User fees under part 130 of this chapter for service (including travel and other expenses incurred in connection with the furnishing of service) under this part shall be paid by the applicant. If required by the Administrator, the user fees under part 130 of this chapter shall be paid in advance. Since the user fees under part 130 of this chapter are for the purpose of reimbursing the Department for all costs incurred in connection with the furnishing of service under this part, the appropriate user fees under part 130 of this chapter to cover any such costs shall be paid even if service is withheld pursuant to § 156.8.