Septic tank maintenance for River Valley homes

A septic system around Fort Smith mostly asks three things of you: get it checked on schedule, keep the wrong stuff out of the drains, and leave the drain field alone. Do that and a tank and field in Sebastian or Crawford County clay can last for decades. Skip it and the field, the most expensive part, is usually what pays. Below is the routine, the sources behind it, and the products you can skip.

The routine: inspections and when a tank is due

The U.S. Environmental Protection Agency's septic care guide recommends having a septic professional inspect a household system at least every three years, and says most household tanks are pumped every three to five years. Systems with float switches, pumps or other mechanical parts, which describes a lot of River Valley systems, should generally be inspected once a year.

Whether a tank actually needs emptying is a measurement, not a guess. EPA's rule of thumb is to pump when any one of these is true:

• the bottom of the floating scum layer is within 6 inches of the bottom of the outlet,
• the top of the settled sludge is within 12 inches of the outlet, or
• sludge and scum together take up more than a quarter of the liquid depth.

Ask whoever opens the tank to write those two layer depths on the receipt. Over a couple of visits they tell you your own household's real interval, which beats any rule of thumb. Until then, the septic pumping calculator gives a starting estimate from tank size and household, and septic tank pumping covers the visit itself.

What not to put in a septic tank

EPA's short version: the toilet is for human waste and toilet paper, nothing else. Things on its do-not-flush list that turn up in Arkansas tanks all the time:

• baby wipes and other wet wipes, including ones sold as "flushable"
• diapers, feminine products, condoms and dental floss
• paper towels, cat litter, coffee grounds and cigarette butts
• medications, and household chemicals such as gasoline, oil, pesticides, antifreeze and paint thinner

At the kitchen and utility sinks, EPA says to keep out cooking oil and grease (butter, fats and cheese included), oil-based paint and solvents, big doses of harsh cleaners, and chemical drain openers. For a clog, use boiling water or a drain snake instead.

The garbage disposal deserves its own line. EPA advises limiting or avoiding it because ground-up food adds solids that mean more frequent pumping, and the Arkansas Department of Health's onsite wastewater rule states that garbage grinders are not recommended for standard septic systems (rule 10.1).

Septic-safe toilet paper

Toilet paper is the one thing besides waste that EPA puts in the "fine to flush" column, and neither EPA's care guide nor the ADH rule calls for a special brand. The trouble comes from things that aren't toilet paper but get treated like it: wipes, tissues and paper towels are built to hold together when wet. Use ordinary toilet paper without guilt and keep a trash can in every bathroom for the rest.

Septic tank additives and treatments: do they help?

Store shelves are full of monthly packets, bacteria starters, enzyme treatments and "drain field restorers." The research doesn't back them:

• EPA doesn't recommend them. Its 2024 septic tank additives fact sheet says a working tank already holds the bacteria, enzymes, yeasts and fungi it needs, that some products can interfere with breaking down waste, contribute to clogging and contaminate groundwater, and that most have only limited independent testing behind their claims.
• Harsh ones do damage. The same fact sheet notes that line and drain field cleaners are often strong acids or lye that can hurt the tank's bacteria and the pipes, degreasers with chlorinated solvents threaten groundwater and are banned in many states, and odor-control products work by killing bacteria the tank depends on.
• Bacteria products can backfire. Kansas State Research and Extension's publication on septic additives reports that the few independent studies found no benefit to tank function, and that one study of a biological additive found it caused so much gas in the sludge that solids lifted back up and were carried out to the field.
• You don't need to "restart" a tank. K-State notes that a tank's microbes re-establish on their own within a few days after pumping or after harsh cleaners are used in the house.
• Never put root killer or hydrogen peroxide in the system. K-State says root-control chemicals should never be added, and that hydrogen peroxide, once sold as a field rehabilitator, was found to destroy soil structure and shorten a field's life.

K-State's bottom line is that regular pumping costs less than the additive makers' recommended doses and is what actually removes sludge.

The septic tank effluent filter

An effluent filter (also called an outlet filter) is a slotted cartridge that sits in the tank's outlet tee and catches small solids before they reach the field. ADH recommends an authorized outlet filter on every septic tank, because filters have been shown to cut suspended solids and the organic load going to the field and so lengthen its life (rule 10.7.6). On low-pressure distribution systems, which are common on River Valley lots, an authorized effluent filter is required (rule 8.9.3). And when a tank has one, the rule calls for a riser to grade over the outlet so it can be reached for service (rule 10.7.6).

A filter only helps if someone cleans it. A clogged one is a common reason for slow drains in a tank that isn't full. Follow the filter maker's cleaning schedule, have it cleaned at every pump-out at the least, and check it sooner if drains start slowing. Lift it out wearing gloves and hose it off over the open tank so the solids go back in the tank, not on the lawn. If yours has no filter, ask the pumper whether an ADH-authorized one can be fitted at the next visit.

Spread out the water

A field in tight clay takes water slowly, so how much arrives at once matters as much as the total. EPA puts indoor use at up to 70 gallons per person per day and says a single running toilet can waste up to 200 gallons a day, enough to flood a small field on its own. The fixes are cheap:

• fix running toilets and dripping faucets right away
• replace old 3.5- to 5-gallon toilets with ones using 1.6 gallons a flush or less
• run full loads, and spread laundry over the week instead of doing it all on Saturday

Protect the drain field

From EPA's care guide, with what each one means on a River Valley lot:

• Don't drive or park on it. Trucks and trailers compact the soil and crush lines; clay compacts easily and doesn't recover.
• Don't pave or build over it. Check with the county health unit before putting a shed, pool or slab anywhere near the field or the secondary area set aside for a future one.
• Grass, not trees or gardens. Roots get into lines, and vegetables shouldn't grow over effluent. Ask a septic pro how far back to plant trees.
• Send rainwater elsewhere. Point roof downspouts, gutters and sump pump discharge away from the field. In a wet Arkansas spring the field already has all the water it can handle.

If the field is already soggy or smelly, see drain field problems.

Aerobic system owners: the monitoring contract covers part of this

If your home has an aerobic treatment unit, Arkansas requires a monitoring contract with an ADH-registered monitoring person and an assessment at least every six months for the life of the system. That covers the aerator, alarms and disinfection. It doesn't cover what goes down the drains or sludge removal: ATUs still need pumping, and everything above about flushing, additives and water use applies just as much.

Ready for an inspection or a pump-out? Call, and we'll connect you with a licensed local septic pro.