(3) A credit union may add additional groups not to exceed two hundred fifty potential members to its field of membership, as necessary, provided the groups reasonably are served by one of the credit union's service facilities, and the group has provided a written request for service to the credit union. However, the Board of Financial Institutions may revoke the power of a credit union to add groups provided by this section upon a finding that permitting additions pursuant to the provisions of this section are not in the best interest of the credit union. The adding of these groups must be consistent with the following:

1. (a) In order to add additional groups, a credit union first shall obtain a letter on the group's letterhead, if possible, signed by an official representative identified by title, requesting credit union service. The groups shall indicate the number of potential members seeking service. This document must be maintained by the credit union permanently with its bylaws.
2. (b) A credit union adding groups shall maintain a log of these groups. The log must include the following: the date the group obtained service, the name and location of the group, the number of potential members added, the number of miles to the nearest main or branch office, and the date of the approval of the group by the board of directors.
3. (c) Upon complying with the above procedures, board approval is not necessary to add groups with no more than two hundred fifty potential members to a credit union's field of membership. Approval of the Board of Financial Institutions must be obtained before the addition of groups in excess of two hundred fifty.