The department may inspect the facilities and review the procedures utilized by any chemical substitutes or antagonists program, residential program, or nonresidential outpatient program that has as a primary purpose the treatment and rehabilitation of persons with substance-related disorders, for the purpose of ensuring compliance with this chapter and the rules adopted pursuant to this chapter. The examination and review may include case record audits and interviews with staff and patients, consistent with the confidentiality safeguards of state and federal law.