Darien officials reassured the community Tuesday that there is not a gas leak near Tilley Pond Park and said the natural gas odor is “very likely” due to algae.

“The fire department reached out to us because they received several calls about potential gas odors in the area,” explained Darien Director of Health David Knauf. “They had the gas company come out multiple times, surveyed the entire perimeter of the park, found there were absolutely no gas leaks at all.”

Knauf said his team investigated Monday and saw the green film coating the pond’s surface.

“We're quite convinced the source of the odors in the area is from the algae in the pond,” Knauf told News 12.

He said the odor isn’t harmful, but there are concerns about the algae being toxic to animals.

“What we do want to tell people is to keep their dogs out of the water when the algae's here because it could be harmful to the dogs if they drink it, get it on their fur, lick their fur,” Knauf said.

Desi Gale was among the people walking their dogs there Tuesday afternoon, and she definitely noticed something different.

“First of all, it smells weird, which is not fun to walk around in,” Gale said. “We weren’t sure what it was.”

Knauf told News 12 there's not really any treatment for the algae. He said staff shut off the pond’s fountains thinking maybe those were aspirating some of the algae and making the odor even worse. Still, the smell came and went Tuesday with certain areas of the pond more pungent.

“With fall and with the cooler weather and rain, it does go away,” Knauf explained. He said this kind of algae isn't limited to Darien. It's being found in freshwater lakes and ponds across the state and even closing swimming areas.