Bonita Springs to consider bioreactor to treat runoff

Bonita Springs wants better water quality and the key might just be wood chips.

At its meeting Wednesday, city council will decide whether to green light a pilot project for a so-called wood chip denitrifying bio reactor on a city-owned block along Felts Avenue and Abernathy Street in downtown Bonita.

The project would include an above-ground, low-impact parking lot and the underground bioreactor, said Public Works Director Matt Feeney.

City staff and South Florida Engineering and Consulting, LLC, the West Palm Beach-based firm tasked with designing the project, negotiated a not-to-exceed price tag of $73,765 that now awaits council approval.

The impetus for the project, Feeney said, is “higher than average nitrogen levels” in stormwater runoff.

“We need to figure out how to filter nitrogen before it gets into the river system,” he said.

The nitrogen, some of which stems from fertilizers, is one of the factors that leads to waterways, such as the Imperial River, being low in dissolved oxygen, Feeney said.

The high levels of nitrogen can cause increased growth of algae, which can lead to accelerated eutrophication – the over-enrichment of water by nutrients – which in turn can lead to oxygen-depleted waters, so-called dead zones.

“Nutrients like nitrogen and phosphorous are naturally present in the water and necessary for the healthy growth of plant and animal life,” said Florida Department of Environmental Protection spokeswoman Dee Ann Miller in an email. “However, an excess of nutrients can lead to water quality problems like rapid growth of algal mats, habitat smothering and oxygen depletion in the water.”