When you turn on your faucet to get a glass of water, does it come out looking white, gray or cloudy?  If so, you might, understandably so, be wondering what causes this visually off putting color.  You also are probably wondering if this affects the cleanliness of the water and whether it is drinkable.

In this article, we explain the possible causes of cloudy, white or milky looking tap water, what this means for you, and what you can do about it.

Causes of White, Cloudy or Gray Water

Air Bubbles

There are a number of possible causes that can make your tap water look white or cloudy. One of the most common reasons is the presence of small air bubbles in the water.  In essence, air that is trapped in the water rises to the top and eventually dissipates.  If you notice that when your water comes out of the tap it looks white or gray, but it becomes clearer from the bottom up after a few seconds, then the different color is likely due to air bubbles.

What explains the presence of air bubbles in tap water?  It is partly due to differences in water pressure.  The water that flows from treatment plants and through the distribution system to your home is somewhat pressurized (which helps it travel along the piping network), and water that is under pressure holds more air than unpressurized water.  Once the water comes out of your faucet, it is under less pressure than while in the pipes, and excess air comes out as bubbles.

If you stop to think about it, this makes a lot of sense.  The more you open up your faucet in the kitchen sink, the more you allow the water in the pipes to come out under pressure, and thus the more air bubbles you’ll find.  If you only open the tap just a little, however, you limit the water pressure and therefore will find fewer bubbles.

Another potential reason is temperature.  Cold water holds more air than warm water, so you might notice that cold water coming out of your faucet is cloudier than the warm water, or that your tap water gets more white during the winter season.  The initially cold water gets slightly warmer while in transit from a treatment facility to your house, causing some air to be released.

As the air bubbles dissipate naturally, there is no need for any action on your part.  If you get tired of waiting for the air to bubble up for each glass of water you drink, try filling a larger, covered jug and placing it in the fridge.

Hard Water

If your glass of tap water never gets clearer after waiting, then you likely have a different issue than trapped air.  And if you notice that your glasses and dishes have white spots on them or even clothes after you put them through the laundry, you may have a high concentration of dissolved minerals in your water.

If so, you’re dealing with ‘hard water,’ which has a high enough mineral content to visibly change the color of your tap water.  Typically, these minerals are calcium and magnesium but can include others as well.  In the U.S., hard water is more prevalent in the central states, especially the midwest.

How does the water become higher in mineral content?  After rainwater falls, it flows along the ground until it gets to a water source like a stream, river, or lake.  Along the way, it picks up and carries with it particles and sediment from the ground itself.  So if a particular region has a lot of chalk, limestone or gypsum in its terrain, this can lead to ‘harder’ water.

If you dislike the taste or for whatever reason want to ‘soften’ your water, investing in a filtration system is often the most effective and convenient solution.  For instance, a reverse osmosis filtration system can be installed into the pipes under your sink and will filter out the excess minerals in your tap water, making it seem less cloudy.

Methane Gas

If you use well water and you notice small, white looking bubbles in your water, it’s possible that methane gas has found its way into your tap water.  You may also notice sputtering when you turn the faucet on.  Methane is a natural gas that can sometimes permeate well water.  It can be hard to detect because often it is colorless, tasteless, and odorless.

If you think you might have methane in your water, get a professional to test your water.  In general, levels below 7mg per liter are considered safe but should be consistently tested to ensure they remain low. For higher levels, either a vented air cap or a complete aeration system will be required.  In either case, consult a well water expert for specific advice. Also consider installing filtration systems designed for well water.

Other Contaminants or ‘Suspended Solids’

If you’ve recently noticed that your tap water has become white looking, and there’s been some drilling or groundwork near your water supply, you may have increased levels of particulates or ‘suspended solids’ from runoff into your water source.

The term ‘Total Suspended Solids’ (TSS) refers to the amount of minuscule solid particulates that don’t settle at the bottom of a glass or tank of water.  These ‘solids’ can include algae, sediment, silt, clay, or specific minerals like iron and manganese.  If you have an unusually high TSS concentration, your water may appear cloudy, white, or gray.

Because tap water is typically heavily cleaned and treated by the local authorities or utility company before it gets to you, this is quite rare.  However, if it does occur, you should contact your water provider to let them know as there is likely a problem in either treatment or distribution of the water.

If the problem persists, or if you supply your own water (eg. from a well), you could filter the water yourself with a basic activated carbon or charcoal filter for mild cases.  However, if the TSS levels are very high, you could also use a multimedia filtration system (usually for commercial/industrial use).

Is White Tap Water Drinkable?

To be sure, most cases of white or cloudy tap water will be caused by air bubbles, which means the water is perfectly safe to drink.  Hard water is also safe to drink, as it has been appropriately treated (filtered, disinfected, etc.) by your local authorities.  However, you may want to invest in a filter if you wish to change the taste or smell.

Water with a high level of TSS or methane gas may be safe to drink, but it is advisable to first get the water analyzed in order to determine the specific levels.  Contact your local water provider to make an appointment, or reach out to a lab that will do a chemical analysis of the water in your area.