On Nov. 27, Portland Water Bureau received results for Cryptosporidium, a potentially disease-causing microorganism as part of ongoing monitoring from the Bull Run Watershed intake. One Cryptosporidium oocyst was detected from a 50-liter sample on Nov. 22. Cryptosporidium was last detected from the Bull Run Watershed intake on Nov. 8, 2017.
The bureau continues to use the Bull Run as its primary source of drinking water. The Portland Water Bureau does not currently treat for Cryptosporidium, but is required to do so and is working to install treatment. At this time, customers are not being asked to take any additional precautions.
Exposure to Cryptosporidium can cause cryptosporidiosis, a serious illness. Symptoms can include diarrhea, vomiting, fever and stomach pain. People with healthy immune systems recover without medical treatment. According to the Centers for Disease Control and Prevention (CDC), people with severely weakened immune systems are at risk for more serious disease. Symptoms may be more severe and could lead to serious or life-threatening illness. Examples of people with weakened immune systems include those with AIDS; those with inherited diseases that affect the immune system; and cancer and transplant patients who are taking certain immunosuppressive drugs.
EPA has estimated that a small percentage of the population could experience gastro-intestinal illness from Cryptosporidium and advises that customers who are immunocompromised and receive their drinking water from the Bull Run Watershed consult with their healthcare professional about the safety of drinking the tap water. The Portland Water Bureau and Burlington, City of Gresham, City of Sandy, City of Tualatin, Green Valley, GNR, Hideaway Hills, Lake Grove, Lorna Portland Water, Lusted, Palatine Hill, Pleasant Home, Raleigh, Rockwood, Skyview Acres, Tualatin Valley, Two Rivers, Valley View and West Slope Water Districts receive all or part of their drinking water supply from the Bull Run. To learn if your drinking water comes from Bull Run, please contact your local drinking water provider.
Public health surveillance during and after a similar series of low-level detections from January through March of this year did not see an increase in Cryptosporidium-related illness.
Water Sampling Results
The public and the media are encouraged to view all sampling results posted to the City’s website at http://www.portlandoregon.gov/water/cryptoresults. The bureau will notify the media and public immediately should further test results indicate a risk to public health and precautions are necessary.
Water Quality Information
Customers with questions regarding water quality can call the Water Line at 503-823-7525.