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.
Our coastal marine ecosystems are near collapse. Adding more development units in the Keys means even more partially-treated sewage effluent discharged from shallow wells, contributing to the nutrient-overload that pollutes our nearshore waters.
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. See Table below.
Marathon water quality is the worst in the entire Keys and it's actually deteriorating. 
Why is the water quality still so bad?
Shallow sewage wells are a major part of the problem.
Key West, Key Largo, and Islamorada 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 almost one 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. Worse yet, they're fast on their way towards the permitted limit of almost 2.5 million gallons a day!
Wastewater effluent injected into shallow sewage wells is not saline; it's more buoyant than groundwater. It can rise to the nearby surface waters through the porous limestone, which geologists know is full of holes, caverns and conduits. 
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. 
The Table below is a statistical trend analysis for the last seven years and shows Marathon's coastal waters are getting even worse. Meanwhile, Marathon's development is skyrocketing!
Summary table of DIN and TP trends at six SHORE stations.
DIN = dissolved inorganic nitrogen
TP = total phosphorus
This analysis of the SHORE station samples of the Halo Zone from the FKNMS database shows persistent non-compliance with EPA water quality Strategic Targets which are "...essential to promote coral growth and overall health."
Analysis of FKNMS data from SHORE sampling stations by scientist Kathleen McKee, MS.
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 in the FOLKs’ reference archive.
 2018 Update to the Florida Keys Reasonable Assurance Plan, EPA, p.9.
 Evaluation of SHORE Monitoring Stations in the Context of Nutrient Compliance Targets in Florida Keys National Marine Sanctuary, Kathleen A. McKee, M.S.
 Comments by Donald M. Maynard, Licensed Florida Geologist, 2-7-21.
 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.
Evaluation of SHORE Monitoring Stations in the Context of Nutrient Compliance Targets in Florida Keys National Marine Sanctuary
"Water quality sampling since 2008 throughout the Halo Zones of the Keys, shows that for one parameter, samples complied only 22.3% of the time; for the other parameter, samples complied 58.1% of the time."
Kathleen A. McKee, M.S.
"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