From The Colorado Springs Gazette (Liz Henderson):
Warmer temperatures and higher nutrient levels in the water have led to more blue-green algae blooms, which are harmful to humans and potentially deadly to pets, said Erik Rodriguez a Health, Safety and Environmental specialist with the city. The daily temperature record in Colorado Springs has already been broken five times this year.
While the city struggles to find a fix, other Colorado towns have used environmentally-friendly machinery that helps aerate the water. Better circulation gives algae less chance to accumulate.
In the Green Ridge Glade Reservoir in Loveland, sit five SolarBee units — solar powered machines that float in the middle of the lake. They keep the water in the reservoir moving, disrupting the stagnant environment that blue-green algae likes, said SolarBee regional manager Dave Summerfield. Each unit costs about $40,000.
Since the units were installed two years ago, the 150-acre drinking water reservoir has been free of algae.
In the past, the popular method among water treatment agencies was to dump algicides such as copper sulfate into the water. But the solution wasn’t sustainable, said Summerfield.
The bacteria would slowly adapt to the sulfate, forcing maintenance to use more and more of it, racking up costs and dangerous toxin levels…
Rodriguez pointed out that several Colorado Springs lakes already have aeration features in them. Monument Valley Park ponds have a few aerators — devices that create small air bubbles to push the water around. Mary Kyer Park has a fountain in the middle that helps with circulation, he said.
Cyanobacteria, which causes the blue-green algae, thrives off nutrients in the water, specifically nitrogen and phosphorous. Nitrogen and phosphorous get into water in runoff from agriculture, fossil fuels, fertilizers, yard and pet waste, even soaps and detergents. The city’s recent warm weather and heavy thunderstorms haven’t helped, Rodriguez said.