The Western Virginia Water Authority maintains over 6,000 fire hydrants in our service area.   These hydrants are connected to the same infrastructure that convey drinking water.   During the spring, summer and fall months, the fire departments in each locality routinely test the hydrants to measure the flow of water and to  make sure that the hydrants are in proper working condition.  This is an important safety step so that our first responders are prepared when they respond to an emergency.  Sometimes the act of opening and closing a fire hydrant can cause water to become discolored.

What Causes Discolored Water?

Changes in water pressure in the water distribution system, often resulting from water main breaks or when fire hydrants are used or flushed, can occasionally cause drinking water to be discolored. The discoloration is caused by sediments in pipes mixing with clear water. The sediments occur naturally from the oxidation of iron in pipes.  After Water Authority crews repair a main, fire hydrants in the area of the break are opened to flush discolored water out of the distribution system.

How Can You Remove Discolored Water?

While discolored water is ordinarily safe to drink, it is best to flush any discolored water from pipes by turning on the cold-water faucet that is at the lowest elevation in your home or business. Avoid turning on hot-water faucets so the discolored water is not drawn into water heaters.  The Water Authority also advises to flush from a faucet that does not have an aerator attached as the sediments you are trying to remove can become trapped by the aerator. 

If you still notice discolored water after a few minutes of flushing, please notify the Western Virginia Water Authority.

Color Coding the Fire Hydrants to Record Flow Rates

The flushing of the fire hydrants is an important maintenance step that takes place every Spring and Summer.  There are over 6,000 fire hydrants in the Authority’s service area.  Each hydrant is flow tested so that the fire department knows how much water will come out of the hydrant in case of a fire emergency.  The flow rate is recorded electronically in a spreadsheet, and the hydrants are color-coded based on the American Water Works standard to visually indicate the flow rate.

Blue bonnets (or hydrant tops) = 1500 gallons per minute or more

Green bonnets = 1000-1499 gallons per minute

Yellow/Orange bonnets = 500 – 999 gallons per minute

Red bonnets = below 500 gallons per minute