Any person, firm or corporation except the state of Washington or the United States, to whom or to which a contract may have been awarded by the district for construction purposes, or for labor or material entered into when the total amount to be paid therefor exceeds one thousand dollars, shall enter into a surety bond to be approved by the district board, payable to the district for at least seventy-five percent of the contract price conditioned for the faithful performance of said contract and with such further conditions as may be required by law.