(a) Charges shall be established by the Assistant Secretary and shall be based upon the total costs (including both direct and indirect) of goods/services to the Government at that locale. A schedule of charges will be made available to the public upon request.(b) All documentation used in establishing charges must be maintained at the appropriate Bureau of Indian Affairs agency or Area Office and shall be made available for review by the public upon request.(c) Established charges may be reviewed, amended, and adjusted monthly, but not less than annually.(d) A flat fee may be charged where it is impractical to measure actual usage by recipients.(e) Security deposits are authorized under this regulation at the discretion of the Assistant Secretary. The deposit may not exceed the amount of one billing cycle. All deposits will be applied to the final bill.