28
2015
How to Protect Your Septic System During Freezing Temperatures
What Causes Septic System Freezing Problems
Freezing temperatures can cause various components of your septic system to freeze up. The most vulnerable areas of your septic system are the pipes leading from the house into the septic tank. Often leaky water fixtures such as faucets and toilets create a constant low flow of water that can easily freeze up, and overtime block the pipe entirely.
The other components of the septic system that can potentially freeze are: the tank, the pipes leading into the drainfield and the drainfield itself.
Septic systems that are used frequently are less susceptible to freezing because of the constant flowing water. Systems that are not in constant use, or that lay dormant for long periods of time, are more likely to have issues in colder climates.
How to Protect your System from Freeze-ups
Preventing Frost
Mulch and snow cover can protect both pipes and the tank from freezing by acting as an insulating layer that prevents frost from penetrating deep into the ground. Snow cover is helpful as long as it is not significantly compacted. Snow that has been compacted from vehicle or foot traffic can drive down frost and increase the chances of freezing.
Mulch can be added to the area covering the septic tank and drainfield if snow cover is inconsistent – especially if grass or other vegetation cover is not available. It is always best to limit any traffic on top of the drainfield (vehicular, human or animal). This limits the possibility of shifting or sinking of drainage pipes.
Fix leaks and Drainage Issues
It is important is to attend to any leaky faucets, toilets or other drainage issues before the worst of the winter sets in. This will help you avoid costly problems during the winter while also conserving water.
What to Do If Your System Freezes
In the event your septic system does freeze this winter, contact a professional pumper or installer to identify the point of freezing and correct the problem. If you can’t immediately fix the issue, the septic tank can be used as a holding tank until it thaws. This is a costly endeavor and is only a short-term solution, but it is sometimes necessary while waiting from the proper equipment or conditions in which to make repairs.
Things you should NOT do:
- Do not add antifreeze, salt, or additives
- Do not attempt to start a fire on the ground above where the tank is located
- Do not continuously run water to try to thaw frozen pipes
By taking the necessary steps to protect your septic system from freezing before the winter sets in you can prevent costly problems. Remember to contact a professional in the event a component of your septic system freezes up to properly address the problem.
I have a septic system at my home. We’ve lived here since built in 1995. My septic tank had ice on the inside. The feeder line from the tank to the drain field froze. I’ve had it cleared 3 times in the past 5 to 6 years. I’ve been covering the septic tanks and feeder line with hay in the fall to insulate the ground. This year our snow cover was not very heavy and we had very cold temperatures. It still froze and had to be thawed. What can I do to insulate the feeder line to the drain field from freezing? This is a costly fix to get thawed out. Phil Chelstrom
Phil: You may have several issues. If you have a condensing furnace (typically exhausts through 2″ PVC pipe vent) you should route the condensate out of the septic tank. The constant dribble of water into the tank causes a constant dribble out to the field and eventually it will freeze the pipe solid with ice.
If the tank has ice on the surface it would indicate that the tank is too shallow. It is not practical to set the tank deeper. If the surrounding grade allows you could add more soil over the top of the tank to keep the frost from reaching the tank. If this is not possible you can put a layer of insulation over the tank. This would require the removal of at least 12″ of soil above the tank. After the soil is removed lay 4″ of closed cell polystyrene insulation (blue or pink foam board) in the hole and cover the insulation with soil. Do not use open cell bead board (white foam insulation) as it will absorb moister and break down. Making the excavation/insulation area 2′-3′ larger than the septic tank surface will improve the insulation. This will shield the frost from penetrating the soil down the side walls of the tank. This same approach can be applied to the outlet pipe from the tank to the field. Again, the wider the insulation path the better.
We have tested the Aero-Stream products in cold climates. We found that aerating the tank even with cold air prevents ice in the tank. In our test, we used a two compartment tank. The tank was downstream of another 2 compartment tank so both chambers contained clarified effluent. The first chamber would develop a 1″-2″ layer of ice even though the water entering it was theoretically warmer than the second chamber. The second chamber was aerated and never developed ice on the surface. The first chamber that developed ice was thermally stratified. The water on the bottom of the tank was warmer because it was below the frost line where the soil temperature is about 50F. The water at the top of the tank was within the frost line and thus much colder. This cold upper layer is what would flow to the drainfield. The second aerated chamber was not thermally stratified because the water was constantly moving from the warm bottom of the tank to the surface. The tank uses the heat of the earth to raise the temperature of all of the water in the tank, thus sending warmer water into the drainfield. Another method to prevent freezing is to add an electric submersible water “stock tank heater”. These can be purchased at any Farm & Ranch store. They consume up to 1500 watts of power, however, it will be less expensive to operate than thawing the pipe. Let us know if you have any further questions.
I have lived in my house since 1974. Only had a problem one other time. When my washer releases the water it overflows the toilet and backs up into the tub. We have a very cold winter with and without snow cover. Had plumber yesterday and they found some lint in the line to the septic tank but that didn’t fix the problem. They think the field could be froze and wait because we’re getting a week of warmer weather. Could this be true. Tank was pumped in spring of 2016 and there’s only me.
Lesly:
I would have the tank pumped and see if this temporarily resolves the back-up issue. When they pump the tank tell the pumper to watch/listen for run-back from the field. This could indicate if the field is frozen or just saturated because it is failing. Call us at 877-254-7093 for a free consultation.
Karl