Hard water is caused by dissolved minerals, mainly calcium and magnesium, that are picked up as water passes through soil and rock. It can interfere with cleaning tasks and leave films on fixtures. Permanent hardness cannot be removed by boiling and is caused by calcium and magnesium sulfates. While hard water does not pose health risks, it can cause nuisance problems like scale buildup and poor soap performance. Water becomes hard when it dissolves calcium and magnesium from geologic formations like limestone and dolomite during passage through the ground.

2. WHAT IS HARD WATER?
Hard water is high in dissolved minerals, both calcium and magnesium. As water
moves through soil and rock, it dissolves small amounts of these naturally-occurring
minerals and carries them into the ground water supply. Water is a great solvent for
calcium and magnesium, so if the minerals are present in the soil around your well
and its water supply, you can end up with hard water. Hard water interferes with
almost every cleaning task, from doing the laundry to washing dishes to taking a
shower. Clothes can look dingy and feel rough and scratchy. Dishes and glasses get
spotted and a film may build up on shower doors, bathtubs, sinks and faucets.
Washing your hair in hard water may leave it feeling sticky and dull. Finally, hard
water can cause a residue to build-up in pipes that can lower water pressure
throughout the house.

3. PERMANENT HARDNESS…
Permanent hardness is hardness (mineral content) that
cannot be removed by boiling. When this is the case, it is
usually caused by the presence of calcium
sulphate and/or magnesium sulphates in the water,
which do not precipitate out as
the temperature increases. Ions causing permanent
hardness of water can be removed using a water softener ,
or ion exchange column. Total Permanent Hardness =
Calcium Hardness + Magnesium Hardness. The calcium
and magnesium hardness is the concentration of calcium
and magnesium ions expressed as equivalent of calcium
carbonate. Total permanent water hardness expressed as
equivalent of CaCO3 can be calculated with the following
formula: Total Permanent Hardness (CaCO3) = 2.5(Ca2+)
+ 4.1(Mg2+)

4. HEALTH EFFECTS OF HARD WATER…
Hardness does not pose a health risk and is
not regulated by state or federal agencies. In
fact, calcium and magnesium in your drinking
water can help ensure you get the average
daily requirements for these minerals in your
diet.
But hard water can be a nuisance due to the
mineral buildup on plumbing fixtures and
poor soap and detergent performance. It often
causes aesthetic problems, such as an alkali
taste to the water that makes coffee taste
bitter; build-up of scale on pipes and fixtures
than can lead to lower water pressure; buildup of deposits on dishes, utensils and laundry
basins; difficulty in getting soap and detergent
to foam; and lowered efficiency of electric
water heaters.

5. HOW DOES WATER BECOMES HARD?
 Water becomes hard by being in contact with soluble,
divalent, metallic cations (positive ions having a valence of 2).
The two main cations that cause water hardness are calcium
(Ca) and magnesium (Mg). Calcium is dissolved in water as it
passes over and through limestone deposits. Magnesium is
dissolved as water passes over and through dolomite and
other magnesium bearing formations. Because groundwater is
in contact with these geologic formations for a longer period
of time than surface water, groundwater is usually harder
than surface water.
 Although strontium, aluminum, barium, iron, manganese,
and zinc also cause hardness in water, they are not usually
present in large enough concentrations to contribute
significantly to total hardness.