Florida has been hit hard with toxic algae blooms over the past several years, in part due to a warming climate, and also because of the runoff of nitrogen and phosphorus from farms and subdivisions, however, Lake Okeechobee, in Central Florida has become the center of the growing environmental menace.
In Moore Haven, on the western shore of the lake, Dan Levy, the vice-president of AECOM, one of the world’s largest engineering and infrastructure companies, has been recently working on a solution to the algae problem. The recurring blue-green algae is not only a nuisance, but because it is actually a cyanobacterium, it can produce toxins that threaten drinking water supplies, local economies and human health.
Dissolved air flotation technology
The technology being tried out on Lake Okeechobee has long been used in water treatment and wastewater facilities. It’s called “dissolved air flotation,” and it is being applied to the algae problem, says Levy. “A lot of effort has been put forward on the academia side, on research and studying it. What we’re trying to do now is bring it to the field.”
On Jan. 20, 2010.
AECOM has already done work on the process in North Fort Myers and in Cape Coral’s Nautilus Canal. Levy explains that the process removes the rich element of algae cells from what’s called the phototropic zone. It’s a nearly one-foot layer below the water’s surface.
“As we pull the water out from this phototrophic zone, it’s going to go into a containment system that has micro-bubbles on the bottom,” Levy said. “So as the water’s there, we’re going to be adding a polymer to it that will allow it to bind up the algae cells. And this microbubble system on the bottom will create essentially a lift to allow these now foreign particles to float up to the top.”
Lake Okeechobee and the River of Grass
Lake Okeechobee, the third largest lake in the U.S., is a large but shallow lake in the middle of the state. It covers 730 square miles and averages nine feet in depth. It is part of a huge watershed system that begins near Orlando, Florida.
A little more than 100 years ago, waters flowed down the 134 mile-long Kissimmee River into Lake Okeechobee, feeding a floodplain of 3,000 square miles. Imagine if you will, when rainfall was especially hard, and the lake became full, a slow-moving river of water 60 miles wide and six-inches deep, flowing from the southern edge of Lake Okeechobee southwestward, all the way to the Bay of Florida, 100 miles away.
That is the way it used to be — before man stepped in and messed with the natural order of the environment. Not long after the Civil War, interest in draining the Everglades took off. A state agency called the Internal Improvement Fund (IIF), whose objective was to improve roads, rail lines, and canals discovered it was in debt. The IIF collaborated with a wealthy Pennsylvania land broker, one Hamilton Disston, who bought up four million acres for $1 million in 1881.
However, things really took off when in 1905, former Florida Governor Napoleon Bonaparte Broward began working on a plan to drain the Everglades as part of his campaign for governor. His campaign slogan was “drain that abominable pestilence-ridden swamp.”
Little did he or his constituents, and later the sugar cane companies that bought up politicians, realize that by the 2010s, what they started had indeed, become a nasty, swampy and algae-filled lake. With heavy amounts of fertilizers being used on the cane fields, water quality in the lake dropped and the loss of water was accelerated.
Loss of water led to the loss of habitats for wading birds, fish and many animals. This has also changed the quality of the water, killed off many native plants, thereby allowing exotic plants to take root. Water loss has also encouraged the growth of algae, adding to habitat loss.
