Bacteria skyrockets to 100 times beyond safe levels in some Fort Lauderdale canals after historic flooding
Fort Lauderdale — known as the “Venice of America” for its many waterways — was marred by water dirtier than a toilet during last week’s historical flooding.
Data collected by Miami Waterkeeper, a nonprofit focused on clean water and ecosystem protection, indicates that on April 13, the day after last week’s record rainfall, while Fort Lauderdale flooded streets drained into area rivers and canals, those waterways had extremely high bacteria levels.
The group collected water samples from 10 sites, and at all 10, enterococci bacteria levels ranged from 38 to 144 times higher than what the Environmental Protection Agency deems safe for swimming.
EPA studies indicate that enterococci, which is associated with fecal contamination, correlates with swimming-associated gastrointestinal illness in both marine and freshwater. A measurement of 70 colony-forming units per 100 milliliters of water results in a swimming advisory.
Miami Waterkeeper’s measurements last Thursday at Fort Lauderdale sites ranged from 2,723 units at Sunrise Bay in Hugh Taylor Birch Park to a whopping 10,112 units at Himmarshee Canal downtown, which empties into the Tarpon River.
That’s 144 times higher than the 70 units that the EPA deems recreationally safe, and 37 times higher than what you might find in a used toilet, according to a 2010 University of Maryland study.
A “normal” measurement for those spots can range from 40 to 300.
Other collection sites include the Tarpon River at Rio Vista Boulevard, Royal Palm Drive at Las Olas Boulevard, and Lake Sylvia.
Miami Waterkeeper found that canal and river contaminants were rising when they took measurements on Tuesday, April 11, the day before the deluge — it had been raining on and off since Sunday, April 9 — but the record-breaking rains led to record-breaking contamination.
“The results on the 13th at some of the sites are the highest that have been detected in the last two years,” said Karim. “We’ve never seen this many sites fail above 1,000, ever.”
Natalia Soares Quinete, a chemist at Florida International University who studies water contamination, said, “Even without flooding, the canals can already have high coliform (bacteria) levels.”
When told of the recent Fort Lauderdale measurements, she said, “That’s a lot. … Those levels are a good indication of the probable overflow of septic tanks. You have a lot of septic tanks in South Florida, and some of them are failing, but even the good ones, with this water, they might overflow.”
She said that there is also water draining into rivers and canals from parks, where there is dog waste and possible human waste.
Soares Quinete warned of other contaminants. “The problem is that these levels of coliforms [such as enterococci] are associated with other types of chemicals … that are toxic, like pharmaceuticals and PFAS [per- and polyfluoroalkyl substances]. We’re not measuring them, but they’re in there.”
Studies indicate that PFAS chemicals at high levels affect animal development and may affect reproduction, thyroid function and the immune systems, says the Centers for Disease Control and Prevention. It is not known how these chemicals affect humans at low environmental levels.
Now that the flooding has started to subside, is it safe to boat, paddleboard, fish or take a dip?
“If you are in a boat and you’re not going to swim, I don’t think that constitutes a risk, but I would not be eating fish that were exposed to those high levels,” Soares Quinete said.
“I would not recommend contact with the water,” Karim said. “Boating should be OK, but fishing, or any sort of interacting with the water I would not recommend until the bloom subsides.”
Many had no choice but to trudge through thigh-deep floodwaters last week. Some chose to swim in it.
The Florida Health website warns that if fecal pollution associated with enterococci is “present in high concentrations in recreational waters and are ingested while swimming or enter the skin through a cut or sore, they may cause human disease, infections or rashes.”
The CDC recommends that if you come into contact with floodwaters:
- Wash the area with soap and clean water as soon as possible. If you don’t have soap or water, use alcohol-based wipes or sanitizer.
- Take care of wounds and seek medical attention if necessary.
- Wash clothes contaminated with flood or sewage water in hot water and detergent before reusing them.
- If you must enter floodwaters, wear rubber boots, rubber gloves and goggles.
How long will it last?
“The bacteria, without an active source, dies off in two weeks,” Karim said. She said the flushing of the tide helps, too. But if there’s an active sewage leak, the bacteria can persist indefinitely. It can also become environmental bacteria that lives in sediments or sea walls. The rivers of Fort Lauderdale generally flush more quickly than the canals, she said.
Tidal flush means the bacteria-laden water will potentially be streaming out onto Fort Lauderdale’s famous beaches, but Karim said that there’s generally not a strong correlation of bacteria blooms in the canals and the waters of the Atlantic. “The beaches see a lot more flushing, but right now we’re also dealing with sargassum [on the beaches], which can act like a petri dish for the enterococci.”
Karim said that they took more measurements Tuesday, and that that data and water advisories will be available Wednesday evening on the TheSwimGuide site, and the Miami Waterkeeper website, under Water Quality Monitoring.
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