# 35.572 Definitions.In addition to the definitions in § 35.502, the following definitions apply to the Clean Air Act's section 105 grant program:*Nonrecurrent expenditures* are those expenditures which are shown by the recipient to be of a nonrepetitive, unusual, or singular nature such as would not reasonably be expected to recur in the foreseeable future. Costs categorized as nonrecurrent must be approved in the grant agreement or an amendment thereto.*Recurrent expenditures* are those expenses associated with the activities of a continuing environmental program. All expenditures are considered recurrent unless justified by the applicant as nonrecurrent and approved as such in the grant award or an amendment thereto.