Water Company explains “murky” water
Davenport, Iowa, January 29, 2026 /PRNewswire/ — At Iowa American Water, we receive the most customer inquiries this time of year. “Why does my tap water sometimes look cloudy or milky?” Iowa-American water quality experts are quick to explain that cloudy or milky water is not a health problem. Small air bubbles in the water can cause a cloudy, or milky, appearance when the water comes out of the tap.”
The reason why water looks cloudy or milky is because air (oxygen) has dissolved in it, and there is no health problem. “Cloudy water from your faucet is similar to foam coming out of a soda when you remove the cap and the pressure is released,” said Tony Roete, Iowa American Water’s vice president of operations, adding that Iowa American Water provides customers with water that meets or exceeds all Safe Drinking Water Act regulations from the Iowa Department of Natural Resources and the U.S. Environmental Protection Agency. Dissolved oxygen in water does not pose a health risk, so there are no water quality regulations.
Dissolved oxygen in water is most noticeable during the winter months when water temperatures are at their lowest. Cold water absorbs more air from the atmosphere than hot water. During the winter, temperatures on the Mississippi River, the water source for Iowa American Water’s Quad Cities region, can drop to 32.5 degrees. Because the water passes through a network of underground sewer mains known as water treatment processes and distribution systems, the temperature of the water does not increase significantly. As the water travels from the treatment plant to the customer, its temperature remains cool, so it remains saturated with dissolved oxygen until it enters the customer’s home or business.
When that cold water enters your home or building’s internal plumbing system, it warms up to room temperature when not in use for long periods of time or at night. This warm water physically cannot hold as much dissolved air, but because the water is under pressure within the pipes of your plumbing system, excess dissolved air cannot escape until the water flows from the faucet. As a result, the water becomes cloudy when you first turn on the faucet. Hot water from a water heater is usually cloudier than cold water.
“Customers can observe dissolved air (oxygen) escaping from a glass of water by holding the cloudy water up to a window with bright light or sunlight and watching the water become clear as small air bubbles rise to the surface. The glass of water should become clear within a minute or two,” Roete added. If the cloudy/milky water does not clear within a few minutes, please call Iowa American Water at (866) 641-2108.