Each of the trustees shall enter into bond with security to be approved by the appointing authority in such sum as the appointing authority may determine.
     A majority of the board of trustees shall constitute a quorum, but a smaller number may adjourn from day to day. No trustee or employee of such district shall be directly or indirectly interested financially in any contract work or business or the sale of any article, the expense, price or consideration of which is paid by said district; nor in the purchase of any real estate or other property belonging to the district, or which shall be sold for taxes or assessments or by virtue of legal process at the suit of said district: Provided that nothing herein shall be construed as prohibiting the appointment or selection of any person as trustee or employee whose only interest in said district is as an owner of real estate in said conservancy district or of contributing to the payment of taxes levied by said district.