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When the drainfield starts talking back
Septic drain field problems show up as slow drains, gurgling, soggy ground, sewage smells or a too-green strip of lawn. Cut water use, keep off the area and call a registered septic contractor.
The drainfield is the part of a septic system that does the quiet work, letting treated water soak into the sand under your lawn. When it struggles, the house usually lets you know first. North of Orlando, a summer of afternoon storms or a tropical system can be enough to push a tired drainfield over the edge.
What are the warning signs?
EPA's list of signs that a septic system is failing reads like a checklist for a walk around the yard. Sewage backing up into toilets, drains or sinks. Tubs, showers and sinks that drain slowly. Gurgling in the plumbing. Standing water or damp spots near or over the tank or drainfield. Sewage smells around the tank or field. And bright green, spongy grass over the system even during dry weather.
EPA also lists algae blooms in nearby lakes and high nitrate or coliform in nearby wells. Our private wells page covers the yearly well test.
Signs and what they may point to
| What you notice | Could point to | First step |
|---|---|---|
| Slow drains in one fixture only | A clog in that fixture's line | Clear the line; watch for a repeat |
| Slow drains or gurgling all over the house | Tank or drainfield | Cut water use; call a registered septic contractor |
| Sewage smell outdoors near the tank or field | Tank or drainfield | Keep people off; get it inspected |
| Sewer smell indoors, drains working | Possibly a blocked roof vent | Have the vent checked |
| Soggy ground or bright green grass over the field | Drainfield | Cut water use; get it inspected |
| Sewage backing up into the house | Tank, line or drainfield | Stop using water; avoid contact; call a pro |
Is every sewer smell a failing system?
No. EPA notes that a sewer smell can come from a blocked roof vent or from downdrafts, and that the vent may need to be cleaned or raised. If drains are moving fine and the smell comes and goes with the wind, the vent is a fair suspect. Checking a roof vent is a job for a licensed plumber.
A smell near the field or tank, paired with wet ground, is a different story. That points back to the system itself.
Why does wet weather make it worse?
Rain fills the soil the drainfield depends on. When the water table rises or floodwater threatens the system, EPA says sewage can back up indoors, and the one defense is sending less water down the drains. Through storm season, from June 1 to November 30, that's a real concern on low lots.
Hold off on pumping while the field is underwater or soaked. An emptied tank sitting in saturated ground can lift, EPA cautions, and its pipe connections can break. Go easy on laundry, showers and dishwashing, and return to normal use only once the soil over the field holds less water than the ground near the house. Our flooded wells and septic story covers the after-the-storm checklist.
What makes a drainfield fail?
Most of the causes are things that happen above it. EPA lists parking or driving on the field, paving over it, building on it, sending roof drains or other rainwater onto it, and planting trees or shrubs whose roots go looking for water. Too much water in too short a time is another; EPA says doing all the week's laundry in one day could flood a drainfield.
Solids are the other culprit. A tank that goes too long between pumpings lets sludge and scum reach the outlet. Our septic pumping and care story has EPA's measurements for when a tank is due.
Who can repair it, and is a permit needed?
Yes, a permit is needed, and the work belongs to a registered septic tank contractor. Florida law says no one may construct, repair, modify or abandon a septic system without a permit, and in Seminole and Orange counties that permit comes from the county health department office. The repair permit runs 90 days from issue. Check a contractor's registration with DEP's online search before you hire.
If your home sits in the Wekiwa Spring and Rock Springs area, a repair on a smaller lot may require a nitrogen-reducing system rather than a like-for-like fix. The details are in our springs-area septic rules story.
How do I clean up after a sewage backup?
Don't touch the sewage, and keep children and pets away. For cleanup indoors, EPA's malfunctions page calls for a disinfecting solution that is 90% water and 10% household bleach; leave the room unused until everything has dried for a full 24 hours or more. For floors fouled by sewage floodwater, EPA's flood page gives a separate mix of a half cup of bleach to each gallon of water.
EPA, Resolving Septic System Malfunctions
What if the ground over the tank sinks?
Keep everyone off it. A broken septic tank is one of the causes of ground subsidence the Florida Geological Survey lists, alongside true sinkholes. Don't try to fill the hole, and don't run water into it. Ask a state-registered septic contractor to inspect, tell the county health office, and notify your insurance company. Dial 911 if the ground is giving way near the foundation, a driveway or the street. Our sinkholes and pipes story explains how insurance treats ground collapse.
Readers often ask
Can a soggy drainfield dry out and recover on its own?
Sometimes the problem is simply a high water table after heavy rain, and easing up on water use lets things settle. If backups, smells or soggy ground persist after the weather dries, have the system inspected.
Should I pump the tank right away if drains are slow?
Not if the yard is flooded or saturated. EPA warns that pumping then can float the tank and damage its pipes. Cut water use and wait for the ground to drain first.
Why is the grass over my drainfield greener than the rest of the lawn?
EPA lists bright green, spongy grass over the field, even in dry weather, as a possible sign of failure. It can mean effluent is reaching the surface rather than soaking in properly.
Can I plant shrubs over the drainfield to hide it?
EPA advises against it. Native grasses and ground covers are the right choice; trees, shrubs and vegetable gardens are not.
Does a drainfield repair need a permit in Seminole County?
Yes. Any septic repair or modification needs a permit, issued in Seminole County by the local health department office.
Where this came from
- EPA — Resolving Septic System Malfunctions — warning signs, vent smells, cleanup mix
- EPA — How to Care for Your Septic System — drainfield care, laundry
- EPA — Septic Systems: What to Do after the Flood — high water table, no pumping when saturated, dangerous gases, floor disinfection
- Florida Statutes s. 381.0065 — permits for repair; repair permit term
- Florida DEP — Onsite Sewage FAQ: Permitting — county health departments issue permits
- Florida Geological Survey — Sinkhole FAQ — broken septic tanks as a cause of subsidence
- NOAA National Hurricane Center — Tropical Cyclone Climatology — hurricane season dates