Typically, there are two types of discoloration complaints received; yellow, rusty, or brownish-colored water or milky, cloudy, or white water. Neither of which have any health risk associated with them.

Yellow, Rusty, or Brownish-Colored Water
This is most common type of discoloration which typically indicates sediment is being stirred up within the water supply system. Over time, minerals such as iron and manganese exiting the water treatment plant can accumulate in the City’s water pipes. Small amounts of these minerals are in all drinking water, and they are not harmful to consume. However, these can become more visible in tap water when flow in pipes increases or reverses direction during water system improvements and repair activities. These activities essentially disrupt the existing debris in the pipe. It’s like a snow globe where the snow settles to the bottom, but when it’s shaken, it starts 'snowing' again!

Milky, Cloudy, or White Discolored Water
This type of discoloration can happen during any type of maintenance mentioned above or after routine repairs to pipes. Essentially, anytime air is introduced into the water distribution system. It can also happen during winter months when air is mixed into the cold water and then the water is warmed as it sits in internal plumbing or hot water heaters. Visually this is similar to the gas bubbles in carbonated drinks. If the discoloration is air bubbles, they will clear up after the water sits for a few minutes.

System Upgrades

Greensboro has been upgrading its electrical and pumping systems at the Townsend Water Treatment Plant since the summer of 2024, which sometimes requires shutting down the plant and supplying water from other sources. During these times, less water is supplied from the northeast, and more water is supplied from the system's southern area. This has caused instances of brown water in the southern part of the system. The latest Townsend Plant shutdown was in early February 2025, and there was a slight increase in complaints following the event. 

Fire Hydrant Testing
Fire hydrant testing is completed every year. It typically starts in April and continues through May. Testing ensures all City water distribution system hydrants are operating properly, which is an integral component of fire protection.

Hydrant Flushing
Hydrant flushing typically occurs in relation to drinking water quality complaints associated with taste, odor, and discoloration. Flushing events happen year round and are an integral part of maintaining drinking water quality.

Water Main Breaks or Construction
While water main breaks can also occur at any time, they often increase during the winter when temperatures drop.

Each of these examples involves opening and closing of hydrants, which can stir up sediment that leads to temporary yellow, rusty, or brownish-colored water at the tap.

The City dispatches workers to address discoloration complaints as they occur. They conduct localized flushing of hydrants in the immediate area until water is clear and the issue is resolved.

Long-term plans include:

• Reduce accumulated minerals in the pipes through unidirectional flushing efforts. These will be communicated to residents and conducted in May. These efforts are not recommended during freezing weather conditions, when water main breaks are more common.

• Following the flushing efforts, the City will determine whether additional efforts are needed to remove accumulated minerals. If so, the City will identify additional options.

• Evaluate the effectiveness of the chemicals added during treatment to coat water pipes by each of Greensboro’s water supply sources. The current study will be completed in 2025.

• Work to reduce minerals through water treatment improvements at all water supply sources.

Customers can prevent discolored tap water from entering their internal plumbing by not using water if they see the City at fire hydrants or construction crews on nearby streets. This includes using your washing machine, dishwasher, or icemaker or any other water-consuming device. If water needs to be used, always test the cold-water side first to ensure discolored water hasn’t entered your internal plumbing.

Remember, it’s always easier to flush internal water pipes (cold water) than it is to flush a hot water heater!

• With yellow, rusty, or brownish-colored discolored water, we recommend running cold water for at least five minutes through a faucet without an aerator, such as an outside spigot or the bathtub, until it is clear. Avoid using your washing machine, dishwasher, or icemaker until flushing is complete.
• With milky, cloudy, or white water, we recommend preforming the “glass test” to confirm its air trapped in the water. To perform the test fill a clear glass with the milky, cloudy, or white water from the tap and if it turns clear in a few minutes then its trapped air and there is no cause for concern. Essentially, the water clears when the warmed water is released from a tap into a glass. The air bubbles rise to the top and out of the water.
• It is always a good idea to determine if the issue is isolated in your home or if the discoloration affects the broader area. Check with neighbors to see if they have been impacted.
  • If it is isolated to your property and there are no signs of construction or maintenance in your area, it may be sediment buildup in your hot water heater or your internal plumbing or fixtures.
  • If the discoloration is predominantly white or shows black particles floating in the water, it may be due to issues with your hot water heater, the degradation of faucet (aerator) gaskets, supply tubing, or pipe coatings. If this sounds familiar, try some basic troubleshooting to help isolate the issue. Determine if the discoloration only occurs at certain faucets or only with hot water. It may be a simple fixture replacement or you may need to contact a professional to service or replace your hot water heater or internal plumbing.
• If discoloration persists or the discoloration is widespread, call Water Resources 24-hour Dispatch at 336-373-2033.