GUIDE // SEPTIC BASICS
Drainfield care.
What not to flush. What not to plant.
Your drainfield is the most expensive part of your septic system and the least forgiving. Replace one and you are looking at thousands, maybe tens of thousands. Take care of it and it can outlast the house. Here is how to keep yours alive.
WHAT NOT TO FLUSH
If it did not come out of you, it does not go down the drain
Every drainfield failure we see traces back to what someone put down the drain. This is the short list of things that will shorten your system's life. Toilet paper is the one paper product that belongs in a septic tank. Everything else on this list goes in the trash.
- Wipes labeled flushable
- They are not. They do not break down. Number one cause of clogged pumps and choked baffles we see.
- Paper towels and tissues
- Built to hold together when wet. That is the opposite of what you want in a septic tank.
- Grease, oil, and fat
- Cools and hardens in the tank. Builds a solid crust that pushes waste out to the drainfield too soon.
- Coffee grounds and eggshells
- Do not decompose. Pile up as sludge and cut your pumping interval in half.
- Cat litter
- Clumping litter does what it is designed to do inside the tank. Do not.
- Harsh chemicals and drain cleaner
- Kill the bacteria that break down waste. A dead tank pushes solids straight to the drainfield.
- Paint, solvents, and gasoline
- Contaminates groundwater and destroys the biology inside the tank. Take to a hazardous waste site.
- Prescription medication
- Same reason. Kills tank bacteria and does not belong in the water table.
WHAT NOT TO PLANT
Roots find the drainfield first
The drainfield is a network of perforated pipes buried a couple feet down. Roots love that. Once a root gets into a distribution pipe it splits it open and the whole field starts to fail. Keep the following off the field entirely.
- Trees of any kind
- Roots find the drainfield first. Willows, maples, and poplars are the worst. Keep trees at least 30 feet away.
- Shrubs with woody roots
- Same problem, smaller scale. Skip the boxwoods and hollies over the field.
- Vegetable gardens
- Do not eat food grown over a drainfield. Effluent can contaminate root crops and leaves.
- Anything that needs watering
- Extra water saturates the field and pushes it toward failure. The drainfield needs to breathe.
SAFE COVER
What is fine to plant
- Native grasses and turfgrass
- Wildflowers with shallow roots
- Groundcover that does not need irrigation
- Basically anything you can mow
DAILY HABITS
Five things that add years to your field
- Spread laundry across the week
- Four loads on a Saturday hydraulically overloads the field. Two per day over the week is much easier on it.
- Fix leaks fast
- A running toilet or dripping tap can double the water your field has to absorb. That is often what tips a marginal field into failure.
- Keep vehicles off the field
- A truck parked over the drainfield compacts the soil and crushes the distribution pipes.
- Divert roof and gutter runoff
- Rain from the house should never drain toward the drainfield. Point downspouts the other direction.
- Pump on schedule
- The single biggest thing you can do for the drainfield is keep solids out of it. That means pumping the tank on time, every time.
FAQ
Common questions
How long does a septic drainfield last?
A well-maintained drainfield in West Tennessee soil can last 20 to 30 years or more. Neglected ones fail in 10 to 15. The difference is almost always whether the tank was pumped on schedule and whether the field got overloaded with water.
Can I put a garden over my drainfield?
Skip the vegetable garden. Effluent can contaminate root crops and leaves. If you want green cover, grass and shallow-rooted wildflowers are fine. Never trees or shrubs with woody roots.
Can I drive over my drainfield?
No. A car or truck compacts the soil above the distribution pipes and can crush them. Keep vehicles, RVs, and heavy equipment off the field entirely.
Do septic additives help the drainfield?
In our experience, no. The bacteria in a working tank are already doing the job. Additives that promise to break down sludge do not remove it, and some kill the good bacteria and make things worse. Pump on schedule instead.
What happens if my drainfield fails?
You will see sewage backing into the house, standing water or soft ground over the field, or a strong sewage smell in the yard. Once the field fails, it does not repair itself. Replacement is expensive. Prevention is a pump-out every 3 to 5 years.
Should I flush toilet paper?
Yes. Regular toilet paper is designed to break down in water and is the one paper product a septic tank can handle. Skip flushable wipes, paper towels, and tissues.
READY?
Worried about your drainfield?
If you have soft spots in the yard, greener grass over the field, or slow drains inside, do not wait. We will pump the tank, inspect the outlet baffle, and tell you honestly what we see. Small problem now beats a drainfield replacement later.
Also useful: How often to pump a septic tank.