Asphalt Over A Septic

Hello everyone, I was just asked this question from a friend who lives here in CA and was hoping one of you can help me out with an answer:

“is there a UPC code re: min or max fill dirt height over a leach field or septic tank? And can you asphalt over a septic, minus the inspection holes? Or is the asphalt just preferance and falls outside of UPC code?”

Any help would be greatly appreciated.

Thanks a bunch! :smiley:

John Robinson
John Robinson’s Inspection Group

An ordinary septic tank is not made to be drove over. You could possibly pour concrete over the tank but you will need to use a lot of reinforcement and some piers.

Most tanks allow no more than three feet of soil on top because the weight of the dirt can crush the tank.

Depends on the system. Some EDAs are designed to be under driveways and have concrete covers to protect them.
Same goes with tanks but I agree with James, most are not designed to be driven on.

Best think to do is find out exactly what type of system is there.

I wouldn’t add fill or paving over an existing septic system unless you were 100% sure it is built for those extra loads AND it’s verified that the underground facilities are in good condition.

JMO & 2-Nickels … :wink:

I would call out a deck, patio, concrete, above ground swimming pool, asphalt, etc. over a septic tank. And have frequently.

John, you left out your friend’s reason for wanting to do this.

I would only recommend doing it if he is planning to completly abandon the system. Even then, surely the most over-regulated, broke State gov’t would have something to say about it.

If he wants to continue to use the system for the long term, adding more than a few inches of fill on top of the tank is a big mistake. Every five years or so the tank will likely need to be pumped out. The deeper the lids are, the harder they are to dig up. If the lids are in poor, cracked or broken condition, they may fall apart.

The cons gretly outweigh the pros of doing what your friend is asking about. If you don’t agree, try digging up the lids now. Then go back and try again after a couple of feet of fill have settled over the top.

Thank you to everyone for all of your messages. I will pass this information along. I hope each and everyone of you are doing well!

John Robinson’s Inspection Group