No structure, other than supports, shall be erected or placed beneath any aboveground tank, nor shall any combustible material, drum, or barrel be stored or kept under any such tank.
34 Pa. Code § 14a.5
This section cited in 34 Pa. Code § 14a.111 (relating to storage and handling); 34 Pa. Code § 14a.141 (relating to scope and application); 34 Pa. Code § 14a.151 (relating to scope and application); and 34 Pa. Code § 14a.161 (relating to general provisions).