Why has it been so smelly in Cutler Bay? Miami-Dade’s sewage problems, explained

When the trucks don’t arrive in time at a sewage plant near Cutler Bay, the smell from 350 tons of tarry black muck leftover from the daily processing of human waste can spread. This is not news to Andrew Scruggs, a married father of four who lives nearby.

“It’s really gotten to the point where I don’t want to walk outside with my kids,” said Scruggs, who is 35 and works in commercial real estate. “It smells like raw sewage.”

Odors can’t be avoided at Miami-Dade’s sewage treatment plants, but county administrators say the last year brought some particularly rank stretches of time to the South District Wastewater Treatment Plant, which sits south of Cutler Bay.

The pungent odors Scruggs and other Cutler Bay neighbors complain about can be traced in part to changes in state law aimed at reducing fish kills tied to algae blooms that can happen when treated sewage remnants mix with rainwater.

Tougher disposal rules on those remnants — the black muck known as “sludge” or “biosolids” that farms have commonly used as fertilizer — have left Miami-Dade scrambling to find haulers willing to clear out the muddy material that accumulates daily. If the muck piles up, administrators say, the odors intensify.

“The smell of 1,000 baby butts will follow you home,” County Commissioner Raquel Regalado said during a recent tour of the county’s Central sewage plant on Miami’s Virginia Key.

Wearing knee-high rain boots and jeans, Regalado stepped into the plant’s “Sludge Barn” that’s the final local stop for human waste in the three-week process that starts with a flush somewhere in Miami-Dade and ends with a truck hauling away the remaining biosolids leftover from the treatment process.

That treatment process involves tanks where bacteria and pure oxygen break down human waste and a series of cascading flumes and bogs where the remaining liquid and solid portions of the treated waste are separated.

The treated wastewater then heads either 3 miles out into the ocean through a disposal system that Florida is phasing out or into deep wells underground that are the preferred alternative to the “ocean outfall” option.

The solid remnants of the treated waste is spun in a centrifuge to remove as much liquid as possible and run through digesters that help extract much of the odor-producing components. Then it’s off to the sludge barn to wait for a 275-mile trip outside Miami-Dade County to a Sumter County fertilizer plant with state clearance for accepting biosolids.

“Because of the regulatory changes that we suffered through last year, that really shrank the number of disposal sites that we had for the biosolids,” said Sandra Hernandez, chief operator of the Central plant.

Unlike at the Virginia Key facility, the South plant currently doesn’t have enough digester equipment to remove liquid from all the biosolids produced from wastewater there, said Billie Jo McCarley, deputy director of the county’s Water and Sewer Department. “A majority of the solids go through digesters in the south,” she said. “But we are treating a small amount of biosolids that are not getting full digestion. They do have a stronger odor.”

Removing liquid tamps down the odor that sludge produces when left to dry, making the Cutler Bay area more susceptible to sludge smells than anywhere else in the county.

“You can tell when they’re not hauling. Because it smells,” said Rafael “Ralph” Casals, town manager of Cutler Bay.

Miami-Dade has misters around both plants that spray scents of citrus and lavender into the air in hopes of masking the smell associated with treating human waste, but the perfumed perimeters can only do so much. The odors have made Casals particularly attune to wind patterns.

“I don’t want to be Ralph the sailor and worry about which way the wind is blowing,” Casals said. “People are calling us.”

Cutler Bay Mayor Tim Meerbott said he’s also become more alert to wind direction after the sludge smell became such a noticeable issue last year. “It’s not as pungent as an open toilet,” he said, “but it’s definitely a sewer smell.”

Florida biosolids crackdown aimed at fish kills

The Florida Legislature in 2021 approved rules restricting the use of biosolids as fertilizer in an effort to reduce the amount of nutrient runoff that is linked to algae blooms and fish kills. The new rules limited biosolid use to land that’s less susceptible to runoff.

Those changes didn’t become a problem for Miami-Dade until disposal permits issued before the law change started to expire last year, said Roy Coley, chief of utilities and regulation under Miami-Dade Mayor Daniella Levine Cava.

“The companies that worked for the county didn’t show up,” Coley told a county committee last fall. “Biosolids had turned into a mountain in the South Dade plant.”

Miami-Dade had a chance to lock in long-term hauling and disposal of the 700 tons of sludge produced daily at the Central and South treatment plants, but county commissioners rejected that deal.

At the Sept. 10 meeting of the commission’s Infrastructure committee, some members objected to Coley’s request for a no-bid contract worth $64 million over three years with a Sumter County company, CompostUSA, that had offered to continue sending up to 30 trucks a day to the two plants to remove the accumulated sludge for $102 a ton. That was a sharp increase from the $57-a-ton rate Miami-Dade’s Water and Sewer Department was paying before it faced the impact of the new rules, Coley said.

“This makes me cringe,” Commissioner Kionne McGhee, who represents parts of south Miami-Dade, said during the hearing. “I cannot swallow the $64 million price tag.”

When commissioners instructed the administration to negotiate a cheaper deal, CompostUSA declined to pursue a long-term contract, Coley said.

Instead, the company agreed to continue hauling away sludge from the Virginia Key plant under a temporary contract but dropped the truck routes requiring the longer haul down to the plant outside Cutler Bay. That left Miami-Dade scrambling to find new haulers willing to remove sludge from the South plant.

“The backlog got created by losing CompostUSA as a vendor,” Coley said. A representative from Compost USA declined an interview request for this story.

The fallout from the loss of the CompostUSA contract left the commissioner representing Cutler Bay, Danielle Cohen Higgins, blaming politics for the sludge mess.

“Unfortunately, all too often, as was the case here, pure politics prevailed over actually solving problems for the people,” Cohen Higgins, who sponsored the legislation needed to approve the CompostUSA contract, said in a statement last month, when sludge pickups were behind schedule. “As a result, we are now facing the return of the biosolid smell affecting the South.”

McCarley, the deputy director of the county’s Water and Sewer Department, said the sludge-hauling situation out of Cutler Bay is more stable now. Using emergency contracts, Miami-Dade is paying two biosolids haulers about $150 per ton to truck 350 tons of sludge a day out of the South plant to facilities in Central Florida approved for taking biosolids.

“I salute those trucks when I see them going up the Turnpike,” McCarley said. “There are so many pieces that have to work together for this to work right.”

The return of sludge haulers have made a difference for Andrea Chiarella’s daily walks. The Cutler Bay resident said she’s noticed a change in the “pungent, overwhelming stench” the breeze used to deliver to her neighborhood.

“So far, no odor,” Chiarella, 38, said in an email on Wednesday. “Even with temperatures reaching 80 degrees.”

Scruggs reported the same good news, noting there hasn’t been a smelly day in weeks. “This has gotten drastically better,” he said.

While the hauling service appears to be keeping up with the county’s sludge piles for now, the contracts were issued under emergency procurement rules that don’t obligate the hauler to continue servicing the plant all day long.

“It’s all hands on deck,” said Catalina Lopez-Velandia, the assistant Water and Sewer director in charge of wastewater operations. “But it’s not guaranteed.”

County administrators hope to win commission approval for long-term contracts for biosolid disposal later in the year, though the price is unlikely to be much lower than the amount that sparked the committee pushback last fall. Even with a long-term disposal contract, sewage administrators say they’re worried changing state and federal regulations will cause problems down the road and leave Miami-Dade with a growing supply of sludge and difficulty getting rid of it.

One option may be burning it.

Modern incinerators are used to burn sludge, reducing 95% of the material into ash and exhaust. While Miami-Dade’s garbage incinerator from the 1980s shut down in 2023 after a fire, county commissioners are debating whether to replace it — a decision complicated in part by objections from President Donald Trump’s resort business, which owns a hotel and golf course a few miles from the old incinerator site in Doral.

Commissioner Eileen Higgins recently urged fellow commissioners not to abandon the county’s long-term quest for a modern incinerator because the new facility will help Miami-Dade get rid of both trash and sewage remnants “without trucking them all over the bloody state at outrageously expensive tonnages.”

“This is another reason we need to be sure we get our new mass-burn incinerator technology up and running as soon as possible,” Higgins said during a Jan. 13 committee meeting.

Another potential fix is in the early stages. Commissioners in January voted to green light pursuing a federal grant to fund the country’s first commercial plant converting sludge into fuel.

Led by AECOM, an engineering firm with multiple county contracts, the effort hopes to secure a Department of Energy grant to subsidize construction of a $130 million facility in Miami-Dade that would turn sludge into crude oil, which then could be used to create gasoline for cargo ships at Port Miami.

Dan Levy, a vice president in AECOM’s environmental division, said the federal grant would cover half the cost of the fuel plant, with a private sector entity covering the rest. If the county eventually agrees, Miami-Dade would pay for the fuel processing with existing hauling dollars once the plant is running, Levy said.

The first step is a small-scale demonstration of the technology, with a mini fuel producer housed in a tractor trailer that’s expected in Virginia Key sometime in March. The big test will come in Washington, when the Trump administration decides whether Miami-Dade qualifies for the grant money.

“We’re expecting a lot of competition,” Levy said.