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Allen's Blog


A Proposed Public-Private Coalition for an Agricultural Based Long-Term Program for Nutrient Removal, Recovery and Reuse from the Kissimmee-Okeechobee-Everglades (KOE) System

E. Allen Stewart III P.E.

June 10, 2019



PASOP is not involved in any sort of fund raising nor does it contribute funds to any cause or political group. It is a platform for sharing ideas and opinions, including periodic Blogs. This document was written solely by the named author, who received no funds, nor seeks to secure funds, nor does PASOP or the author represent any other entity or seek any political or pecuniary favor from any other entity, now or in the future. Neither PASOP nor the author will seek, or accept any form, direct or indirect, of monetary compensation for any actions taken as a result of the ideas expressed here, but will if asked provide pro bono services as may be appropriate to assist in development and implementation of any such actions.    


“There are no other Everglades in the World. They are, they always have been, one of the unique regions of the earth… ”

This is how Marjory Stoneman Douglas famously opens her 1947 book The Everglades-The River of Grass.  She continues with a description of how the Everglades formed, and how it is bound to Lake Okeechobee to the north and to the water yielding machinery of the Florida peninsula.

It is quite amazing that a woman like Marjory Stoneman Douglas, so conditioned to the relative comfort of urban environs, found herself enthralled, even mystified, by such a large expanse of nature which was largely devoid of the human interactions to which she had become accustomed as a student in Massachusetts and later as a journalist in Miami. In fact she did not really enjoy spending a great deal of time in the Everglades, finding it “too buggy, too wet, too generally inhospitable.”  But she did recognize its importance to the order of things, including the lives of people.

Her understanding of the ecological dynamics of the Everglades was enhanced through her association with Arthur R. Marshall, a University of Miami ecologist who assessed the Everglades as part of a complex system involving not just Lake Okeechobee, but also the attached Kissimmee River Basin with its myriad lakes, whose watershed extends all the way to the western reaches of the Orlando area—including Disney and the collection of theme park attractions along the I-4 Corridor. Marjory Stoneman Douglas said of Art Marshall, “More than any other person, he stretched our idea of the Everglades and how we are connected, which created the most powerful arguments for restoring the ecosystem.”

From Marshall’s work [1], combined with the extraordinary, but often unappreciated intellect of H.T. Odum of the University of Florida, the study of Systems Ecology emerged. If an analogy would help in understanding the premise of Systems Ecology, that analogy would be modern medicine. Just over 200 years ago medicine was practiced with little knowledge of the interaction of the various organs, and the complexity of communications among these organ systems to maintain a balanced functioning body.


As an example, our first president, George Washington, was killed in 1799 by incompetent doctors who still believed that “bleeding” was a useful treatment, and using blistering agents helped the body recover. These actions of course did nothing but worsen Washington’s condition, resulting in his early death. Today Washington’s inflamed epiglottis would have been diagnosed based upon a Systems approach and he would have been effectively treated to survive well beyond his 67 years. This same Systems approach needs to be applied to reclamation of complex ecosystems such as the KOE.


So how would we use Systems Ecology to facilitate meaningful reclamation of the KOE? Let’s start with an understanding that there is a conflict between short-term monetary gain associated with high rates of natural resource consumption, and the expectations—some might say a mandate-- stated within the Preamble of our Constitution that promoting the general welfare and securing the blessings of liberty shall be conducted with equal consideration of “ourselves and our posterity.” This is clearly a message—perhaps a directive--from our Founding Fathers that we conduct our business such that society itself is sustainable and preserved for the benefit of future generations—what Jefferson called usufruct, meaning use without destruction, i.e. preserving resources for others. H.T. Odum noted as such in his book Environment Power and Society  [2] when he said; (you) “shall not take from man or nature without returning service of equal value”.

The constitutionality of short-term economic based decisions has become a serious question that is now being vigorously debated within our courts[3] as they explore the obligations we have to protect the biosphere such that its benefits can be sustained not just for ourselves, but also for our posterity. It is the same conundrum we are facing as we seek some degree of restoration of the KOE. It is a difficult challenge, but then Americans have always been up for a good challenge, and I believe if we discard our prejudices and preconceptions we can find reasonable and effective solutions. But we must give heed to science, even when it demands extensive changes.

In the past, as we developed plans such as the Comprehensive Everglades Restoration Plan (CERP), we have tried to negotiate with established scientific laws and principles such as conservation of mass and energy . Such laws however are not available for negotiation (aside from nuclear reactions), therefore we have no choice but to establish a higher degree of sensitivity to science based facts, for rejecting, ignoring or denying science will not eliminate the inevitability of its influence--what I call the Humpty Dumpty Axiom.

PASOP Humpty Dumpty.png

Offered within this report is a proposed strategy that when aided by political will, creativity, sound science and patience will prove both reasonable and effective. And at its core is a new agricultural approach whose development is to be guided by those who have consistently proven to be the most skilled at initiating and implementing innovation—the American entrepreneur.


The Kissimmee-Okeechobee-Everglades System (KOE) is a diverse collection of ecosystems which includes rivers and streams, lakes, freshwater herbaceous marsh, cypress stands and domes, saw grass marsh, pine forests, rock pinelands, bay hammocks, temperate hardwood and cabbage palm forests, bay heads, tropical hardwood forests, scrub, Everglades Islands, mangrove, salt marsh, sea grass, tidal bays and sloughs, open water estuary and various combinations of these and other ecosystems. All of these component ecosystems over the previous 5,000 years shared materials and energy largely through movement of water, but also through wind, fire, atmospheric fallout, actions associated with indigenous peoples, and wildlife dynamics.

The KOE may be considered an amalgamation of its component ecosystems, adapted to fluctuations in physical condition over the last 5,000 years. These fluctuations included not only seasonal changes, but also severe events such as hurricanes, heavy flooding, fire and extensive drought. The KOE therefore retains stability and a state of dynamic equilibrium[4], or near equilibrium, as long as the environmental stresses do not exceed these fluctuations experienced during the course of its development. This range of tolerance may be thought of as a homeostatic[5] limit, which is essential for the long-term survival of any system, whether it is an expansive system like the KOE, or the human body, or a single celled organism.

When stresses persist which exceed these homeostatic limits, the system will change and will depart from the state of dynamic equilibrium and these changes are often unpredictable and irreversible[6]. Actions by our society have exceeded the previously established homeostatic limits of the KOE, and indeed the system changes have proven to be unpredictable and largely irreversible. How can we bring the system back into a near equilibrium state?

The KOE developed from an elongated 10,000 square mile depression between a central ridge which rose about 100 or more feet above the coastal plain to the west of the KOE depression and a lower elevation ridge to the east which separated the KOE from the Atlantic Coastal Plain and the Upper St. Johns River basin. The St. Johns River parallels the Kissimmee River, but flows northerly, the opposite of the southerly flowing Kissimmee. The positioning of the KOE within the Florida peninsula is noted in Figure 1.


Figure 1:Limits of the KOE in relation to contiguous drainage basins


About 20,000 years before the present (ybp) sea level around Florida was over 300 feet lower than today. This resulted in low groundwater levels, and much drier conditions than we see today. Then sea level began to rise rather rapidly, and at about 5,000 ybp stabilized at levels similar to what we see today.  This higher sea level resulted in higher groundwater, which allowed water to accumulate or “perch” within the KOE Basin. The KOE then began to develop as a series of wet depressions with interspersed uplands. During the wet season (typically mid-June to mid-October) these wetlands would overflow, and this excess water would form slow moving serpentine rivers, such as the Kissimmee River[7] which allocated flow across the gentle north-south slope towards the KOE terminus in Florida Bay some 320 miles to the south. Along the way these flows would encounter a large expanse known as Lake Okeechobee, which provided storage and periodic release of water to the Everglades to the south, and at times to the Big Cypress to the southwest and the Caloosahatchee Basin to the west. 

And so over the past 5,000 years or so, the KOE has functioned to store and allocate flows collected during the wet season, through a strategy I call “Seep and Creep”. In other words, water distribution was rarely in surges or pulse, but rather was modulated by its circuitous routing, the mild slopes, and the frictional resistance offered by the wetland vegetation. This abundance of slow-moving shallow surface water, combined with ample sunlight and optimal year-round temperatures, have allowed the KOE to become biologically diverse and stable. Ironically it is this very feature that our society attacked with such determination. It is only during the past 140 years that this “modern” society has seriously disrupted the KOE.

So when we began to drain and “develop” the KOE--departing from "Seep and Creep" to a "Surge and Purge" water management strategy, the homeostatic limits were eventually exceeded, and the system changed in rather dramatic ways. The first efforts to drain the KOE around the late nineteenth and early twentieth century were comparatively feeble, but by the thirties things got serious, beginning with construction of the Hoover Dike around Lake Okeechobee, followed by a massive and ambitious program known as the Central and Southern Florida Project for Flood Control and Other Purposes or C&SF, in 1948.


By the time the C&SF was completed in the sixties, the Kissimmee River was no longer a serpentine oxbow river, but rather a deep straight canal which accelerated the rate of delivery of flows to Lake Okeechobee; and twenty-seven percent of the Everglades, some 1,000 square miles, just south of Lake Okeechobee had been drained and converted to an intensive farming area known as the Everglades Agricultural Area or EAA. The EAA eliminated the protection this region had previously given to the southern reaches of the Everglades. In addition, throughout the KOE, canals, control structures, and pump station were constructed to control water levels in Lake Okeechobee well below historical levels, and to protect the Dike by providing quick release outlets to the east, west and south.

The intent of the C&SF was to accommodate the needs of both agricultural and urban development, while hopefully protecting the ecological integrity of the KOE; at that time the major environmental concerns were muck fires, salt water intrusion, and disruptive releases to the Caloosahatchee and St. Lucie Rivers. Phosphorus had yet to be recognized as a serious issue. That of course changed when the Everglades began to lose its saw grass marshes and the associated biological diversity. Even Marjorie Stoneman Douglas at first thought the C&SF might be a good plan, but as the environmental degradation continued and even worsened, she withdrew her support.

There are four primary reasons why this degradation of the KOE continued. I call these The Four Horseman of the KOE Apocalypse, as noted in Figure 2. These are:

  1. Flow Manipulation

  2. Excess Phosphorus

  3. Exotic and Invasive Species

  4. Toxic Chemicals

PASOP Four H.png

Correcting the impact of flow manipulation is largely a challenge to recover floodplain. In their 2015 report, The University of Florida’s Water Institute [8] suggested that over 1,000,000 acre-ft. of water storage is needed north and south of Lake Okeechobee, as well as over 500,000 acre-ft. along the Caloosahatchee and St. Lucie Rivers (C-43 and C-44).

Some have suggested that deep reservoirs would use less land, but deep water impoundments are not congruent with the historical dynamics of the KOE, and serious concerns have been raised by EPA officials [9] and others that these deep reservoirs would themselves become incubators for undesirable Cyanobacteria (often called blue-green algae), and that the reservoir would eventually become overloaded with organic sediment—better known as muck—as the excess productivity of the Cyanobacteria settles and accumulates, much as is seen in Lake Apopka[10].

Shallow impoundments which emulate historical conditions are more likely to facilitate a return to near equilibrium conditions, and the South Florida Water Management District (SFWMD) is now pursuing a fee-based program to lease lands from private landowners to allow periodic flooding in an effort to regain floodplain. This program was initiated as Northern Everglades Payment for Environmental Services (NE-PES), and is now called Dispersed Water Management or DWM. This PAY-FOR–PERFORMANCE concept is similar to that to be discussed further into this text. Of course the 500 pound water storage gorilla is the 650,000 acre EAA which could, upon procurement, be converted, with some effort, to provide the needed storage as well as treatment prior to release to the south—which was this area’s historical role before its conversion to the EAA. But that is a discussion for another day. Let’s talk now about that second horseman, excess phosphorus.   



The biological dynamics of the KOE is influenced by what might be called The Phosphorus Paradox. Being isolated from its neighboring basins, and having no communication with the large rivers coming into Florida from Georgia and Alabama, such as the Suwanee, the Apalachicola and the Escambia, the KOE had to rely almost entirely upon phosphorus delivered by rainfall and atmospheric fallout, and to a lesser degree from wildlife immigration and groundwater inputs. Considering the low concentration of phosphorus within rainfall/fallout, and an average annual rainfall of 53”, it can be calculated that about 300 tons per year of phosphorus were delivered to the Kissimmee-Okeechobee segment of the KOE.

While estimates vary, with the development of agriculture and urbanization, the phosphorus load contributed now to this segment is over 3,000 tons per year—or a ten-fold or greater increase—see Figure 3. The KOE had never experienced such a consistent dramatic change, and so its homeostatic limit was exceeded, and it moved away from a near equilibrium state. The system’s first response was to try to sequester this excess phosphorus by storing it in the soil and lake sediments. But the storage capabilities of the system have become overwhelmed.

PASOP P loads.png

Where does this excess phosphorus come from? And here is the paradox. It comes from right next door—from the Peace River and West Central Coastal Basins. While the KOE development was influenced by a scarcity of available phosphorus, the basins to the west, which were characterized by shallow seas and estuaries some 15 million ypb, accumulated large amounts of phosphorus from alluvial sources and from chemical precipitants. These accumulations now exist largely as phosphorus rich rock known as phosphorite, within what is called the Bone Valley Formation. Discovered in the nineteenth century, the Bone Valley represents the largest phosphorus deposit in the United States, and one of the largest in the world. Over 3,000,000 tons of phosphorus are taken annually from this formation, and a large portion is converted to fertilizer—often in the form of diammonium phosphate. Florida’s phosphate provides 75% of the phosphorus used in the United States, and 25% of the world demand. And it is the source of the excess phosphorus brought into the KOE. So thanks to its neighbors, the KOE now has more phosphorus than it knows what to do with—and it is comparatively cheap, at least until it is lost to the environment where it becomes a pollutant.

In the eighties, when Cyanobacterial blooms on Lake Okeechobee first got everyone’s attention, including Governor Bob Graham, the SFWMD formed a series of Technical Advisory Groups, including the Lake Okeechobee Technical Advisory Committee or LOTAC. This was a period when eutrophication of lakes was getting a great deal of attention throughout the United States, and models were being developed to assess the impact of nutrient loading—particularly phosphorus—on the rate of algae production within lakes. The SFWMD, as I recall, ran the Vollenweider Lake Eutrophication Model [11] on Lake Okeechobee, and the results at the time did not seem too alarming. There was a  problem however with this model, for it was developed for northern lakes, not shallow subtropical lakes, and it included a presumption that a portion of the incoming phosphorus load was retained within the lake sediments and generally assumed to be rendered biologically unavailable—expressed in the model as a phosphorus retention coefficient. Along with several scientists, I was concerned that this retained phosphorus would eventually return to the water column and become biologically available—I had done my Masters’ thesis on this subject[12]. I wrote a letter in 1987 to the LOTAC expressing this concern—quoting from this letter, “the Committee is placing great confidence in the presumption that biological availability of phosphorus within the lake will be reduced and that sediment held stores cannot be biologically exploited; a presumption in which I personally have little confidence.”

Move forward now to the UF Water Institute Report of 2015, where the writers talk about this excess stored phosphorus, which they call legacy phosphorus, but I prefer to call rogue phosphorus or Stored Excess Anthropogenic Phosphorus (SEAP). As expected this legacy phosphorus has emerged as a serious problem, and it is estimated that over 110,000 metric tons as available phosphorus is now held within the Lake Okeechobee Watershed. Consider the following statements from the 2015 report.

“Phosphorus that remains in the watershed and is stored in soils is considered a legacy pool that can contribute to overall P(hosphorus) load even after P(hosphorus) imports are decreased…. legacy (rogue) Phosphorus in the Lake Okeechobee watershed (110,000 metric tons) could sustain contemporary Phosphorus loading rates, i.e. 500 metric tons per year, for more than two centuries.

​Beyond existing and planned approaches, the substantial reservoir of legacy (rogue) phosphorus in the Northern Everglades watersheds (i.e. Kissimmee-Okeechobee watersheds) will necessitate new and more aggressive strategies to combat the mobility of phosphorus.…Legacy Phosphorus  in the Lake Okeechobee watershed is of particular concern because current efforts to achieve the Lake Okeechobee TMDL (Total Maximum Daily Load) have proven inadequate. None of the current BMAPs (Basin Management Action Plans) for the Lake Okeechobee, St. Lucie or Caloosahatchee watersheds will achieve their respective TMDLs within the next 5 years”

To translate, what is being done is insufficient to manage phosphorus, for not only should aggressive efforts be implemented to greatly reduce imports, but new technologies are needed to manage this massive legacy store. In the 2015 report reference is made to immobilizing this phosphorus, but includes no real indication what immobilization means other than somehow rendering legacy phosphorus unavailable biologically. This presumption of course is what got us in trouble in the first place. I suggest therefore that immobilization is best accomplished by actual recovery and removal from the basin. How can this be done?

Some of you may be asking, why is phosphorus of such a concern. The answer--because it can stimulate excessive production of primary producers (photosynthetic organisms), which in lakes includes suspended algae and photosynthetic bacteria such as Cyanobacteria. As a result of this legacy phosphorus, there has been documented a steady rise in the concentration of total phosphorus in Lake Okeechobee, increasing from about 50 micrograms per liter or parts per billion (ppb) in 1970 to a present level of about 130 ppb, as noted in Figure 4.    


Figure 4: Total Phosphorus Concentration in Lake Okeechobee 1973 to 2000

As an example of how such change in phosphorus concentration could impact the lake's ecology, imagine two species of suspended algae. Suppose one is non-toxic and is a beneficial component of the systems ecology. Suppose there is also present a toxic algae, which in low concentrations may not have a deleterious impact, but which can have far-reaching toxic effects when the concentration increases. 

It is well known that different species of plants, including algae, have different innate growth rate potentials, and that this potential is approached at different levels of availability of critical nutrients. In our example, the non-toxic algae, as might be expected in a phosphorus scarce  condition, would be characterized by a low growth rate--growth rate being the fraction of biomass change per unit time--but an ability to achieve this rate at low phosphorus concentrations. The toxic algae conversely may have a high growth rate potential, but require higher phosphorus levels to achieve this rate. In his book Chemical Kinetics and Process Dynamics in Aquatic Systems Pat Brezonik[13] gets into the details of such dynamics.


For this exercise then, consider two 14-day periods when all other conditions are steady and optimal. The first period considered is characterized by phosphorus concentrations around 50 ppb--conditions similar to what was noted in Lake Okeechobee in the seventies. Here the non-toxic algae as shown in red in Figure 5, dominates the toxic algae, producing 69,069 cells as compared to just 8,955 cells for the toxic algae. But look what happens when phosphorus increases to 130 ppb, characteristic of conditions in 2000. 

PASOP Growth Curves.png

The toxic algae not only assumes dominance, it explodes to over 21,000,000 cells. While this is a hypothetical example, and perhaps a bit simplistic, it is based upon established scientific pinciples. Considering this example, we should not be surprised when toxic Cyanobacteria gain a selective advantage when phosphorus becomes readily available to a system which for 5,000 years developed with relative scarcity of phosphorus.  

Figure 5: Example of potential impact of excess phosphorus on algal species dominance

Presently the involved agencies, including SFWMD, the Florida Department of Environmental Protection (FDEP) and the Florida Department of Agriculture and Consumer Services (FDACS) in an effort to manage this excess phosphorus use systems such as unharvested wetlands called Stormwater Treatment Areas (STA’s), or as with agriculture, holding and storage systems as part of their Best Management Practices or BMP’s. These of course are not treatment systems at all, but rather storage systems. There is no net removal of legacy phosphorus—in fact these systems actually increase legacy phosphorus by retaining new imports within the basin. Again, we are back to the “retain phosphorus and hope it disappears” approach, or as I sometimes call it, “the spreading of Magic Dust”--see Figure 6.

PASOP magic ust.jpg

Figure 6: The application of "Magic Dust" in hopes that stored excess phosphorus somehow remains sequestered and biologically unavailable within the KOE.

These presumptions violate the basic law of conservation of mass, and yet everyone from scientists and academicians, to activists, to politicians and agency people seem to suffer from “group think” and call STA’s treatment wetlands, and BMP’s treatment systems. Those who wrote the 2015 Water Institute report certainly recognize this misconception, but they also supported expanding STA acreage, as they are a key component of CERP and related programs. They do however hint that some type of aggressive management may be needed once these systems become saturated.

Now if you remain a believer in the STA or "Magic Dust" approach consider two more facts. The first is that STA’s store phosphorus at a low rate when compared to other options—typically about 15 pounds are removed from the water column and stored within the STA soils each year for each acre or 133 acres for each ton of phosphorus removed annually.

The second fact relates to cost. If it is necessary to develop programs to deplete the legacy load of 110,000 tons, at least 2,000 tons of phosphorus would need to be removed annually for 50 years, or stored as in the case of STA’s. This would require about 276,000 acres of STA, or over five times what is presently available, and would produce an estimated 17,000,000 cubic yards of muck at 5% solids each year, representing over 1,000,000 loads of a 16 cy dump truck. Noted in Figure 7 is a muck removal operation associated with an STA type system known as The City of Orlando’s Easterly Wetland. The Orlando system is modest in size when compared to the STA's in the KOE--both existing and proposed. The magnitude of the effort to remove this material from thousands of acres, and then locate to an environmentally acceptable depository site would be overwhelming. 

A study by the University of Florida Institute of Food and Agricultural Sciences (IFAS)[14] provides indication that on a 50 year present value cost for removal basis, one pound of phosphorus using STA type systems varies from about $34 to over $500 (excluding any muck removal or hauling), depending upon initial concentrations, percent reduction and other factors. Technologies which rely upon the periodic harvesting of cultivated aquatic plants—systems known as Managed Aquatic Plant Systems or MAPS, were considerably lower in cost, even without consideration of developing products from the harvest, and the return from sales of these products. 


So as a pollutant, phosphorus is very expensive to remove. As a fertilizer, one pound of phosphorus on the retail market may be worth about $1.80. To remove one pound of phosphorus as a water pollutant in the KOE typically costs well over $100.

But remembering that pollution is nothing more than a misplaced resource, suppose we approach phosphorus in our waters not as a pollutant, but as free fertilizer. The remaining question then is, a fertilizer for what crop? Well, phosphorus is a pollutant because it acts as a fertilizer promoting aquatic plant and algae growth. So perhaps aquatic plants and algae would be the logical crops. If aquatic plants and certain types of algae can be cultivated in phosphorus polluted water, then the grower would have available two sources of income—the environmental service fee for actually removing phosphorus from the water, and the return from sales of products developed from the harvested aquatic plant and algae crop. In simpler terms, it is innovative farming. And assuming the environmental service fee were less than what is presently being paid for STA’s and related non-harvested systems, then the agencies also derive financial benefit. So how do we implement such an approach?

First, let’s take a quick look at the history and present status of aquatic plant cultivation. There is indication that the Mayan Indians actually cultivated aquatic plants within canals leading from their cities over a thousand years ago. These plants would be periodically harvested and composted on land or allowed to compost and collect as muck in the canals. The compost replenished the tropical soil, which often deplete quite quickly. By replenishing these soils, the community was able to sustain a fixed location within the jungle. This allowed the development of a more complex and diverse culture.

In the late nineteen sixties through the eighties the cultivation of aquatic plants such as the water hyacinth was seriously considered for nutrient removal from wastewater. Later the concept was expanded to include other aquatic plants as well, such as attached (periphytic and epiphytic) algae, with engineered systems developed to reduce nutrients from impaired surface water. These types of systems are now called Managed Aquatic Plant Systems or MAPS—see Figure 8. They are presently being applied all over the world. The Chinese for example are cultivating and harvesting contained stands of water hyacinth in some of their large reservoirs to reduce nutrients and to inhibit development of Cyanobacteria[15]. In Indian River County, Florida two 10 MGD Algal Turf Scrubbers® or ATS™ are being used to help meet the TMDL requirements for the Indian River Lagoon. In Baltimore the Maryland Port Authority is in the planning and design phase for an ATS™ to be used for meeting nutrient reduction needs for Chesapeake Bay.

A number of products have been associated with MAPS programs, including Biogas generation; livestock feed; compost and potting soil; fiber products, including manufacture of furniture from water hyacinth fiber; and various extracts. Duckweed is presently being developed for its high protein content[16], and has shown to out-pace the protein production of crops such as soybean by several-fold. And these are just vanguard investigations and applications for the most part; serious product and system development has not yet been initiated on a large regional scale. How do we get the entrepreneurial sector more excited about the potential of MAPS? 


Figure 8: (a) Hyacinth Harvesting S-154 facility north of Lake Okeechobee (b) Chopping hyacinths at the same facility. Many of these chopped hyacinths were fed to nearby cattle. (c) Harvesting a 10 MGD ATS™ facility near Vero Beach, Florida that has been in operation for nearly 10 years (d) collected harvest from a full scale ATS™ unit. (e) Composting windrows, harvested aquatic plants (f) Biogas production from chopped water hyacinths.


Figure 7: Excess Muck and Phosphorus Removal City of Orlando's Easterly Wetland 


If a PAY-FOR-PERFORMANCE program is to work there must be a long-term public need for the development of technologies to solve a particular challenge(s). Think of the need for weaponry and support vehicles for 

World War II, and the response by private groups such as General Motors, American Motors and Ford. Also, consider the space race of the fifties and sixties. The Government provided PAY-FOR-PERFORMANCE opportunities to companies such as General Dynamics, Martin and Douglas, and they responded.


I remember in the middle of the scrambling to get to the moon first, some complained of the high costs. Considering the contributions the resulting technical advances have made to our computer driven society and its economy, there is little question the return on investment far outweighs the initial costs. And so there is precedence for a PAY-FOR-PERFORMANCE approach to solving problems while also promoting new paradigms and new economic opportunities.

PAY-FOR-PERFORMANCE for phosphorus removal and recovery within the KOE would as a minimum require the following:

  1. The involved agency(ies), e.g. the SFWMD, must provide a written commitment that for each pound of phosphorus actually removed from impaired surface waters and taken out of the KOE, the private service contractor would receive a set dollar amount, which could be negotiated on a case by case basis or could be set as a fixed amount.

  2. This commitment would be applied in perpetuity in order to provide risk protection to interested entrepreneurs and to entice them to participate. The actual fee structure(s) could be revisited every few years to adjust to economic and operational changes.

  3. The net removal goal for the KOE would be at least 2,000 tons of phosphorus each year. This might be done by a number of technologies, and the technology used by the private service contractor will be selected solely by the service contractor, who will be responsible for its permitting and implementation and all liabilities associated with products.

  4. Performance would be monitored jointly by the agency and the private service contractor, who would assess the actual pounds of phosphorus removed as product exported from the KOE basin. There would be no “presumed” removal, but rather documentation of actual, verifiable removals.

  5. All PAY-FOR-PERFORMANCE facilities and associated activities would be properly permitted by the private service contractor and have no significant impact on other features of the environment.

  6. All costs associated with land purchases, construction, start-up, operation and maintenance, and product development, processing, marketing and distribution will be the sole responsibility of the service contractor. Monitoring costs will be assumed by both the involved agency and the private service contractor as duplicate assessments.

  7. It is my opinion that if the entrepreneurial community is not included as a key participant in the KOE restoration program, there will be no meaningful restoration. Their involvement is not just important, it is vital. This has proven true in many situations in this country’s history, including the war effort, the space race, and upgrading of the nation’s wastewater infrastructure per section 201 of the Clean Water Act.   



Managed Aquatic Plant Systems is but one technology which might help meet the phosphorus removal goals of 2,000 tons per year from the KOE. I have worked in the development of MAPS for about 40 years—with some projects being successes, and some not so successful. While it can be embarrassing to face mistakes made, I always remember the words of John Stuart Mill—“ error is a necessary component of knowledge.” As example, many of you may remember the early days of the space race. My brother was one of the Wunderkinds working with General Dynamics. I remember the first Atlas missile they shot from the Cape. It blew up after just a few seconds in the air. The press treated it as a dismal failure, but the engineers on the program learned a great deal from that first flight. Obviously they finally got it right. This PAY-FOR-PERFORMANCE idea may well suffer some of the same challenges and set-backs, but certainly a society that can develop driverless cars, put a rover on Mars and investigate the nature of Dark Matter, should be able to improve the efficiency of aquatic plant cultivation and product development. 


Over the years I have helped develop growth dynamic based design models for MAPS, including water hyacinth systems, and Algal Turf Scrubbers®. Generally these systems remove phosphorus at a rate five to ten times higher than non-harvested STA’s. It is not unusual to see removals in the range of 150-250 pounds of phosphorus per acre per year. Therefore with a goal of 2,000 tons of phosphorus removal per year, about 30,000 to 40,000 acres of actual MAPS cultivation units would be required, considering access and freeboard, etc. Adding acreage for storage and processing of the harvest; pumping facilities and force mains and gravity piping; security; monitoring; and administration and maintenance, the total required area might approach 80,000 to 90,000 acres. Envisioned is perhaps 70-90 facilities each about 1,000 acres located around the lake and possibly at the interface with the EAA. Each facility would remove and recover about 120 pounds of phosphorus each day, and flows for each facility would be from 80-120 million gallons per day (MGD).

The MAPS facilities would include a process train of several different types of MAPS, which together would serve as a “kidney “ unit, taking low quality water from the lake or designated reservoir, and returning a higher quality water lower not only in phosphorus but also turbidity, while high in dissolved oxygen. In combination these facilities would turn over the lake volume about 2-4 times a year.  Shown in Figure 9 are before treatment and after treatment pictures from a 10 Million Gallons per Day (MGD) Algal Turf Scrubbers® MAPS owned and operated by Indian River County. Noted in Figure 10 is the lake which receives the treated effluent from this facility. A large bass can be seen near the cypress tree in the picture. Based upon such long term operational evidence, it is reasonable to expect that effluent from each of the proposed “kidney” MAPS facilities associated with Lake Okeechobee would be effective fish attractors, and contribute to overall health and fecundity of the fishery.   

PASOP Egret Marsh.png

Figure 9: Quality of source water from an agricultural canal in Indian River County compared to the same water after treatment through a 10 MGD Algal Turf Scrubbers® Facility 

PASOP Bass.jpg

Figure 10: Receiving lake Algal Turf Scrubbers® MAPS Effluent Indian River County


Figure 11: Typical Integrated MAPS Facility as a "kidney" system

The process train for each MAPS facility could involve a combination of floating aquatic plants, floating littoral mats (BeeMats™ [17]), ATS™, and submerged and emergent wetlands managed through periodic harvesting (STA-MAPS). A general schematic of a practical MAPS process train is shown as Figure 11. 


There is little debate that agriculture is a major contributor of phosphorus to the KOE, particularly north of the lake. Portions of fertilizer phosphorus used on pasture and crop farming, as well as that contained within livestock feed have a way of finding the closest water body either through direct discharge or seepage of groundwater through phosphorus saturated soils.

I have been a farmer in Okeechobee County, so I know how difficult farming can be, and how risky it is as a business venture. If it is not the weather, it is the market or pests, or power outages, or diseases that are attacking the bottom line. When you add increasingly stringent regulations, it is not difficult to understand any skepticism the farming community might have towards environmental projects within the KOE.

But suppose agriculture could be a nutrient consumer not a nutrient polluter. MAPS is in fact this form of agriculture. I describe MAPS as follows:

Managed Aquatic Plant Systems (MAPS) are agriculture and offer an “agricultural solution to an agricultural problem”. It is a variant of typical agriculture, for the primary intent is not to maximize productivity of a targeted crop as with conventional agriculture, but rather to maximize reduction of pollutants from an impaired water source. In other words, MAPS operations do not involve adjustment of nutrient levels in the feed water to ensure high levels of crop production and quality, but rather involve adjustment of crop selection and operational strategies to ensure high rates of nutrient reduction from the raw feed water, such as a nutrient enriched, impaired surface water. With conventional agriculture the crop is the primary product, while with MAPS, enhanced water quality is the primary product, although crop recovery and utilization are important. This approach represents a significant paradigm shift from the general acceptance of agriculture as a net pollutant contributor, to the reality that there are forms of agriculture that can offer substantial net pollutant removal and recovery."

Now imagine using a MAPS approach to convert phosphorus from the KOE to   substantial quantities of high valued products—say for example a dairy feed ingredient. Indeed testing has been done on the use of aquatic plants as a livestock feed ingredient, and they have generally been favorable. The challenge relates more to quantity; reliability of the supply train; and quality control.

So consider an example. Suppose a dairy has a requirement for a certain quantity of phosphorus in its feed. Also suppose a private  PAY-FOR-PERFORMANCE service contractor has several MAPS facilities and is able to process his/her aquatic plants into a high quality feed ingredient that contain most, if not all of the dairy’s phosphorus needs. This service provider would negotiate a reasonable contract with the dairy for this ingredient, recognizing that the dairy farm could significantly reduce the transportation costs associated with importing phosphorus containing products. When the dairy farmer then sold milk, he/she would be exporting a product which contained phosphorus from the KOE, hence he/she would be paid by the administering agency of the PAY-FOR-PERFORMANCE agreement for the phosphorus contained in the milk. At the present value of milk at about $15-20 per hundredweight, this PAY-FOR-PERFORMANCE return could amount to as much as a 25% increase in the value of the milk. A schematic of this strategy is shown as Figure 12.   

PASOP Dairy2.png

Figure12: Proposed Pay-For-Performance Strategy  KOE Dairy Positive feedback

Want another example? Consider a nursery that grows and sells native plants for habitat restoration, reclamation or roadside cover. These plants might be wetland plants, salt cord grass, Muhly grass or sea oats—all of which are used extensively throughout the state. Say these plants could be grown hydroponically within impaired surface water from Lake Okeechobee through the use of BeeMats™ or other  

similar methods, or in compost generated from the MAPS harvest. In both instances, the sole source of phosphorus for these plants would be from KOE surface water. When the nursery owner delivers the plants to projects outside the KOE, he/she would receive payment for the phosphorus contained within these plants. It does not take much imagination to think of other examples.


This PAY-FOR-PERFORMANCE proposal is ambitious, and it will take an extended transition period for successful full-scale implementation. It needs to be realized that MAPS technology, and other technologies which might be applicable to this program, need further refinement, especially with development of products and markets, and with design of more efficient harvesting and initial processing systems. These developments can only happen if the entrepreneurial community is convinced of future payoffs and are certain they are dealing with a level playing field. This can be provided through firm long-term incentives from government, primarily as written commitments to pay for removed phosphorus.  Other incentives could be short-term subsidies for product development through demonstration and research projects and encouraging other agencies to give purchase priority for products associated with phosphorus removal from the KOE—for example FDOT may first seek plant purchases for roadside use from vendors who use recovered KOE phosphorus as the sole fertilizer for plant cultivation.

As this proposal undergoes review by scientists, engineers, farmers, agency personnel, politicians and others, I would expect many reasons will be given why it will not work. I would ask these same people give reasons why it could work. It will take patience and political will to see such a  program to successful full-scale implementation, but we have taken on such challenges before.


The answer to this question is straight forward--the citizens within the KOE and visitors to the KOE pay in proportion to their phosphorus contributions. With 2,000 tons (4 million pounds) of phosphorus to be removed each year, if the PAY-FOR-PERFORMANCE fee averages $100 per pound of phosphorus removed, the annual cost for meeting this fee is $400 million. Administrative and monitor costs would be added to this. Suppose then the annual budget for the administering agency is $500 million. If we spread this equally among the 1-2 million or so permanent citizens of the KOE, this would amount to $250-500 per year or $21- 42/month for each citizen. But what about the 72 million annual visitors to the Orlando theme parks which are within the KOE? If each visitor paid an additional $5 fee, the income to the program would be $360 million. This would lighten the imposition on permanent residences considerably.

A KOE PAY-FOR-PERFORMANCE Utility with authority to impose and collect fees will be required to develop and implement a user fee plan. This plan would be like user fee plans presently required for water and wastewater utilities.


A MAPS based PAY-FOR-PERFORMANCE program would generate jobs and new business opportunities. Direct operational employment for the proposed 70-90 facilities would likely be between 2,000 to 3,000 jobs. There would also be new jobs for support entities, such as companies providing transport, public relations, accounting, fabrication, engineering, utilities, human resources, etc.


A real benefit with development of more efficient means of harvesting and processing aquatic plants would be the eventual transition away from the use of herbicides within lakes and canals, which simply recycle nutrients within the water body, in favor of effective mechanical harvesting programs, which do remove nutrients from the water body. The mechanical harvesting contractors would be eligible for the PAY-FOR-PERFORMANCE fee as long as they showed the same level of removal required of others. This added income is likely to increase the interest of potential Mechanical Harvesting Contractors.

An effective PAY-FOR-PERFORMANCE program will result in enhanced property values and improved water quality, which will improve fisheries and increase revenues associated with recreational fishing and other outdoor activities. This program would also provide relief to the Caloosahatchee and St. Lucie Rivers from heavy phosphorus loading from Lake Okeechobee.


Of equal importance are the benefits which would be associated with the development of a new agro-industry based upon technologies such as MAPS. Like the technological development associated with programs such as the aerospace industry, the spin-offs from a widespread application of innovative concepts such as MAPS will likely be more extensive than what can initially be anticipated, and accordingly will provide society a healthy return on investment. And in keeping with our Constitution, this PAY-FOR-PERFORMANCE program would be congruent with our obligations to “ourselves and our posterity” by moving the KOE towards a more stable, near equilibrium status.      


[1] For a collection of Art Marshall's writings

[2] H.T. Odum (1971) Environment Power and Society John Wiley and Sons ISBN 0 471 65270 9; LOC 78-129660

[3] Julianna et. al. vs. United States of America. Young people suing the government for promoting fossil fuel consumption when knowing the harmful long term health impacts on the plaintiffs’ lives. 

[4] Dynamic equilibrium occurs when a system that otherwise is prone to changing in fact is displaying no overall change. This lack of overall change is a consequence of a balance between forces that otherwise would result in a change to the system and those forces that instead serve to restore the system.

[5] Homeostasis is defined as a self-regulating process by which biological systems tend to maintain stability while adjusting to conditions that are optimal for survival. The stability attained is actually a dynamic equilibrium, in which continuous change occurs yet relatively uniform conditions prevail.

[6] The reactions of biological systems in near-equilibrium and far-from-equilibrium states has generated interest in the complexity of systems and how they self-organize, and has led to development of chaos theory and better understanding that the nature of systems' reactions to stresses depends upon the initial conditions, and hence there is an unavoidable uncertainty and irreversibility as systems departs from near equilibrium conditions. 

[7] I have read that while it is not certain, there is some indication that Kissimmee was a Calusa word meaning “Crooked Waters”

[8] Options to Reduce High Volume Freshwater Flows to the St. Lucie and Caloosahatchee Estuaries and Move More Water from Lake Okeechobee to the Southern Everglades An Independent Technical Review by the University of Florida Water Institute March 2015

[9] This concern was clearly expressed by Richard Harvey of USEPA in 2005 see Orlando Sentinel article


[10] Lake Apopka in Central Florida was, because of poor understanding and abuse, transformed in the fifties and sixties from a clear spring fed lake of high economic value and high biological diversity to a hypereutrophic, turbid lake of much less value, which maintained a constant bloom of Cyanobacteria.

[11] Vollenweider, R.A.1976. Advances in defining critical loading levels for phosphorus in lake eutrophication. Mem. 1st. Ital. Idrobiol. 33: 53-83. 

[12] E. Allen Stewart 1976 University of Central Florida, Master's Thesis A Study of Differences in Vertical Phosphorus Profiles Within the Sediments of Selected Florida Lakes as Related to Trophic Dynamics

[13] Brezonik, P.L.1993 Chemical Kinetics and Process Dynamics in Aquatic Systems CRC Press, Inc ISBN 0-87371-431-8

[14] Sano D., A. Hodges, and R. Degner. 2005, Economic Analysis of Water Treatments for Phosphorus Removal in Florida University of Florida IFAS, Gainesville, Florida



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