This is part 2 of our 3-part series about elements. Last time we met nitrogen, today, it’s partner in crime and in life – phosphorus.
WLRN Environment Editor Jenny Staletovich has gotten to know the main character of this story pretty well after reporting on the environment in South Florida for more than a dozen years. Bone Valley in Central Florida has quietly fed the world’s hunger for phosphorus, even as its waters, in particular the Everglades, suffer from the fallout.
In this episode, you'll meet fishing captains turned environmental crusaders, hear about Guano Wars fought over this "Devil's Element," and learn how some are figuring out how to fix our phosphorus paradox.
CREDITS
WLRN Environment Editor Jenny Staletovich reported this story. The episode was hosted by Executive Producer Carlyle Calhoun. This episode was edited by Eve Abrams. Editing help from Carlyle Calhoun, Michael McEwan, Ryan Vasquez, Alana Schrieber, and Eva Tesfaye. Sound design by Dennis Funk, and our theme music is by John Batiste.
Sea Change is a WWNO and WRKF production. We're a part of the NPR Podcast Network and distributed by PRX. Sea Change is made possible with major support from the Gulf Research Program of the National Academy of Sciences, Engineering, and Medicine. WWNO's Coastal Desk is supported by the Walton Family Foundation, the Meraux Foundation, and the Greater New Orleans Foundation.
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TRANSCRIPT
COLD OPEN
[Ambi of traffic speeding by]
Just west of Miami sits an industrial neighborhood in the city of Hialeah. It borders old rock mines, which used to be swampy Everglades. When it rains here, there is A LOT of stormwater.
Ali Ebrahimian: So this is called a catch basin or an inlet. That's the first point where the stormwater off of the street gets into our storm sewer network.
Ali [Ah-lee] Ebrahimian [Ebb-rah-heem-ian] is a water resources engineer at Florida International University, a major research university in South Florida. They do a ton of work on wetlands.
Ali Ebrahimian: You see a lot of these, you know, on your streets, right?
Jenny: Everywhere.
Ali Ebrahimian: Everywhere.
[underbed traffic ambi]
Ebrahimian let me tag along on field work with some students who’ve been collecting and analyzing stormwater to check for phosphorus and other chemicals in water. They’re looking for pollution hotspots. This one looks like it certainly fits the bill: There’s a LOT of traffic, a big rig truck parking lot across the street and a metal works shop a few blocks down.
Ali Ebrahimian: Right now here, we're in a commercial area.
Jenny: I was gonna say it's a little smelly. I don't know if that's from this or we're near something else.
Ali Ebrahimian: Well, there's a food truck here too, I dunno. Ha ha ha.
Could be. The food truck sells ceviche. Or it could just be the storm drain. It’s one of those super-sized drains that collect stormwater.
You can find them all over – in almost any city.
And stormwater, especially along the coast or towns that front lakes and rivers, is a growing problem. It’s one of the main ways pollution gets moved around, especially phosphorus.
At this drain, a couple of Ebrahimian’s students have been collecting water so they can see what exactly is running off the street, like phosphorus that can pollute freshwater. To do that, they drop some plastic tubing into the drain and attach the other end to a pump in the back of their pickup. That’ll suck up the water to fill collection jugs that they’ll test in the lab later in the day. They also attach a filter to collect micro plastics. But the water is so polluted, that within just a couple minutes, the filter clogs and pops off the hose…
Ali: Oooh. [Jenny laughing]
… which sprays me in the face with the stormwater
These are the things that can happen in the field.
Jenny: I did not expect that.
Ali: No, it happens.
One of the students, Chloe McGuire, grabs a pack of wet wipes.
Chloe McGuire: I bring those for when that happens. Just to get yourself cleaned up.
The filters clog a lot. Because all that pollution in the stormwater, especially from these kinds of urban neighborhoods dump really dirty water into canals, rivers and estuaries like Biscayne Bay here in South Florida. It’s the same up and down the state and all along the Gulf Coast.
And that is a real problem.
CARLYLE: That’s WLRN environment editor Jenny Staletovich. And you’re listening to Sea Change. I’m Carlyle Calhoun.
This is part 2 of our 3-part series about elements. Last time we met nitrogen, today, it’s partner in crime and in life – phosphorus. We can’t live without either; But when we unleash too much of them, they become something darker: the invisible force behind toxic blooms, dead fish, and sickened communities.
Jenny has gotten to know the main character of this story pretty well after reporting on the environment in South Florida for more than a dozen years. And Florida is the perfect location to tell this story from—a state where a place known as Bone Valley has quietly fed the world’s hunger for phosphorus, even as its waters suffer from the fallout.
Jenny takes it from here.
***************
In the natural world, phosphorus binds itself to things - like rocks and bones. But we keep mining it to produce fertilizer, and adding more to the planet.
We also keep adding more people to the coasts. And that worries stormwater engineers like Ebrahimian. The more people who build houses that pave over wetlands, make more stormwater AND add pollution, the harder his job becomes to manage stormwater in a way that doesn’t hurt the planet.
Right now, the coasts make up about half the country’s population. But he says in 30 years…
Ali Ebrahimian: It's gonna be around 75% or 80%.
So you gotta find a way to deal with phosphorus and all the other pollution.
The dilemma with phosphorus is that it can be both our friend and our enemy. It is essential to life. It literally holds our DNA together. It makes our bones strong. And we absolutely need it for fertilizer to grow food, so it’s a matter of food security. We use it in household cleaners and in semiconductors, radar and pharmaceuticals. But too much of phosphorus out in the wild, in lakes and coastal estuaries where people boat and swim, can be a bad thing.
The Everglades and its liquid heart, Lake Okeechobee, evolved without hardly any phosphorus. It’s why the Everglades has the River of Grass, which grows in the Glades’ mucky peat, instead of a river of cattails, which explode when water loaded with phosphorus floods the swamp.
What’s ironic is Florida is partly to blame for our phosphorus problem. Back in the 1800s, a surveyor with the U.S. Army Corps of Engineers discovered the largest deposit of phosphate in the nation in Central Florida. Phosphate is the mineral that forms from phosphorus.
FILM 1970: Three fourths of all the phosphate now produced in the United States is mined within 25 miles of Lakeland by huge drag lines.
All that mining created one of Florida’s most lucrative industries – what would come to be called Bone Valley. We’ll get to Bone Valley a little later.
What we didn’t fully appreciate were the risks and trade-offs from all that mining.
Randall Parkinson is a geologist at FIU. He says all the fertilizer made growing food a lot easier. But so did polluting the planet with too much phosphorus.
Randall Parkinson: So you have almost immediate deleterious impacts from phosphate mining, or application of fertilizers and ag land and uncontrolled runoff, hence the Everglades.
He’s talking about all the phosphorus pollution in the Everglades.
Randall Parkinson: Uh, and then as humans are, we didn't know or didn't care, didn't think about it at the beginning, but it takes a lot more money and time to fix it than it would've been to prevent it.
******
We’re gonna start with what can happen when you get too much of a good thing.
Daniel Andrews: I forgot to sign up for classes one summer.
Captain Daniel Andrews is a former fishing guide on Florida’s Gulf Coast.
…My parents were out of town for about a month and they got home and they’re like, what are you doing? Why aren’t you in school? I’m like, oh, I’m a fishing guide now. Signed up for captain’s license. And school’s not quite for me and this is, uh, what I’m going to do now.
This was in 2011. As Andrews would find out, water pollution can kill business.
Andrews grew up in Fort Myers, where the Caloosahatchee River empties into Pine Island Sound and then, into the Gulf of Mexico. He says he’d race through the week, to get to the weekends, when he would cross the causeway to get to his grandmother’s on Sanibel Island.
[Daniel CfCWp1 1:10] We’d usually go out there every weekend, sometimes Saturday and Sunday. And it was the anchor of my week. Every week.
He remembers the moment he thought he’d one day be a guide: he was in elementary school on a trip to North Carolina with his family. And his dad booked him a day with a fly fishing guide.
Daniel Andrews: We were tearing through the mountains in this beat up Toyota truck, this tiny little truck, trying to get to the next stream before we ran out of time for the day and I remember thinking wow, this is awesome. This guy lives the life!
It helped that Andrews’ backyard was the Gulf's storied waters in the Sound and near Boca Grande Pass. They’re considered the tarpon capital of the world. People still come from all over to hunt for the prehistoric fish. They can get as big as a human, but a human powered by a jet engine. So Andrews didn’t have to go far to build a booming business as a flats guide, with days booked nearly every day of the year.
Daniel Andrews: High two hundreds, number of days a year. Probably 260, 280 days a year.
But pretty soon Andrews began to notice the fishing wasn’t as good as when he was a kid. Then two years after he started guiding in 2013, a severe red tide slammed the area. Red tide is an algae bloom in saltwater that can be worsened by too much nitrogen, not phosphorus. Phosphorus is mainly a problem in freshwater. But they kind of go hand in hand because they can both be found in fertilizer and human waste. That’s why you often hear scientists say nutrient pollution instead of one or the other.
We’re talking about phosphorus and freshwater blooms. But to a fishing guide like Andrews, it doesn’t really matter. A freshwater bloom killing fish in the Caloosahatchee River can be just as damaging to business as a red tide killing tarpon. And any time excessive amounts of water are released from Lake Okeechobee, in the center of the peninsula, there’s a risk that either can happen.
Just two years after he started guiding, the Army Corps started releasing huge amounts of water from the lake to lower levels while the Corps worked on repairing the old 1940’s era dike. That triggered goopy mats of algae blooms on the St. Lucie River making national news. The red tide bloom on the Gulf Coast, which was also worsened by the lake releases, was getting less attention. But Andrews was paying plenty of attention.
Daniel Andrews: Once the water cleared up that fall, you know you looked at the grass flats that were healthy, I was fishing three days a week I’d fish a flat, that were just completely barren sand. I knew the answer but I just kept asking the old time guides, or whenever I’d see a biologist at the boat ramp, you know when is the grass going to come back over there? and it’s like, it’s NOT! That’s it. It’s dead.
Meaning, the place where fish hunt for food is dead. Three years later, when another tide hit, and Andrews’ clients started heading to the Bahamas or someplace else to fish. Andrews and a buddy decided something needed to be done about the lake releases. So they asked for a meeting with the guy in their small town that they thought could make things happen.
Daniel Andrews: The mayor here in Fort Myers at the time was my Little League coach. We had no idea the politics that were behind it, the history at that point.
The history at that point had lasted more than three contentious decades – more if you count the original sin committed when the government drained the Everglades and allowed wetlands to be replaced with farm land.
After the meeting, Andrews and his friends got together with all the fishing guides they could muster. They formed Captains For Clean Water and waded into a water battle that started long before Andrews was born.
Daniel Andrews: It just became clearer and clearer that this was not a fishing guide problem in Fort Myers. This was a very large issue // that wasn’t just us sitting on the sidelines. The vast majority of Floridians were sitting on the sidelines.
So for the last decade, Andrews has been making a lot of trips to the capital in Tallahassee and around the state to push for better water quality.
He’s seen wins and losses: dirty water releases from Lake Okeechobee are down by more than a third thanks to the completion of repairs to the lake’s old Herbert Hoover dike. But water polluted with nutrients keeps coming. Health warnings are consistently issued for algae blooms in the Caloosahatchee. And in 2021, a phosphate mine had a huge leak and spilled millions of gallons of water that spiked levels of phosphorus and nitrogen in Tampa Bay. The nitrogen wreaked havoc. Ultimately, more than 100 manatees died. And just two years later, all that nitrogen meant a red tide was back.
NEWS ARCHIVAL: ] Here on Indian Rocks Beach, the red tide’s pretty bad. It seems like there’s dead fish nearly everywhere you look.
The next year, it was phosphorus’s turn again.
NEWS ARCHIVAL: Breaking at three, the Florida Department of Health in Lee County has issued a health alert for the presence of blue-green algae blooms in the Caloosahatchee River near the Alva boat ramp …
Over the years, Captains For Clean Water, has become a powerful advocate with some influential friends. The Everglades Foundation, which was started by Paul Tudor Jones, provided start-up money. The magazine Garden & Gun profiled Captains. Best-selling crime writer and former fishing guide Randy Wayne White wrote an Op-Ed for the New York Times and gave them a shout out. Between 2020 and 2024, Captains For Clean Water raised over $12 million dollars.
Andrews still wears a plaid fishing shirt like a lot of guides. He keeps his rod handy. When we talked, he’d just returned from a three-day fishing trip in the Everglades, where he camped in a tent and, he says thankfully, got no cell phone service.
Daniel Andrews: To me that place, I mean I get goosebumps when I put my boat in there in the morning and just the exhilaration when I’m getting the boat on a plane. It’s very bittersweet leaving the park.
So I asked him: are you mad that all the state’s water problems dragged you away from guiding just as you were starting your career. It’s been nearly a decade since Andrews began asking the state to finish restoring the Everglades and stop polluting waters with excess nutrients.
Daniel Andrews: It opened my eyes so much to how the world works that I’ll never see it through the same lens that I did as a 24-year-old when Captains started. And that, to some degree, I think has permanently stolen the freedom that I had as a fishing guide here in Pine Island Sound.
******So how did we get here? Phosphorus wasn’t always the bad guy.
1970’s Film: The phosphate industry employs between five and 6,000 workers with an annual payroll of over $32 million.
This is from that 1970s film by the General Development Corporation, Florida’s largest land developer at the time. Because of advances in agriculture – mechanization of harvests, better crop varieties and corporate takeovers -- Florida’s phosphate industry was booming.
1970’s Film: Centered in Florida's rolling Lake Ridge section between Tampa and Orlando. Lakeland is ideally situated for manufacturing and distribution.
Elemental phosphorus was first discovered by an alchemist in the 17th century looking to turn metal into gold. Times were hard, so he boiled down about a thousand gallons of urine. Instead he got a glowing, explosive blob. Not gold. He named it for the Greek god of the morning star, also named -- you guessed it –Phosphorus.
For the next couple of centuries, phosphorus was mostly a source of fascination because of its luminescence. Early scientists would wow courts with its intense light.
EGAN: It's called the devil's element because this waxy substance, if it warmed just a tick above room temperature, it combusts and it burns insanely hot.]
Dan Egan is author of The Devil’s Element. He’s also a former reporter and two-time finalist for a Pulitzer.
EGAN: I went to a guy at Johns Hopkins University who specializes in alchemy, and trying to reproduce some of the early works. And he tried to make his own phosphorus out of his own urine. And I was gonna try the same thing. And he said, don't! He said, a) it's gross, and b) it's really, really dangerous 'cause the closer you get to making it, the closer you get to blowing yourself up.
Later on, that would make it useful in war, beginning in World War I and during the Vietnam War.
EGAN: The brighter, positive side is that it's required by every living cell on the planet. It's an essential crop nutrient along with nitrogen and potassium.
Back in the 1800s, other chemists began to connect the dots between that glowing, gooey stuff distilled from pee and what made things grow. Here’s Egan explaining in a PBS Wisconsin interview in 2024.
EGAN: In the early, early 1800s during the little Ice Age, the famine was ever a threat, if not ever present. And so the agriculture tinkering began. And they would put blood on crops, they'd put fabric. They put bones. And bones really turned out to be a very potent fertilizer.
Egan says at this point they didn’t realize it was our frenemy phosphorus that made bones such good fertilizer.
They did, however, know that manure also made things grow. And that understanding led to the key discovery about phosphorus when another scientist decided to take a closer look at fossilized dinosaur dung.
EGAN: The chemist thought, you know, if human manure and animal manure is such an effective fertilizer, maybe this fossilized manure is. So he did an analysis and he realized, he was able to figure out and isolate: this is phosphorus that we're after.
From there, the hunt for phosphorus was on.
Initially, poop from seabirds was the main source. Indigenous people in Peru had been using it to grow things since before the Incas. Once the guano was identified as a source for phosphorus, it became WHITE GOLD. Sailors returning to Europe from the Americas would fill empty holds with the guano GOLD.
By the mid 1800s, a brisk trade route between Europe and the Americas was underway. That naturally triggered a war - the Guano Wars - after Spain tried to recapture several islands from Peru, which had just gained its independence from Spain about a decade earlier.
The US, which had been using bones and manure, also jumped into the fray, and urged its citizens to stake a claim on ANY island with poop from seabirds. Egan says Peru exported over 28 billion pounds of guano in just over 40 years.
So no surprise, the supply was tapped out by the turn of the century and another source needed to be found. Enter Florida.
Myrtice Young: Hello, and welcome to Polk County, the heart of Central Florida.
About the time the Guano War was being fought in the Pacific, a U.S. Army Corps of Engineer surveyor in Central Florida was working on dredging a canal. During dredging, he stumbled on the answer to the bird poop shortage. [fade up music]
Myrtice Young: Today's stop on the Heritage Trail brings us to the Mulberry Phosphate Museum. Located in the heart of the Bone Valley mining area.
Bone Valley. Central Florida mines would go on to become the largest phosphate source for the country.
Randall Parkinson: They're huge…
Randall Parkinson, the geologist and research professor at Florida International University, says the deposits date back millions of years…
Randall Parkinson: I think it's Miocene…
Back then a channel separated Florida and Georgia. But when the Suwannee Channel filled in, upwelling from the deep ocean delivered phosphorus rich water as the area piled up.
Randall Parkinson: Organic matter and fish bones and all that have phosphate in it. And then they'd die and settle down on the bottom and then it accumulated. So these phosphate mines in Florida and off the coast are related to these ancestral zones of the high productivity.
For three more epochs, that phosphorus stayed put. Unlike nitrogen, which can be ventilated back into the air by plants, phosphorus binds itself to things, which then leave behind the mineral deposits found in Bone Valley.
Randall Parkinson: Plants were growing on top of it or water was moving through, everything was in equilibrium because it just took, you know, over eons for everything, just to kind of be there if they needed to be there or not. So they're just chilling with equilibrium, stasis. And then we come in, scrape the top off, start dredging everything up, and there's instantaneous change in the soil and groundwater geochemistry.
Florida mines now cover about a half million acres. They produce a quarter of the world’s fertilizer and about 60 percent of fertilizer in the U.S.
Randall Parkinson: They use these drag line buckets that uh, there's a picture of the field group that went on this trip, there was like 30 of us that we didn't even fill the bucket.
The buckets scoop up a top layer of sandy soil to reach the thick clay loaded with phosphate beneath it.
But that mining can create a bunch of problems.
NEWS ARCHIVAL: Mandatory evacuations are expanding along Florida's Gulf Coast, after toxic radioactive water began leaking from what's called the old Piney Point, phosphate mine, that's about 40 minutes south of Tampa.
That leak dumped 215 million gallons of polluted water into Tampa Bay in 2021. Remember, that’s when a red tide algae bloom also appeared and killed about a hundred manatees – and dried up business for fishing guide Daniel Andrews.
During mining, a waste slurry is created. It’s packed with radio active material that occurs naturally. That makes it too dangerous to be used. So the slurry is dumped in these lined pits that can rise as high as a 50-story building and be unstable. In the 1990s, another pit created a sinkhole that was about180-feet deep and 120-feet wide.
Plus, Parkinson, the geologist, points out that not all of that fertilizer leaves the state. It’s used in citrus groves, dairy farms, ranches and sugarcane fields where, until the 1980s, not much was done to control the excess phosphorus running off land.
Randall Parkinson: We humans come in and we make these changes suddenly and they're very large. And the natural systems that evolved around all this over millions of years cannot adjust.
Matt Cohen: You know everybody that lands at an airport in Florida is sort of, it's like a homecoming for their bones because so much of the nation's phosphorus is mined here in the state.
That's because so much of Florida’s phosphorus goes into the food that Americans eat. Matt Cohen is an ecohydrologist and director of the Water Institute at the University of Florida. It’s his job to try to figure out how to deal with the nutrient pollution fouling the state’s waters…and how to regain balance across a state that has a LOT of phosphorus in some places and hardly any in others.
Matt Cohen: There's these incredibly enriched deposits of phosphorus, and also like by extension, places where phosphorus is extraordinarily depleted. And that's, that I think is one of the real challenges of thinking about managing this element in the state and, and more broadly, you know, across the world.
And we desperately need phosphorus.
Matt Cohen: If we don't have phosphorus, we can't grow. Fundamental fact. Arguably that is the reason we can feed eight and a half billion people. Right? If there wasn't that enterprise of finding phosphorus, mobilizing it and putting it in our, in our crops, we wouldn't, we wouldn't be able to do that. And so I don't think of phosphorus as a bad thing. I think of phosphorus as like the, our ability to find, mobilize and deliver phosphorus is miraculous.
But like with everything, it’s best in moderation. Our over-use means that waters have become saturated. And not just the water, but muck at the bottom, which can act like forever fertilizer triggering algae blooms.
Matt Cohen: Phosphorus, once it's in the system, it's in the system forever. It's gonna be leaking out for hundreds of years. And so a lot of it is trying to mitigate its movement, but we haven't really successfully cracked that nut. And so Lake Okeechobee is continually enriched with phosphorus, but even if we were to turn off the phosphorus in a lake, the supply of internal phosphorus from the lake sediments is also huge.
So how do we crack that nut?...To keep it from both moving around and polluting things, and be able to provide a steady flow to fertilize crops and protect our food supply – which by the way is growing more tenuous with the war in Iran. About a third of the world’s fertilizer supply gets shipped through the Strait of Hormuz.
Paul Westeroff: If you take the top 200 cities, it accounts for half of the phosphorus flow through the urban system. So you can really envision, you know, these big cities are these places where we can mine, you know, the, the wastewater.
So there IS another way to both mine phosphate and recycle it.
Paul Westeroff [Wester-hoff] is professor of environmental engineering at Arizona State University. He’s also deputy director of the National Science Foundation’s Science and Technologies for Phosphorus Sustainability Center, a mouthful which goes by the STEP center.
For now, he says, engineers rely on just two ways to control phosphorus in wastewater. They mix it with iron, because phosphorus attaches itself to solids – that’s why we get phosphate rock. That iron mix can then be dumped in landfills or incinerated.
Or they mix it with bacteria. The bacteria will eat the phosphorus to create a kind of muddy, yeasty mix which can then be used as a fertilizer, called biosolids. It’s mostly used on non-food crops, like cotton in Arizona where Westerhoff lives.
But he says that can be hard to engineer.
Paul Westeroff: It's like engineering yeast, you know. When you're making bread, they're kind of like wild strains and you know, it's hard to like keep them happy all the time.
And because the phosphate rock is so cheap, and the recycled bio-solids are even cheaper, it’s hard to kick start a sustainable recycling industry.
Paul Westeroff: W e can remove phosphorus from anywhere, but the challenge is phosphorus rock, is really cheap. And so who’s willing to pay for this phosphorus recovery?
He’s hoping that’ll happen with growing demand. In the past, phosphorus was mostly used for fertilizer. But now?
Paul Westeroff: Phosphorus is used in pharmaceuticals, phosphorus is used in herbicides and pesticides. It's used in a whole range of military and industrial applications…in semiconductors and communications and radar. 'cause phosphorus at this atomic level has really interesting properties. It's like. You know, in the antenna in your cell phone.
So the center is trying to find that new white gold that fed the Guano craze.
Paul Westeroff: I imagine making a computer chip with phosphorus that used to be in your wastewater. Like that's really, I, I think, if you're asking me like, what do we really want to do? I think finding this ability to make phosphorus a higher value added commodity, and then be able to track that phosphorus, be sure that that phosphorus was sourced in the United States maybe, so we can think about it in terms of national security as well as food security. And so I think where we're trying to get to is really understanding this economics of phosphorus and where we can have this biggest benefit of phosphorus recovery and reuse.
At this point, they’ve got a lot of ideas, but no real white gold yet.
Egan, the author of the Devil’s Element, says this is a real looming crisis that the general public hasn’t quite grasped.
Egan: We're stuck in a paradox here. We're overusing it at the same time that we're running out of it, so we're, we're turning a critical nutrient into a pollutant, which is just zany and it works well enough to keep food on the shelves for grocery stores right now, but it's just not a sustainable path that we're on. And not enough people realize it. They haven't had to think about it, but someday in the not too distant future, they're gonna.]
The U.S. Geological Survey estimates the country has about a billion tons in phosphate reserves, which would only last about 50 years. In February, President Donald Trump cited national security when he signed an executive order to protect phosphate production.
In the meantime, the phosphorus pollution problem is likely to get worse, especially as climate change warms the planet and sets the stage for more severe algae blooms.
That’s why I was excited about talking to Ali Ebrahimian, the stormwater engineer at Florida International University.
Ali Ebrahimian: So this is our wetland here. We are in the shallow part of the wetland. It's, we can get a good view from here. [JS] So we're walking across a little bridge. [Ali] Yes. [JS] Oh, wow.
This pond is one of the ways scientists are experimenting with how we can address the phosphorus pollution. Ebranimian is using the same principles as the treatment marshes in the Everglades – what the federal government has built over decades to deal with phosphorus pollution from farm fields. But these ponds are smaller and more manageable to fit an urban landscape. They both rely on the same principle: use nature to fix the problem.
Ali Ebrahimian: This is like a good solution. This is a green infrastructure. The alternative approach was just to use storm sewers. Collect your water, then as soon as possible, connect it to your canals.
Jenny: Same old, same old.
Ali: Same old, same old.
The pond looks like a natural wetland, like it’s still part of the Everglades just a few miles away. It’s tear-shaped and about three-quarters as long as a football field. At the bottom of the tear, it’s nearly twice as wide. Water lilies float on the surface and sawgrass grows along the edges, just like in the Everglades.
Ali Ebrahimian: All these plants, they're like natural filters when water gets through, when water's in contact with these, a lot of the pollutants in the water can get filtered and…
Jenny: the water's a little muddy, but it's clear. I mean, I can see, I see fish.
Ali: Well, well again, yeah, that's, you do see the fish here.
It’s surrounded by native trees and plants: black olive, Caribbean mahogany and gumbo limbo. There’s butterflies and dragonflies. There’s also a culvert that connects to the stormwater drain, in case the water gets too high and starts to flood the adjacent street.
Ali Ebrahimian: The longer you can retain the water here, that means more opportunity for water quality improvement. That’s the simple way you can, you know, consider that.
To make sure the wetland actually does its job, Ebrahimian has set up monitoring wells to test nearby groundwater. Other monitors tell him when it rains and when the temperature changes. He’ll use that data to create a digital twin, so he can design similar treatment ponds in different shapes and sizes, depending on the location.
Ali Ebrahimian: You can fit them where needed. You can just fit them in the existing spaces. Right.
The idea is these water gardens could help reduce the need for canals that slice and dice the landscape and deliver plugs of pollution – loaded with phosphorus – to natural water bodies. He says they could also be a more affordable solution than other treatment methods.
Jenny: It just seems lovely, like under a train track, you could make a water garden.
Ali Ebrahimian: Distributed solutions or decentralized solutions or addressing the problem at its source, not end of the pipe.
Jenny: Because the end of the pipe is bad. Yeah.
Ebrahimian says we’ll always have canals. In a flood, you need to get rid of water fast. But these water gardens could provide a way to balance what now is so out of whack in South Florida and other parts of the country.
Back over by the convocation center, the university has created another mini wetland planted with native cypress trees like you can find in swamps. Cypress knees pop up under a cool canopy in an otherwise really sunny stretch of campus. It doesn’t look like someone has designed it.
Jenny: I know I keep going back to how pretty they are, but this kind of thing makes me happy. 'cause it's not concrete.
Ali Ebrahimian: That’s true. And that's one of the reasons that we like this. This is an approach like trying to green the urban area, but they are actually infrastructure.
A tiny sign explains the cypress dome is a way to let nature help solve the problem.
It seems like a poetic solution – or at least part of the solution – to the phosphorus paradox that Dan Egan writes about in his book. Phosphorus has allowed humans to flourish, but it’s also doing serious damage to the planet. So we need to get back on better terms with our frenemy. To find a way to recycle the phosphorus we already have and stop digging up what the dinosaurs and oceans left behind.
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