WHAT IS…HARD WATER & WATER SOFTENING
According to the U.S. Geologic Survey, 85 percent of the United States has to cope with hard water, which is water with excessive levels of calcium and magnesium. While hard water is not considered to be unhealthy for people to drink, it can be very unhealthy for household plumbing, cleaning processes, and water-using appliances. The minerals present in hard water can accumulate in the form of a hard scale which can build up and eventually clog pipes and damage water-using appliances. These minerals also affect the ability of soap to clean kitchen and bath surfaces, dishware and laundry.
The problems associated with hard water have been known for quite some
time. Earlier generations coined the phrase "hard water" because they found it
hard to clean with. They collected soft rainwater in a barrel to be used in laundering and
other cleaning operations - which is hardly an option in the modern world of indoor
plumbing and automatic washing machines. Some water utilities offer municipal softening,
but water treated in this manner typically falls short of being soft water. It is
generally left up to the home or business owner to find their own solutions to the hard
water problem.
What is Hard Water?
The U.S. Department of the Interior classifies hardness based on the
grains per gallon (gpg) concentration of the hardness minerals. To put this in
perspective, a typical aspirin equals about five grains of material. If the aspirin were
dissolved in a gallon of water it would add 5 gpg of "aspirin" to the water.
Where hardness is concerned, water containing 1-3.5 gpg of the hardness minerals calcium
and/or magnesium is classified as slightly hard; water in the 3.5-7.0 gpg range is
considered to be moderately hard; at 7.0-10.5 gpg water is considered to be hard; and very
hard water is classified as water with concentrations greater than 10.5 gpg. Soft water
has a hardness of less than 1 gpg.
If you live in an area of moderately hard or had water, you may not be
fully aware of the problem because it is difficult to see or taste any difference between
hard and soft water. However, even moderately hard water can make a noticeable difference
in the ease of cleaning and the use of cleaning products. On the other hand, hard and
extremely hard water can have very discernible effects in areas ranging from bathing to
the noticeably shortened life of household pipes, plumbing fixtures (like faucets and
toilet flushing units), and water using appliances.
Hard Water Scale
The minerals in hard water gradually settle out forming a hard scale.
Scale centimeters thick can build up over time in hard water areas. Scale build up will
eventually clog pipe, and can decrease the life of toilet flushing units by 70 percent and
water faucets by 40 percent according to a report published by the American Water Works
Association (AWWA). Hardness scale can also shorten life of washing equipment,
dishwashers, and clothes washers by as much as 30 percent according to the AWWA report.
Another area where hard water can have a financial impact is on your
household water heater. Scale tends to form on the heating elements and heat transfer
surfaces in these units, which leads to a shortened operational life and reduced
efficiency. A 1981 study conducted by New Mexico State University determined that scale
build-up can reduce a gas water heater's efficiency by as much as 29.57 percent, and an
electric water heater's efficiency by as much as 50 percent through scale build-up.
Hard Water and Household Cleaning
Hard water has a direct effect on household and business cleaning tasks.
All water based cleaning and washing is less effective and efficient with hard water.
Cleaning with hard water requires greater physical effort and the use of greater
quantities of cleaning agents for surfaces such as floors, sinks, and bathtubs. It also
leads to spotting on dishes and glassware.
A comparison of hard and softened sources of water for household use conducted by Ohio State University indicated that the time required for typical cleaning tasks was increased by almost 50 percent. This is largely due to the formation of soap "curd" which can also be known as "soap scum," or "soap film." The curd tends to build up on sinks or bathtubs where soap use is frequent. Removing heavy curd can require some "elbow grease" and may eventually require the use of specialized cleaning agents which chemically neutralize the hardness component of this film.
Curd formation can also result in streaks, spots and film on glass and dishware which can harbor bacteria. Also, some unbuilt synthetic detergents react with hard water to form soluble calcium and magnesium compounds which cut down on dishwasher cleansing action.
Hard Water in Laundry Operations
Hardness minerals affect laundry in a gradual manner which tends to get
hidden in today's automated washing process. People accustomed to washing in hard water
may not notice the increased detergent use, yet the waste is still there. Soap was the
primary cleaning agent for laundry before the development of synthetic detergents. Soap is
usually made from natural fatty acids and alkali substances, such as caustic soda, which
give it excellent cleaning properties. This is particularly true with vegetable-based
fabrics like cotton.
Soap works well to suspend dirt in the wash and helps "lubricate" the fabric prolonging its life. Unfortunately, hardness minerals combine with soap to produce insoluble "curds" which remains as a residue on washed laundry and washing machines, and also tends to counteract soap's alkalinity. Even "builders" added to soap to overcome this problem tend to be less than effective.
Synthetic detergents based on petroleum were introduced in the 1950s primarily to overcome hard water's soap curd problem. However, unlike unbuilt soaps which are over 90 percent active ingredients, most unbuilt detergents contain only 20 to 40 percent active ingredients and up to 50 to 65 percent neutral salts which are a manufacturing by-product. The remaining ingredients are made up of surfactants, suspension agents, whitening agents, and cosmetic additives.
Most modern detergents also contain builders to increase the alkalinity, but unfortunately, the builders tend to be consumed in softening hard water. This limits their ability to clean and requires the use of greater quantities of detergent. The latest generation of concentrated liquid detergent does compensate for this somewhat.
Hard water also influences fabric life and fading according to a 1991 Purdue University study. The study indicated that fabrics washed in hard water tend to wear out up to 15 percent quicker than fabrics washed in soft water. This is probably due to the presence of hardness residues in the fabric making it stiffer and more brittle, leading to increased friction and wear as the fabric flexes.
The Purdue study also found that hard water generally has a negative
effect on colors and whites. Colors were found to fade and whites to darken more quickly
in hard water. In addition, the study found that laundry washed in hard water became
resoiled with greater ease.
Soft Water Solutions
Softening hard water typically involves the use of ion exchange water
softener. A typical water softener works on the principal of "cation exchange"
in which the ions of hardness minerals (an ion is an electrically charged atom or group of
atoms) are exchanged for sodium ions, effectively reducing the concentration of hardness
minerals to insignificant levels. As the water enters the softener is passes over a resin
bed in a special tank. The resin is made up of tiny beads of styrene and divinylbenzene
which attract and hold sodium of potassium ions. The beads will exchange these ions
whenever they encounter another ion such as calcium or magnesium.
After a period of use the sodium or potassium ions are completely exchanged and the unit has to be "backwashed" or "regenerated," which recharges the resin beads with sodium or potassium ions. This requires the use of sodium or potassium chloride which is loaded into a "brine tank" where it dissolves in water forming a brine used to recharge the system. The recharging is generally done by one of two common methods: Automatic softeners initiate the process on a set time cycle according to anticipated need, and Demand Initiated Regeneration (DIR) process which uses a meter of sensor to monitor the actual hardness levels or the amount of water the unit has processed.
A note for people concerned about the presence of sodium ions in their water. Use of sodium ions does not make the water noticeably salty or cause a significant increase in a person's sodium intake. In fact, the FDA defines water that would result from softening 75 gpg hard water (where much more sodium ions would have to be exchanged that is typically the case) as a "low sodium" beverage.
Whatever type of system is used, the applications can be quite
affordable and highly worthwhile for those in hard water areas. A typical household water
softener costs around $1,000 to $1,500 with a monthly operating expense of around $2 to $8
if sodium is used, and $3 to $15 if potassium is used. Look for the WQA Gold Seal to find
products that have been successfully tested to industry performance standards; and to
Certified Water Specialists (CWS I-V), Certified Sales Representatives (CSR) and Certified
Installers (CI) for advice on your treatment needs and equipment installation.
Conclusion
Hard water waste can cost hundreds of dollars each year as it impact
laundry operations, water heater, efficiency, household cleaning, and the life expectancy
of water-using appliances and plumbing. When it all adds up, hard water is a waste that
can be done without. The solution to these problems is as easy as buying a water softener.
For more information on the benefits of water softening contact your local Certified Water Specialist (CWS), Water Quality Association member company, or write to the: Water Quality Association 4151 Naperville Road Lisle, IL 60532 USA