Septic tank or city sewer? How to find out for sure

Knowing where your drains go changes how you use water, what you flush and who you call when something backs up. In Florida it is far from a sure thing: the state's Onsite Sewage Program counts roughly 2.6 million septic systems serving about 30% of residents. North of Orlando you'll find both on the same road.

Why isn't it obvious which one I have?

Most of the system is underground either way. A septic tank and drainfield sit buried in the yard, and a sewer lateral runs under the lawn to a main in the street, so neither shows from the porch. In some neighborhoods sewer arrived after the houses did, and not every owner connected, so a home near a sewer main may still be on septic.

Look at the water and sewer bill first

The quickest clue is the monthly bill. City and county utilities in this area run both water and wastewater service; Sanford, for one, files them together as its Water & Sewer department. If your bill lists a sewer or wastewater charge, you're most likely connected. If it shows only water, or you have a private well and no water bill at all, a septic tank is likely.

One caution: a reclaimed water charge is a separate thing: reclaimed is treated wastewater sent back out for lawns, and Seminole County bills it as its own line item, per the county's reclaimed water page. It says nothing about where your toilets drain.

Who keeps septic records for my address?

In Seminole and Orange counties, the Florida Department of Health office in each county still issues septic permits and does the inspections, even though the state Department of Environmental Protection has overseen the program since July 1, 2021, according to DEP's permitting FAQ. That makes DOH-Seminole or DOH-Orange the natural place to ask whether a permit is on file for your lot.

Florida law also says septic permits for installation, modification or repair transfer with the title when a home sells. If a seller had the system repaired, that permit belongs with the house, so ask for copies at closing.

What clues can I find in the yard?

The ground gives hints, though none settles it alone. Look for a concrete or plastic lid at ground level somewhere in the yard. A long, even rectangle where the grass grows differently may be a drainfield. A cleanout cap near the street side of the yard points toward sewer.

EPA lists bright green, spongy grass over a tank or drainfield "even during dry weather" as a sign of trouble, so a lush strip in April tells you two things at once. Don't pry open a tank lid to check. EPA warns that only trained specialists should open tanks because they can hold dangerous gases.

What's different in my part of the county?

The pattern changes from town to town. The newer the subdivision and the closer to a city center, the more likely it's on sewer, but there are exceptions in every direction.

Why does it matter day to day?

On sewer, the main worries are clogs in your own lateral and what the city asks you not to pour down drains. On septic, everything you flush and every gallon you run lands in your yard. EPA's list of things never to flush, its pumping timeline and drainfield care are in our septic pumping and care story, and warning signs are in drainfield trouble.

It also matters for the water heater, softener and well. A softener's regeneration uses about 50 gallons each time, which Penn State Extension notes may or may not overload a septic system. Our water softeners page has more on that.

What about converting from septic to sewer?

Conversion depends on whether a public sewer main reaches you and whether the utility is running a program. Orange County's Wekiwa Springs program is converting almost 2,000 homes in phases, per its Septic 2 Sewer page. Seminole County asked the state in 2024 for money toward a conversion project near Bear Lake, but the county's website blocked our requests and we could not confirm where its program stands now. Call Seminole County Utilities for the current word.

Readers often ask

Can a house be on city water but still have a septic tank?

Yes. Water supply and wastewater are separate services, so a house can get city water and still drain to a tank in the yard. Check the bill for a sewer charge and ask the county health department about permits.

Will my home inspector tell me if it's septic?

Often, but don't count on it. Florida law bars any government from requiring a septic inspection at the point of sale, so it's up to the buyer to ask for one.

Does a reclaimed water meter mean I'm on sewer?

No. Reclaimed water is treated wastewater piped back out for irrigation. Having a reclaimed meter says nothing about where your own drains go.

My neighbor is on sewer. Does that mean I am too?

Not necessarily. Sewer may have arrived after your house was built, and some owners never connected. Your bill and the utility's records are the reliable answer.

Where do I find the old septic permit for my house?

Ask the Florida Department of Health office in your county. In Seminole and Orange counties, that office issues septic permits and keeps the records, even though DEP oversees the statewide program.

Where this came from

1. Florida DEP — Onsite Sewage Program — number of systems, share of residents, DEP's role since 2021
2. Florida DEP — Onsite Sewage FAQ: Permitting — county health departments still issue permits in Seminole and Orange
3. Florida Statutes s. 381.0065 — permits transfer with title; no point-of-sale inspection mandate
4. EPA — Resolving Septic System Malfunctions — green-grass warning sign
5. EPA — Septic Systems: What to Do after the Flood — only trained specialists should open tanks
6. Seminole County Utilities — Reclaimed Water (archived) — reclaimed billed separately
7. Orange County — Septic 2 Sewer — Wekiwa Springs conversion program
8. Penn State Extension — Water Softening — regeneration water and septic systems
9. Florida DEP — Wekiwa Spring and Rock Springs BMAP, 2018 — Altamonte Springs sewer requirement for new development