We had a little snow this morning, and I notice in my front walkway, there is a strip of warm section which extends to the lawn. If I understand correctly, this is where sewage pipe is which connects to the septic tank. The section of walkway is also slightly depressed. Not sure if this is new or has been there from let go. But I noticed this first time. Any suggestion what I should do?

 

There may be nothing wrong. It would not be unusual for the ground to be slightly warmer over a sewer line, especially if it's not very deep in that area. And you had so little snow it would only have be very slightly warmer to melt that bit of snow. The area could be sunk in a little due to settling of the backfilled soil over the pipe. That's the good scenario.

Or, there could be a leak in the pipe causing warm water to enter the soil, and causing soil to wash out causing the depression. That's the bad scenario.

I would just keep an eye on the area. If it continues to settle, or you see signs of sewage oozing up, then it would be time to take action.

If you are really concerned about it, you could have a plumber with a sewer cam inspect the pipe from the inside, looking for a break or crack. IIWM, I'd wait and watch.

 

If you wait to summer, in addition to CT's post, check the depression again. It could be a result of frost lifting the cold area of the sidewalk but not the warm section. I don't know how deep your frost currently is but by spring I would expect it to rise more, especially with little to no snow. I guess we are getting that snow tomorrow, 5 to 8 they say.

Bud

 

I doubt your sewer pipe would warm the ground over that wide an area unless it is leaking. That would also help explain the sinking in that area. It is also possible that the melted area is your septic tank. A long thin steel rod can be stuck into the ground to feel for it. This method can also be used to locate your drain line.

 

Based on septic plan, the melted area is directly above 4" sewage pipe. The tank is on the left side of the pic under the garden bed.

I understand your concern. But it is such a regular shape following the pipe. If there is a leaky spot, the warm section should not be that regular. Am I missing anything?

 

When was the last time the tank was pumped?

Bud

 

about 2 years ago. We cleaned the filter last spring. The technician checked the tank. Everything was fine. It is 1500 G tank with 4 people.

 

Just checking. If it were full to the top it could be leaking back out around the inlet pipe and that might explain why there is no melting to the right of the sidewalk, source would be to left.

Hope not, just a thought.

Bud

 

I guess if that is the case, I should see the slow drain in the house. I didn't see it.

 

I have exactly the same situation. Half of tank is is under walk, and snow melts there first. PITA to access cleanout for pumping. Steve

 

I have seen melted snow perfectly outline the septic tank. It is possible to have two tanks. Are you certain your tank or one of your tanks is not underneath the walkway.

 

I have a septic tank that is only 4" below the ground and eventually it will melt the deepest of snow.

The inlet pipe is about a foot deep and it never melts the snow, it can't there is nothing in there for enough time to heat the ground.

That is not from the pipe, it's got to be the tank extending under the walkway and should be of no concern!

 

Checked Title V and septic plan, there is pipe under the walkway, not the tank. The inlet of tank is 19 ft away from the house, and I measured, it is where under the garden bed.

 

Take septic plans filed with the Healt or Environmental Services Dept. with a grain of salt. Quite often they are only good for a general reference and things are often not where they show. What is on file may have been the "plan" but things often change during construction and I've never seen a septic installer actually measure the location of the tank. If it's within 10 feet of what the drawing shows I'd say that's pretty good.