So there's a septic tank behind the house marked by a pile of rocks. I need to get past it with a pickup but am leery of a cave-in. How close can a person get?

How old? Does it go to a leach field or a sand mound? Does it have one cleanout or more?

If you stay 15' away from the center you should be good. You could get closer depending on what one it is.

Depends

Construction, soil type and depth all are factors.

Poured with remesh or rebar stronger. Soft soils can push one in with a close pass. Deeper has more soil over the to to carry and spread a load.

Best to avoid it if in doubt.

So many variables determine the size of a septic tank; date of installation and water usage, number of bedrooms, number of occupants at that time. The minimum we used to install in a standard in-ground septic system was a 1,000 gallon tank (concrete). They are about eight feet long and six and a half feet wide.

They used to bury barrels and steel tanks for a septic tank and they will cave in pretty easy. You could use a smooth 5/16'' rod and after a good rain poke around to find the edges, kinda like they poke in cemeteries to find the grave next to where they are going to bury their next door neighbor to be.

This is in NW Arkansas where it's rock, not dirt. The house was built in 2007 so it should be fairly new. No idea if it's concrete or plastic. It's puzzling to me as the only gate going into the yard is right in front of the septic tank. I may just put in a new gate on tother side of the house.

Even more concerning than the size or what the tank is made of, would be the location and the fact that vehicles would be driving over the field lines. With a lot of rain and a soggy field, the last thing that needs to happen is for the field lines to be crushed. Also if there’s well water, there are specifications for the min distance between. May not affect you if you are paying cash or obtaining conventional financing, however it could affect future sales for buyers who might be getting FHA or government backed financing

It is not just the septic tank that you should avoid but you should not drive on the disposal field either. Some states have the septic systems online. In theory your town office should have one in your property file. If you could find the design plan, it would help you locate everything. Good luck.

Mac

Yes, but was the septic system new then? If there is an existing system some places allow you to use it.

I think I'll avoid it.....

i found one the hard way with a concrete mixer truck once, wasnt where the plan showed and i was being directed by the home owner so wasnt at fault. luckily the other axle held the truck up till a heavy recovery wrecker showed up & got me out of a stinky situation! costly error, probing with a tapered steel rod is the only sure way to find it, or as mentioned check with your town/county office, if its that new there should be a septic plan on file with a benchmark nearby.

Mine is concrete 1000 gallons and I drive over it all the time...it's in my gravel driveway. Been in for 33 years and have yet to pump it.