Watch the water
I've been considering how they are finding these ballots in ditches, under rocks in the middle of nowhere and now I hear in a dump in Philly? It's a conundrum for sure.
I have a theory and it may have been told by Q already many times. He says "watch the water. "
Here's the theory.
Deuterium used in a solution to watermark the ballots. AKA known as heavy water.
The deuterium in the Heavy water molecule can be excited by transmitting a radio signal @ 400 Mhz. nearby it and it will in turn produce a corresponding signal that can be read at 61 Mhz.
So to find a ballot in the middle of nowhere is as simple as producing the signal and triangulation.
It's entirely possible that deuterium is not the correct isotope. However I suspect this is how they are doing the locating.
Watch the water
Watch the watermark.