Water is essential to life. Current recommendations from the Centers for Disease Control and Prevention say people should consume between 11.5 and 15.5 cups of fluids each day, and drinking tap water is an easy way to achieve that.
However, depending on the pH value of the water in your home, you may need to install a softener to prevent hard water and make your home's tap water more drinkable.
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Tap water with a neutral pH is healthier, typically has a better flavor and can help keep your home's plumbing running smoothly too. Read on to learn more about the pH value of tap water, how to prevent hard water and when to use a water softener.
Impact of pH Imbalance
The letters "pH" stand for "potential hydrogen"; according to the University of Massachusetts Amherst's Water Resources Research Center (UMass), "pH is a measure of the hydrogen ion concentration of the water as ranked on a scale of 1 to 14. The lower the pH of water, the more acidic it is. The higher the pH of water, the more basic, or alkaline, it is. pH affects many chemical and biological processes in the water, and different organisms have different ranges of pH within which they flourish."
Our drinking water ideally should have a pH value of around 7, making it neutral. According to established World Health Organization guidelines, drinking water normally falls between 6.5 and 8.5 on the pH scale.
Water with a slightly acidic pH level of less than 6.5 may contain metals such as zinc and copper. This type of water is considered "soft" and could corrode metal piping, leaching metals from the pipes into your water supply. Acidic water can also create "aesthetic problems, such as metallic or sour taste, laundry staining or blue-green stains in sinks and drains," according to Wisconsin's Marathon County Health Department (MCHD).
Water that measures greater than 8 on the pH scale is overly alkaline, and considered "hard." "High alkalinity does not pose a health risk," per the MCHD, "but can [also] cause aesthetic problems, such as [making] coffee taste bitter, scale build-up in plumbing, and lowered efficiency of electric water heaters."
Hard water can keep soap and shampoo from lathering, too. "Hard water has a high concentration of calcium and magnesium," according to the United States Geological Survey. "The minerals ... react with most soaps to create a 'soap scum,' which is an insoluble substance that can temporarily adhere to your hands or the shower walls. When using hard water, you may have a harder time working your soap into a lather and you may need to use more water to rinse the scum from your hands."
To measure the pH of the tap water in your home or office, use litmus paper. Litmus paper has been "infused with lichens which are environmental indicators of air quality," according to the Office of Water Programs at California State University in Sacramento (CSUS).
Dip the strip into a glass or water, or just put a drop of water on it; the color of the paper will change, indicating the water's pH value. Red indicates a pH value of less than 5, while blue means the pH is more than 8, explains CSUS. Purple means the water is neutral.
Why Water pH Matters
The pH of water is a measure of its acidity, and the Environmental Protection Agency (EPA) maintains strict standards for appropriate pH levels in drinking water.
Excessively acidic water can be harmful, per the EPA. Drinking water must have a pH value of 6.5 to 8.5 to fall within EPA standards, and even within the acceptable pH range, slightly high- or low-pH water can be unappealing for several reasons.
High-pH water has a slippery feel, tastes a bit like baking soda and may leave deposits on fixtures, according to the EPA. Water with a low pH, on the other hand, may have a bitter or metallic taste, and may contribute to fixture corrosion.
Why Water pH Varies
The pH level of tap water is influenced by a number of factors. Before it gets to your house, the water's pH is affected by the minerals present at the water's source in nature, and in the rock the water flows through along the way. pH is also affected by environmental factors such as pollution and acid rain.
Sources of Acidity
Water from areas affected by acid rain may have low pH. "The pH of acid-impacted rain is generally below 4.5 on the pH scale," according to the New Hampshire Department of Environmental Services. "Acid rain can leach copper, aluminum and other heavy metals out of the soil and into runoff and drinking water."
Sources of Alkalinity
High-pH water can result from different dissolved minerals, per December 2019 research in Applied Water Science. Groundwater in areas with limestone, for instance, commonly has a higher pH.
Wastewater contamination of drinking water can also raise pH, due to the presence of chemical detergents and other cleaning agents. Additionally, many municipal processing plants artificially increase the pH of water to prevent acid corrosion of pipes.
How to Neutralize Hard Water's pH
A whole-house water-softening system can get hard tap water closer to 7 on the pH scale, neutralizing it at its point of entry into your home.
If you have an especially alkaline water supply, installing a softener can help balance your tap water's pH, thereby ensuring that your water is healthy to drink, that "appliances run well" and the "taste, smell or look of your water" is improved, per the Minnesota Department of Health (MDH).
Water softener systems neutralize tap water through the use of resin beads that "trap the [hard] calcium and magnesium and exchange them for sodium or potassium. Once the resin beads become full of calcium and magnesium, a highly concentrated salt or potassium solution removes the calcium and magnesium from the beads," according to the MDH. Result: water with a more neutral pH.
Note: Water softeners do require regular maintenance and replacement of the chemicals, which can require special handling.
As the MDH and others point out, people on low-sodium diets should consult a physician before installing a sodium chloride- or sodium carbonate-based water system in their home, because the additional sodium can cause potential health effects.
- USGS Water Science School: pH -- Water Properties
- Office of Water Programs: "Litmus Paper"
- Centers for Disease Control and Prevention: "Get the Facts - Drinking Water and Intake"
- Minnesota Department of Health: "Home Water Softening"
- World Health Organization: "pH in Drinking Water"
- Marathon County Health Department: "Interpreting Test Results"
- United States Geological Survey: "Frequently Asked Questions - Water"
- Environmental Protection Agency: "Drinking Water Regulations"
- University of Massachusetts Amherst Water Resources Research Center: "Analysis Method for pH and Alkalinity"
- Applied Water Science: "Local Determinants Influencing Stream Water Quality"
- New Hampshire Department of Environmental Services: "Environmental Fact Sheet - Acid Rain"