tire depth for state inspection?

Hi all,

I just have my car done with PA state inspection, the garage warned me
that my car's tires are worn too thin(they barely passed the
inspection) and should need new tires very soon. Then, I have tire
rotated at walmart, the tire depth reading for all 4 tires of my car
are 8/32, are they too thin for 8/32? What is the average tire depth
requirement for most of state inspection? thx.