I recall some folks pulling 10" balls out of there years ago. One told me it was miserable owing to discharges from a nearby creosote plant and the water burned their skin. Perhaps they meant these tar discharges described as coming from a gas plant in the article. Coal tar is also a listed carcinogen -- an identified cause of testicular cancer, men, so this may only be suitable work for the Plumber's Maxim camo bikini clad digging buddy...
Anyway, however tempting this cache sounds, its not worth messing with these things in my opinion to recover 10" balls!