25 Pa. Code § 3.21 – Interim response.

(a) This section does not apply to emergency interim responses taken under section 501(g) of the Hazardous Sites Cleanup Act (act) (35 P. S. § 6020.501(g)).
(b) Under section 505(b) of the act (35 P. S. § 6020.505(b)), the Department may take an interim response before the development of the administrative record when there is a reasonable basis to believe that prompt action is required to protect the public health or safety or the environment.
1. (1) If the Department takes an interim response before development of the administrative record, it will provide notice of the action within 30 calendar days of initiating the interim response.
2. (2) The notice provided under this subsection will conform with § 3.22 (relating to notice of prompt interim response).
(c) For any other interim response, the Department will provide notice in conformance with § 3.23 (relating to notice of proposed response).