Cryptosporidium Monitoring Update

The Portland Water Bureau detected low levels of Cryptosporidium in the Bull Run Watershed, which supplies drinking water to Portland and surrounding areas. One oocyst was found in 50 liters of water sampled on November 4 and 5, 2025, while earlier samples showed no presence of the microorganism. Although the bureau does not treat for Cryptosporidium, it is required to implement filtration by September 30, 2027, as part of compliance with state regulations. In the interim, the bureau is enhancing watershed protection and monitoring efforts. Public health officials have stated that no additional precautions are necessary for the general public, but individuals with compromised immune systems should consult healthcare professionals.

Cryptosporidium can cause cryptosporidiosis, which may lead to severe illness in vulnerable populations. The bureau commits to notifying the public of any changes in water safety status. Customers can contact the Water Quality Line for any inquiries regarding water quality.