By Tom Mustin

DENVER (CBS4)– Crews with pitchforks full of putrid green slime pushed the growing piles away from the banks of Ferril Lake at Denver’s City Park on Wednesday.

“I think the river is very yucky and I never want to swim in it,” little Charlie Retallack told CBS4’s Tom Mustin.

This summer, City of Denver crews are out in force scooping up mounds of the algae, hoping to keep the water clean enough for park visitors like Charleton and Veronda Smith.

“Looks like grass. Like you could mow it,” laughed Veronda.

Wednesday, the couple traveled to the park to celebrate their 20th wedding anniversary. When they arrived, they found the paddle boats out of service, surrounded by a sea of algae.

“It’s like 75 percent of the lake so it takes away from the beauty of being able to walk around,” said Veronda.

The slime has been a problem at City Park for several years.

Scott Gilmore with Denver Parks and Planning says the city drainage system ends at City Park, causing contaminants to flow into the lake. That’s why other parks rarely have the slime problem.

“It is the end of the line. So a lot of times we do get some additional runoff and things that end up in this lake,” said Gilmore.

Hot weather also causes the algae to grow rapidly. But the city is fighting back. The lake has been aerated, and will be skimmed, vacuumed and treated with chemicals as necessary throughout the summer.

After hearing the city’s plan, Charleton still had some questions, “After they skim it off what happens to it then? Does it reoccur?”

“They sell it at Whole Foods,” joked CBS4’s Mustin.

And with a long, slime filled summer ahead, Charleton and Veronda are taking it all in stride, “Denver rocks still. We still love the city.”

The gathered slime will be taken away by the city where it will decompose in a safe area. Experts say the slime will eventually dissipate on its own, but with several hot days ahead, “when” is up to mother nature.

Tom Mustin is CBS4’s Weekend Anchor. He has been with CBS4 since 2002, and is always looking for great story ideas. Connect with Tom on Facebook or follow him on Twitter @TomCBS4.