On December 19th, Portland Water Bureau (PWB) announced a complete switch to groundwater from Portland’s Columbia South Shore Well Field in response to higher amounts of organic material suspended in the Bull Run Watershed after this week’s heavy rainstorm. City ratepayers receive water from two primary sources that utility operators can switch between or blend together based on supply and environmental conditions. Groundwater sources are often activated by PWB during the dry summer season, as the Bull Run water supply diminishes in capacity, and they try to extend its availability by mixing the two sources. However, water from wells can take over for Bull Run if that source is threatened by wildfire contamination or by turbidity from excessive rain.
A similar event occurred in November 2022, when a massive rain event increased the flow of streams feeding the Bull Run watershed, contributing to a rapid increase in organic material washed into the supply, which takes time to settle. Almost a million people depend on water supplied by the Water Bureau. Long-term investments have added well-water sources to the City’s water supply, enhancing resiliency against weather-related events. The new Bull Run filtration facility, when it comes online, should reduce the need to switch to groundwater after storms. Federal water quality regulations require PBW to activate the extra water treatment capability by September 2027. The filtration facility will remove sediment, organic material, and other contaminants, including disease-causing microorganisms that could threaten drinking water safety.
The Portland Water Bureau assures residents that the Columbia South Shore Well Field water supply meets or surpasses all federal and state drinking water regulations. However, they make it a policy to notify the public when activating groundwater sources so sensitive water users can take precautions. Ratepayers can sign up at the Portland Water Bureau’s website to receive notifications regarding changes to the water system. In 2022, that took less than 30 days. Customers with questions should call the Water Line at 503-823-7525 and watch for updates to this article when Portland’s water system returns to 100 percent Bull Run watershed-sourced water.
Update December 27, 2025: The Portland Water Bureau reactivated the Bull Run water supply after elevated turbidity from heavy rains subside. It can take up to two weeks for the system to completely clear of groundwater and deliver 100% watershed sourced water. Ratepayers may notice a tea like color in the Bull Run water as harmless fine organic matter continues to settle within the reservoirs post storm.
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