How a tiny Utah town eliminated toxic algal blooms in its reservoir

A treatment called Lake Guard Oxy was applied late last year, and the water was safe for recreational activities within weeks.

Across the world, lakes, rivers, and streams are being poisoned and choked by toxic algal blooms. The most common culprit is cyanobacteria, also known as blue-green algae because of its tendency to turn previously pristine bodies of water a suspicious shade of teal. These blooms are health hazards for humans, pets, and fish, and they can take a toll on local economies that rely on revenue from tourists looking to get out on the water in the warmer months.