We bought a house a year ago and the septic system was totally inadequate for the size of the house. We didn’t know anything about septic systems then, but if we knew what we know now we would have never bought the place. Oh well, live and learn.

The old tank was buried deep in the ground, the top of it was a good 3 feet or so deep, so the tank was mostly below or completely below the frost line. The new tank for the system we just had installed to replace the old system isn’t anywhere near as deep. In fact the outlet side of the tank is a good 10-12” above grade while the inlet side is just a few inches below grade. Over half the tank is going to be above the frost line (we live in northern Illinois). We are waiting on the weather to cooperate so the excavator who installed the system can bring in a few loads of dirt and get everything buried and graded out.

My biggest question right now is whether we need to take any precautions to prevent this new tank from freezing in the winter due to how shallow it’s buried. I’m seeing these septic blankets out there that supposedly trap in heat and prevent septic system freeze issues. If it’s advisable to get one then I have no problem doing so. The house is our primary residence so the system will get used every day during the winter with the exception of over the Christmas holiday for typically 3-4 days if we go to my inlaws for Christmas. Is daily use still enough to keep a shallow tank like this good enough to prevent freezing?

This message has been edited. Last edited by: Largefarva,

We live with a septic system. Ours was installed a couple of years ago and the inlet and outlet were required to be below the frost line.

I would think there is an inspection process for the installation. I would also think the health department would have the requirements for your area.

There is an inspection process here too, the EPA requires it. Most septic systems in our area cannot be buried below the frost line due to the high water table. The frost line in this area is around 36 inches or so and the water table is around the same depth...maybe a bit deeper. Drain fields have to be above the ground water, in our case it could only be buried 19” into grade. So there’s only 6-7” of soil above the drain field here. Can’t have the tank buried below the drain field in a gravity fed system, so they are generally buried pretty shallow here, but usually I believe not quite as shallow as ours.

Our septic tank is about 18 inches below grade. Never ever had we had any problems with freezing. Remember, it "perks" and this bacterial action creates heat. Also, you need to access it pretty easily to perform any maintenance.

Yeah I’ve been informed about the bacterial action and it’s heat creation. I wasn’t too worried about this until I came home the other day and saw that the tank was basically buried either at grade or above grade in the case of the outlet side. It’s going to be completely buried after they can get more dirt in here but it looks to be only around 6-8 inches or so. It’s gets really cold here (Chicagoland area) and I’m curious if the heat created from the bacteria and daily usage is still going to be enough to prevent freezing.

I think you will be OK. Remember also that these tanks are big and the bottom of the tank should be well below the frost line. This will also help to keep from freezing.

You are colder that we are down here but it gets pretty damn cold in Missouri in the winter. Temperature in the teens or single digits are quite common in our short winters.

Your water table is so high that the tank can't be lower???

How can the field get rid of the waste water then (or pass a perc test)?

Go to the building department and talk to the person that approves and inspects these for an explanation.

The tank can’t be lower because the tank outlet has to be higher than the drain field for gravity to work. That’s the way it is in this area. The bottom of the trenches can’t be any lower than 19” down to have sufficient filtering in the soil prior to reaching the ground table high level.

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Go to the building department and talk to the person that approves and inspects these for an explanation.

Yes the Code office will know. When I lived in Wisconsin, the frost level one winter was nine feet below the surface. There were issues.

It’s already been inspected by the health department. Like I’ve said, tanks being rather shallow is extremely common in this area due to the high water table. Hooking up to sewer wasn’t an option that we could afford...that would have been a 40-50k price tag that we do not have.

Where I live the tanks are deep, but the leech field is shallow. The water level in my tank is 3 to 4 feet below the surface, whereas the lines are about 18" deep.

The tank is furthest from the house and is a regular septic tank with a line running from it to a pump tank. The pump tank then pumps back to a huge sand filter. Gravity then takes it to a distribution box and the leech field from there. I would have thought that freezing would have been an issue being so shallow, but it hasn't seemed to cause any issues.

When I asked the woman with the County about it she said that these types of systems are shallow to allow evaporation to help.

Another septic system question for those who know, I have one that feeds to a drip system after processing. The drip line zigzags my entire backyard which feeds my grass.

My question is, what should I do for maintenance of this system? My neighbors says to pour in a certain amount of chlorine directly into the tank each month, but that seems like it would kill the organisms that do all of the work.

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Originally posted by ftttu:
My neighbors says to pour in a certain amount of chlorine directly into the tank each month, but that seems like it would kill the organisms that do all of the work.

Call your county health department. Everything I hear is to minimize use of bleach, other disinfectants, and don't flush your antibiotics.

If you want the correct answers on septic systems in YOUR county you must go to Your counties building codes dept. Only the counties can set those codes and most have several ways of doing it. It just depends on the soil condition in your immediate area. To answer the posters original question: If you maintain the system properly by dumping yeast,sugar, or a commerial ingredient ( found at any hardware store )that is designed to keep the bacteria working you should be good to go. the tank should be inspected and pumped if necessary no longer than every five years. Another good source for info is your local tank pumping service. I would not go to the building code office ( You could open a can of worms )without talking to a septic tank cleaner first.

quote:

Originally posted by ftttu:
Another septic system question for those who know, I have one that feeds to a drip system after processing. The drip line zigzags my entire backyard which feeds my grass.

My question is, what should I do for maintenance of this system? My neighbors says to pour in a certain amount of chlorine directly into the tank each month, but that seems like it would kill the organisms that do all of the work.

What you have is an aeration unit. It’s basically a small scale sewage plant similar to what public work facilities operate for towns and cities. Some of them, especially the ones that can discharge to use bleach as part of the final disinfectant stage prior to discharge to your lawn. It’s advisable to have maintenance done on these types of units every six months to ensure proper operation. It’s one of the options when we were in the design stage of our septic system, but due to the extra maintenance and cost we went with a conventional gravity drain system.

quote:

Originally posted by chansen92:
If you want the correct answers on septic systems in YOUR county you must go to Your counties building codes dept. Only the counties can set those codes and most have several ways of doing it. It just depends on the soil condition in your immediate area. To answer the posters original question: If you maintain the system properly by dumping yeast,sugar, or a commerial ingredient ( found at any hardware store )that is designed to keep the bacteria working you should be good to go. the tank should be inspected and pumped if necessary no longer than every five years. Another good source for info is your local tank pumping service. I would not go to the building code office ( You could open a can of worms )without talking to a septic tank cleaner first.

You must have missed the part where I said this is a brand new system, installed a couple of days ago. In fact, we’re waiting on it to dry out in order to finish burying and grading everything because of rain the last couple of days. It’s been inspected and everything so there’s no can of worms to open by asking questions to the health department. I’m not sure if they would really be able to answer my questions about freezing in the winter anyway. I might have to call around to see if anyone might be able to give me some insight.

I’m hoping that just regular usage and the bacterial action in the tank will be sufficient to prevent freezing in the winter, but was hoping someone here from a northern climate might have experience in this matter.

Here’s some information from the Minnesota pollution control on septic systems in cold climates. https://www.pca.state.mn.us/fe...septic-system-freeze

We have a septic tank. But it never freezes that long here in Georgia. The top of ours is about 3' down and it is a 1,000 gallon tank. We have it pumped every 4 years. We use the "World Cup" as our reminder that it is time to pump the tank.

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I’m not sure if they would really be able to answer my questions about freezing in the winter anyway

If they are qualified for their position, this would seem to be a very common and simple question. I do not think an advanced degree in pollution control systems is required. Of course if it is a political appointment all bets are off.

Their job entails determining whether or not a septic system design is ok for the environment. Ensuring that it doesn’t pollute ground water and water wells is all they really are concerned about. There might be someone there with personal experience with this matter, but no guarantees. It’ll be a shot in the dark, kinda similar to what I was hoping for when I created this thread.