WILSONVILLE, OR — Samples of local water delivered to a Seattle-area laboratory for testing on Friday, June 1, revealed no detectable level of microcystins in the local water supply, the cities of Wilsonville and Sherwood announced today.

A ‘non-detect’ result was returned this morning for three samples – source water, finished water and distributed water – supplied by the City of Wilsonville.

As an additional measure to ensure the health of the water supply, Wilsonville is sending samples to two laboratories to analyze seven straight days (June 1-7) of water.

Additionally, the California lab handling the Willamette Water Treatment Plant’s EPA-guided testing under the Unregulated Contaminants Monitoring Rule (UCMR4) delivered a promising preliminary follow-up report on the sample that initially detected microcystins. The “Algal Low 9” test, which analyzes eight variants of microsystins and nodularin, returned non-detect for all nine variants this morning.

On Thursday, May 31, Wilsonville learned that a UCMR4 sample detected 0.34 µg/L, slightly over the EPA’s guideline value for microcystins—one of the four cyanotoxins of greatest concern in drinking water. 

For more information on Wilsonville water, visit www.ci.wilsonville.or.us.  For general questions about water quality, people can visit the Oregon Health Authority’s website or call 2-1-1 for more information.

Contact:     City of Wilsonville
Bill Evans, Communications and Marketing Manager
503-570-1502; evans@ci.wilsonville.or.us

City of Sherwood
Craig Sheldon, Public Works Director
503-925-2310; sheldonc@sherwoodoregon.gov

Oregon Health Authority
Delia Hernández, OHA External Relations
503-422-7179; phd.communications@state.or.us
Jonathan Modie, OHA Public Health Media Contact
971-673-1102 jonathan.n.modie@state.or.us.