Hardness in water is the most common water quality problem reported by U.S. consumers. In fact, hard water is found in more than 85 percent of the United States. Hard water occurs when excess minerals in the water create certain nuisance problems. While these water problems can be frustrating, water hardness is not a safety issue. Hard water is safe for drinking, cooking, and other household uses. Hard water can cause several problems for consumers including decreased life of household plumbing and water-using appliances, increased difficulty in cleaning and laundering tasks, decreased efficiency of water heaters, and white/chalky deposits on items such as plumbing, tubs, sinks, and pots and pans. Consequently, it is no surprise that according to the 1997 National Water Quality Survey, one out of five Americans surveyed is dissatisfied with the quality of his/her household water supply.
Causes of Hard Water
Approximately 22 percent of the earth's fresh water is ground water, and naturally, as it flows through soil and rock, it picks up minerals. Hard water results when an excessive amount of calcium and magnesium are present. Total hardness is measured in grains per gallonof water (gpg) or milligrams per liter (mg/l). Grains per gallon (gpg) is a unit of weight for a volume of water, as is milligrams per liter (mg/l). Sometimes hardness is measured in parts per million (ppm). Parts per million (ppm) measures the unit(s) of a substance for every one million units of water. Milligrams per liter (mg/l) and parts per million (ppm) are roughly equal in water analysis. One gpg (1gpg) is equivalent to 17.1 ppm or mg/l. When conducting chemical analysis, laboratories usually measure hardness minerals in either grains per gallon (gpg) or milligrams per liter (mg/l). You can evaluate the hardness of your water supply by referring to the following chart.
Identifying Hard Water
The best way to determine whether or not your water is hard is to have it tested. However, you can usually detect hard water by the evidence in your home, including:
- Increased water heating costs due to scale buildup and mineral deposits, and more frequent replacement of hot water heating elements
- Soap scum on bathtubs, shower tiles, and basins
- Film left on the body resulting in dry skin and dull, limp hair
- Decreased sudsing and cleaning capabilities of soaps and detergents, resulting in dingy laundry and reduced life of
- Increased buildup of scale on plumbing fixtures and cooking utensils such as a tea kettle, coffee maker, pasta pot, and dish
- Clogged pipes or appliances resulting in reduced water flow and increased repairs
The most common method to treat hard water is through ion exchange water softening. Ion exchange water softening is a process in which the hardness ions, magnesium and calcium, are exchanged with either sodium or occasionally, potassium ions. This is accomplished by directing the flow of hard water over a bed of plastic resin beads. Each bead has a slight electric charge, which holds the sodium on the bead. As the water flows over the beads, the hadness minerals (ions) are attracted to the beads. When the hardness minderals attach themselves to the beads, the sodium ions are displaced. Hence, the hardness ions are replaced by the sodium ions. As some point the plastic resin beads will be covered with hardness ions and will no longer be able to remove hardness from the water. In order to remove the hardness ions from the beads, a brine or salt (sodium chloride) solution is added to the resin bed. This solution contains a high concentration of sodium ions, which remove the hardness ions from the beads. Next the solution and the hardness ions are flushed out of the resin bed with fresh water, and once again the beads can remove hardness from the water. This process is called regeneration.
How to Select a Water Softener
There are many different kinds of watr softeners available. Before purchasing a water softener you should make sure that the unit has sufficient water softening capacity for your family. A typical person uses 100 gallons of water per day. Another important feature to consider is how the equipment initiates the regeneration process. Water softening equipment uses three general methods of controlling water softener regeneration:
- demand initiated regeneration
Of these three methods, demand initiated regeneration is considered to be by far the most efficient method of regeneration. Both this method and the metered method offer savings in salt and water usage over the time clock method. Other important factors to consider are the warranty and the reputation of the manufacturer. Consumers can check with the Better Business Bureau for references and complaints. Furthermore, consumers are encouraged to talk to a Water Quality Association Certified Water Quality Specialist and research which products are needed before purchasing water softeners. Certified Water Quality Specialists are individuals who work in the water quality improvement industry and have passed the Water Quality Association certification examinations. Water Quality Association member dealers can be located by looking under "Water Treatment Companies" in the yellow pages of your telephone directory. Another helpful tip is to look for the Water Quality Association Gold Seal on the product. This seal assures consumers that the equipment has been tested against industry standards and validated for performance capabilities. Likewise, consumers can look for the NSF, National Sanitation Foundation, certification mark to ensure that they are purchasing quality products.
Health Related Concerns Associated with Softened Water
Softening of water with a common sodium-based ion exchange water softener does increase the sodium content in the water. Therefore, if you have health concerns about your sodium intake, consult your physician. It is important to note that many of these water softeners have a by-pass feature that will allow you to bypass the cold water in the kitchen. This will enable you to use unsoftened water for drinking and cooking. In addition, bypassing the cold water tap in the kitchen will prevent minerals from being removed from the water. In most cases, hard water does not provide a significant amount of minerals needed for good health. However, minerals add to the "taste" of water and can provide a trace amount of nutritional benefit. Sometimes in moderately hard water cases, only the hot water is softened. This is a compromise between reducing the hardness of water and increasing the sodium content.
Benefits of Softened Water
Consumers with even slightly hard water can benefit from using a water softening device. In fact, according to a New Mexico State University study, water heating efficiencies for softened water may be increased up to 29 percent when heating with gas and up to 22 percent when heating with electricity. Other possible benefits include:
- Increased life expectancy and efficiency of the plumbing system due to reduced clogging from scale
- Increased life expectancy and performance of water-using appliances
- Reduced soapy residue on clothes, skin and hair
- Reduced filmy deposits on tubs and shower tiles
- Reduced scratching of bathroom fixtures and sinks
- Savings in the amount of soaps and detergents used
- Decreased spotting, white chalky deposits, of dishes, pots and pans and glassware, etc.
Iron in drinking water
Iron is one of the earth's most plentiful resources, making up at least five percent of the earth's crust. Rainfall seeping through the soil dissolves iron in the earth's surface and carries it into almost every kind of natural water supply, including well water. Although iron is present in our water, it is seldom found at concentrations greater than 10 milligrams per liter (mg/1) or 10 parts per million (ppm). Iron is not considered hazardous to health. In fact, iron is essential for good health because it transports oxygen in your blood. In the United States, most tap water probably supplies less than 5 percent of the dietary requirement for iron. Under Department of Natural Resources (DNR) rules, iron is considered a secondary or "aesthetic" contaminant. The present recommended limit for iron in water, 0.3 mg/I (ppm), is based on taste and appearance rather than on any detrimental health effect. Private water supplies are not subject to the rules, but the guidelines can be used to evaluate water quality. For instance, when the level of iron in water exceeds the 0.3 mg/l limit, we experience red, brown, or yellow staining of laundry, glassware, dishes. and household fixtures such as bathtubs and sinks. The water may also have a metallic taste and an offensive odor. Water system piping and fixtures can also become restricted or clogged.
Types of Iron
Iron is generally divided into two main categories:
1) Soluble or
"Clear water" iron, is the most common form and the one that creates the most complaints by water users. This type of iron is identified after you've poured a glass,of cold clear water. If allowed to stand for a few minutes, reddish brown particles will appear in the glass and eventually settle to the bottom.
When insoluble iron, or "red water" iron is poured into a glass, it appears rusty or has a red or yellow color. Although not very common in Wisconsin's water wells, insoluble iron can create serious taste and appearance problems for the water user.
Because iron combines with different naturally occurring acids, it may also exist as an organic complex. A combination of acid and iron, or organic iron, can be found in shallow wells and surface water. Although this kind of iron can be colorless, it is usually yellow or brown. Finally, when iron exists along with certain kinds of bacteria, problems can become even worse. Iron bacteria consume iron to survive and leave a reddish brown or yellow slime that can clog plumbing and cause an offensive odor. You may notice this slime or sludge in your toilet tank when you remove the lid. Actions you can take to correct an iron problem Once you determine whether you have "clear water", "red water", "organic" or "bacterial" iron in your water, you can take steps to correct the problem. Keep in mind that no one treatment method will work for every type of iron problem.
Test Your Water
Before you attempt to remove anything that appears to be iron-related, it is important to have your water tested. A complete water test to determine the extent of your iron problem and possible treatment solutions should include tests for iron concentration, iron bacteria, pH, alkalinity, and hardness. If you receive your water from a public water system and experience red water problems, it is important to contact a utility official to determine whether the red water is from the public system or your home's plumbing or piping.
Depending on local land conditions, it is sometimes possible to extend a "well casing" or "screen" deeper into the groundwater and avoid the water with high iron levels. Talking to your neighbors about their well depths and iron levels will give you some idea of what well depth would pump the lowest amount of iron. It is also helpful to talk to a well driller or pump installer about local conditions and the cost of drilling a new well in your area. The cost of well work should be compared to the long term (perhaps twenty years) cost of treating the water for any iron related problems.
The following list contains treatment considerations for the various forms of iron. For additional information on water treatment systems, contact your County Extension Office or Extension Publications, RM. 245 30 N. Murray street, Madison, WI 53715 and ask for publication G3558-5, "Choosing a Water Treatment Device".
Treatment considerations for various forms of Iron
- Aeration: Introducing oxygen to the water source to convert soluble iron to its insoluble form.
- Filtration: Media used to entrap and screen out oxidized particles of iron. Usually requires backwashing to remove accumulated iron.
- Water Softener: Removal of soluble iron by ion exchange.
- Manganese Greensand: An ion exchange sand material which is capable of removing iron. Adsorbs dissolved iron and requires chemical regeneration.
- Catalytic Filtration "BIRM": A granular filter medium that enhances the reaction between oxygen and iron and then filters the insoluble iron.
- Ozonation: A specialized form of aeration using ozone to convert soluble iron.
- Ion Exchange: Substituting an acceptable ion (such as sodium) for soluble iron.
- Sequestering: Adding chemical agents to water to keep metals like iron in solution to prevent characteristic red stains.
- Chlorination: Chemical oxidizer used to convert soluble iron to an insoluble, filterable form.
Important points to remember if you are considering an iron treatment system
When you choose a water treatment method or device, make sure you have answers to the following five questions:
- What form of iron do I have in my water system?
- Will the water treatment unit remove the total iron concentration (determined by the water test) in my water supply? (Total iron refers to both soluble and insoluble iron combined).
- Will the treatment unit treat the water at the flow rate required for my water system?
- Considering the results of my water test, will this method effectively remove iron? (For example, pH may need to be adjusted before beginning a particular treatment).
- Would well construction or reconstruction be more cost effective than a long term iron removal treatment process?