(1) As provided in 20-4-302, 20-4-402, and 20-4-403, a pupil may be suspended by a teacher, superintendent, or principal. The trustees of the district shall adopt a policy defining the authority and procedure to be used by a teacher, superintendent, or principal in the suspension of a pupil and in defining the circumstances and procedures by which the trustees may expel a pupil. Expulsion is any removal of a pupil for more than 20 school days without the provision of educational services and is a disciplinary action available only to the trustees. A pupil may be suspended from school for an initial period not to exceed 10 school days. Upon a finding by a school administrator that the immediate return to school by a pupil would be detrimental to the health, welfare, or safety of others or would be disruptive of the educational process, a pupil may be suspended for one additional period not to exceed 10 school days if the pupil is granted an informal hearing with the school administrator prior to the additional suspension and if the decision to impose the additional suspension does not violate the Individuals With Disabilities Education Act, 20 U.S.C. 1400, et seq.