1634 240 313http://www.midkentwater.co.uk Portsmouth Water PlcPhone: +44(0)23 9249 9888http://www.portsmouthwater.co.uk South East Water LtdPhone: +44(0)1444 448 200http://www.southeastwater.co.uk South Staffordshire Water PlcPhone: +44(0)1922 638 282http://www.south-staffs-water.co.uk Sutton & East Surrey Water PlcPhone: +44(0)1737 772 000http://www.waterplc.com Tendring Hundred Water Services LtdPhone: +44(0)1206 399 200http://www.thws.co.uk Three Valleys Water PlcPhone: +44(0)1707 268 111http://www.3valleys.co.uk What can I do about hard water?There are 2 options that are available to you depending on your needs; Products called water softeners will improve the efficiency and increase the life of hot water appliances throughout a building. If installing a water softener is too difficult or costly then you could consider protecting specific devices that are plumbed into the mains with a scale inhibiting filter. The types of devises that may be protected in this way include mains water coolers and all types of water boilers and heaters. These filters are installed inline between the mains pipes and the machine itself and contain scale inhibiting elements. About Water Softeners A Water Softener is a device that monitors and reduces the hardness of the water, it does this by removing the calcium and magnesium salts from a water supply and replacing them with a saline solution. All water softeners work in essentially the same way, the incoming water enters the softener and passes through ion exchange resin. The resin removes the magnesium and calcium ions that create lime scale by swapping them with a small amount of salt, this leaves the softened water to enter your water system. The machines often contain an automatic timer control which will periodically clean or regenerate the resin. This is done by passing salt water through the resin which swaps places with the stored magnesium and calcium ions and allows the trapped minerals to be flushed down the drain. If you are considering this option then please be aware: When installing your Water Softener the UK Water Bylaws require that one tap in the house is left unsoftened. This may be accomplished by installing a third dedicated tap at the kitchen sink. In effect the whole house has softened water and the dedicated tap provides hard water for drinking, cooking etc. It’s also recommended that any outside taps are fed with unsoftened water to avoid waste.There is evidence of less heart disease in hard water areas than in soft water areasMost water softeners work by replacing the hardness with sodium which can cause issues with babies and those with heart conditions Some water supplies contain impurities that may affect your softener if left untreated. Iron, dirt, silt, organics and bio film may not be removed by the salt regeneration system and older resin beds may start to suffer from iron fouling. Soft water can release lead from any lead pipes Once the scale is removed it can open up old leaks that have been sealed by the historic scale build-upSofteners require ongoing maintenance and need to be topped up with the correct type of saltYou purchase the system from a reputable supplier