7 Signs Your Septic Tank Is Full

The signs, from earliest to most urgent

1. Slow drains everywhere. One slow sink is usually a local clog. Every drain slowing down at once points to the tank.
2. Gurgling sounds. Air is being pushed back through the pipes because liquid cannot flow out of the tank freely.
3. Sewage smell outdoors. Odour near the tank lids or over the leaching bed means gases or effluent are escaping.
4. Unusually green grass over the bed. Effluent is reaching the surface and feeding the lawn. It looks healthy but it is a warning.
5. Wet or spongy ground. Pooling or soft ground over the bed means the soil cannot absorb what is coming out of the tank.
6. Toilets slow to flush or refill strangely. Another sign the system is backed up toward the house.
7. Sewage backing up. Usually into the lowest drain, such as a basement floor drain or shower. Stop using water and call right away.

What to do now

• Cut back water use: spread out laundry, run full dishwasher loads only, and take shorter showers
• Do not drive or park over the tank or the bed
• Do not add chemical drain cleaners, which kill the bacteria the tank depends on
• Book a pump-out, and ask for the baffles and effluent filter to be checked at the same time

When it is more than a full tank

If the signs come back soon after pumping, the problem may be the leaching bed itself, a broken baffle or a blocked pipe. An inspection finds out which, so you do not pay to pump a tank that is not the cause.