Well water testing in Marion County, Florida (2026)

WellTestList · Wednesday, October 28, 2026 · county page · back to the Florida page

Marion County has an estimated 68,321 households on private wells by EPA’s 2020 model. That’s the most of any Florida county and sixth in the country. The county health department says only about a third of residents are on public water. Most rely on private wells and small water systems. The wells draw from the Floridan aquifer, which here is limestone close to the surface, the same rock that feeds Silver Springs and Rainbow Springs. That makes it easy for what goes on the ground to end up in the water. Here is who to call, which certified labs are near Ocala, what they charge, and what Marion County wells should be tested for.

The short version

1. Test for bacteria every year, and add nitrate. The Florida Department of Health (FDOH) and DOH-Marion both say to test a private well for bacteria at least once a year. FDOH adds nitrate to that yearly test. In the karst around Silver Springs, rain can carry surface water down to a well fast.
2. The cheapest posted bacteria test near Marion is $25. DOH-Alachua’s water lab in Gainesville charges $25 a bottle (it suggests two), Monday to Thursday. It’s about 40 miles from Ocala, and the sample has to get there on ice within 15 hours.
3. There’s a certified lab in Ocala. Marion County Lab on SE 45th Court is state-certified for bacteria, sends other tests out to partner labs, and emails results. It doesn’t post prices, so call (352-694-6042).
4. For a home sale, use a lab that posts a lender package. AEL in Gainesville lists an FHA/VA package (bacteria, nitrate/nitrite and lead) for $225. Florida doesn’t require a well test when a house sells, but most lenders do.
5. Test your house for radon, and test PFAS if you’re near the Fire College. One in three Marion County homes has elevated radon in the air, per FDOH. PFAS from firefighting foam was found in private wells near the Florida State Fire College north of Ocala.

Who to call

• Florida Department of Health in Marion County (DOH-Marion), Environmental Health. 1801 SE 32nd Ave., Ocala, FL 34471 · 352-622-7744 · EHInfoMarion@FLHealth.gov · Environmental Health is open weekdays 8–4. Its drinking water page says the county health department supervises private wells and small water systems, collects and evaluates water samples, and investigates contamination. Call to ask whether they can take or pick up a sample. We couldn’t find a posted DOH-Marion fee. FDOH says county health departments usually charge about $20–$30 a sample, plus $30–$40 if staff collect it.
• Well permits. DOH-Marion issues well construction permits for the county on behalf of both water management districts (Southwest Florida and St. Johns River). Your licensed well contractor applies.
• Free state testing near contamination. DOH-Marion staff take up to 300 samples a year from drinking water wells near known contamination sites. Through FDEP’s Water Supply Restoration Program, this testing costs the owner nothing, and FDEP can help with a filter or a hookup if a well is contaminated. If you live near a gas station, landfill, old grove or industrial site, ask whether your well qualifies.
• Radon. In 2020, DOH-Marion gave out free radon test kits at its main office. Ask Environmental Health at 352-622-7744 whether any are left.

Certified labs near Ocala

Florida certifies drinking water labs through NELAP. Each lab below is on FDOH’s list of certified labs for homeowner drinking water testing (bacteria at minimum), and none sells water treatment equipment as far as we could find.

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FDOH’s state lab (Bureau of Public Health Laboratories, Jacksonville) also runs a coliform and E. coli test: $40 if you send it yourself, or $17 if it goes through a county health department (904-791-1600). The list also has ABC Research and BCS Laboratories in Gainesville, which we didn’t check tonight. We left off a Silver Springs listing that’s a water and sewage service company. You can check any lab in FDEP’s NELAP Certified Laboratory Search. We only list labs we could verify, and we skip anyone who sells water treatment.

What’s in Marion County groundwater

Marion County sits on the Floridan aquifer, where the limestone is close to the surface and full of sinkholes and springs. Water moves through the rock quickly, so wells, springs and land use are closely linked.

• Nitrate. The state’s 2025 cleanup plan (BMAP) for the Silver and Rainbow springsheds says the nitrogen reaching the springs has to drop by 80% to meet their nitrate target of 0.35 mg/L, measured as a long-term monthly average. FDEP estimates where the nitrogen reaching groundwater comes from: septic systems 32%, livestock waste (Marion is horse country) 23%, lawn fertilizer 20%, farm fertilizer 9%, and rain and air 9% (FDEP, June 2025). In monitoring wells, median nitrate was 0.76 mg/L in the Silver springshed and 1.44 mg/L in the Rainbow springshed (2021–2024). Both are well under the 10 mg/L drinking water limit, but they’re medians. FDOH’s private well samples near Silver Springs averaged 3 mg/L and topped out at 31 mg/L, and most came from a known contamination area near Lake Weir (FDEP TMDL report). If a well is near a septic field, a pasture or a heavily fertilized lawn, test nitrate. If there’s a baby under six months in the house, test now, and don’t boil the water (boiling concentrates nitrate).
• Bacteria. Karst lets surface water reach a well with little filtering, especially after heavy rain or a flood. DOH-Marion’s advice is a bacteria test at least once a year. If a test finds coliform, the usual fix is to shock-chlorinate the well and retest.
• Old contamination (EDB and solvents). FDEP has mapped “delineated areas” of known groundwater contamination in Marion County, on the Belleview, Lady Lake, Lake Weir, Ocala East and Ocala West map sheets. Most of Florida’s delineated areas are for the old grove fumigant EDB (FDEP delineated areas). A new drinking water well in a delineated area needs a stricter permit and has to pass a county health department test before anyone drinks from it. If you’re near Lake Weir or Belleview, ask DOH-Marion whether your lot is inside one.
• Radon. In Marion County radon is mostly a soil and air problem. FDOH told the county commission in 2020 that one in three Marion homes has elevated radon, compared with one in five statewide (Ocala Gazette), because the local rock is higher in uranium and radium. A home air test is the first step. Radon in well water is a separate test that most panels don’t include.
• Arsenic. Marion isn’t in the area where FDOH specifically recommends arsenic testing: the west coast from Dixie County south to Hillsborough, plus western Polk (FDOH arsenic fact sheet). Still, test arsenic once in a wider panel. It’s in the Tap Score and NTL mail-in kits, and Marion County Lab offers it.
• PFAS. In 2018, FDEP found 250 ng/L of PFOA plus PFOS in the drinking water well at the Florida State Fire College on NW Gainesville Road, where firefighting foam had been used in training. FDOH then tested private wells within a mile, and its 2021 report found some of them had PFOS at levels that could pose a health risk if people drank the water unfiltered (FDOH health consultation). If you’re near the Fire College, an airport or a landfill, test PFAS once. AEL posts a $395 PFAS test, and our PFAS page covers which method to ask for.

These numbers describe the county, not your lot. Results change from one well to the next, so only your own test tells you.

New wells and home sales

New wells. A licensed water well contractor pulls the permit through DOH-Marion, which handles permits for both water management districts in the county. Inside an FDEP delineated area, state rules (Chapter 62-524) add stricter construction and a required county health department water test before the well is cleared for drinking. Outside those areas, we didn’t find a Marion rule that requires a water quality test on a new house well. Ask DOH-Marion when you apply, because some Florida counties require a passing bacteria test before a new home can be occupied. Either way, have the contractor disinfect the well and test bacteria and nitrate before anyone drinks from it.

Home sales. FDOH says Florida has no state requirement to test a private well when a house sells. For a sale, it suggests testing coliform, nitrate and lead. FHA, VA and many conventional lenders require a test, so ask the underwriter which lab and tests they accept before anyone samples. AEL’s $225 FHA/VA package covers those three and needs a third party to take the sample. Marion County Lab says its reports meet lender requirements. Our home purchase / lender page covers the details.

After a positive bacteria test. FDOH’s fix is to shock-chlorinate the well and retest. Marion County Lab and licensed well contractors do this. Do it before you buy any treatment system.

Mail-in kits that email a PDF

If you want metals, minerals and nitrate in one report without driving to Gainesville, independent mail-in labs ship to Marion County. Listed prices checked October 28, 2026:

• Tap Score / SimpleLab Essential Well: $209. It covers coliform and E. coli, nitrate and nitrite, and 25 metals including arsenic, uranium, manganese and lead, plus sodium and chloride. It doesn’t test VOCs, radon or PFAS.
• Tap Score / SimpleLab Advanced Well: $399. It adds VOCs and common petroleum compounds, which is useful near old fuel tanks or EDB areas, and includes overnight shipping to the lab.
• National Testing Laboratories WaterCheck Basic: $220. It covers bacteria, 22 metals and minerals (arsenic included), and 7 inorganic chemicals. Next-day return shipping isn’t included, so budget for it on the bacteria bottle.

For the yearly bacteria test, DOH-Alachua’s $25 bottle or your county health department is the better deal. Mail-in kits make sense once, for a wide first look. Radon in water and PFAS are separate tests. Ask a lender before using a mail-in kit for a sale.

Side by side for a Marion County well

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Related: Florida well testing · Lancaster County, PA · Worcester County, MA · Suffolk County, NY · Fairfield County, CT · Oakland County, MI · How to read a well water report · PFAS 533 / 537.1 · Home purchase / lender · back to the directory.