Keeping your septic system from freezing this winter
Shenandoah Valley winters get cold enough to freeze septic lines, especially during long cold snaps with no snow on the ground. A frozen line means drains that won't drain and toilets that won't flush, and it's a miserable thing to fix in January. Most freeze-ups can be prevented with a little work in the fall.
The tips below come from North Dakota State University Extension, which knows a thing or two about frozen ground (NDSU Extension).
Before it gets cold
Fix dripping faucets and running toilets. It sounds backward, but a slow, constant trickle of water is more likely to freeze than normal use. NDSU notes that continuous low flow can freeze where the sewer line leaves the house.
Insulate where the pipe leaves the house. A thick layer of straw or hay over the line where it exits the foundation helps, and so does a snow fence to catch snow there.
Cover exposed parts. Insulate risers, inspection pipes, the tank lid and any distribution box that sits near the surface.
Mow the drainfield a little higher in late fall, or leave the grass a bit long. Plant cover helps hold snow and insulates the ground. (That's a common recommendation, not from the NDSU release.)
Have a soggy drainfield checked now. NDSU warns that a wet drainfield can freeze, and wetness may be a sign of other problems. Fix it before winter, not during it. See septic problems.
Pump before winter if you're due. If your 5-year pump-out is coming up, fall is a good time. Ground access is easier, and haulers aren't fighting frozen soil and snow.
During the winter
Let snow stay on the system. According to NDSU, snow is a good insulator, and "any accumulation over 12 inches will provide significant frost protection." Don't plow or shovel snow off the tank or drainfield.
Keep vehicles and foot traffic off. NDSU notes that compacted snow insulates poorly. A temporary snow fence around the drainfield helps keep people and trucks off. (Vehicles should stay off the drainfield all year anyway.)
Use water normally. Regular use sends warm water through the system, which helps keep it from freezing. Spreading laundry out over the week, instead of one big day, is easier on the system too.
Going away? NDSU says a tank in a house that will sit empty for a week or more should be covered with at least a foot of insulation extending 5 feet past the tank's edges. At the least, arrange for someone to run water at the house regularly.
If you think it's frozen
Signs: drains in the whole house slow down or stop, toilets won't flush, or you see sewage backing up into the lowest drain, usually a basement floor drain or tub.
- Stop using water to keep sewage from backing up into the house.
- Call a septic professional. Thawing a line is a job for someone with the right equipment, such as steam or jetting equipment.
- Don't pour antifreeze, salt or chemicals into the system to thaw it. They can harm the system and the groundwater. In the Valley's karst areas, groundwater is especially easy to contaminate. See well water and septic.
- Don't run a constant trickle of water to "keep it moving." That's how freeze-ups often start.
If a backup gets into the house, keep children and pets away, and don't clean up raw sewage without gloves and protective gear.
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