PORTLAND, Ore. (KOIN) — Cryptosporidium has been detected in the Bull Run Watershed for the first time since May.

The Portland Water Bureau said two Cryptosporidium oocysts were detected in the 50-liters collected on October 22. The last detection of Cryptosporidium was on May 12.

The amount of the potentially dangerous microorganism is low and does not pose a risk to public health. However, those who are immunocompromised may experience gastro-intestinal illness.

Portland is working to install filtration by September 2027.