40 CFR § 8.9 - Measures to assess and verify environmental impacts.
(a) The operator shall conduct appropriate monitoring of key environmental indicators as proposed in the CEE to assess and verify the potential environmental impacts of activities which are the subject of a CEE. The operator may also need to carry out monitoring in order to assess and verify the impact of an activity for which an IEE has been prepared.
(b) All proposed activities for which an IEE or CEE has been prepared shall include procedures designed to provide a regular and verifiable record of the impacts of these activities, in order, inter alia, to:
(2) Provide information useful for minimizing and mitigating those impacts, and, where appropriate, information on the need for suspension, cancellation, or modification of the activity.