With little or no snow cover, Jack Frost may be nipping at your
It’s beginning to look a lot like potential problems for rural septic
systems this holiday season.
“It may not be such a happy new year for some households if we don’t get
snow cover before temperatures really start to drop,” Dan Olson, public
information officer with the Minnesota Pollution Control Agency (MPCA),
said. “Snow helps to insulate septic systems and keep them from
freezing. Fortunately, temperatures across the state have remained
relatively mild so far, but that could change any time.”
The University of Minnesota Onsite Sewage Treatment Program provides tips
for homeowners on how to prevent septic system freeze-ups and how to deal with
them should they occur:
• Place a layer of mulch eight to 12 inches thick over the pipes, tank and
soil treatment system to provide extra insulation. This can be straw,
leaves, hay or other loose material that will stay in place and not become
compacted. This is particularly important for new systems that were
installed so late in the year that vegetative cover could not be
established. However, if the system is currently frozen, don’t add mulch
now; it will delay thawing in the spring.
• Let the grass or native vegetation growing over the tank and soil
treatment area get a little taller in the late summer and fall to provide
insulation and help hold snow.
• Use water ― the warmer the better ― if you’re worried that your system
is starting to freeze. Spread out your laundry schedule so you run one
warm/hot load a day. Use the dishwasher and take hot baths.
However, DO NOT leave water running all the time, as this will hydraulically
overload the septic system.
• Going away for an extended period? Plan accordingly. Have
someone use warm water in your home regularly while you are gone or have your
septic tank pumped out before you leave. If a shallow tank is left full
for several winter months, the sewage will become very cold and can freeze.
• Fix any leaky plumbing fixtures or appliances in your home. This
will help prevent freezing problems and help your system perform better all
• If you have appliances that generate very low flows, such as high-efficiency
furnaces, you can put heat tape in the pipe, and have someone come by and run
warm water for a while you are on vacation. Alternatively, install a
small condensate pump that holds and discharges two gallons per cycle.
• Keep all vehicle, animal and human traffic off the system. This is
a good rule to follow all year long as compacted snow and soils cause frost to
go down deeper and faster. Pay special attention to the area between the
house and the septic tank.
• Make sure all risers; inspection pipes and manholes have covers.
Sealing them and adding insulation is a good idea. Insulation may be
added during construction particularly if the top of the septic tank is within
two feet of the surface.
• Keep an eye on your system. If any seeping or ponding occurs,
contact a septic systems professional to help determine the cause and remedy.
• Add more insulation to your system. This could include replacing
pipe with insulated pipe, installing expanded foam panels over the septic tank,
or adding more soil cover.
A common cause of freeze-ups are pipes that are not installed with the
proper slant or that have settled, resulting in dips in the line. Where a
dip or flat spot occurs, sewage can collect and freeze. Pump lines can
develop a dip right next to or above the septic tank as a result of soil
backfilled during tank installation settling.
If your septic system freezes, call a septic system professional.
Other methods used to fix a freezing problem include adding heat tape and
tank heaters. Cameras can be sent down pipes to determine where freezing
is occurring. If the soil treatment system is full of ice, or there is
evidence of leaking, skip trying to thaw the lines leading to the treatment
area as it cannot accept liquid until the area thaws in spring.
If it’s not feasible to correct a problem, the only option is using the
septic tank as a holding tank until the system thaws naturally. Have a
pumper empty the tank when it starts to fill up. In this situation,
reduce water use by limiting the number of toilet flushes, taking short
showers, and using the dishwasher at full capacity.
There are some things you should NEVER do to try to fix a frozen system:
•DO NOT introduce antifreeze, salt or a septic system additive into the system.
•DO NOT pump sewage onto 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 thaw the system. This can
overload the system.