Sherwood waiting on test for drinking water contamination
Residents of Wilsonville are waiting until Monday to find out if there's a contaminant in their drinking water.
Now Sherwood residents face the same waiting game.
Wilsonville city leaders learned Thursday, May 31, that a treated water sample, which was recently tested for contaminants, revealed trace levels of microcystin, a cyanotoxin produced by cyanobacteria, sometimes referred to as blue-green algae.
Sherwood obtains its drinking water from the same source, the Wilsonville-Willamette River Water Treatment Plant.
"We understand that the City of Wilsonville has taken a sample for analysis and is expecting results Monday, June 4th," Sherwood Police officials announced via email. "Based on the results of the sample a public advisory maybe issued per state and federal guidelines."
Sherwood City Manager Joe Gall said that although the cities were not required to inform residents before receiving results of the re-test, they decided to do so out of an abundance of caution, particularly because Salem's drinking supply recently tested positive for the same toxins.
"We're not necessarily advising residents of anything," Gall said. "We were just out of caution, because of what's going on in Salem, alerting folks that we had a test that was slightly elevated and we have to re-test, and we'll get those results back on Monday."
Based on the result of the test, Wilsonville will determine if a public advisory is necessary. The Environmental Protection Agency recommends obtaining results from a confirmation sample prior to issuing a public advisory.
Salem sent out a "vulnerable population" alert last week because of cyanotoxins in its drinking water system.
"We're being abundantly cautious here, and providing information that allows our community members to make an informed decision," said Wilsonville City Manager Bryan Cosgrove. "We're diligently following protocols put in place by the EPA as well as recommendations from state and local authorities, and will put out an advisory if we receive confirmation that we're above acceptable levels."
If the test results come back positive, the public advisory likely would apply to: children younger than 6; people with a compromised immune system; those who receive dialysis treatment; those with a pre-existing liver condition; anyone who is pregnant or nursing; and people with, "other sensitivity concerns."
Gall expressed optimism that "hopefully those tests will come back below the threshold on Monday, and everything will be fine."
"If they are above the thresholds, then we would issue the same kind of advisory — and Wilsonville would as well — that Salem has been dealing with," he added. "It would mean the same kind of caution for elderly folks and kids 6 years and under."
Wilsonville's water facility uses ozonation, a practice deemed effective by the EPA for reducing potential exposure to cyanotoxins in drinking water by destroying microorganisms and degrading organic pollutants through the infusion of ozone.
As a precaution to reduce cyanotoxins that may be present, Wilsonville has adjusted ozone levels at the facility.
Boiling water is not an effective method of removing cyanotoxins. Cyanotoxins are not absorbed through the skin, so daily tasks like washing hands, bathing, cleaning dishes and laundry pose no health risk.
For more information about water quality, people can visit the Oregon Health Authority website or call 2-1-1.
The water test that revealed the contamination is part of a series of previously scheduled tests administered over a four-month period in 2018. Three previous tests in this series found no cyanotoxins.