Septic Tank Care: The Dos and Don’ts

A well-built septic system can serve a house for decades, but how long it lasts depends heavily on the people living above it. Most failures come from a short list of habits: solids that never get pumped, things that should never go down a drain, too much water at once, and damage to the bed. None of the fixes are expensive. This guide gathers them in one place, with the Ontario winter in mind.

What should never go down a drain

The tank can only separate and partly digest ordinary household waste. Anything else either clogs it, kills the bacteria that do the work, or passes straight through into the soil.

• Wipes of any kind, including those labelled flushable, plus paper towels, dental floss, cotton swabs, condoms and menstrual products. They do not break down and they clog baffles, filters and pumps.
• Cooking fat, grease and oil. They thicken the scum layer fast and can coat the soil in the bed. Wipe pans and put fat in the garbage.
• Cat litter, even the clumping or flushable kinds. It behaves like sand and builds sludge.
• Medicines. Return unused prescriptions to a pharmacy take-back program instead.
• Paint, solvents, fuel, pesticides and strong chemicals. They kill bacteria and can contaminate groundwater. Take them to a household hazardous waste depot.
• Coffee grounds and food scraps. Compost them. A garbage disposal adds solids and shortens the time between pump-outs.

Normal amounts of toilet paper, mild soaps, and household cleaners used as directed are fine. It is bulk and strength that cause trouble: four litres (a gallon) of bleach poured down at once, or daily use of antibacterial drain cleaners, does more harm than a little cleaner in mop water.

Spread out your water use

The leaching bed is sized for a certain volume each day. It copes well with a steady flow and poorly with a flood. Six loads of laundry on a Saturday morning push a surge of water through the tank, stirring up solids and sending more liquid to the bed than it can absorb at once.

• Spread laundry through the week, one or two loads a day.
• Fix running toilets and dripping taps quickly. A running toilet can add hundreds of litres a day.
• Use high-efficiency toilets, showerheads and washers when you replace fixtures.
• Never connect roof downspouts, sump pumps or foundation drains to the septic system.
• Run the dishwasher and washing machine with full loads.

Water softeners and iron filters

Many rural homes on well water have a softener, an iron filter, or both. When they regenerate, they flush a backwash of water, and in a softener’s case brine, into the drain. Opinions differ on how much this matters. Some designers and manufacturers are comfortable sending it to the tank, while others prefer it be routed elsewhere where that is allowed, citing the extra volume and the possible effect of salt on bacteria and soil.

The sensible approach is to ask the person who designed or services your system, set the softener to regenerate based on water use rather than on a fixed timer, and make sure it is not regenerating more often than it needs to. If a treatment unit is part of your system, check the maker’s guidance, since some have specific instructions about softener discharge.

Additives: generally not needed

Shelves are full of products promising to boost bacteria, break down sludge or clean the bed. A tank that receives ordinary household waste already has all the bacteria it needs. Additives are generally unnecessary, and none of them replaces pumping: solids that bacteria cannot digest still accumulate and still have to be removed. Some chemical products can even stir up sludge and push it out to the bed. Save the money for the next pump-out.

Protect the leaching bed

The bed is the most expensive part of the system and the most vulnerable to damage from above.

• No driving or parking on it, not even a lawn tractor in wet weather, a delivery truck or a trailer. Weight compacts soil and crushes pipes.
• No structures over it: sheds, decks, patios, pools, hot tubs or playground pads.
• No trees or large shrubs nearby. Roots seek out moisture and grow into pipes. Grass is the ideal cover.
• Keep surface water away. Divert downspouts and grade the yard so runoff does not pool over the bed.
• Don’t add soil or fill over the bed without advice; extra depth can starve it of oxygen.

Knowing exactly where the bed is makes all of this easier. If you are not sure, a contractor can locate it during a pump-out or a septic inspection.

Winter care

Southern Ontario winters are hard on any system that is lightly used or poorly insulated. Snow is actually a friend here: a good layer of undisturbed snow insulates the tank and bed. The problems start when that snow is compacted.

• Keep snowmobiles, ATVs and foot traffic off the tank and bed, and do not pile plowed snow on them.
• Mark the tank lids with a tall stake before the ground freezes so a pumper can find them in January.
• Fix dripping taps and running toilets before winter. A thin trickle can freeze in a line where a normal flow would not.
• Keep using the system normally. Regular warm water helps keep it from freezing.
• If the system freezes, do not pour antifreeze, salt or additives into it, and do not run a fire or torch near it. Call a contractor.

Long vacations and seasonal homes

A septic system copes well with being left alone for weeks; the bacteria recover quickly once use resumes. Before a long trip or closing a cottage, fix any leaks so water is not trickling in unattended, and switch off a softener so it does not regenerate on a timer while you are away. If you have a pump chamber, make sure the alarm is powered.

One caution about timing: ask before having a plastic or fibreglass tank pumped in spring when groundwater is high, because an empty lightweight tank can shift in saturated soil. Many seasonal owners book their pump-out at the start of the season or in late summer for this reason.

A simple care calendar

1. Every month: check for slow drains, odours or wet spots over the bed, and test any alarm.
2. Every year: clean the effluent filter if you have one, and service any treatment unit as its agreement requires.
3. Every three to five years: have the tank pumped and the baffles checked; see how often to pump a septic tank.
4. Every time something changes: more people, a home business, a new softener or an addition. Ask whether the system is still sized right.

If you notice warning signs, the signs your tank is full guide explains what is urgent. For routine septic pumping or a septic repair in Hamilton, Haldimand, West Lincoln, Brant or Norfolk, send one request and we will pass it to one licensed local contractor.