“This is an example of #climatechange in our own backyard. The reasons there are more algal blooms is because the temperatures are slightly warmer every year” — Ed Hall #ActOnClimate

Cyanobacteria. By NASA – http://microbes.arc.nasa.gov/images/content/gallery/lightms/publication/unicells.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=5084332

From 9News.com (Marc Sallinger):

The City of Greeley said algae is to blame for bad-tasting drinking water in the city.

Recent hot weather caused algae blooms in two lakes where Greeley gets its water.

Lake Loveland and Boyd Lake provide more than 20 million gallons of drinking water to the City of Greeley every day. The algae bloom left that water tasting like dirt and metal.

“People don’t like water that tastes dirty,” said Ed Hall, Assistant Professor Department of Ecosystem Science and Sustainability at Colorado State University.

The blooms happen when there are nutrients in the water, hot days and not much wind…

Algae releases byproducts that cause the water to taste and smell strange. Right now, Greeley’s water department said the byproducts released from the algae are 250 times stronger than usual.

“This is an example of climate change in our own backyard. The reasons there are more algal blooms is because the temperatures are slightly warmer every year,” said Hall. “This isn’t going to go away. We really need to start thinking about how to protect ourselves and live with these as the earth becomes warmer every year.”

[…]

The city said they are now treating the water to try and get all the taste and smell from the algae out of the water. They said it should be almost back to normal by the time it gets to your sink.

From The Greeley Tribune (Cuyler Meade):

When the roughly 40 million gallons per day of potable — or drinkable — water consumed by Greeley residents started tasting and smelling noticeably different last week, the Water Department didn’t wait long to react. The department believes its swift response last weekend has effectively solved the problem, and Greeley water should now taste better.

The problem: Concurrent algae blooms in both Boyd Lake and Lake Loveland, the major peak-months water sources from which the department draws and treats the water delivered to Greeley…

That meant, Chambers said, that the option of turning off sourcing from one of Boyd Lake or Lake Loveland — from which much of the area’s water is drawn during the “peak” summer months — was not sufficient. While the department did end up turning off its delivery from Lake Loveland, where Chambers said it was determined the algae situation was “about four times” as bad as it was in Boyd Lake, the water coming from Boyd Lake was still affected with an unappealing taste and smell…

The solution, then: Increase the activated carbon used to treat the water at the Boyd Lake treatment plant.

“Activated carbon is a good way to remove (the poor taste and smell),” Chambers said. “It’s also very expensive, and it’s hard to get the dosage exactly right for the amount that we’re measuring, which is in parts per billion. Tiny, tiny molecules that have a fair amount of influence on taste and odor…

Normally, activated carbon is used to treat the water in the 25 to 27 milligrams per liter range, Chambers said. But this dual algae bloom required more.

“Last Friday, we turned off our Lake Loveland supply, which allowed our activated carbon dosage to do a better job pulling those odor-causing molecules out,” Chambers said. “Then we upped the dosage, as well.”

Chambers said they began treating the water with about 35 milligrams per liter, up about 40% from the normal dosage. The department is continuing to use that increased dosage for the time being.

“Our internal sampling has led us to believe that’s perfectly adequate for removing what’s needed,” Chambers said.

The more southerly lakes become critical sources of water in the high-usage summer months, but the “workhorse” treatment plant is actually at the Poudre River Basin in Bellvue.

“We treat our water at those two locations near the foothills where you can grab higher-quality source water than you can find in Greeley and deliver the water to Greeley,” Chambers said. “Visionary system that was developed in the early 1900s up at Bellvue.”

Chambers emphasized the fact that even before treatment, while the water may have tasted differently, it was at no time unsafe to drink.

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