CapnStinxy
Member
I don't know how true this is but I was told by a local a few years back that Florida's fresh water supply is basically from the swamps.
True, but perhaps not in the way you think. Swamps occur in low-lying areas much like lakes. The surrounding land drains into the swamps, so they act as catch basins. In a swamp not surrounded by development (good luck finding one of those) those plants, critters, and bacteria act as an excellent filter, trapping and digesting oraganic compounds. In a pristine swamp, the water quality is good. The water slowly permeates into the underlying limestone and down hundreds of even thousands of feet. It has a high degree of dissolved minerals, including calcium and sulfur, but it's not polluted in the sense that it's harmful to life.
Now, when a swamp is eaten away by and surrounded by development, then its effectiveness diminishes. Paving and other impervious cover reduces the area for water flow, meaning it gets to the swamps faster. Artificial organic chemicals, like petroleum products and fertilizers, get picked up along the way. Then there's sewage runoff from septic systems or inadequate "packet" treatment plants as well. This overwhelms the swamp filter, and some that pollution works its way into the groundwater.
Private and municipal water supplies in Florida use wells almost exclusively, which tap that swamp-filtered water. The surface water doesn't occur in large or deep enough bodies to be practical for a potable water supply. 50 years ago, one could drink well water "straight." The sulphur smell was quite off-putting, but a simple aeration treatment (spraying the water into a vented tank, which allows the sulphur to dissipate as a gas) could solve that. That would be a considerable health risk today.
The icing on top of all this, at least in coastal areas, is that the increasing demand for water is drawing down wells at the upper Hawthorne depth (approx 200 feet), allowing salt water to intrude.
All of these factors lower the quality of groundwater, requiring costly and sophisticated filtering and chemical treatment. We could do with vastly expanded, healthier swamps. In fact, we're spending a great deal of money to restore the ones destroyed over the past 100 years.