Reno correct me if im wrong but uf cable here in mass must be buried to a minimum of 18". 6" just wont cutit. What are the requirements where you are? Either way its a shoddy installation at best. I have done lighting for parking lots before and we always use pvc schedule 40 buried 18" below grade with the caution tape on the pipe and 12" above the pipe then buried. I also totally agree with you about the box corroding in the cement. These were not designed for this purpose. Shoddy at best and I know it could not be to code even 20 years ago.
