I had a customer once who just moved in from Boston... he was out of town wife was there, told her I'd mount the dish on the corner of her house right on the foundation right near her power meter... she ok'd it, put me on the phone with the husband to tell him what my plans were, he argued with me left and right that there is no possible way I could get signal that low off the ground.
Long story short install came out clean, never heard back from them. Drove by it a few times afterward weeks and months later and still there. I'm sure it's still there.
Dishes can be right on the ground, or in some cases in which I've once installed one, below the ground.