Cottage Q&A
QUESTIONPreviously, we have used our cottage in winter with no trouble, but last year the early cold, with little or no snow, froze our septic tank, and the ensuing back up "reeked" havoc. Is a less-used system more likely to freeze? Would bales of hay over the tank keep it from freezing?
ANSWER
In parts of Ontario, last winter brought a biting cold before a good layer of insulating snow could build up, driving frost unusually deep into the ground. Though it's unlikely that even a less-used system would actually freeze solid, septic system consultant Alex Campbell, with Judan Enterprises in Bradford, says that five or so centimetres of ice on the surface of the septic liquid could block the outlet to the septic bed or plug up the inlet baffle. Prevented from entering or exiting the tank, it might back up as you describe. Since you don't have trouble most winters, piling hay (or straw) bales over both the sewer line from the cottage and the tank itself might just do the trick. If not, you'll need to insulate the sewer line, and possibly the tank as well. Dig down to expose the line and run insulation wrap around it, or spray on insulating foam. Septic tank contractor Andy O'Brien of Grand Bend Sanitation, in Grand Bend, Ont., has had good results using 2"-thick blue Styrofoam, which comes in 2' x 8' sheets. Dig down to the sewer line and set the full 2' width right on top of it, he advises, to prevent frost from getting at the pipe and the earth around it. Additionally, you could expose the tank itself and lay Styrofoam sheets right over the top, overhanging the edges by five centimetres or so. Another tip is never to have your tank pumped in fall before closing, because you want lots of bacterial activity all winter.
* Published in the November/December 2004 issue of Cottage Life
