Portland Water Bureau finds disease-causing microorganism in drinking water source

PORTLAND, Ore. (KOIN) – A potentially disease-causing microorganism has once again been detected in Portland’s main drinking water source.

The Portland Water Bureau announced they had detected a sample of cryptosporidium during their regular monitoring at the Bull Run Watershed on May 7 and May 8. It was also seen in the water as recently as April 22.

However, officials say customers do not need to take any action at this time.

Cryptosporidium is a parasite known to cause cryptosporidiosis, a serious disease with symptoms ranging from diarrhea, vomiting, fever and stomach pain.

Although those with healthy immune systems can recover from cryptosporidium exposure without medical help, immunocompromised individuals may experience more severe symptoms. In rare cases, it could lead to serious or life-threatening illness.

The Portland Water Bureau does not currently treat for cryptosporidium, though it is required to do so under drinking water regulations. Plans are in place to upgrade the filtration system as soon as September 2027.