UPDATE (1:40 p.m. PT) — Salem has issued yet another drinking water advisory Wednesday for the city's vulnerable populations – just four days after lifting an initial advisory that prompted Gov. Kate Brown to issue an emergency and activate the National Guard.
The new advisory is based off of water samples taken on June 3-4.
Related: Salem Lifts Drinking Water Advisory, Declares Water Safe For All Residents
The city says it once again detected cyanotoxins in water quality samples received Wednesday morning. The results show cyanotoxin levels that exceed Environmental Protection Agency guidelines for children and vulnerable populations. The samples were taken June 2, June 3 and June 4.
This is the second time Salem has issued an advisory in the past two weeks. The city has said it bases its public advisories on days-old water samples, which it sends to out-of-state facilities for testing, creating a delay in reporting.
Oregon Gov. Kate Brown's emergency declaration from the initial advisory is still in effect. On Wednesday afternoon, Brown re-activated the National Guard to help distribute water around the city. The city says the sites will operate around the clock until further notice.
The advisory applies to children under 6, people with compromised immune systems, people receiving dialysis treatment, the elderly, pregnant women or nursing mothers and pets.
The city said it would post the results of the June tests on its website. Immediately after announcing the second water advisory on Facebook, the website appeared to be down.
Salem City Manager Steve Powers said the city is expecting new test results as early as Thursday. The city will need two days of clear results before it can lift the advisory.
Related: Salem's Mayor Orders Investigation Of Cause Of Detroit Lake Algae Blooms
"In the past few years, algae can be seen in Detroit Reservoir, Salem’s drinking water source, from late spring through early fall," the city said on Facebook.
"What was different in late May 2018 – and what caused the City to issue its initial drinking water advisory – is that for the first time, we saw cyanotoxins in our water distribution system. We have a comprehensive and rigorous testing regimen in place to help ensure safe drinking water for the health of our community and all our water customers."
The city first issued an advisory May 29 after water samples showed low levels of cyanotoxins caused by algae blooms in the Detroit Lake.
Detroit Lake flows downstream into the North Santiam River, the source of the city’s water supply. It’s believed to have been the first time the potentially harmful toxins made their way into the distribution system of an Oregon public water system.
Editor's Note: This story has been updated to reflect when Salem officials collected water samples used to determine the June 6 advisory. Initial information released by the city implied incorrect dates.