(a) TVA will identify, as appropriate, measures to mitigate expected significant adverse environmental effects in an environmental document. Those mitigation measures to which TVA commits must be identified in the associated FONSI or decision document (or the documentation, if any, prepared for a categorical exclusion).

(b) Circumstances may arise that warrant modifying or cancelling previously made commitments. TVA may modify or cancel a commitment after considering the environmental significance of such a change.