How to troubleshoot discolored water
Discolored water can be caused by your home plumbing, water system maintenance in your area, or other water system activity in your neighborhood, such as fire hydrant use. People with discolored water usually describe it as yellow, brown, or rust-colored. Follow the steps below to determine the cause of discolored water, learn what you can do to resolve it, and know when to report it to us. You can also find this information in our Customer Guide to Water Quality and Pressure:
Follow these steps to determine if your home plumbing is the cause or if there is a discolored water event in your neighborhood.
Step 1: Compare hot and cold water.
- If only the hot water is discolored: The color is likely from your water heater or pipes. Your water heater may need to be flushed or serviced. In some cases, color is from sediment inside the tank that has been temporarily stirred up. Copper or iron pipes that connect the water heater and the faucet can also contribute color. Depending on what color your water is, you will have different steps to take. See the colors later on this page for help.
- If only the cold water is discolored, or the color is appearing in both hot and cold: Go to Step 2 to determine the extent of discolored water.
Step 2: Check all faucets inside and outside your home, including toilets.
- If you see discoloration at some faucets, but not all: You may have an issue with the plumbing in specific locations in your home, not with the water coming into your home from the street. Find tips below for the specific color you're seeing.
- If you see discoloration at all faucets, including toilets: The color is not from a specific location in your home. Go to Step 3.
Step 3: Run a cold water faucet for one to two minutes.
- If running the water does not resolve discolored water: A discolored water event may have happened on your street or in your neighborhood. Find tips below for the specific color you're seeing and report ongoing discoloration to the Water Quality Line.
- If the discoloration clears quickly after you run the water: There may be an issue with the plumbing in your home, as the color resolved when you brought in fresh water from the water main (pipe). If your home has older plumbing, you may often see discolored water when you turn on the tap after it hasn't been used for awhile. Find tips below for the specific color you're seeing.
Yellow, brown, or rust-colored water
There's color when you first turn on the water, but it clears after you run it
This is due to old iron plumbing inside your home. You can run your faucet as needed to bring in fresh water from the water main, purchase a water filter, or consider replacing your pipes. Contact the Water Quality Line and ask for a water test kit that includes testing for iron. Iron is an essential nutrient and is not a health risk.
The color stays, even after you run a cold faucet
This is typically due to a temporary discolored water event in your neighborhood. Discoloration can happen when the flow of water suddenly changes in your area, causing natural sediments inside water pipes to be stirred up.
Follow these steps if you have yellow or brown cold water that doesn't clear after running your water:
- Check our WaterWorks map to see if there is work happening in your neighborhood.
- Report discolored water to the Water Quality Line.
- Follow our tips on what to do during a discolored water event.
Blue, green, black, or white discolored water
Blue water or green water
This is commonly caused by new copper plumbing or existing copper plumbing that is corroding. Run your faucet as needed to bring in fresh, uncolored water from the water main. Contact the Water Quality Line and ask for a water test kit that includes testing for copper. Copper is an essential nutrient, but it can be harmful in large doses.
Black water or gray water
Rubber may be breaking down in your plumbing gaskets, or carbon pieces are leaking out of your household water filters. Replace both as needed. You may have iron or manganese adding color from old corroded pipes. Contact the Water Quality Line and ask for a water test kit that includes testing for iron and manganese. Iron is not a health risk, but higher levels of manganese may pose a health risk.
White water or milky water
Fill a glass of water and wait three minutes. If the water clears from the bottom to the top, the discoloration is just tiny, harmless air bubbles in the water. These air bubbles can form when water temperature fluctuates or when there is more air in the water. If hard white particles remain, or you find them clogging your aerator screens, the plastic dip tube inside your water heater may have failed, or there's mineral buildup inside the tank. Place the particles in vinegar and wait a few hours—plastic from the dip tube won’t dissolve, but mineral buildup will. Your water heater may need maintenance or repair if white particles remain.
Pink or grey stains or slime
This is caused by bacteria on surfaces in your home. These bacteria grow in moist environments. The bacteria commonly form small colonies in sink drains, create rings around toilet bowls, or appear on surfaces in the shower. These “biofilms” are like plaque that forms on your teeth, and you'll want to clean toilets, sinks, and other moist surfaces regularly to keep them under control. Control humidity in your home and ensure good ventilation in bathrooms that have showers. Mold can also grow in these humid locations.