Section 148. Any engineering plans or specifications for engineering work or services that could pose a material risk to public safety, as determined by the department pursuant to clause (l) of section 81R of chapter 112, developed by or on behalf of a gas company shall bear the stamp of a professional engineer certified under section 81E of said chapter 112; provided, however, that any such plan or specification shall be housed within the applicable gas company, subject to review and audit by the department, and shall be deemed to be filed with a public authority within the meaning of section 81M of said chapter 112. The department may promulgate regulations as necessary to implement this section and applicable provisions of subsection (l) of section 81R of said chapter 112.