Black walnut is a dirty tree but the wood is highly valuable and the nuts are good.
I guess it’s only dirty considering where you plant it.
I had my Aunt in Green Bay, Wisconsin send me some of their native Black Walnuts about 30 years ago (I currently live in northern California).
The ones I planted out on the mountain side haven’t done very well but the ones I planted down by the spring and in the creek bottom are doing great.