By: Carly Peach, hydrogeologist, Texas Water Utilities
Earth Day, celebrated annually on April 22, reminds us of the importance of preserving our planet for future generations. A vital element to sustaining life is water, which covers 71 percent of the Earth. Across the United States, water sources vary widely, ranging from freshwater lakes and rivers to underground aquifers and reservoirs, each playing a crucial role in water supply. Depending on the geological composition of a region’s water source, the amount of dissolved minerals in the water can differ.
In Texas, hard water is common and is characterized by elevated levels of dissolved minerals, particularly calcium and magnesium. Telltale signs of hard water include reduced effectiveness of soap, soap scum, scale buildup on pipes and appliances, and a film that remains on the skin after bathing. Texas has diverse geological formations, some of which are composed of limestone, dolomite and gypsum, that play a significant role in water hardness. As water moves through underground formations, it dissolves minerals from rocks and sediments. The longer water is underground, referred to as residence time, the harder it can become because it has more time to dissolve the minerals.
Texas is 6th in the nation for statewide average water hardness, and although this varies across the state, our water hardness average is over 200 parts per million. On the hard water scale, a measurement of 200 ppm falls within the very hard water category.
A common misconception is that hard water is unsafe to drink. Although it can impact everyday water use, it is safe for consumption. Our bodies need minerals like calcium and magnesium and many of us take these supplements to make up for what we are not getting in our diets. Some studies even show that hard water is linked to lower mortality rates for cardiovascular disease.
Texans receive water from various sources, including aquifers that supply groundwater such as the Ogallala, Edwards, Trinity and Gulf Coast, and surface water like Lake Travis, the Brazos River, the Trinity River and the San Jacinto River. Lakes fed by groundwater sources can be rich in dissolved minerals and may have harder water than lakes primarily filled by surface-water runoff and direct precipitation. Occasionally, water utilities will use lime softening on groundwater systems, which uses the addition of the mineral lime to remove water hardness.
Water utilities adhere to stringent water quality testing and monitoring requirements to ensure our water meets state and federal health and safety standards. As required by the Texas Commission on Environmental Quality and the U.S. Environmental Protection Agency, water utilities publish the results of their water testing programs in annual water quality reports, which you can typically find online and include details about your water source to help you understand your water’s test results. You should also receive an annual water quality report attached to your water bill.
If hard water is affecting your skin, hair or appliances, consider a whole-home ion exchange water softener. When choosing a water softener, it is important to consider its capacity to handle the needs of your household. Other methods for addressing hard water include using vinegar to descale appliances, installing reverse osmosis treatment as an alternative to water softening if you are concerned about introducing sodium into your water, and in some cases, boiling can remove temporary hardness. Setting your water heater to a lower temperature can also help reduce calcium scales. More information on hard water causes, effects and solutions can be found here.
Understanding the geological factors contributing to hard water can empower us to find solutions if the naturally occurring minerals are impacting everyday water use. By sharing this knowledge with others, we can all enjoy and appreciate our water more as we celebrate this Earth Day. Protecting our planet and its water sources ensures the availability of clean water for generations to come.
