Phosphate Mining and its Effect on the Environment

Today, Lieutenant Planet was in Mulberry, Florida. Mulberry is the self-proclaimed Phosphate Capital of the World and home to a major phosphate mining and processing company called Mosaic. But what is phosphate? Why do we need it, and what effect does mining and processing it have on the surrounding environment?

When people think Florida economy, they think tourism, hospitality, oranges, sugar, and Boiled P-Nuts from roadside stands. But Florida is also the single biggest source in the country for phosphate. Phosphate is used to make calcium phosphate nutritional supplements for animals, phosphorus for industrial purposes, and most widely for fertilizer for agriculture. Most of the phosphate fertilizer used in the US has an origin in Florida.

Mosaic’s New Wales phosphate plant from the border of the property outside of Mulberry, Florida.

Though phosphorus fertilizer can be made from bone meal and manures, mineral sources of phosphate are cheaper. This is where Mosaic and phosphate mining come into play. How does Mosaic obtain phosphate? Via their website:

“Phosphate rock is usually found 15-50 feet beneath the ground in a mixture of phosphate pebbles, sand and clay known as phosphate “matrix.” The sandy layer above the matrix, called the overburden, is removed using electrically operated draglines. Equipped with large buckets, these draglines remove the overburden, placing it in the previously mined voids, and excavate the matrix, depositing it into a shallow containment area or slurry pit. There, high-pressure water guns turn the material into a watery mixture called slurry, which is sent through pipelines to a processing facility, referred to as a beneficiation plant, where phosphate rock is physically separated from the sand and clay in the matrix.

At the plant, the slurry is moved through a series of washing stations and vibrating screens that physically separate clay, sand and pebble-sized particles. The separated phosphate pebbles are moved through dewatering tanks and onto an inventory pile via conveyor belt. The clay particles are then pumped through pipelines into storage ponds (clay settling areas) where these particles sink to the bottom. These ponds function as reservoirs and help Mosaic recycle or reuse approximately 90 percent of the water at its phosphate facilities, while also supporting a variety of wildlife.”

So they reuse 90% of the water they use to make the slurry to the plant. Sounds great, right? But let’s ask about the other 10 percent. The leftovers that sit in their “storage ponds,” referred to as “stacks” by many because the clay stacks up on the bottom and the sides to form an almost natural-looking hill. But they aren’t hills. They are giant (hundreds of yards across and over a hundred feet tall), aboveground pits filled with mining runoff called phosphogypsum. What’s wrong with phosphogypsum? According to a 1992(!) report titled “Environmental Impacts of Phosphogypsum” from the University of Alberta,

“The main environmental concerns associated with phosphogypsum are: (i) movement of fluoride, sulfate, total dissolved solids, certain trace elements, and radionuclides from the U-238 decay series below phosphogypsum stacks into groundwater supplies; (ii) radon-222 exhalation which may pose a health risk to workers on the site or people living close to stacks; (iii) acidity; and (iv) radon-222 exhalation from soil into residential homes when agricultural land previously treated with phosphogypsum is converted to residential usage.”

You read that right- these sites leak radioactive material and other environmentally disruptive chemicals into the groundwater and surrounding ecosystems. Though these chemicals are naturally occurring, the shift and concentration of these elements from underground and sporadic to aboveground and highly concentrated presents a major problem. These stacks are prone to Florida sinkholes, natural disasters like tornadoes and hurricanes, and size limitations. When they are in danger of overfilling, all that can be done is to release the chemicals back into Florida waterways in diluted form. Though this diluted overflow is technically legal, it introduces a lot of new nutrients into the Florida wetlands and rivers.

Last year in Florida there was a record-breaking red tide and green algae bloom event. It dragged on through the summer and fall, killing hundreds of thousands of marine animals off the coast of Florida and in the freshwater waterways. Phosphate mining is a major contributor to this event and other like it in the past. Mosaic in particular has a long and checkered history with environmental mishaps, including one that cost them nearly $2 billion in a federal lawsuit a few years ago. Though they sponsor and fund a lot of environmental projects, one must assume it is only necessary public-relations work for an industry that is inherently bad for the surrounding environment.

The Alafia River at Alafia River State Park, just a few miles from the Mosaic phosphate plant outside Mulberry, Florida. We were hard pressed to find water on the river that wasn’t coated by green algae.

Phosphate, like oil, is becoming increasingly harder to find in large deposits. The world’s supply mainly derives from China, the western Sahara, and Florida. Sensing a looming shortage, China has severely reduced its phosphate exports, and the US has stopped exporting entirely. What does this mean? Well, in industries like this, it means the race is on. As cheap phosphorus becomes more scarce, it’s value rises, and these industries stand to make more money than ever before until the resource is all but exhausted. Currently, Mosaic is the largest phosphate mining company in the world, and is in the process of expanding some of their current mining sites in Florida.

So what can we do? First, we can demand our government to curb mining site expansions and force the start of the breakdown of phosphogypsum stacks. Second, we need to look into how best to reclaim the land used for these sites. Currently they are open sores on the Florida landscape. Third, we need to start a discussion about farming without a cheap source of fertilizer to replenish phosphates in the soil. The shortage is coming regardless, and we have to be ready for it. Alternatives to mineral phosphates include the use of animal manures, growing tap-rooted cover crops that bring phosphorus up from the subsoil, using bone-meal sources, and even using human waste as fertilizer.

These changes won’t happen by themselves. Though the federal government has come down on Mosaic, the Florida government has been woefully inadequate at curbing the phosphate giant’s destructive practices on the state’s ecosystem, probably due to the size of the industry and the economic clout they hold for as long as there is phosphate to be mined here. The people of Florida need to stand up and demand change. For many, this discussion has always been. Since this past year’s state of environmental emergency, the discussion has expanded.

Wondering what the water used to look like…

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