It’s that time of the year when Iowa American Water experiences one of its most common customer inquiries, “Why does my tap water sometimes appear cloudy or milky looking?”

According to a news release, Iowa American’s water quality professionals are quick to explain that cloudy or milky-looking water is not a health concern. Tiny air bubbles in the water can create a cloudy or milky appearance as the water is released from the tap.

“Cloudy or milky-looking” water, caused by dissolved air (oxygen), is not a health problem. The phenomenon of cloudy water from the tap is like bubbles being released from a carbonated beverage when the cap is removed and pressure released,” said Brad Nielsen, vice president of operations for Iowa American Water. He adds that Iowa American Water provides its customers with water that meets or surpasses all Iowa Department of Natural Resources and U.S. Environmental Protection Agency Safe Drinking Water Act regulations.

There are no water quality regulations pertaining to dissolved oxygen in water because it does not present a health risk. Dissolved oxygen in water is most evident during winter months when the water temperature is the coldest.

Cold water absorbs more air out of the atmosphere than warm water. During the winter months, the temperature of the Mississippi River, Iowa American Water’s source of supply in its Quad Cities District, drops as low as 32.5 degrees. The water temperature does not increase significantly, as it passes through the water treatment process, and the network of underground water mains, known as the distribution system.

Since the water temperature remains cold as it travels from the treatment plant to the customer, it remains saturated with dissolved oxygen until it enters the customer’s home or business. When that cold water enters the internal plumbing system of a home or building, it warms up to room temperature during extended periods of non-use or overnight. This warmer water physically cannot hold as much dissolved air, but because the water is under pressure within the plumbing system’s pipes, the excess dissolved air cannot escape until the water flows

from the faucet. The result is cloudy water when the faucet is initially turned on. Hot water from the water heater is typically cloudier than cold water.“Customers can observe dissolved air (oxygen) escaping from a glass of water by holding the cloudy water up to a bright light or sunlit window and watching the water clear from the bottom of the glass up as the tiny air bubbles rise to the surface. The glass of water should clear in a minute or two,” Nielsen adds.

If the cloudy/milky water does not clear up within a few minutes, please call Iowa American Water at 866-641-2108, the release says.

Customers with questions or concerns about their water quality should contact Iowa American’s water quality experts or, for a copy of the company’s latest water-quality report, visit here.