(a) This subchapter is applicable to all insurers providing insurance or other financial assurance to owners or operators of underground storage tanks for the purposes of meeting financial responsibility requirements established under the Water Code §26.352.(b) All provisions of this subchapter except §5.9107 (relating to Disciplinary Actions by the Commissioner of Insurance) also apply to any other entity providing, holding, or maintaining financial assurance for the owners or operators of underground storage tanks for the purposes of meeting financial responsibility requirements established under the Water Code §26.352.(c) This subchapter applies only to notices required to be issued under the Water Code §26.352(e-1) and that are issued on or after May 1, 2008, regardless of when the insurance policy or other form of financial assurance was issued or created.