Work underway on South County project to curb pollution of lagoon

Indian River County has begun work on an $8.4 million water purification and recreation project near South County Park that will reduce the amount of harmful nitrogen and phosphorous flowing into the beleaguered Indian River Lagoon.

The 83-acre stormwater park and nature preserve will capture nearly half the daily water flow from the South Relief Canal, putting it through a series of treatment ponds, marshes and a “floway,” removing nutrients and particulates before the water flows back into the canal and then into the lagoon.

Called Osprey Acres, the project will work in conjunction with the county’s adjacent Osprey Marsh water clean-up facility, which opened in 2015.

Osprey Marsh mixes 1.5 million gallons a day of briny water from the South County Water Treatment Plant’s reverse-osmosis process with up to 10 million gallons a day of South Relief Canal water. The water is put through an algae scrubber and “polished in wetlands” before it re-enters the canal.

Beginning this summer, treated Osprey Marsh water and about 1 million more gallons of South Relief Canal water will flow through Osprey Acres for more nutrient removal. Together the two facilities will clean up nearly half of the 26 million gallons of murky water that flows through the South Relief Canal each day, removing chemicals that feed ecology-killing algae blooms and helping meet Florida Department of Environmental Protection mandates aimed at protecting the Indian River Lagoon, which has been designated an Estuary of National Significance.

The county bought the property half a mile east of the intersection of 5th Street Southwest and 20th Avenue Southwest for $1 million in April 2016. It had been slated to become a housing development before the economic downturn.  West Construction, located in Lantana, was awarded the $7.4 million park construction contract in July.

The county got three grants to help pay for the project, $1.2 million from the state Department of Environmental Protection, $1.2 million from St. John’s River Water Management District and a $1.23 million Florida House Appropriations Grant. The county will fund the remaining $3.8 million from the one-cent local option sales tax, according to county documents.

County Public Works Stormwater Engineer Keith McCully, P.E., who designed the project, said, “It wasn’t too hard to get the grants. Everybody seemed to like the ideas.”

Only 18 of the 83 acres will be developed, the rest to be “left as a nature preserve,” McCully said. What will be put in will look natural – two deep settling ponds, two shallow ponds planted with floating water lettuce, the hanging roots eating nutrients, and two “filter marshes” planted with eel grass or reeds.

There will be two of everything because water will flow through side-by-side pond/marsh systems in the park.

“The treatment ponds were designed to be linear and parallel so we could take any pond offline if we need to,” McCully said. Occasionally the water lettuce and eel grass will need to be harvested and turned into compost and the settling ponds dredged. Therefore the nutrients captured from the canal will fertilize the land “instead of buying new bags of fertilizer,” McCully said, recycling and reducing the local nutrient load.

A natural vegetation buffer and fence will surround the 83 acres and internal trails will be built for hiking, the park to be open for educational purposes. A 10-space coquina-paved parking lot will be constructed for use by visitors. Osprey Acres should come online in July.

McCully said the Florida Department of Environmental Protection has set the nutrient load allowable for the county’s reach of the lagoon, but hasn’t divvied up how many pounds of nutrients each governmental entity must remove. The divvying-up process was blocked by Gov. Rick Scott shortly after he took office seven years ago, McCully said, and when it will be decided is unknown.

“We’re just doing the best we can for each of the canals for now,” McCully said.

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