The application shall be accompanied by full documentation of the fees and expenses incurred after initiation of the adversary adjudication, including the cost of any study, engineering report, test, or project for which an award is sought. With respect to a claim for fees and expenses involving an excessive demand by the Bureau, the application shall be accompanied by full documentation of the fees and expenses incurred after initiation of the adversary adjudication, including the cost of any study, engineering report, test, or project for which an award is sought attributable to the portion of the demand alleged to be excessive and unreasonable. A separate itemized statement shall be submitted for each professional firm or individual whose services are covered by the application, showing the hours spent in connection with the proceeding by each individual, a description of the specific services performed, the rate at which each fee has been computed, any expenses for which reimbursement is sought, the total amount claimed, and the total amount paid or payable by the applicant or by any other person or entity for the services provided. The adjudicative officer may require the applicant to provide vouchers, receipts, or other substantiation for any expenses claimed.