Cryptosporidium Monitoring Update

The Portland Water Bureau detected low levels of Cryptosporidium in the Bull Run Watershed, the primary source of drinking water for the city. One oocyst was identified in samples collected on October 22 and October 26, 2025, while other samples returned negative results. Although the bureau is required to treat for Cryptosporidium, it currently does not and plans to install filtration by September 30, 2027. Interim measures, including watershed protection and additional monitoring, are being implemented to safeguard public health. Health officials confirmed that customers do not need to take extra precautions at this time.

However, those with compromised immune systems are encouraged to consult their healthcare professionals about the safety of drinking tap water. The Environmental Protection Agency also advises immunocompromised individuals to seek guidance regarding their water supply. For further information, the public can view sampling results on the City’s website.