An ever-expanding population in Florida is having a frightening impact on a finite amount of water. Driven by the illusion that the resource is pure and plentiful and protected, we conduct business and pleasure as usual, while our water source suffers the folly of fools.
That folly, notably man-made nitrate contamination, is suddenly surfacing from Florida's aquifer -- the state's underground water motherlode -- via her springs. Although the amounts vary among locations, it is important to note that nitrate nitrogen does not occur naturally in the aquifer; that while the state sets 10 milligrams per liter as the maximum safe-drinking level, some places are pushing that limit; and a new study shows that discharge of more than 2 milligrams per liter damages aquatic life.
Meanwhile, a study last year reported elevated nitrate levels from contamination by animal and/or sewage in Sanlando, Starbuck, Blue, Gemini, Wekiva, Palm and Ponce de Leon springs. Additional contamination in Rock and Seminole springs is thought to be from fertilizers, according to St. Johns River Water Management District geologist David J. Toth.
"We know inorganics -- nitrates -- from fertilizers being spread on homeowner lawns, golf courses, road rights-of-way, agricultural fields and pastures are draining into the aquifer, and that whatever we put on the land is going to move down into the aquifer and will, in time, come out in our springs," says Jim Stevenson, a senior biologist and member of the Florida Springs Task Force for the Department of Environmental Protection.
"Three springs in the Suwanee River basin exceed drinking water standards for nitrates," he says. "Sulfur Springs in Tampa is closed to public use due to bacteria contamination. Rock Springs was closed for two weeks the last two years, also because of bacteria contamination. Mission Springs shows algae growth, [and] Silver Springs is now discharging 821 tons of nitrates a year."
There is the impulse to begin a story about troubled water -- especially one about Florida's springs -- with prose, like how they are mysterious surges from some deep, Paleocene past that, in the moonlight, quench the thirst of fawns.
Who pays attention to prose, though?
Instead, call up a childhood memory: face-down in the swift spring that was as clear as good air, moving like a minnow over undulating eel grass.
How many adult Floridians were children here, however?
That leaves the science, and discussions of Karst topography; surficial, intermediate and lower aquifers; diminishing supply; isotopic aging; nitrate nitrogen levels.
Eyes glazed? Perhaps.
But it is that science we had better read and heed.
Most of this state's topography is of the Karst variety, meaning it is devoid of the multilayered aquifer systems found primarily south of Central Florida. With unique, unstable underpinnings, Karst regions are those that spawn sinkholes, underground rivers, caves and springs. In fact, no Karst, no springs.
But the same features that allow the springs to form now contribute to their decline: Everything that falls on Karst land seeps easily into the earth, moving unimpeded directly into the deep water reserve known as the Florida aquifer.
Elsewhere in the state, the first layer of earth -- the surficial aquifer system -- is mostly permeable soil, containing unconfined water. We drill shallow wells at this level for noncommercial irrigation; that level also loses water via evaporation, seepage and leakage. All kinds of sources contribute to recharge the surficial system, from septic tank effluent to stormwater to lakes to upsurges from the deeper aquifer itself.
Deeper is the intermediate aquifer system, layered with the likes of ancient sands, phosphates, limestone, dolomite and clay. Water here is confined. This system is recharged by the surficial aquifer above and the Floridan aquifer below.
Deepest is the Floridan aquifer system. It is the most active aquifer on the planet, producing 7.7 billion gallons of water a day. Here is the main target of utilities' deep-drill wells that suck fresh groundwater from its pervious limestone channels and from the nooks and crannies of its lacy catacombs.
The formula for recharge of, and discharge from, the aquifer is simple: When water levels in its upper two systems exceed that of the underlying aquifer, those systems' excess water flows deeper into the chambers of the Floridan. Discharge happens when the opposite occurs.
Once a pristine resource, the Floridan's historical, constant renewal is part of a complex hydrologic system now under red-flag stress.
Gregg Jones, with the Southwest Florida Water Management District, has tracked sources of groundwater contamination. His findings can be summed up in two words: land use.
"In the late 1990s, we started sampling and studying seven major spring groups that collectively discharge 1.3 billion gallons of water every day," says Jones, who will join a Florida Springs Task Force conference this weekend in Gainesville that represents a full-steam effort to save Florida's springs. "We found in many of them that nitrate levels are increasing from zero, which is normal, to concentrates considerably higher."
The main culprits were not midnight cowboys dumping toxic waste but heedless homeowners. While scientific detectives did pinpoint different sources, most was attributable to residential lawn and agriculture fertilizers. Although some components were tracked to dairy farms and septic tanks, all other sources combined were secondary to lawn fertilizers. In some cases -- citrus, for example -- growers were practicing good management, by fertilizing less often, with low-dose, time-released fertilizer. Row-crop farmers did not earn the same accolade.
Jones' research also indicates that even though a recharge area may cover hundreds of square miles, the most concern is for land within a few miles of the spring. "The recharge closest to a spring really seems to control the quality of its water," he says. "So, land use near them needs to be careful. You don't have to go miles away to find their nitrate problem."
Another predicament under-evaluated in the past is how nitrate, discharged from the springs, flows into rivers, causing overgrowth of vegetation. In turn, that vegetation can devour the river's oxygen, silencing its biological heartbeats.
The thing about land use, says David Hornsby, water-quality analyst for the Suwanee River Water Management District, is that only local governments can control it.
"The buck always stops with local government," he says. "Citizens' comprehensive plans, written to help protect local resources and environment, are always being changed. Such variances bring strong potential for a serious impact."
Most folks mistakenly believe that surely some state or federal regulatory agencies can intervene to save the day. In reality, no agencies can.
The Suwanee district -- that moss-draped, lazy-river land of Stephen Foster myth -- suffers land-use consequences in a big way, with nitrate levels in some springs occurring in milligram concentrations of 4, 6, 10, "even in the 20s, in a couple of cases," says Hornsby. "Unfortunately, most people don't think of groundwater as a resource that needs protecting. It's a case of out of sight, out of mind."
He adds: "The whole Floridan aquifer -- from central Georgia all the way down to Okeechobee -- suffers similar problems. Part of the puzzle is to date the water, and that's what we're all trying to do -- figure out how old it is, how old are the nitrates."
Such dating will reveal just how quickly water and contaminates are moving through -- and just how many years of management must pass before any changes can be effective.
Brian Katz, a research hydrologist with the U.S. Geological Survey (USGS), has worked long and hard to devise reliable age-testing for water and nitrates. He is also able to distinguish among contaminants between artificial fertilizer and sewage waste -- and has found the culprit in most springs to be artificial.
"Concentrations we're seeing in the water today are indicative of land use from 30 to 40 years ago," he says. "This sends us the important message that even if we were to drastically reduce or eliminate the amount of nitrogen from various sources today, it may take tens of years to see a substantial decrease in nitrate contamination."
Compounding the problem is the cumulative effect. As nitrates increases in the springs, that discharge runs into -- in the case of Katz's district -- the Suwanee and Santa Fe rivers.
"Groundwater really needs to be regulated as tightly as surface water," says Katz. "It's very vulnerable to contamination, to what takes place on the surface."
Throughout the state there is only a thin layer of sand overlying the aquifer, and with sink holes near the surface, contaminants enter the system speedily. "Although we don't know where all the conduits are," he adds, "we do know that some of our water here is close to the state maximum-contaminant level, and that two springs along the Suwanee are in the 20s -- twice the legal limit."
Trudy Phelps, an USGS hydrologist, recently completed a four-year study that tracked nitrate nitrogen tied to land use in, among other places, the St. Johns River Water Management District. When nitrogen loading was found in the discharge of Silver Springs, "that alerted us to 'uh-oh, something's happening here,'" she says.
What was happening there, beneath the glass-bottomed boats that ferry tourists across deceptively clear water, was concentration of nitrogen at roughly double the amount first recorded in 1971 -- an increase Phelps found "staggering."
Moreover, she speculates that since Silver Springs' discharge draws from a 1,200-square mile recharge area, many years of fertilizer application across that zone may be just now appearing.
"The aquifer is like a sponge," she says. "Things get absorbed and slowly released; slower through spongy parts, faster through its channels. Also, the water appears to come from different sources, a blend of that fast and slow movement, young and old water."
While Phelps concedes that more people are now aware of the springs' plight, she wonders whether there is a corresponding increase in gumption. "The problem always is having the political will to look the issue straight in the face and do something." Unlike more concentrated contaminations that command attention and can be cleared up more quickly, "If it's a big, basinwide problem, with years of fertilizer application, you can not remediate."
Meantime, work to document the extent of the problem in Florida's springs continues, its ancient alligators, sunning turtles and stately wading cranes -- not to mention its tourists -- oblivious.
There is no questioning the ongoing imperative: The causes of Silver Springs' contamination must be found, and the areas most sensitive to future land use must be identified and managed. Until then, the springs' nitrate-laden discharge continues its hurried course along its run, to join the Ocklawaha River and eventually the sprawling St. Johns.
"What's in the groundwater today will be flowing to the springs tomorrow," says Phelps. "Hopefully, we will slowly piece together information that will help local people when they're making decisions. Often they don't know, don't have the facts about land-use issues, and anybody looking to benefit from those kinds of decisions can always find an expert witness with credentials who, for enough money, will come forward to speak."
Yet another problem looms for the springs, one that, if realized to its most terrible potential, would make all other concerns moot. The volume of water flowing from some vents is on the decline -- as much as 25 percent at Rock Springs, and 15 to 20 percent at Wekiva.
"Definitely, some of the springs have declined in flow," says hydrologist Hal Wilkening, of the St. Johns River district. "One thing that made it difficult to arrive at the amount of decline is that springs naturally fluctuate in flow. So we had to look at long-term trends and at what's anticipated."
The result was a regional water-supply plan that took five years to complete. Among its projections: If all the large water utilities develop in the manner they want -- that is, by continuing to pump groundwater -- some springs will fall below established minimum flows. Those flows are based on requirements to keep the river healthy.
A water-supply plan to avert catastrophe must be put in place, says Wilkening. And alternatives -- such as expanding the recharge area -- have been discussed. But as urban sprawl continues, the opportunities to widen the recharge area decrease. A decade-old effort to capture urban runoff by directing some parking-lot water into recharge basins is already in place. Another initiative urges the use of more reclaimed water for irrigation.
But while alternatives will be more costly and the price of water will increase, there is little option if we are to have enough water for the growing population while saving sensitive ecosystems.
A veteran cave diver and cartographer, Wes Skiles is arguably the state's premier underwater cave photographer. As director of photography and co-producer of Arts & Entertainment's 1997 "Polluting the Fountain of Youth," Skiles documented the excursions of a group who dove 140 feet down and 1,000 feet back into the aquifer to release a dye packet, simulating nitrates, that would eventually prove their suspicions: Nitrates can enter the Ichnetucknee water system from groundwater, ride the river, vanish underground and resurface in the springs.
"After swimming into the far reaches of the aquifer and determining where the water is coming from, what kind of structures it's flowing through, we realized that this water is not from long ago and far away," he says.
"This water has gone through the simple process of falling as rain on local lands, permeating local soils and, as it permeates, passing by our septic tanks, our leaking gas tanks, by our dairies and farms, our yards and golf courses, and is carrying the leachate from our overfertilized world right down into the ground."
Skiles shares the belief of many scientists that we unwittingly guaranteed our groundwater's sorry fate by excluding it in protections written for surface water. "In my county, Gilcrist, the land is so permeable that rain vanishes into the earth as soon as it hits," he says. "Still, unbelievable land-use permits are being approved. The last 15 were all for industrial-waste sites."
First, he says, the DEP should consider equal rules for ground and surface water. Now. Big farming spreads need to be on treatment packages, and we need to figure out how to eliminate septic tanks in Karst regions.
"Don't think for a minute that septic tanks or applying high-nutrient-loaded waters to grass and plants is uptaking the nitrates. It is not happening," he says.
"What is happening is that rain comes from the sky. We capture it from bodies of water either above or below ground, pass it through us, and the great hydrologic circle begins again."
Skiles has seen a two-fold change in the springs: quality and quantity. Springs that were once gin-clear now are tinged with brown. He sees algae bloom in slime-green water, choked springs and rivers. "I also see much less water coming from some springs, and if you reduce quantity, because of the dilution factor, you reduce quality."
Jim Stevenson seems well-appointed as head of the Florida Springs Task Force -- a hands-on guy with 50 years of experience with state waters.
Stevenson was part of the Ichnetucknee study group featured in the A&E program, and he believes that in order to protect any body of water, to influence any land-use decisions, advocates need to cooperate with private landowners and local governments upstream. He's unequivocal about where he places the responsibility.
"In my point of view, our system is one whereby the citizens determine the outcome, and if they don't care enough individually to reduce what they put on their lawns, maintain their septic tanks or join a group to go and inform officials about what is important, then they do not care enough to save these springs, and the springs are going to be lost."
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