Last week, more than 300 residents living near the abandoned fertiliser plant at Piney Point, were ordered to evacuate their homes because one of the plant’s wastewater reservoirs had sprung a leak, and was releasing hundreds of millions of gallons of contaminated water into Tamp Bay. While local officials were initially concerned about the effect of the gushing wastewater on human life – given that it was potentially radioactive – the affected households have since been able to return to their homes, as the authorities have sought to reassure everyone that the water was merely acidic (with high concentrations of nitrogen and phosphorus) and not radioactive, as originally feared.
But, this is not the first time that local officials have had to order an evacuation as a result of a leak at Piney Point. Since its construction in 1966, the fertiliser plant has had a tortured existence, with the lax environmental standards of its various operators making frequent headlines, until the plant was shut down in 2001. But even though it is no longer operational, toxic legacy of the plant continues to haunt the Tamp Bay area.
While the creation of fertiliser is a lucrative business – being worth an estimated $196.97 billion globally in 2019 – it is also has a massive environmental impact. In fact, Florida is home to more than 80% of all the phosphate mines in the US, and produces 25% of the world’s entire supply. One of the main components of fertiliser is phosphate, an ore that must first be mined and then chemically treated in order to convert it into usable phosphoric acid. Both the mining and the treatment process are extremely damaging ecologically, creating not only air, ground and water pollution, but also large amount of toxic waste in the form of hazardous heavy metals and radioactive by-products (known as phosphobypsum).
According to the phosphate mining industry’s own estimates, more than 5 tons of phosphobypsum is produced for every ton of phosphoric acid. Since phosphobypsum has little to no commercial value, it ends up being stored in waste stacks which are surrounded by wastewater reservoirs. Currently, there are basically no regulations governing the construction, maintenance, or oversight of phosphobypsum stacks, of which there are more than 70 in the US, and range between 3 to 60 meters in height, which makes these waste sites a ticking environmental timebomb. Because not only is the phosphobypsum itself radioactive, but the surrounding wastewater is acidic, with high concentrations of phosphorus, nitrogen, and ammonia.
While both phosphorus and nitrogen are important nutrients for plant life in the bay area, excessive levels tip fragile marine ecosystems over the edge, creating potentially irreversible damage. One of the main concerns is that the significantly higher than normal levels of phosphorus and nitrogen in the bay will lead to an explosion of algae. While algae occurs in marine ecosystems naturally, it can wreak havoc on plant and animal life if its growth runs out of control, as it cuts down the amount of light able to enter the water and decreases water oxygen levels. One of the biggest worries is that rampant algae growth will destroy seagrass stocks, which is not only essential for maintaining water quality, but also provides food and shelter for various marine life, including the already endangered manatee.
To compound matters, once the contaminated water is in the marine ecosystem, there is nothing that can be done to remove it, or the resulting algae. The best that local scientists and conservationists can do is monitor the spread of the nutrients in the water and try to mitigate their effects locally.
So, even though a major humanitarian disaster had been narrowly averted at Piney Point – as local officials have been able to sufficiently drain the affected reservoir so that it did not flood the surrounding properties – scientists are warning that the environmental fallout from the leak will be huge. Not only is the health of the bay still very fragile due to the extensive levels of pollution it experienced during the 1950s and 1960s, but it is also at the risk of continued contamination events given that the area is prone to hurricanes, which frequently damage the retaining walls of wastewater reservoir, or cause them to overflow.
Given the increased frequency and intensity of tropical storms over the past few years, scientists fear that the bay will not have enough time to recover from the Piney Point spill before it is hit with another influx of contaminated water when hurricane season arrives. And, in the words of Todd Crowl, director of the Institute of Environment at Florida International University, if a fragile ecosystem is hit too many times in quick succession, it may never recover.