Reduce chances of your septic system freezing

By Valerie Prax, University of Minnesota Extension Service

Valerie Prax is a water resource management educator with the University of Minnesota Extension Service.

ST. PAUL, Minn. (12/4/2006) - A combination of cold weather and lack of snow is one reason home septic systems can freeze.

Other reasons include irregular use, leaking plumbing fixtures or a pipe that's not installed with the proper change of elevation. If the soil over a pipe is compacted, the elevation of the pipe may shift, causing a loss of gravity flow. This results in water left standing in pipes, and the water can easily freeze.

Here are some ways to reduce chances of a frozen septic system:

• Provide insulation by adding an 8-12-inch layer of mulch, leaves or loose hay or straw over the pipes, tank and soil treatment area.
• Make sure all risers, inspection pipes and manholes have properly fitting caps with no cracks.
• Keep all types of heavy traffic off the system. This includes family activities, snowmobiles and ATV vehicles. This is especially important in winter, but is also a good rule to follow all year. Compacted snow can lead to freezing in the soil treatment area.
• Use normal amounts of water - the warmer, the better.
• Plan ahead if you're going to be gone for an extended period. This could include pumping the tank before leaving, or in the case of a lake cabin, not returning until warmer weather.
• Fix any leaky plumbing.
• High-efficiency furnaces produce a small drip of water. This trickle of water can freeze in the pipes, since there is no velocity to push the water into the tank. It is best to re-route this into a sump pump or directly outdoors.
• Since most systems depend on gravity flow, have the pipes televised by a septic professional if you suspect improper slopes to the pipes.

More detailed information is available at the Extension website, http://septic.umn.edu.

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