The winter of 2002/2003 was a very hard year for onsite septic systems due to the lack of snow cover combined with cold temperatures. In some counties, up to 30 percent of the septic systems were frozen. Even in a normal Minnesota winter, freezing can occasionally be a problem. Identifying and correcting a potential freezing problem is far easier than dealing with a frozen system.

Some of the common causes of septic system freeze-ups can be:  lack of snow cover, compacted snow, compacted soils, lack of plant cover, irregular use of the system, leaking plumbing fixtures, pipes not draining properly, cold air entering the system, and a water-logged system.

What To Do if the System Freezes?

If your septic system freezes, the first step is to call an onsite professional.  If you have a pump system and hear water constantly running in a pump tank (a sign that the system may be frozen), disconnect the pump and call an onsite professional.  Many pumpers and installers have steamers and high-pressure jetters to try and unfreeze system piping. Unless the cause of freezing is corrected, the piping will refreeze. Other methods used to help a freezing problem include adding heat and tank heaters. If the treatment area is full of ice, or there is evidence of leaking, there is no need to thaw the lines leading to the treatment area as it cannot accept liquid until the area is thawed in the spring.

If it is not feasible to correct the problem, the only other option is to use the septic tank as a holding tank (which will require regular pumping) until the system thaws naturally.  In this case, reduce water use and in the spring find the cause of the freezing problem so it can be addressed to prevent future freeze-ups.

There are many misconceptions about how to deal with a frozen septic system: 

·        Do no add antifreeze, salt or a septic system additive into the system.

·        Do not pump sewage on to the ground surface.

·        Do not start a fire over the system to attempt to thaw it out.

·        Do not run water continually to try to unfreeze the system. 

What Can You Do To Prevent Freezing?

There are several steps you can take to prevent septic systems from freezing. It is not necessary to do all of these, pick and choose what is best for your situation.

1)     Place a layer of mulch (8-12 inches) over the pipes, tank
and drainfield area to provide extra insulation.

2)     Let the grass in your lawn get a little longer in the late summer/fall over the tank and drainfie
ld to provide extra insulation.

3)     Use water, the warmer the better!  Usually water conservation is the best practice, but if freezing is a concern, spread out water use, possibly doing a warm/hot load per day, using your dishwater and maybe even taking a hot bath.  Do not leave water running all the time because it will overload the system.

4)     If you know you are going to be gone for an extended period of time, plan accordingly to have someone use sufficient quantities of water in your home or pump out your tank before leaving.

5)     Fix leaking plumbing fixtures or appliances in your home.

6)     Keep all types of vehicles and high traffic people activities off of the septic system- it’s a good rule to follow year round.

7)     Make sure all risers, inspection pipes and manhole have covers on them.

8)     Keep an eye on your system.  If any seeping or ponding occurs, contact an onsite professional to determine the cause and remedy.