City of Issaquah public works officials have deactivated one of the city’s wells while it awaits analysis of the well’s water and the apparent presence of toxic perfluorochemicals detected at low levels.

That shutdown may have occurred as long as one week ago, Public Works Engineering Director Sheldon Lynne said, or as soon as a few days ago.

But according to Councilmember Paul Winterstein, City Council members didn’t know about the shutdown until Wednesday, when they received an email from the deputy city administrator.

At a special council infrastructure committee meeting Wednesday night, Winterstein expressed surprise and puzzlement at the news.

“I’d just like it to be known, the basis for that decision,” he said. “What I want is the safest possible thing, but there were risks associated with [a shutdown].”

Winterstein referred to a conversation of the infrastructure committee that took place in February, in which city officials weighed the benefits and risks of shutting down a well — Well 4 — that had detectable levels of perfluorooctane sulfonate, also known as PFOS.

In January, the city found itself handling a public relations crisis after The New York Times Magazine published a feature about perfluorochemicals in public water.

Though the article focused on attorney Robert Bilott’s lawsuit against DuPont USA for the dumping of PFOA in water near a West Virginian farm, the article mentioned Issaquah by name in a reference to other American cities with detectable perfluorochemicals in their water.

Perfluorochemicals are not contaminants actively regulated by the federal government, but Issaquah participates in a voluntary testing program for unregulated contaminants run by the Environmental Protection Agency.

Since 2013, that program has detected several perfluorochemicals in the water of Well 4, located off Northwest Gilman Boulevard along with Well 5.

The highest levels of perfluorochemicals have come from PFOS, which was detected at a level of 0.6 parts per billion in 2013 and reduced to 0.472 parts per billion by 2015. After being blended with water from the city’s other wells, the detectable amount of PFOS in February was 0.0772 parts per billion, less than half the EPA’s recommended safe limit.

As noted in the Time Magazine article, the EPA’s safe level has been a subject of dispute among public health academics and thus city leaders began a serious conversation in February about whether and how to proceed with the operation of Well 4.

If Well 4 continued to operate, public works officials worried PFOS could migrate over to and contaminate Well 5. But if Well 4 were to be shut down, they worried the source of contamination could wind up being drawn by Well 5, Winterstein said.

Council President Stacy Goodman said the hypothesis that Well 5 could draw up contaminants was more of an uncertainty than a risk, but also expressed concern that action was taken without elected officials’ knowledge.

Goodman was particularly frustrated that a sample sent to Eaton Labs and Oregon State University for a full “fingerprint” of its contamination  had not come back with results, she said.

“Is this really that complex, or is it just not urgent?” she said. “We were giving a lot of ‘I-don’t-knows’ to people who were worried at our council meeting last week and I think we should be offering more information than that.”