How to tell your septic tank is full, and what to do

A septic tank (بيارة) collects the waste water from the house. The solids settle at the bottom as sludge, and the tank slowly fills until there is no room left. When that happens, the water has nowhere to go and starts to back up towards the building.

The first sign is usually slow drains everywhere, not just in one sink. Toilets take longer to empty, showers leave water standing, and the pipes gurgle or bubble when you flush. Next comes the smell: a sewage odour in the yard, near the tank's manhole cover or from floor drains inside. The last stage is the one everyone wants to avoid: dirty water rising through the lowest floor drain in the house, or spilling out around the manhole. Damp patches and flies near the tank cover are warnings too.

The signs of a full tank and a blocked pipe look alike, so it helps to look at the pattern. If only one sink or one bathroom is slow and the rest of the house is fine, the problem is probably a local blockage in that line. If every drain is slow and the smell is strongest near the tank, the tank is the likely cause.

If the tank was emptied not long ago and the drains still back up, the pipe between the building and the tank may be blocked with grease, sand or wipes. In that case emptying the tank alone won't fix it; the pipe needs drain jetting. Our Super Combi carries both jetting and suction, so one visit can empty the tank and clear the line.

Use as little water as you can until the tank is emptied. Hold off on the washing machine and the dishwasher, keep showers short, and avoid running taps.

Keep children, pets and workers away from the tank and any wet ground around it. Don't lift the cover to have a look. Then call or WhatsApp a suction truck with your location and what you are seeing. Al Makki empties septic tanks 24/7, including Fridays and nights, and we arrive in 3 to 4 hours within Doha.

Never climb into a septic tank or lean into the opening, even for a moment. Sewage gives off gases that can make a person collapse with little warning, and people have died trying to rescue someone who went in first. Leave the tank closed and leave the work to a crew with the right equipment.

Don't pour bleach, acid or drain cleaners into the toilets to deal with the smell. They don't empty the tank, and strong chemicals can damage pipes and the tank itself. Don't pump the sewage onto the street or into a storm drain with a small pump either: it is a health risk for everyone nearby and against the rules.

There is no single answer. It depends on the size of the tank and how many people use it, and a busy household fills a tank much faster than a small one. The best guide is your own tank's history: note the date each time it is emptied and how full it was, and you will soon see a pattern.

For compounds and buildings with several tanks, waiting for each one to overflow is costly and unpleasant for residents. An annual maintenance contract lets you empty them on dates agreed in advance, before the warning signs start.