Cottage Q&A: Will the septic pump freeze?

A septic tank buried in sand By Gozzoli/Shutterstock

I have a septic tank built into the side of a hill with minimal protection from frost. A submersible effluent pump moves the contents directly to the weeping tiles. I have always removed the pump in winter for fear of damage caused by freezing. Is this necessary or can I just leave it in the tank?—Stumped by the Pump

“I’ve seen lots of pumps freeze solid in winter and then thaw fine in the spring,” says Dale McLure, the president of the Alberta Onsite Wastewater Management Association. Still, better safe than a mangled pump. “If you’ve been successful in removing the pump every winter, there’s nothing wrong with continuing to do that.” As long as you keep doing it correctly, taking out the pump guarantees nothing will happen to it and, as McLure points out, “it’s not really an exorbitant amount of time or effort.”

6 things that should never go in your septic tank

In general, anything you can do to shield your septic system from a winter beatdown gets the thumbs up from the experts. This includes protecting the line from damage (by having it buried below the frost line, so it’s insulated; by keeping it heated; or by draining it completely), and insulating the septic tank with, for example, a layer of 2″ SM insulation or extruded polystyrene foam overtop, covered with soil, says septic inspector Sandy Bos. “It’s good for the overall health of the system. Bacteria thrive in warm temperatures, not cold ones.”

Got a question for Cottage Q&A? Send it to

Featured Video