Cyanotoxin Monitoring

TVWD is testing for cyanotoxins at various entry points to the water distribution system. This monitoring was scheduled in 2017 as part of the EPA's Unregulated Contaminants Monitoring Rule (UCMR4). If cyanotoxins levels are detected at or above the Oregon Heath Authority guidelines, TVWD will notify its customers of any health risks and the necessary precautions individuals should take.

TVWD customers receive water from the Portland Water Bureau and the Joint Water Commission. TVWD is working very closely with both provider agencies to respond to the need to monitor, test and communicate.

TVWD Testing For Cyanotoxins


Completed Sample Date

Impacted Population


7/5/18 (results pending)


All populations

No detection.


All populations

No detection.

Samples are being processed every other week from June through September 2018 as scheduled in 2017. All test results will be posted here as they are received.

What do I need to do now?

TVWD encourages customers to prepare and store water, 14 gallons per person, for use in an emergency. Click here for emergency water storage instructions.

What are cyanotoxins?

Cyanotoxins are produced by certain types of bacteria, generally referred to as blue-green algae. When the right conditions occur, they can grow rapidly and form what looks like a "harmful algal bloom," which can lead to the production of cyanotoxins.

Want to learn more?

What is the testing process?

  • TVWD takes samples at various points where water enters TVWD's distribution system.
  • Samples are sent to certified laboratories. There are currently no labs certified to test for cyanotoxins in Oregon, so samples are sent out of state.
  • Testing results received as soon as they are available, 48 hours.

TVWD will notify customers of test results as we receive them.

For more information on cyanotoxins:

For more information on water sources:

For information on how to prepare emergency water supplies: