[USA] The pinkish tint some Oregon residents noticed in their tap water over the weekend was caused not by algal toxins, but by efforts city crews were taking to prepare for summer algae blooms on Lake Erie.
Doug Wagner, superintendent of Oregon’s water treatment plant, said Monday operators accidentally put too much potassium permanganate in raw western Lake Erie water drawn in through Oregon’s intake crib while testing new equipment designed to help combat algae. Oregon recently installed feeders that allow it to put more potassium permanganate into its crib.
“It carried through the plant into the clear well and into the distribution system,” Mr. Wagner said. “It takes very little to tint the water.”
Potassium permanganate is commonly used at the beginning of the water-treatment process in Oregon and Toledo, as well as in other water-treatment plants. The treatment helps with taste and odor control, kills off zebra mussels, and reduces free-flowing organic materials. It also serves as a first line of defense against the algal toxin microcystin.
“We wanted to make sure we’re ready in case the algae does come,” Mr. Wagner said.
Oregon hasn’t detected any of the algal toxin in its intake crib yet, nor has Toledo.
Andy McClure, Toledo water-treatment plant superintendent, said it doesn’t take much potassium permanganate to make the water pink. Raw water entering Toledo’s Collins Park Water Treatment Plant has occasionally turned pink from too much potassium permanganate being released at its intake crib. But Toledo water-treatment plant workers always have been able to make adjustments before any of the tinted water got out to the public, Mr. McClure said.
The Ohio Environmental Protection Agency said Monday health risks were “minimal.”
Agency spokesman Dina Pierce said an excessive amount of potassium permanganate is rare but is occasionally known to occur within treatment plants. wShe said the agency, which was notified by Oregon at 9 p.m. Saturday, is still gathering information about how the pinkish water got out to the public and how Oregon will prevent a recurrence.
Any Oregon residents who still have a pinkish tint in their tap water are encouraged to open their faucets and flush out their household pipes, Mr. Wagner said. Mr. Wagner said he’s not aware of any houses that still have problems.
He said Oregon flushed out its distribution lines for five hours, from 10 p.m. Saturday to 3 a.m. Sunday, and that any residual discoloring would be caused by potassium permanganate remaining in pipes in individual homes.
Oregon acknowledged an excessive release of potassium permanganate on its Facebook page on Saturday night, posting two updates as its flushed out its distribution system.
Microcystin was recently found at low levels in a part of the Maumee River near Defiance but not enough to pose a threat to the drinking water there. Defiance draws from a reservoir that had an even lower concentration of microcystin.
View original article at: Algae-fighting chemicals turn Oregon’s water pink