Algae overgrowing seagrass from nutrient overloading 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 sewage, and more fertilizer, gas and oil in the stormwater runoff, all of which contributes to the nutrient-overloading that endangers our nearshore waters.   

Click here for short videos of real water quality problems in the back country.

Taxpayers spent a lot of money for sewer and stormwater upgrades. Didn’t it work?

  • It worked for cleaning up a lot of the bacteria from the septic tanks and cess pits which had caused a lot of the beach closures. 

  • But the shallow waters along our coastline – the nurseries for our fisheries – are still impaired and don’t meet state water quality standards.  

  • This nutrient-overloading can result in algal blooms.

  • Algal blooms can be toxic and endanger human health. They can cause seagrass die off and coral death in the shallow waters that support our outdoor recreation, our fisheries, our tourism industry, our way of life.


Why is the water quality still so bad?  Why is it getting worse?

  • Well, some places in the Keys are doing better than others
    in terms of addressing the problems.  

  • But 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.[i]

    • Only 22% annual average compliance with EPA Strategic Targets for
      dissolved inorganic nitrogen (DIN). DIN is one of the EPA’s two major water quality
      metrics for the Halo Zone (within 500 meters of shore). 

    • Only 58% annual average compliance with EPA Strategic Targets for total phosphorus (TP) – the second EPA major water quality metric for the Halo Zone waters. And that’s a steady 7-year deterioration from a high of 98% annual average compliance in 2011.

  • Marathon has the worst coastal water quality of any major municipality in the Keys! And the trend analysis for the last seven years, the Table below, shows Marathon coastal waters getting even worse.

Keys Coastal Waters - Compliance with EPA's
water quality Strategic Targets: 

only 22% for DIN 
 58% for TP

Summary table of DIN and TP trends at six SHORE stations.

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 "...essential to promote coral growth and overall health." 2017 Florida Keys National Marine Sanctuary Annual Report, Florida International University

FOLKs has transmitted the SHORE analysis to the state Department of Environmental Protection and requested it to require Marathon to undertake studies to determine whether its shallow sewage wells are contributing to water quality deterioration.

Analysis of FKNMS data from SHORE sampling stations by independent scientist Kathleen McKee, MS.

  • Marathon’s five separate wastewater treatment plants are permitted to dispose a total of about .8 million gallons a day (2017 numbers) of partially treated sewage effluent into 5 shallow sewage wells, all located within the 13-mile-long City of Marathon. All are disposing to about the same depth, between 90–120 feet, into porous limestone.

  • Studies conducted by Monroe County for the Cudjoe Regional shallow sewage wells showed water injected into the shallow wells rising rapidly to the nearby surface waters through the porous limestone. [1]

  • FDEP acknowledges the problems with shallow sewage wells. As far back as 2008, according to the minutes of a meeting concerning Cudjoe Wastewater Treatment Plant, FDEP advised FKAA 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." [2]

  • A deep well is the only way to achieve 100% nutrient reduction from sewage effluent at the nearshore waters, the estuary for the rest of our fragile coastal waters, and the waters most impacted by humans. [3]

  • So, Monroe County settled a citizen lawsuit by digging a deep well for Cudjoe Regional. 

  • Key West has a deep well. Islamorada uses Key Largo’s deep well.

  • And to paraphrase the scientists’ concerns, what happens in Marathon doesn’t stay in Marathon; the pollution travels and affects the nearshore waters and the reef tracts throughout the Keys. [4]


Property values, our tourist industry, the health of all who use our nearshore waters are at risk. Our nearshore waters and our reefs are what make the Keys the Keys.


If you’d like to help us make a difference, convincing the Marathon City Council to dig a deep well would really improve water quality for EVERYONE in the Keys. Citizens convinced Monroe County to dig a deep well for the Lower Keys at Cudjoe Regional.  Facts, and citizen pressure, matter!

Write all City Council Members at, and copy George Garrett, Planning Director at and Gus Rios, Department of Environmental Protection, Program Administrator, for DEP regulatory programs at

Please read the source material for this paper in the FOLKs’ reference archive.  Click here.


[1] Design and Implementation of dye-tracer injection test, Cudjoe Key, Florida Keys, Final Report,’ 2014.

[2] 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.

[3] 1995 Fla. ENV LEXIS 129; 95 ER FALR 14, p. 10.

[4] Ibid, at p. 56.

Link to the complete Water Quality Study

Evaluation of SHORE Monitoring Stations in the Context of Nutrient Compliance Targets in Florida Keys National Marine Sanctuary
by Kathleen A. McKee, M.S.


FOLKs is a group of concerned residents who want to preserve the low-density community character of the Lower Keys. We oppose adding 1300 more ROGOs (building allocations) because they undermine 30+ years of science-based and court-approved growth limitations for the Keys. Hurricane evacuation becomes more dangerous and everyday traffic unbearable. Our fragile environment cannot stand more development: the marine ecosystem is continuing to deteriorate even without additional development. We say NO to 1300 more ROGOs!

Proudly created with