BOULDER – Officials in Boulder and Aurora are warning residents about "potentially" toxic blue-green algae found in lakes in those cities.
The algae was confirmed in Wonderland Lake in north Boulder and the Quincy Reservoir in Aurora, officials said Friday. Algae was also reported in Thunderbird Lake in Boulder but it's not believed to be blue-green.
Earlier this week, a resident reported blue-green algae in water at Chatfield State Park. Initial tests came back negative, but Colorado Parks and Wildlife officials were still waiting for further test results.
None of the reported algae sightings have been in lakes that are used for drinking water, but officials are still warning residents to stay away from water. And warning them to keep their pets away from the algae, too.
Here's what you should know:
What to watch for
People and pets should avoid drinking from or swimming in water with heavy accumulations of algae. Toxic algae blooms should be visible and might look like thick pea soup or spilled paint on the water's surface. The algae can also create a thick mat of foam on the shoreline.
What's toxic and what's not
The blue-green algae, or cyanobacteria, is potentially toxic but not always. Some blue-green algae can produce both toxic and non-toxic strains, according to the City of Boulder. Algae can only be confirmed as toxic through testing.
What leads to blue-green algae?
Lakes with high nutrient levels are most susceptible to producing blue-green algae, according to Colorado Parks and Wildlife. Warm temperatures and calm waters also contribute to algae growth.
How to keep your pets safe
Toxic algae can poison your dog, so be sure to keep them on a leash near shorelines, especially if you suspect blue-green algae is present. If they do get in potentially harmful water, remove them immediately and don't let them lick their fur or paws. Symptoms from the algae can arise anywhere from 15 minutes to several days after exposure, according to the Environmental Protection Agency. Take your pet to the vet immediately if they begin suffering from diarrhea or vomiting; weakness or staggering; or drooling, difficulty breathing or convulsions.