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The Floridan Aquifer acts as a giant water savings account for the people of Florida.  If you do not want to deplete your savings, your deposits (the part of rainfall that infiltrates) must be as large or greater than your withdrawals. Should part or all of your assets become frozen (such as when water becomes polluted) you may be able to use only parts of it, or in extreme cases none at all. 

There is not much that we can do about rainfall. But we can do much about making sure that we conserve as much water as possible and that the water that recharges the aquifer is as uncontaminated as possible. For a long time, the focus of concerns about aquifer contamination put the spotlight on point sources, in other words, places where we could clearly see where the pollution originated from. With the increased awareness of the insidious effects of many chemicals on living things, (think of DDT as just one example) we have become much more sensitive to non-point sources of aquifer pollution. 

Because there are virtually no clays in this area to slow down and filter inflowing water, contaminants in the area percolate through the thin sandy soils with little or no filtration, or they mainline into the aquifer through sinkholes, cave entrances, fractures and joints. Once in the underground aquifer, they can travel fast and far through solution-enlarged passages (conduit flow). 

1. Nutrients. Nitrates, for example, are a significant pollutant with bad health effects. Fertilizers rich in nitrates easily enter ground water, especially if too much is applied, or at the wrong time. Manure also contains nutrients that will percolate from areas where livestock or wildlife is allowed to or forced to congregate; extreme examples of this would be dairy farms, feed lots, chicken coops and hog farms.  Another problem is due to allowing livestock access to sinks and cave entrances. Bird rookeries are significant nitrate contributors.  Outhouses and improperly working septic tanks also add to the load. There is a direct relationship between land use and nitrate pollution. 

2. Pesticides. Since WWII there has been an increased use of pesticides nation-wide. They are used for many functions, from killing weeds and insects, to controling diseases. They are usually applied in some form of solution. Like nutrients, most pesticides infiltrate into ground water after rainy episodes where they definitely affect the drinking water. In caves and springs they can kill fish and crayfish and other cave life. They will also affect the bats either directly or as they consume contaminated insects. 

3. Bacteria and viruses
Bacteria and viruses come from animal and human wastes, either  by infiltration or when dead animals and wastes wash, fall or are thrown into sinks and caves 

4. Sediments
Sediments that wash into solution features can carry nutrients,  pesticides, pathogens and other pollutants to ground water. They fill solution passages, alter underground drainage patterns, and cause ground water to be turbid. 

5. Other Contaminants
We have become aware of an increasing list of contaminants due to human activity. For example, salts in ground water can come from animal feeds and irrigation. Contamination comes also from improperly disposed fuels, oils,  from leaking tanks, discarded cans and containers; discarded equipment (junk);  chemical and household wastes, septic wastes, spills etc.. It used to be common practice to dispose of used motor oil by pouring it at the base of  fence posts. While this worked very well to protect the posts from termites, bacteria and fungi that cause rot, it introduced significant amounts of hydrocarbons in the water supply.  For the longest time also, sinkholes and caves were considered convenient private and semi-public dumps, contributing in no small measure to pollution. And this is but a small part of the entire list.