POLLUTION IN OUR KEYS COASTAL WATERS...
Algae overgrowing seagrass near site of probable sewage effluent plume in coastal waters off Marathon, May 2019.
Healthy seagrass meadow.
Every year there's another study confirming what many of us already know – our coastal marine ecosystems are near collapse. Whether it’s deterioration of our coral reef, loss of seagrass meadows and the marine animals dependent upon them, unhealthy levels of pharmaceuticals and other toxins in our fisheries, humans in the Florida Keys are having a terrible impact.
Overdevelopment is a basic cause – more people in the Keys means even more sewage to be discharged, but one solution is to move from shallow sewage wells to deep ones. Most cities of the Keys and unincorporated Monroe County have already done so, but Marathon’s 12 shallow sewage wells are a big part of deteriorating water quality.
Taxpayers spent a lot of money for sewer improvements. Didn’t it work?
It worked to clean up a lot of the bacteria from the septic tanks and cess pits which had caused beach closures.
But the shallow waters along our coastline still don’t meet state water quality standards or federal law, according to the EPA. None of the Keys coastal waters – part of the Florida Keys National Marine Sanctuary (FKNMS) – complies on an average annual basis with EPA water quality standards. 
Marathon's coastal water quality is not compliant with EPA Strategic Targets 78% of the time for Dissolved Inorganic Nutrients (DIN) and 67.9% for Total Phosphorus (TP) and shows increasing non-compliance. 
Why is the water quality still so bad?
Shallow sewage wells are a major part of the problem.
Key West, Cudjoe Regional, Islamorada and Key Largo use deep wells for sewage effluent disposal.
Marathon is the only major population center in the Keys that still relies on shallow sewage wells... lots of them.
Marathon's five separate wastewater treatment plants dispose over 1.5 million gallons a day of partially-treated sewage effluent into 12 shallow sewage wells, all located within the 13-mile-long City of Marathon. All dispose to the same depth, between 90-120 feet, into porous limestone, full of "caverns and conduits" allowing rapid transit of the sewage effluent to the nearby surface waters. 
Wastewater effluent injected into shallow sewage wells is not saline; it's more buoyant than groundwater and travels quickly to the surface waters. And the partially-treated effluent contains pollutants, legal pharmaceuticals and illegal drugs – all harmful to the fisheries and marine ecosystems and our tourist industry.
In spite of its violations of water quality laws, Marathon is currently seeking a DEP permit to almost double its shallow sewage well disposal at one of its 5 wastewater treatment plants.
The Florida Department of Environmental Protection (FDEP) acknowledges the problems with shallow sewage wells. As far back as 2008, according to the minutes of a meeting concerning the Cudjoe sewage treatment plant, FDEP advised that "...most shallow wells in the Florida Keys are only operational when the tide is receding. FDEP cited several plants with shallow wells that do not work." 
And to paraphrase the scientists' concerns, what happens in Marathon doesn't stay in Marathon. As the EPA reports, the pollution travels to the nearshore waters and the reef tracts throughout the Keys. 
Meanwhile, Marathon's development is skyrocketing!
Yearly EPA Strategic Target compliance/non-compliance for DIN at the two Marathon stations over the timeseries 2012-2018.
Yearly EPA Strategic Target compliance/non-compliance for TP at the two Marathon stations over the timeseries 2012-2018.
How can water quality be improved?
A deep well is the only way to prevent partially treated sewage effluent from rising to the nearshore waters.
Our shallow nearshore waters are nurseries for our fisheries and the waters most impacted by humans. 
What can we citizens do?
Citizens convinced Monroe County to dig a deep well for the Lower Keys at Cudjoe Regional. Facts, and citizen pressure, matter!
If you’d like to help us make a difference – again – please click below to sign our on-line petition. Our petition will be sent to FDEP and EPA, too. They have the authority to require Marathon to dig a deep well.
Please read the source material below or visit "Studies" in the Menu at the top of the page.
 2018 Update to the Florida Keys Reasonable Assurance Plan, EPA, p.9.
 Assessment of Trends in Marathon Coastal Water Nutrient Concentrations and EPA Target Compliance within the Florida Keys National Marine Sanctuary, Steven M. Lombardo, M.Sc, 9-9-21.
 Comments by Donald M. Maynard, Licensed Florida Geologist, 2-7-21. Bimodal Transport of a Waste Water Plume Injected into Saline Ground Water of the Florida Keys, Kevin Dillon, D. Reide Corbett, Jeffrey P. Chanton, William C. Burnett, Lee Kump, Jul/Aug, 2000.
 B&V Project 163528 December 22, 2008, Black & Veatch International Company, Meeting Memorandum, Florida Keys Aqueduct Authority and Florida Department of Environmental Protection, Cudjoe Key Wastewater Treatment Plant.
 2018 Update to the Florida Keys Reasonable Assurance Plan, EPA, p. 13: Effect of Nutrient Addition on Marine Ecosystems of the FL Keys, James W. Fourqurean, Ph.D.
Assessment of Trends in Marathon Coastal Water Nutrient Concentrations and EPA
Target Compliance within the Florida Keys National Marine Sanctuary
Statistical analyses of official EPA data show "consistent time periods of increasing non-compliant nutrient concentrations."
Steven M. Lombardo, M.Sc.
"These tests demonstrate that in the karst geology of the Florida Keys, shallow sewage well injection
is the functional equivalent of a direct discharge to surface waters."
Donald M. Maynard, PG
"..the plants and animals ... of the Keys – the seagrass and corals – are quickly killed and replaced by fast-growing, noxious seaweed if nutrient delivery is increased."
James W. Fourqurean, Ph.D.
"Throughout the Keys, all of the areas within the Halo Zone waters (up to 500 meters offshore)... are impaired for nutrients...." “The Florida Keys are a linear collection of small watersheds which are hydrologically connected at the local level
by near shore waters.”
Florida Department of Environmental Protection, 2018
"First we documented elevated nutrient concentrations (DIN, TN, TP, and SiO2) in waters close to shore along the Keys.
These changes, associated with land/human development, have become even more obvious by the addition of 10 stations
located very close to shore..."
Henry O. Briceño & Joseph N. Boyer
Southeast Environmental Research Center OE-148, Florida International University
Design and implementation of dye-tracer injection test,
Cudjoe Key, Florida Keys, Final Report, 2014
"We conclude that ... injected freshwater at the current injection depth of 80’ to 120’... readily migrates ... to surface waters. These results are similar to those found by other researchers elsewhere in the Florida Keys."
Henry O. Briceño, Reinaldo Garcia, Piero Gardinali, Kevin Boswell, Alexandra Serna