The City of Portland is fortunate to have a source water supply of such high quality that filtration is not required as part of the water treatment process. Like any unfiltered water supply, over time a very fine layer of sediment can deposit along the bottom of water distribution mains. This harmless natural sediment consists of organic material from the Bull Run Watershed, and on rare occasions it can get stirred up and cause discolored water. When this happens, customers commonly describe their water as “dirty” or muddy in color.
What causes a dirty water event?
Sediment can be stirred up when the direction or flow of water changes in the water mains. Common causes include hydrant use, hydrant replacement, valve turning, routine maintenance, firefighting, main breaks, or nearby construction.
Is the water contaminated?
There are no health hazards associated with the sediment in the water. The sediment is always in our system but is only visible when a change in flow is enough to disturb the sediment. Customers may choose to drink bottled water while they wait for the discoloration to clear.
What should customers do if they experience “dirty” water?
In most cases the water will clear on its own within two hours or less. If your water is discolored:
- Use the water to flush toilets, but avoid running the water through filters, hot water heaters, and washing machines.
- Wait an hour for the system to settle, then run water at one tap for 2-3 minutes to see if it clears. If it does not clear, wait another hour and try again. When the water runs clear, run water throughout the house to flush any sediment that may have been drawn into your pipes.
- If the water does not clear in a few hours, or if there is also a significant loss of pressure, call the Water Line at 503-823-7525.
- To help the Water Line monitor these events, customers can call and report a dirty water event as soon as they notice the discoloration.
The Water Line is available 8:30 am – 4:30 pm Monday-Friday at 503-823-7525 or WBWaterLine@portlandoregon.gov. If you have a discolored water-related emergency after these hours, please call 503-823-4874 to speak with a Water Bureau Emergency Dispatcher. To learn more about home water quality, visit the Water Bureau’s Drinking Water Quality at Home page.