The Portland Water Bureau has reported findings of Cryptosporidium, a protozoan parasite that can cause unpleasant gastrointestinal illness, in the city's primary drinking water source, the Bull Run Watershed. According to a recent update published on the Portland Water Bureau website, routine monitoring conducted from March 2 to March 5 resulted in the detection of one Cryptosporidium oocyst on March 2 and two on March 3, with no detections on subsequent days; before these, the latest detection was on February 26, 2025.
While the detected levels are relatively low, the presence of Cryptosporidium in the water supply is a cause for concern, particularly for individuals with compromised immune systems who may experience more severe symptoms that include diarrhea, vomiting, fever, and stomach pain, which could lead to serious or even life-threatening conditions. The Portland Water Bureau has not instituted treatment protocols specifically targeting Cryptosporidium, yet the bureau is on track to install filtration systems by September 30, 2027, conforming to a compliance schedule mandated by the Oregon Health Authority, and in the meantime, they are taking interim measures to ensure public health like watershed protection and additional monitoring.
Public health officials have consulted and agreed that the general population need not take extra precautions at this time, however, the Environmental Protection Agency strongly advises immunocompromised individuals, who draw their water from the Bull Run Watershed, to discuss the safety of the tap water with their healthcare provider. A considerable number of districts, including the City of Gresham, the City of Sandy, and Tualatin Valley, along with other water districts, rely wholly or partially on the Bull Run for their water supplies.
For those with questions about water quality or to learn if their water comes from Bull Run, the Portland Water Bureau encourages reaching out to their local drinking water provider or calling their Water Quality Line at 503-823-7525. The bureau also pledges to promptly notify the public through the media of any further test results that may pose a risk to public health, and the public can stay informed by checking the ongoing sampling results posted on the bureau's website.
