Tennessee Code Title 69. Waters, Waterways, Drains and Levees § 69-5-704

Each person bidding for such work shall deposit with the treasurer of the board of directors in cash or certified check a sum equal to ten percent (10%) of the amount of the bid, not in any event, however, to exceed ten thousand dollars ($10,000), or file a solvent bond for that amount conditioned to execute the contract if entered into. The deposit or bond shall be returned to the person if the bid is not successful; if the bid is successful, the deposit or bond shall be retained as a guarantee only of the person's good faith in entering on the contract.