Thanks for this information -- what you said is certainly good news! I spoke to the contractor about all this just this morning, and he advised me that his truck is lighter than I had recalled -- he said it weighs 9 tons. And even at that weight, he said he takes great care to cover the lawn...
As an EE, my CE training was minimal (understatement). That said, I need to have some work done in my front yard where a very heavy bucket truck/man-lifter will need to be parked directly over a buried 4 inch sanitary sewer pipe. I don't remember the truck's exact weight, but I do recall that...