In employing enforcement officers, the department shall use the criteria as required by the Office of Human Resources and the department. The criteria must include, but are not limited to, a written examination, physical examination, and interview. Each applicant is required to perform at minimal levels as required by the Office of Human Resources and the department. The department shall employ the most qualified applicants. If an enforcement officer does not reside in the county for which he is employed, he shall move to the county at his expense within three months of employment. Enforcement officers must be compensated from funds provided to the department in the annual general appropriation act.