Florida has approximately 800,000 registered private wells, according to the Florida Department of Environmental Protection. Those wells are not regulated by a public water utility, so the responsibility for testing, treatment, and maintenance falls entirely on the homeowner. In Central Florida, private wells draw from the Floridan Aquifer, one of the most productive aquifer systems in the world according to the U.S. Geological Survey. The Floridan Aquifer is a thick limestone formation, and as water moves through it over years, it dissolves minerals and picks up naturally occurring compounds that affect water quality. The Florida Department of Health recommends that private well owners test their water at least once a year. Osceola County and Orange County both have significant populations on private wells, and FLDEP and FDOH guidance identifies hydrogen sulfide, iron, manganese, arsenic, nitrates, and hardness as the contaminants most commonly found in Central Florida well water.
How many Florida homes rely on private wells, and what does FLDEP track?
Florida's approximately 800,000 registered private wells serve households, farms, and businesses that are not connected to a public water system. The Florida Department of Environmental Protection oversees private well construction standards and permitting through Chapter 62-532 of the Florida Administrative Code. Every new well drilled in Florida requires a permit from the appropriate water management district and must meet construction standards designed to prevent surface contamination from entering the aquifer.
Unlike water delivered by a public utility, private well water is not treated before it reaches the tap, and no government agency routinely monitors the water quality inside a private well after it is constructed. That responsibility belongs to the homeowner. The FLDEP well construction standards address the physical integrity of the well casing, grouting, and sanitary seal, but they do not guarantee that naturally occurring minerals or surface-derived contaminants will be absent from the water.
Florida statutes govern private wells under Section 381.0065 of the Florida Statutes, which places regulatory responsibility for private water supply wells with the Florida Department of Health. The FDOH sets minimum standards for well construction and provides guidance on testing frequency and contaminants of concern. Their private well guidance is available at floridahealth.gov/environmental-health/drinking-water/private-water-wells.html.
FLDEP's source water protection program and well construction permitting information can be reviewed at floridadep.gov/water/source-drinking-water-protection/content/private-water-wells. Homeowners who want to understand the regulatory framework for their well should review both the FDOH and FLDEP pages, as each agency covers a different aspect of the well lifecycle.
What contaminants does FDOH flag in Central Florida private wells?
The Florida Department of Health identifies several contaminants of concern for private well owners in Florida. In Central Florida, where wells draw from the Floridan Aquifer limestone system, the contaminants most commonly documented include iron, manganese, hydrogen sulfide, arsenic, nitrates, and total hardness. Each of these appears in the Floridan Aquifer at concentrations that can affect water quality, fixture condition, appliance lifespan, and in some cases human health.
FDOH recommends that private well owners test for coliform bacteria, nitrates, and pH at a minimum on an annual basis. Coliform bacteria testing is the most critical routine check because bacterial contamination can result from surface water intrusion, well casing failures, or proximity to septic systems. The EPA sets a maximum contaminant level of zero for total coliform bacteria in drinking water under the Safe Drinking Water Act primary standards at epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations.
Beyond the core annual panel, FDOH recommends that Central Florida well owners also test for iron, manganese, arsenic, and hardness, because these contaminants are naturally present in the Floridan Aquifer at elevated concentrations in many parts of Orange and Osceola Counties. A comprehensive baseline test when a well is first used, and after any flooding event, gives homeowners the data they need to select appropriate treatment and to track changes over time.
If you have not tested your well water recently, our water testing page explains the process and Pure Agua Enterprises offers free water testing to Central Florida homeowners. Call us at (407) 512-8342 or request a free water test online.
What USGS data shows about Osceola and Orange County groundwater
The U.S. Geological Survey operates the National Water Information System, which collects and publishes groundwater quality data for monitoring wells across Florida. NWIS data for Florida is accessible at waterdata.usgs.gov/fl/nwis and includes chemical analyses from Floridan Aquifer monitoring wells in Orange and Osceola Counties.
USGS monitoring data from the Floridan Aquifer documents naturally occurring arsenic in groundwater at concentrations that in some wells approach or exceed the EPA maximum contaminant level of 10 micrograms per liter. USGS tracks arsenic using NWIS parameter code 01000. Arsenic in the Floridan Aquifer is geogenic, meaning it originates from natural rock chemistry rather than industrial or agricultural contamination. Limestone and associated mineral deposits in the aquifer matrix contain trace arsenic that dissolves into groundwater over long timescales.
USGS data also documents iron, manganese, hydrogen sulfide, and hardness minerals as characteristic features of Floridan Aquifer groundwater chemistry throughout Central Florida. These are not pollution events. They are the natural geochemical signature of an aquifer moving slowly through a thick limestone and carbonate rock formation over decades. Understanding them as natural phenomena rather than contamination events helps homeowners make better decisions about testing priorities and treatment technology.
USGS publishes Florida-specific groundwater reports and aquifer characterization studies that are freely available. Homeowners with specific questions about their area can search by county or aquifer name in the NWIS database.
Hydrogen sulfide: the rotten egg problem in Floridan Aquifer wells
Hydrogen sulfide gas is the contaminant that Central Florida well water owners most frequently report noticing without a test. The compound produces a distinctive rotten egg odor that is detectable at concentrations as low as 0.5 parts per billion in water. In Central Florida's Floridan Aquifer, hydrogen sulfide results from sulfate-reducing bacteria that metabolize dissolved sulfate naturally present in the limestone formation. The bacteria produce hydrogen sulfide gas as a byproduct, and it dissolves into the groundwater.
Hydrogen sulfide has no EPA primary drinking water standard because it does not pose a health risk at the concentrations typically found in residential well water. However, it does appear in EPA secondary drinking water standards as an aesthetic contaminant at a suggested level of 0.05 mg/L, referenced at epa.gov/sdwa/secondary-drinking-water-standards. Secondary standards are not federally enforceable but serve as guidance for taste and odor.
The practical problems with hydrogen sulfide in well water go beyond odor. The gas is corrosive to copper pipes, fixtures, and appliances. It can cause water heater anode rods to fail prematurely, and it reacts with iron in water to form black iron sulfide deposits that stain fixtures and laundry. High hydrogen sulfide concentrations can also affect the effectiveness of chlorine disinfection if shock chlorination is used as a treatment method.
Treatment options for hydrogen sulfide in Central Florida well water depend on concentration. At low concentrations, catalytic carbon filtration is effective. At moderate to high concentrations, aeration followed by carbon filtration, or a chemical oxidation system using potassium permanganate or hydrogen peroxide injection followed by filtration, is the standard approach. Our detailed guide to hydrogen sulfide treatment for Central Florida well water covers the options in depth. Pure Agua Enterprises has been solving hydrogen sulfide problems for Central Florida homeowners for more than 10 years and can test and size a system at no charge.
Iron and manganese staining from Osceola and Polk County wells
Iron and manganese are the two contaminants most responsible for the visible staining that Osceola and Orange County well water owners experience on toilets, sinks, showers, and laundry. Both are naturally occurring metals that dissolve into Floridan Aquifer groundwater as it moves through iron-bearing minerals and manganese oxide deposits in the limestone formation.
The EPA sets secondary drinking water standards for both iron and manganese. The suggested level for iron is 0.3 mg/L and for manganese is 0.05 mg/L. These are aesthetic standards, not health-based primary standards. However, iron above 0.3 mg/L produces visible rust-colored or orange-brown staining on any surface the water contacts. Manganese above 0.05 mg/L produces black or dark brown staining and is also associated with a metallic taste. More recent EPA health guidance has identified manganese as a neurodevelopmental concern at higher concentrations, and the EPA published a health advisory for manganese in 2020. The primary standards documentation is at epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations.
In Osceola and Orange Counties, iron concentrations in private well water frequently exceed 1 mg/L and in some wells reach 5 to 10 mg/L. Manganese concentrations above the secondary standard are also commonly documented. Iron in well water exists in two forms: dissolved ferrous iron, which is invisible when the water is drawn but oxidizes and precipitates when it contacts air, and particulate ferric iron, which is already oxidized and visible as reddish particles. Treatment selection depends on which form is present and at what concentration, which is why a water test is the essential first step.
Common treatment approaches for iron and manganese in Central Florida well water include greensand filtration with potassium permanganate regeneration, air injection oxidation followed by filtration, and whole-home catalytic oxidizing media systems. Read our complete guide on iron and manganese treatment for Central Florida wells for a side-by-side comparison of the available technologies. Pure Agua Enterprises sizes and installs iron and manganese filtration systems throughout the Kissimmee and Orlando area.
Arsenic and nitrates: why annual testing matters under Florida Statutes 381.0065
Arsenic and nitrates are the two contaminants in Central Florida private well water that carry enforceable federal maximum contaminant levels under the EPA Safe Drinking Water Act, even though private wells are not subject to federal regulation in the same way that public water systems are. The federal MCLs exist as the standard of comparison for private well testing, and FDOH uses them as the benchmark in guidance under Florida Statutes 381.0065.
The EPA arsenic MCL is 10 micrograms per liter (0.010 mg/L), a standard that took effect in 2006. At concentrations above 10 micrograms per liter, long-term arsenic exposure in drinking water is associated with increased risk of bladder, lung, and skin cancers according to EPA risk assessment documentation. Arsenic in Floridan Aquifer groundwater is geogenic and has been documented by USGS in monitoring wells across Central Florida at concentrations that approach or exceed this threshold. Because arsenic is colorless, odorless, and tasteless at these concentrations, it cannot be detected without a laboratory test.
The EPA nitrate MCL is 10 mg/L measured as nitrogen. Nitrate in private well water in Central Florida can result from agricultural fertilizer application, septic system effluent, or naturally occurring mineral nitrogen in the aquifer. In areas with dense residential development on large lots with septic systems, nitrate contamination from adjacent sources is a documented concern. Infants under six months of age are the primary health concern for nitrate exposure because nitrate interferes with the blood's ability to carry oxygen, a condition called methemoglobinemia.
FDOH specifically recommends annual testing for nitrates as part of the minimum private well testing program. Annual testing is also important for arsenic because groundwater chemistry can shift over time as the water table fluctuates, drought conditions concentrate dissolved minerals, or changes in local land use affect recharge water quality. A test that came back below the arsenic MCL five years ago is not a guarantee of current water quality. For testing options available to Central Florida homeowners, see our water testing services page or call (407) 512-8342.
How to test your private well in Central Florida
Testing a private well in Central Florida starts with collecting a water sample and sending it to a state-certified laboratory. The FDOH directory of certified drinking water laboratories in Florida is available at the FDOH website, and most Central Florida counties have local certified labs or can direct homeowners to mail-in certified labs. The FDOH private well guidance page at floridahealth.gov/environmental-health/drinking-water/private-water-wells.html includes guidance on sample collection procedures.
At minimum, FDOH recommends testing private well water annually for coliform bacteria, nitrates, and pH. The FDOH also recommends baseline testing for a broader panel when a well is first placed into service, and after any significant event such as a flood, a change in water taste or odor, new agricultural or industrial activity nearby, or a change in local land use.
For Central Florida homeowners concerned about the contaminants documented in Floridan Aquifer wells, a comprehensive panel that includes iron, manganese, hydrogen sulfide, arsenic, total hardness, total dissolved solids, pH, nitrates, and coliform bacteria provides the most complete picture of what is actually in the water. Pure Agua Enterprises provides free on-site water testing for Central Florida homeowners. Our testing covers the parameters most relevant to Floridan Aquifer well water. Request a free water test and one of our licensed technicians will come to your home, collect samples properly, and walk you through the results.
Florida well construction and testing regulations are maintained by FLDEP under Chapter 62-532 FAC and by FDOH under Section 381.0065 Florida Statutes. Homeowners who have questions about their well's construction record can request permit documentation from their local FLDEP district office.
What treatment options remove the contaminants FDOH identifies
Treatment for Central Florida private well water must be matched to the specific contaminants found in the water test results. There is no universal treatment system that addresses all possible contaminants at once, which is why a test is always the first step. The following overview covers the primary treatment technologies for the contaminants most commonly found in Floridan Aquifer well water in Osceola and Orange Counties.
Hydrogen sulfide: Aeration, catalytic carbon filtration, and chemical oxidation followed by filtration. The right approach depends on concentration measured in mg/L. Below approximately 1 mg/L, catalytic carbon alone is often effective. Above that threshold, an aeration or oxidation pretreatment step is typically required before filtration.
Iron and manganese: Oxidizing filtration media such as Birm, greensand, or manganese dioxide-based catalytic media. For dissolved iron below about 5 mg/L, an oxidizing media filter sized to the flow rate is the standard approach. Higher concentrations may require chemical oxidation injection before filtration. A water softener alone does not remove iron above trace concentrations and is not the appropriate treatment for high-iron well water.
Arsenic: Reverse osmosis at the point of use is the most effective residential treatment for arsenic removal. RO membranes remove greater than 95% of dissolved arsenic. Adsorptive media filters using iron oxide-coated media are also used in whole-home applications. NSF/ANSI Standard 58 covers RO systems for contaminant reduction, and NSF/ANSI Standard 53 covers adsorptive media.
Nitrates: Reverse osmosis at the point of use removes nitrates effectively. Ion exchange systems designed specifically for nitrate reduction are also available for point-of-use and point-of-entry applications. Standard water softeners that use sodium chloride do not reliably remove nitrates.
Total hardness: A whole-home water softener using ion exchange removes calcium and magnesium ions responsible for hardness. Floridan Aquifer well water in Central Florida is typically very hard, and a properly sized softener is the standard solution for preventing scale and protecting appliances. Contact Pure Agua Enterprises for a free consultation on the treatment approach best matched to your water test results.
Pure Agua Enterprises is NSF/WQA certified, Florida licensed, and has served more than 2,000 Central Florida homeowners over more than 10 years. We hold a 5.0 star rating with more than 200 reviews and service the Kissimmee, Orlando, and surrounding Central Florida area.
Frequently asked questions about Central Florida well water contamination
How often should I test my private well water in Florida?
The Florida Department of Health recommends testing at minimum once per year for coliform bacteria, nitrates, and pH. A comprehensive panel covering iron, manganese, arsenic, hydrogen sulfide, hardness, total dissolved solids, and pH should be done when the well is first used and after any flooding, odor change, or nearby land use change. Annual testing is the baseline, not the ceiling.
Is hydrogen sulfide in my well water a health risk?
Hydrogen sulfide in well water at the concentrations typically found in Central Florida's Floridan Aquifer is not considered a health risk at residential exposure levels. The EPA secondary standard suggests a maximum of 0.05 mg/L for aesthetic reasons. The gas does cause a strong rotten egg odor, is corrosive to copper plumbing and fixtures, and can interfere with other treatment processes. It requires treatment, but for a different reason than a health-based contaminant.
What is the EPA limit for arsenic in drinking water?
The EPA maximum contaminant level for arsenic in public drinking water is 10 micrograms per liter, a standard that took effect in January 2006. Private wells are not regulated by this standard directly, but FDOH guidance uses the federal MCL as the reference point for advising private well owners. USGS data documents arsenic in Floridan Aquifer monitoring wells across Central Florida at concentrations that in some cases approach this level, which is why arsenic testing is recommended for Central Florida private well owners.
Can I use my water softener to remove iron from my well water?
A standard cation exchange water softener removes small concentrations of dissolved iron, typically below about 1 to 2 mg/L. Above those concentrations, iron fouls the softener resin and the system loses effectiveness. Central Florida Floridan Aquifer well water frequently contains iron above 2 mg/L. The correct approach for high-iron well water is a dedicated iron filtration system installed before the softener. A water test is the only way to determine how much iron is present and what treatment sequence is appropriate.
What Florida law governs private wells?
Private water supply wells in Florida are governed primarily by Section 381.0065 of the Florida Statutes, which assigns regulatory authority to the Florida Department of Health. Well construction standards are established in Chapter 62-532 of the Florida Administrative Code, maintained by the Florida Department of Environmental Protection. Water management districts issue construction permits. There is no state requirement that private well owners test their water after initial construction, which is why FDOH guidance and routine annual testing by the homeowner are the primary safeguards for well water quality.
Does nitrate in my well water pose a risk to infants?
Yes. The EPA maximum contaminant level for nitrate is 10 mg/L as nitrogen specifically because of the risk of methemoglobinemia in infants under six months of age. At concentrations above 10 mg/L, nitrate in drinking water can interfere with an infant's blood oxygen-carrying capacity. Adults and older children are not at risk from nitrate at these concentrations. If your well tests above 10 mg/L nitrate, do not use that water for infant formula preparation or feeding until a treatment system is installed and verified.
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