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The City of Portland, Oregon

Portland Water Bureau

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MEDIA RELEASE 09/24/2018: Bull Run Drinking Water Supply Not Treated for Cryptosporidium

While small amounts of Cryptosporidium were detected coming from the Bull Run source starting in 2017, Cryptosporidium has not been detected in Portland’s drinking water since April 10, 2018. Over the next nine years, the Portland Water Bureau will be installing a new treatment plant to remove Cryptosporidium from Bull Run drinking water.

Until the filtration plant is online, the Portland Water Bureau is also committed to continued monitoring of the Bull Run and a range of actions to maintain public health protections. This includes informing the public of the potential risks of Cryptosporidium in drinking water and Portland’s plan for filtration by sharing the following information with the public on a quarterly basis.  

The Portland Water Bureau does not currently treat for Cryptosporidium but is required to do so under the drinking water regulations. Portland is working to install filtration by 2027 under a compliance schedule with the Oregon Health Authority. In the meantime, Portland Water Bureau is implementing interim measures such as watershed protection and additional monitoring to protect public health. Consultation with public health officials has concluded that at this time, customers do not need 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 Center 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 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.

The Environmental Protection Agency has estimated that a small percentage of the population could experience gastrointestinal illness from Cryptosporidium and advises that customers who are immunocompromised and receive their drinking water from the Bull Run Watershed consult with their health care 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 water provider.

Under the direction of Commissioner Amanda Fritz, the Portland Water Bureau plans to seek public feedback on the type of filtration and other details of the project prior to moving forward with a future filtration plant. Opportunities to provide input will be announced in the next few weeks.

The public and the media are encouraged to view all sampling results posted to the City’s website at The bureau will notify the media and public immediately should further test results indicate a risk to public health and if precautions are necessary.

Customers with questions regarding water quality can call the Water Line at 503-823-7525.