MSHA - Code of Federal Regulations - 30 CFR 56.9304
30 CFR § 56.9304
(a) Dumping locations shall be visually inspected prior to work
commencing and as ground conditions warrant.
(b) Where there is evidence that the ground at a dumping location may
fail to support the mobile equipment, loads shall be dumped a safe distance
back from the edge of the unstable area of the bank.