Septic tank pumping around Chattanooga

A septic tank is a holding pond for solids. Everything that leaves the house settles out: heavy material sinks into a sludge layer, grease and lighter material float up as scum, and the clearer water in the middle flows on to the drain field. Bacteria break down some of the sludge, but never all of it. Pumping is how the rest leaves the property. Skip it long enough and the sludge and scum crowd the outlet, solids ride out into the field lines, and the soil around them clogs. That last step is the expensive one, and on the rocky, sloped lots common around Chattanooga there often isn't much spare ground to put a new field.

Signs the tank is due

• You can't find a receipt for the last pumping, or it's been more than about three to five years (the EPA's typical range for a household tank).
• Drains run slow all over the house, not just in one sink.
• Gurgling in the pipes after a toilet flush or a washer drain cycle.
• Odor near the tank lids or the cleanout.
• Grass over the tank or field lines that's greener and spongier than the rest of the yard in dry weather.

Not sure how often your household should be on the schedule? The pumping frequency guide works it out from bedrooms, tank size and the number of people at home.

What a pump-out visit should include

1. Finding and opening the lids. Older tanks around here are often buried with no risers, so expect some digging. Tanks installed in Tennessee since 1991 have two compartments, and both should be pumped.
2. Pumping solids, not just liquid. A good pumper breaks up the scum cap and sludge so the tank empties properly instead of just lowering the water level.
3. A look at the baffles and the inlet and outlet. A missing outlet baffle or filter lets solids walk straight into the field.
4. Watching for backflow. If water pours back into an empty tank from the field side, the field is saturated, and that's worth knowing before you close the lids.
5. A record. Ask for the date, gallons removed and anything they noticed. Tennessee requires pumping contractors to keep monthly logs of every pumping, including the address and gallons, so the information exists. Get your own copy.

Checking that the pumper is legitimate

Tennessee requires a septic tank pumping contractor permit from TDEC's Division of Water Resources for anyone in the business of removing and disposing of septage. To keep that permit, the company has its truck inspected every year at a TDEC field office, shows written permission from the treatment plant or land site where loads get dumped, and keeps those monthly logs. The truck has to carry the business name, address and permit number in letters at least two inches tall on both sides, plus a department sticker. If the truck in your driveway has none of that, ask.

Before the truck comes

• Know roughly where the tank is. A Hamilton County permit record or an old drawing from when the house was built often shows it.
• Keep the driveway clear for a heavy truck, and keep it off the drain field. The EPA warns that vehicle weight compacts soil and can crack pipes.
• Go easy on water for a few hours before and after. Laundry can wait a day.

Cost

Each contractor sets its own price, and things that change it include tank size, how deep the lids are buried, how far the truck has to reach, and whether a second compartment or a pump chamber is involved. Ask for a price before they start, and ask whether locating and uncovering the tank is included or extra.

Good questions

Do both compartments need pumping?

Yes. Tennessee has required two-compartment tanks since January 1, 1991, and solids collect in both. Ask the pumper to confirm both sides were emptied.

Should I add a bacteria or enzyme product after pumping?

The EPA guidance on septic care centers on pumping, inspections, water use and keeping the wrong things out of the drains. Additives are no substitute for pumping.

Can the tank be pumped in the rain?

Often, yes, but a saturated yard can make it hard to get a truck in without rutting the field area. If the ground is soaked, ask whether the job can wait a few dry days unless it is an emergency.