25 Pa. Code § 245.431 – Spill and overfill control.

(a) Owners and operators shall ensure that releases due to spilling or overfilling do not occur. The owner and operator shall ensure that the volume available in the tank is greater than the volume of product to be transferred to the tank before the transfer is made and that the transfer operation is monitored constantly to prevent overfilling and spilling.
(b) The owner and operator shall report, investigate and clean up spills and overfills in accordance with Subchapter D (relating to corrective action process for owners and operators of storage tanks and storage tank facilities and other responsible parties).

This section cited in 25 Pa. Code § 245.403 (relating to applicability).