The director of finance shall be the head of the department of finance and, as such, have charge of: (i) the administration of the financial affairs of the county, including the budget; (ii) the assessment of property for taxation; (iii) the collection of taxes, license fees and other revenues; (iv) the custody of all public funds belonging to or handled by the county; (v) the supervision of the expenditures of the county and its subdivisions; (vi) the disbursement of county funds; (vii) the purchase, storage and distribution of all supplies, materials, equipment and contractual services needed by any department, office or other using agency of the county unless some other officer or employee is designated for this purpose; (viii) the keeping and supervision of all accounts; and (ix) such other duties as the board requires.