Minerals in the water, including magnesium and calcium, characterise hard water. While the water rigidity remains unchanged, mineral ions are present. As a result of weathering processes, the greater the number of ions, the harder the water.
You can classify hard water based on the amount of dissolved minerals present:
- - Soft – 0.1.17.1 mg/L
- - Slightly hard – 17.2-60 mg/L
- - Moderately hard 60.1-120 mg/L
- - Hard – 120.1-180 mg/L
- - Very hard – 180.1> mg/L
Location and water supply source are the two biggest factors that affect hard water levels for certain areas. For example, the Central and East of England have the hardest water supplies. This results from the water source coming from reservoirs in limestone-heavy areas, such as the Peak District.
Water supplies source the majority of their water from reservoirs and rivers. The water within these sources is already hard. Rainwater, which is soft, percolates the limestone rocks, causing the minerals to dissolve into the water. This water then enters the rivers and reservoirs that make up our water supply.
Soft water areas, such as Wales, have their water supply sourced from rivers and reservoirs with no limestone rocks. The hard water maps below can help identify areas affected by hard water and the hardness of the local water supplies.
These maps of water hardness represent the average
water hardness of an area. Your water quality may differ depending on the water hardness level. If water hardness affects water quality, solutions such as a water descaler can relieve such problems.
Hard Water in England and Wales
The British Drinking Water Authority provides information indicating that drinking water in England largely falls under ‘very hard’. Around 60% of all households in the UK have hard water supply. The South East regions of England have the hardest water supplies. London experiences the hardest water supplies of up to 370 PPM.
You can find more information on the
drinking water standards and regulations from the Drinking Water Inspectorate (DWI).
PPM (or parts per million) is a measurement to measure mineral content within the water. The higher the PPM, the greater the mineral content. PPM levels are similar to the mg/L levels listed above. You can classify PPM and water hardness as follows:
- - Soft - up to 50 PPM
- - Moderately soft - between 51 and 100 PPM
- - Slightly hard - between 101 and 150 PPM
- - Moderately hard - between 151 and 200 PPM
- - Hard - between 201 and 275 PPM
- - Very hard - between 276 and 350 PPM
- - Aggressively hard - above 350 PPM
Most Southern and Eastern areas of England exhibit above 200 PPM (very hard) for the calcium carbonate equivalent. Wales, Devon, Cornwall, and parts of North-West England are softer water areas ranging from 0 to 200 PPM.
Hard Water in Ireland
Hard Water in Spain and Portugal
Hard Water in the United States
Many American homes suffer from hard water (more than 85%). Some streams in most regions throughout the country contain hard and very hard water. The hardest waters (greater than 1,000 PPM) are in streams in Texas, New Mexico, Kansas, Arizona, and southern California.
Moderately hard waters are common in many of the rivers of the Tennessee, Great Lakes, Pacific Northwest, and Alaska regions. The softest waters occur in parts of the New England, South Atlantic-Gulf, Pacific Northwest, and Hawaii regions.
Hard Water in Canada
Prairie provinces (Saskatchewan and Manitoba) contain high quantities of calcium and magnesium, often as dolomite. These are soluble in the groundwater and have high concentrations of trapped carbon dioxide from the last glaciation.
In these parts of Canada, the total PPM hardness of calcium carbonate equivalent exceeds 200 PPM. However, this is if groundwater is the source of potable water. The west coast, by contrast, has soft water derived from mountain lakes fed by glaciers and snowmelt.
Some typical values are:
- - Vancouver < 3 PPM
- - Winnipeg 77 PPM
- - Montreal 116 PPM
- - Toronto 121 PPM
- - Saskatoon < 140 PPM
- - Charlottetown PEI 140 - 150 PPM
- - Calgary 165 PPM
- - Regina 202 PPM
Hard Water in Australia
The Australian Water Association’s analysis reveals a wide range of water hardness levels in major cities. Adelaide experiences very hard water supplies, while Melbourne has a very soft water supply.
Total hardness levels of Calcium Carbonate in PPM are:
- - Melbourne: 10 - 26
- - Hobart: 5.8 - 34.4
- - Darwin: 31
- - Sydney: 39.4 - 60.1
- - Canberra: 40
- - Perth: 29 - 226
- - Brisbane: 100
- - Adelaide: 134 - 148
Hard Water Solutions
You may benefit from a hard water solution for those living in a hard water area. Multiple solutions are available, including an electronic water descaler or water softeners. Both devices are different and better suited depending on the water hardness levels.
Limescale build-up inside heating elements, washing machines, and shower heads are all problems with hard water supplies.
Hard water can also affect hair and skin.
Areas with a moderately and slightly hard water supply (up to 200 PPM) may benefit most from an electronic water descaler. You can fit these small devices to your main water supply to alleviate hard water problems.
A small electromagnetic field disrupts the mineral ion's behaviour. As a result, hot water systems, heating systems, and appliances do not suffer from limescale build-up. A water descaler is also very cost-effective, using very little power.
Read more about how electronic water descalers work.
Installing a water softener is another hard water solution. A water softener uses an ion exchange process to soften the water. Sodium replaces the hard water minerals. With the high cost, very hard water supplies will benefit from a water softener.
The ion exchange process requires regular replenishments of salt pallets for the regeneration process to work. The resin beads inside a water softener require regular flushing to work. Both salt and water regenerate the resin beads. This process also results in a high amount of wastewater.
The hard water solution you choose will depend on your location and the hardness of the water supplies. You may benefit from a water descaler for those with moderate hard water. Those with very hard water will benefit most from a water softener.