Provides that the commissioner of the department of environmental management (commissioner) may not issue an order or proceed in court to require the owner or operator of an underground storage tank to undertake corrective action with respect to a release of a regulated substance from the underground storage tank until the commissioner has received and reviewed the initial site characterization of the site of the release prepared by or for the owner or operator of the underground storage tank (initial site characterization). However, allows the commissioner to require the owner or operator to undertake corrective action without having received and reviewed the initial site characterization if the commissioner reasonably believes that the release from the underground storage tank creates a threat to public health or the environment great enough to necessitate an order or proceeding before the initial site characterization is submitted to the department of environmental management. Also provides that, if a quantity of the released regulated substance remains or may remain underground at the site, the commissioner is prohibited from: (1) requesting that the owner or operator of the underground storage tank execute a restrictive covenant applying to the site of the underground storage tank; (2) making a determination of no further action being required at the site of the underground storage tank; or (3) approving closure of the site of the underground storage tank; unless the commissioner has received and reviewed the initial site characterization.