The department of social and health services shall be responsible for the costs relating to the treatment of persons committed to their custody whether in a secure facility or under a less restrictive alternative as provided in this chapter. Reimbursement may be obtained by the department for the cost of care and treatment of persons committed to its custody whether in a secure facility or under a less restrictive alternative pursuant to RCW
43.20B.330 through
43.20B.370.