Why do we have so many springs in Florida?

Why do we have so many springs in Florida?

Jackson Blue Springs discharging from the Floridan Aquifer. Jackson County, FL. Image: Doug Mayo, UF/IFAS Extension.

Florida has one of the largest concentrations of freshwater springs in the world. More than 1000 have been identified statewide, and here in the Florida Panhandle, more than 250 have been found.  Not only are they an important source of potable water, springs have enormous recreational and cultural value in our state. There is nothing like taking a cool swim in the crystal-clear waters of these unique, beautiful systems.

How do springs form?

We have so many springs in Florida because of the state’s geology.  Florida is underlain by thick layers of limestone (calcium carbonate) and dolomite (calcium magnesium carbonate) that are easily dissolved by rainwater that percolates into the ground. Rainwater is naturally slightly acidic (with a pH of about 5 to 5.6), and as it moves through the limestone and dolomite, it dissolves the rock and forms fissures, conduits, and caves that can store water. In areas where the limestone is close to the surface, sinkholes and springs are common. Springs form when groundwater that is under pressure flows out through natural openings in the ground. Most of our springs are found in North and North-Central Florida, where the limestone and dolomite are found closest to the surface.

Springs are windows to the Floridan Aquifer, which supplies most of Florida’s drinking water. Image: Ichetucknee Blue Hole, A. Albertin.

These thick layers of limestone and dolomite that are below us, with pores, fissures, conduits, and caves that store water, make up the Floridan Aquifer. The Floridan Aquifer includes all of Florida and parts of Georgia, South Carolina, and Alabama. The thickness of the aquifer varies widely, ranging from 250 ft. thick in parts of Georgia, to about 3,000 ft. thick in South Florida. The Floridan is one of the most productive aquifer systems in the world.  It provides drinking water to about 11 million Floridians and is recharged by rainfall.

How are springs classified?

Springs are commonly classified by their discharge or flow rate, which is measured in cubic feet or cubic meters per second. First magnitude springs have a flow rate of 100 cubic feet or more per second, 2nd magnitude springs have a rate of 10-100 ft.3/sec., 3rd magnitude flows are 1-10 ft.3/sec. and so on. We have 33 first magnitude springs in the state, and the majority of these are found in state parks. These springs pump out massive amounts of water. A flow rate of 100 ft.3/sec. translates to 65 million gallons per day. Larger springs in Florida supply the base flow for many streams and rivers.

What affects spring flow?

Multiple factors can affect the amount of water that flows from springs. These include the amount of rainfall, size of caverns and conduits that the water is flowing through, water pressure in the aquifer, and the size of the spring’s recharge basin. A recharge basin is the land area that contributes water to the spring – surface water and rainwater that falls on this area can seep into the ground and end up as part of the spring’s discharge. Drought and activities such as groundwater withdrawals through pumping can reduce flow from springs systems.

If you haven’t experienced the beauty of a Florida Spring, there is really nothing quite like it. Here in the panhandle, springs such as Wakulla, Jackson Blue, Pitt, Williford, Morrison, Ponce de Leon, Vortex, and Cypress Springs are some of the areas that offer wonderful recreational opportunities. The Florida Department of Environmental Protection has a ‘springs finder’ web page with an interactive map that can help you locate these and many other springs throughout the state.

https://nwdistrict.ifas.ufl.edu/nat/2020/04/09/the-incredible-floridan-aquifer/

Streak-ed Heads, Softshells, Yellow-bellies and Red-bellies: River Turtles of North Florida

Streak-ed Heads, Softshells, Yellow-bellies and Red-bellies: River Turtles of North Florida

Identifying North Florida river turtles can be quite challenging, given the fact that several species are collectively referred to as “streak-ed heads” by many people.  Although you will not find this term in the scientific naming conventions, it is actually an apt description for many turtles in the Southeast that have dark skin with thin, yellow pinstripes on their head and neck.  North Florida has at least half a dozen species that fall into this general grouping.  They include the Suwannee cooter, river cooter, Florida cooter, chicken turtle, yellow-bellied slider and a couple of map turtles.  We even have a disjunct population of Florida red-bellied turtles on the Apalachicola River that are isolated from the main group, which is restricted to peninsular Florida and extreme Southeastern Georgia.  Overall, we have about 25 species of turtles in Florida.

turtles basking on log

Suwannee cooters at Lafayette Blue Springs, Lafayette County, Florida, 2021.
FWC Photo by Andy Wraithmell

As you might guess, the key to accurate river turtle identification lies in the details and the details can be tough to see.  Most basking turtles tend to tumble off their logs into the water long before you are close enough to scrutinize their features.  However, a few tips and tricks may improve your chances when going afield.  A good pair of binoculars and a reptile field guide are must-haves. You need to be able to see if the yellow on the side of the head is a wide splash (as on the yellow-bellied slider), or a series of thin lines (as on various cooters). If the top shell (carapace) is very dark and the bottom shell (plastron) shows orange color, you might have a red-belly or Suwannee cooter (higher dome on red-belly, relatively).  Two of our native species have what are referred to as “striped breeches”.  When viewed from the rear, the stripes on the hind legs are vertically oriented on the yellow-bellied slider and the Florida chicken turtle.  The chicken turtle is distinguished by a relatively narrower head and a wide, yellow stripe on the front legs.  Separating the various cooter species gets a little trickier.  You need to use characteristics like the pattern on the plastron, the occurrence of “hairpin-shaped” stripes on the head, or the pattern of lines on particular carapace scutes.

So how do you get those clues in the wild?  A good telephoto lens may work if you are fortunate enough to own one.  This will give you the opportunity to study detailed features at your leisure.  Otherwise, you may not be able to identify a turtle to the species level.  Getting close to a wary turtle is not easy.  However, on busy stretches of our waterways, where wildlife are desensitized to people and boats, turtles generally have a wider comfort zone.  Especially if you are in a canoe or kayak and minimize your movement and sound as you glide in for a better view.  Lastly, go looking on a bright sunny day and your opportunities will vastly increase as turtles climb out of the water onto logs to soak up some of that good old Florida sunshine.  One species that you should have no trouble naming when encountered, is the softshell turtle.  Softshells will extend their extremely long neck upward when basking and their flexible, smooth shell will appear flattened in profile.  They are the only turtles here with a tubular snout. Never try to pick one up if encountered crossing a road, as they do not hesitate to bite and have extremely sharp and powerful jaws.  In general, even if you are confident in not getting nailed, you will probably be wrong, given the extremely long neck that can reach more than halfway back on the shell.  Also, all of our water turtles have very sharp claws on their hind feet and will manage to get in a few good rakes before you decide to put them down, or worse yet, drop them on the pavement and injure them.

Now, when you think you are getting good at basking turtle identification, start looking for some of our less obvious, smaller species. These include stinkpots, musk turtles, mud turtles, map turtles and box turtles; all very cool critters.  But if you think you want to pick up one of the cute little buggers, beware.  Most of the little ones will bite too…hard!  Believe me. Happy “turtling!”

Reducing the Impact of Septic Systems Through Advanced Nitrogen Treatment

Reducing the Impact of Septic Systems Through Advanced Nitrogen Treatment

Many of Florida’s historic first magnitude springs are classified as nitrogen impaired. Image credit: UF/IFAS Communications

Septic systems are an effective means of treating wastewater when they are properly designed, constructed and maintained. Conventional systems are designed from a public health perspective and have been widely used since the 1940s to remove pathogens and protect human health. About 30% of Florida’s population relies on septic systems, which treat and dispose household wastewater drained from bathrooms, kitchens and laundry machines.

However, septic systems were not designed to remove nutrients. A conventional system removes only about 30 percent of the nitrogen that flows into it. Even a well-maintained system will become a source of nitrogen (particularly nitrate-nitrogen) to the surrounding soil in the drainfield, and may leach to groundwater. Excess nitrogen in Florida’s waterbodies can be a contributing factor to ecological community degradation and increases in algae.

What alternatives are there to conventional septic systems?

Many enhanced nitrogen removal technologies exist, but only those approved by the Florida Department of Health (FDOH) can be installed. Conventional septic systems are made up of a septic tank and a drainfield (or leachfield). Advanced treatment systems add steps to conventional system processes to improve contaminant removal. Types of advanced nitrogen removal technologies available include:

  • Aerobic Treatment Units  ATUs are made of fiberglass, polyurethane or concrete. Unlike conventional systems, ATUs introduce air into the sewage in the tank using a pump. By aerating waste, the organic matter in the tank is broken down faster than in a conventional system. Effluent from an ATU is discharged into a drainfield for further treatment in the soil, just as with a conventional septic system. ATUs require higher energy input than conventional septic systems to power the aerator, and regular operation and maintenance to sustain performance   ATU example from the US EPA
  • Performance Based Treatment Systems PBTS are specialized systems designed by professional engineers to meet specific levels of contaminant removal based on site and/or situation requirements. There are many proprietary commercial options available. Designs often include an ATU. Like ATUs, PBTS require higher energy input than conventional septic systems to power pumps, and regular maintenance is needed to sustain performance.
  •  In-Ground Nitrogen Removing Biofilters INRB are also referred to as modified drainfields. These systems are passive, which means they require no electric aerators or pumps to treat wastewater, and maintenance requirements are lower than those for ATUs and PBTS. INRBs are nitrogen-reducing media layers placed underneath a conventional drainfield.

Ammonium-nitrogen in wastewater leaving the septic tank moves down through the Drainfield Area soil and an additional oxygen-rich zone (Unsaturated Nitrification Soil) to promote conversion into nitrate-nitrogen. Wastewater then passes through a low-oxygen, carbon-rich zone to promote denitrification (Woodchips/Soil Mix Denitrification Media). Denitrification is a process by which specialized bacteria convert nitrate into nitrogen gas that escapes into the atmosphere. This reduces the amount of nitrogen that can leach into groundwater.

FDOH provides comprehensive information about advanced treatment systems and requirements on their product listing and approval requirement web page.

 Where are advanced treatment systems required?

The short answer is wherever a septic system remediation plan to protect Florida Springs has been put into place. The 2016 Florida Springs and Aquifer Protection Act was passed to protect 30 ‘Outstanding Florida Springs.’ The majority are historic first magnitude springs, springs with flows of more than 100 cubic ft/second. Twenty-four of these springs are identified as nitrogen impaired by the Florida Department of Environmental Protection.

If septic systems contribute more than 20% of the nitrogen load to the impaired spring, a remediation plan takes effect in specific areas (Priority Focus Areas) that are particularly susceptible to nitrogen pollution. Septic system remediation plans require new development to connect to central sewer where available. If this isn’t an option, new construction on lots of less than 1 acre must include advanced nitrogen-removal technology. In the Panhandle, areas around Wakulla Springs and Jackson Blue Springs have remediation plans.

The best source of information about specific remediation plans and whether or not you live in a Priority Focus Area is FDOH. Contact your local County Department of Health Office to find out if you live in a PFA or if you have questions about septic tank requirements, permitting and  approved advanced nitrogen-treatment features for septic systems.

For more information and resources about conventional septic systems and advanced treatment system visit our UF/IFAS Septic Systems website.