Brown, red, orange or yellow water is usually caused by rust. The major causes of rust include water pipes in your building or water mains.
Intermittent brown, red, orange or yellow hot water. If your water is discolored only for a minute or two after you turn on the tap, the cause may be the internal plumbing. The zinc coating on the inside of galvanized iron pipe can wear thin and expose your water to bare iron. The different colors can be attributed to varying chemical oxidation states of the iron (rust). The longer the water sits in the pipes, the worse the discoloration will be. This is why this problem is most noticeable the first time you turn on the tap in the morning. If only a few taps are affected, only a portion of your internal plumbing has galvanized pipe.
After running your tap for a few minutes, clean water from your water heater or the water main will replace the discolored water. Since iron is an essential nutrient, this condition poses no health hazard. If the discoloration bothers you, however, flush the tap until the water becomes clear and save the water for iron-loving plants.
Consistent brown or yellow cold water. Normal pipeline flow allows silt, sediment and other materials to settle to the bottom of the pipe. A disruption of normal flow can cause these materials to get stirred up and suspended in the water and cause the water to look light yellow to dark brown. The discoloration is caused by dissolved iron which is stirred up in naturally-occurring sediments.
The following conditions commonly cause flow reversals in water mains and sediment to be disturbed.
- Planned cleaning of the water mains to remove pipeline sediment in the near vicinity.
- Pipeline repair work or construction activity in the area. Valves may have been closed for the work.
- Vehicular accident resulting in a nearby water hydrant being knocked over.
- Hydrant being used to fight a fire.
The discoloration does not indicate that the water is unsafe or that the integrity of the water main has been compromised. A disinfectant residual is maintained in our system to ensure that the water is safe for household use, including cooking and drinking. For aesthetic reasons, we recommend you avoid doing laundry until the water clears up. We also recommend that you do not use the hot water as it will draw cold, rusty water into the tank and it may need to be flushed out later.
If the water at the front hose bib is discolored after running for two minutes, the problem may be coming from our water main and you can contact us at 925-688-8156.Back to Troubleshoot Water at Your Tap