We had some less than stellar workmen do some work a few weeks ago, and one of them spilled a substantial amount of petrol onto our front lawn. There is now an area about 100cm in diameter where the grass is completely dead.
I was not able to do anything about it until now (about 3 weeks later), so I have dug up the entire dead area, down to about 30cm. This is as far as I can reasonably dig, because we live in a clay area (Sydney Australia - almost all of the west is just clay).
The clay still stinks of petrol though, as did all of the dirt and grass I dug up.
Is there any way I can repair this? Do I just leave it dug out for a few weeks to "dry"? (It's summer at the moment, so lots of long, hot 30°C days and hotter)?
If I throw some fresh dirt from another part of the yard into the hole and plant new grass seeds, will the petrol that's in the clay just re-contaminate it? Or is that area going to be dead forever?