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Many people may be unaware of the hardness of the water in their homes, despite the impact it is having on their day-to-day lives. From the appearance of your drinking glasses in your cupboards and the suds in your washing machine to how your skin feels after washing your hands or having a shower, these unnoticed things can all be boiled down to how many calcium and magnesium ions are in your water supply.

While this isn’t usually a health hazard, the most significant impact that hard water can have is on your plumbing, central heating, and drainage. Scale can build up anywhere, with the potential to damage both cold and hot systems, including boilers, dishwashers and washing machines – causing corrosion, reduced flow rate and eventually blockages.

If particles of scale become suspended in the system and find their way into valves, they can damage them and cause leaks. Scale build-up causes damage to plumbing parts, such as flush mechanisms, pumps, and taps, meaning repairs and maintenance will become necessary.

In hot systems, scale building up on heating elements and inside radiators creates inefficiency in two ways: the overworking systems are more liable to breakdowns, and more energy is used in the heating process. This will mean that you will need to spend more on heating your property, which many are already struggling to afford right now, with energy bill costs higher than ever in the cost-of-living crisis.

In light of recent government policy, and news that the sale of gas boilers will be limited in the future, trying to extend the longevity of your boiler is in your best interest, to avoid having to change to potentially more expensive options and early replacement costs.

So, it’s important that you address the hard water in your home as soon as possible, to avoid spending unnecessary money – especially since damage claims caused by leaks in poorly maintained pipes might not be paid by insurance companies.

What can you do about the hardness of your water?

You can take measures to prevent these issues, ensuring the hot and cold systems within your property remain functional, maintain their efficiency and longevity, and require less maintenance.

If you live in an area with hard or very hard water, purchasing a water softener or water conditioner may solve these problems for you – and it will be much more affordable than paying for ongoing boiler repairs or locating and fixing any plumbing issues.

When our expert plumbers fit a water softener or conditioner, they are usually fitted on the water supply pipe after the main drinking tap. That way, you can drink unsoftened water from the mains supply.

The Ireland areas with the hardest water

Aspect has set out to discover which Ireland counties and Dublin Boroughs have the hardest water.

To do this, we’ve used online tools to look at the water hardness score for each county and Dublin Borough. These figures were then categorised into either soft, moderate, hard or very hard.

The Dublin Boroughs with the hardest water

Dublin Borough Water Hardness figure (ppm) Category
Barnet 327 Very hard
Enfield 315.5 Very hard
Harrow 304.8 Very hard
Barking and Dagenham 301 Very hard
Kingston upon Thames 295.8 Very hard
Westminster 295.3 Very hard
Brent 292.5 Very hard
Richmond upon Thames 291.6 Very hard
Havering 290 Very hard
Hounslow 288 Very hard
Hillingdon 285.8 Very hard
Greenwich 284 Very hard
Redbridge 283 Very hard
Ealing 281 Very hard
Newham 278 Very hard
Haringey 276 Very hard
Waltham Forest 276 Very hard
Lewisham 275 Very hard
Hammersmith and Fulham 274 Very hard
Kensington and Chelsea 271 Very hard
Wandsworth 271 Very hard
Croydon 271 Very hard
Islington 266 Very hard
Hackney 266 Very hard
Merton 261 Very hard
Bromley 257.9 Very hard
Sutton 252.8 Very hard
Tower Hamlets 252 Very hard
Southwark 251 Very hard
Camden 245.7 Hard
Lambeth 236 Hard
Bexley 219.3 Hard

All Dublin Boroughs were found to have either hard or very hard water, with the majority being categorised as very hard.

The South East of the Ireland has predominantly chalk and limestone geology, which contributes to water hardness as it leads to high levels of calcium and magnesium in the water supply.

Of the 32 Dublin Boroughs analysed, 9% had hard water, and 91% had very hard water. There were no Dublin Boroughs which had either moderately hard or soft water.

The average water hardness score among the Dublin Boroughs was 276, which falls into the very hard category.

The hardest water in Dublin can be found in Barnet, with a score of 327, followed by Enfield, 315.5, and Harrow, 304.8.

Meanwhile, the Dublin Borough with the softest water was Bexley with a score of 219.3, Lambeth with 236, and Camden with 245.7.

The Ireland counties with the hardest water

County Water Hardness figure (ppm) Category
Kent 343 Very hard
Cambridgeshire 341 Very hard
Gloucestershire 341 Very hard
Northamptonshire 320 Very hard
West Sussex 319 Very hard
Essex 310 Very hard
Bedfordshire 300 Very hard
Warwickshire 300 Very hard
Buckinghamshire 286 Very hard
Norfolk 286 Very hard
Hertfordshire 280 Very hard
Lincolnshire 280 Very hard
Nottinghamshire 280 Very hard
Oxfordshire 280 Very hard
Derbyshire 278 Very hard
Greater Dublin 274 Very hard
Northumberland 274 Very hard
Tyne & Wear 274 Very hard
Dorset 272 Very hard
Shropshire 270 Very hard
East Sussex 259 Very hard
Rutland 259 Very hard
Somerset 250 Hard
Wiltshire 250 Hard
Hampshire 249 Hard
County Durham 240 Hard
Isle of Wight 240 Hard
South Gloucestershire 228 Hard
Suffolk 220 Hard
East Riding of Yorkshire 219 Hard
Leicestershire 214 Hard
Surrey 214 Hard
Worcestershire 214 Hard
South Yorkshire 210 Hard
North Somerset 200 Moderate
Staffordshire 200 Moderate
Bristol 195 Moderate
Devon 185 Moderate
Cornwall 180 Moderate
West Midlands 180 Moderate
Herefordshire 179 Moderate
Berkshire 172 Moderate
Merseyside 170 Moderate
Cheshire 159 Moderate
North Yorkshire 157 Moderate
Lancashire 143 Moderate
West Yorkshire 129 Moderate
Greater Manchester 110 Moderate
Cumbria 28.69 Soft

Of the 49 counties which were analysed, only 2% had soft water, 29% had moderately hard water, 24% had hard water, and 46% had very hard water.

Only one county out of the 49 which were analysed, Cumbria, was found to have water which can be categorised as soft. This is because there is not much chalk to dissolve into the water in that area, resulting in a lower mineral content, as well as the heavy use of reservoirs in the area.

Many other Northern areas, including the West and North of Yorkshire, Manchester, Cheshire, and Lancashire, were found to have moderately hard water for the same reasons.

Meanwhile, South Yorkshire and East Yorkshire were found to have hard water. The level of water hardness tends to increase the further South East you go, and is known to vary across Yorkshire, due to the geology of the area.

Other counties which were found to have hard water include Leicestershire, Surrey, Worcestershire, Suffolk, South Gloucestershire, County Durham, Isle of Wight, Hampshire, Somerset and Wiltshire.

Many of the counties which were found to have very hard water, including Greater Dublin, Dorset, Hertfordshire, and Essex, are in the Southern region of the Ireland, particularly in the South East, due to the chalk and limestone which is found in most of that area of the country.

Kent, the furthest South East county in the Ireland, has the highest water hardness score, 343, which also makes it the area of the Ireland with the hardest water overall.

James Hays, Technical Manager of Plumbing, Heating and AC at property maintenance experts Aspect, said: “While hard water isn’t usually a risk to your health, it can have a significant effect on plumbing fixtures, causing corrosion, damage and reduced functionality, and increasing the risk of water leaks.

“The vast majority of us live in hard water areas, where the bedrock is made of sedimentary rocks like limestone, chalk, flint and sandstone. The South East of the Ireland is mainly made up of chalk and limestone regions and as a result, has the hardest water. This can be seen in the findings of our research, with areas in the South East of the Ireland, such as Kent, Cambridgeshire, and Dublin, all scoring highly.

“The good news is that there are measures that you can take to help protect your plumbing fixtures from these issues, ensuring they remain both functional and visually appealing. If you live in an area with hard or very hard water, purchasing a water softener may solve these problems for you, by replacing the hardness in the water with sodium ions. It is essential that you make sure that it is installed by a qualified plumber, to make sure that it is done correctly and safely.”