How often to book a septic tank cleaning?

It can be hard to determine how often your septic tank needs to be pumped out, and you definitely don’t want to wait until it’s too late and you’re getting sewage back-up into your home or seeping around your septic lid. But you also don’t want to be doing it too frequently: aside from being an unneccessary cost, it can also reduce the efficacy of the septic tank’s bacteria, which are essential for the proper functioning of your septic system.

The general recommendations sound something like “every 1-5 years” but that’s not particularly helpful. In the Okanagan - Similkameen / Princeton BC area where we operate, we’ve found that most household tanks are 700 - 1000 gallons (3100-4500 litres).

The frequency of septic tank pumping depends mostly on the number of people in the household full time. Infrequently used recreational properties can add a year or two to these estimates.

700 gallon / 3100 litre tanks
- 2 people: septic tank pump every 4 years
- 4 people: septic tank pump every 2 years
- 6 people: septic tank pump every year

1000 gallon / 4500 litre tanks
- 2 people: septic tank pump every 5.5 years
- 4 people: septic tank pump every 2.5 years
- 6 people: septic tank pump every 1.5 years

Things that increase the frequency for septic tank pumping:
- using a garbage disposal
- running a home-based business like hair salon or other business with frequent water usage
- having a water softener system that back-flushes into the septic tank (this can dilute the septic tank bacteria and result in less effective solids break-down, necessitating more frequent pumpings)
- pouring cooking oils/grease down the drain
- using excess amounts of detergents or cleaning products

You can check for yourself if your tank needs to be done by following these steps:
- open the lid. It’s normal for the septic tank to be ‘full’. The liquids discharge into your septic field from the upper third of the tank, and the solids sink to the bottom.
- there will be a sludgey or crusty layer floating on top. Using a shovel, poke/cut the layer to determine how thick it is.
- if the sludge layer is around 12” thick (or thicker), it’s definitely time to pump out your tank. A thicker layer can begin to block the discharge pipe and cause damage to your septic field.
- if the sludge layer is under 6” thick, you can wait another year or so.

Most septic specialists recommend that if it’s been longer than 5 years since your septic tank has been pumped, it might be time to get it done. Contact Similkameen Septic Service Ltd. at office@simseptic.com or 1 (250) 295-7994 for a quote for your pumping in Princeton, BC and area.