A Sumter County landfill that’s been the subject of odor complaints since January is going to try to bury the funk underground instead of evaporating it.
That’s Heart of Florida Landfill officials’ most recent answer to the question of what to do with their trash tea, the nonhazardous but noxious liquid that forms when rain trickles through mounds of garbage.
Before this year, trucks carted off the garbage juice, known as leachate, to a wastewater treatment facility. Tailpipe emissions and processing costs mounted as the landfill grew. Its parent company, industry giant Waste Connections, set a goal to process more than half of leachate generated at its 100+ facilities on-site by 2033.
In February, the landfill installed a leachate evaporator: a metallic behemoth that heated the liquid until it turned to steam, funneled it into the air and left behind a condensed portion of chemicals. It handled about 30% of the landfill’s leachate while the wastewater facility received the rest.
The number of Sumter County residents complaining of odors grew.
Florida Department of Environmental Protection regulators didn’t single out the evaporator as a culprit of the complaints, but noted “a strong objectionable odor,” emanating from it during a July inspection. The site paused the system a week later.
Foul smells continued throughout August, neighbors reported, but became less frequent in early September. FDEP didn’t respond to WUFT’s question whether the agency had determined the evaporator or other potential contributors to be the source of residents’ odor complaints.
After a two-month pause, landfill staff dismantled the machine.
“We have made the business decision to permanently shutdown the leachate evaporator,” wrote landfill management to the FDEP on Sep. 5. Don Grigg, Southern Region engineer for Waste Connections, didn’t give a reason for the shutdown in his letter to the agency. He withdrew the company’s pending applications to evaporate more leachate.
Injection instead
To deal with leachate, landfills have limited options: boil it off, cart it out, make a pond or pump it down.
Heart of Florida Landfill staff began investigating pumping, better known as deep-well injection, more than a year ago. The landfill contracted with Tampa-based JMG Engineering and Riverview-based HydroGeo Consulting to evaluate the area’s underground structure and design potential injection and monitoring wells.
FDEP granted an exploratory permit in March, allowing drilling to gather data from below-ground.
The landfill isn’t allowed to send any wastewater down the well in this phase; only to evaluate if the underground looks and behaves as the engineers expected. It applied to modify the exploratory well’s design in August and hasn’t yet received FDEP approval.
The site’s proposed well would inject leachate into a layer of porous rock deep beneath the lower Floridan Aquifer at a maximum rate of 250 gallons a minute The well is 3,200 feet deep. Flipped above ground, it would stand as tall as two and half Empire State Buildings.
Seen from above, it would look more like a bullseye than a building.
Concentric rings of steel casing and cement nest inward in the plans, surrounding a central tube. Those rings overlap with each other underground, forming a telescoping structure meant to seal the well in place and prevent water from flowing into porous layers of rock.
“They're trying to get down below the deepest place where there's potable water,” a standard approach for municipal and commercial wastewater disposal, explained Jon Martin, a professor in the Department of Geological Sciences at the University of Florida.
Such wells that deposit waste beneath the lowest source of drinking water are designated “Class I” by the U.S. Environmental Protection Agency.
Florida is home to more than 180 active Class I wells statewide, according to the FDEP, the vast majority of them concentrated in coastal regions south of Tampa and Melbourne where freshwater layers are thin. Deep injection wells are rare in sinkhole-prone Central Florida, where freshwater is thick. There are none in Sumter County.
Lower-cost alternatives may help explain why, Martin said. “You can imagine how expensive it is to build this,” he said, pointing to sketches of nested casing. Landfill management didn’t respond to WUFT’s request for a cost estimate of the project.
Though the bottom of the well would sit about a thousand feet beneath the lowest source of drinking water, “every time they drill through one of those aquifers that have potable water in them, they have to cement that casing in there so that the leachate can't get out into that part of the formation,” Martin said.
The telescope would end in the Upper Cretaceous Permeable Zone: a rocky layer with water-filled nooks and crannies into which leachate can filter. Two, 800-foot thick layers of much less permeable rock sandwich the zone, limiting leachate’s vertical movement to the Floridan Aquifer.
The wastewater, charting a path of least resistance, should spread sideways through the watery web. Consultants estimated that ten years of daily injection would spread leachate to a quarter mile radius underground.
If all goes to plan, it will stay there.
Injection wells, though prevalent, aren’t immune from failures. Leaks can happen if cement layers don’t set properly, casing pipes crack or wastewater finds a natural or manmade path through which it can snake up to the surface, according to the EPA.
Environmental groups in Florida have scrutinized a number of deep well injection permits in recent years. The Manatee County Commission proposed such a well at the Piney Point phosphate plant in 2011, after a 170 million gallon wastewater spill, but environmental and agricultural groups rallied against it. Regulators denied the permit in 2016 but approved a successive version in 2021 after another spill contaminated Tampa Bay.
In August, FDEP issued Tampa-based phosphate giant Mosaic Fertilizer draft permits for exploratory injection wells for wastewater at two Polk County plants, generating significant pushback from environmental groups.
Many rounds of testing and permitting remain before the Heart of Florida Landfill could inject its leachate. But Dan Gudgel, division landfill manager for Waste Connections in Florida, confirmed that’s the site’s ultimate goal. “We have decommissioned the evaporator,” he wrote, “and we do intend to utilize the FDEP permitted well for leachate disposal, upon completion.”
City oversight
Throughout the exploratory well’s drilling and beyond, the City of Bushnell plans to hire an environmental consultant to oversee compliance with local regulations.
City staff began searching for a firm in August but struggled to find one with no ties to the landfill or other local waste facilities, according to a Sept. 4 statement from Bushnell City Manager Michael Eastburn.
After “an extensive search”, staff selected Arcadis USA, the stateside arm of the Amsterdam-based consultant.
“An emergency agreement with Arcadis USA, Inc. has been drafted and is currently under legal review by the City Attorney,” Eastburn wrote. “Once finalized, Arcadis USA, Inc. will assist in assessing compliance with environmental standards and best practices, providing an objective third-party evaluation of landfill operations.”
The landfill has until Dec. 1 to comply with Bushnell’s odor ordinances, which prohibit “all disagreeable or obnoxious odors and stenches.”
