What type of snake is this?
If the underside is white or lighter, its a black rat snake. This could could be a black king snake, but it would be weird. My money is with black rat snake or eastern rat snake. This snake is not venomous.

It matches the pattern and has white inbetween the scales, so I believe it to inbetween youth and adult phases. This decribes the faint white pattern.

I would let it go, it's obviously busy keeping other pests from staying around.