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Portland Water Bureau

From forest to faucet, we deliver the best drinking water in the world.


1120 SW Fifth Ave, Suite 600, Portland, OR 97204

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Information on Cryptosporidium

Drinking water regulations require systems to provide source water treatment to specifically address Cryptosporidium (a waterborne pathogen). The Portland Water Bureau does not currently treat for Cryptosporidium; the State of Oregon issued Portland a variance for these treatment requirements of LT2 in accordance with federal and state law.

On May 19, 2017, the Oregon Health Authority (OHA) informed the Portland Water Bureau that the treatment variance granted in 2012—which exempted the Water Bureau from having to treat its water for Cryptosporidium—was being revoked. The order revoking the variance also required that the Portland Water Bureau submit to OHA the following:

  1. The treatment technology to be used
  2. A proposed schedule for design and construction
  3. A proposed Cryptosporidium sampling schedule and measures to reduce the public’s risk of exposure to Cryptosporidium until treatment is in place.

On August 2, 2017, the Portland City Council unanimously approved water filtration as the Cryptosporidium treatment technology to be used.

On October 9, 2017, the Portland Water Bureau submitted to OHA a proposed schedule for design and construction of a water filtration plant. This proposal also includes interim measures to reduce Cryptosporidium related risk that are at least as protective as the conditions of the Cryptosporidium treatment variance. Among the proposed actions are:

  • Treatment: Design and construction of a water filtration plant by July 2027.
  • Monitoring: Continued monitoring at the Bull Run intake. A minimum of 100 Liters over 2 days per week. If Cryptosporidium is detected at the intake, monitoring will increase to minimum of 200 L over 4 days each week, until at least 2 consecutive weeks with no Cryptosporidium detections.
  • Watershed Protection: The Portland Water Bureau will continue its commitment to protect the Bull Run Watershed, including maintaining or strengthening all City of Portland legal and operational protections.
  • Notification: Notify the public and health partners when Cryptosporidium is detected at the Bull Run intake.

More Information

PDF: Proposal Letter to OHA on Filtration and Interim Measures

Sent Oct. 9, 2017 to the Oregon Health Authority