The department shall administer and enforce this section. It shall appoint an attorney to be designated “collection and deportation counsel” and other necessary assistants. The department may delegate to the collection and deportation counsel such other powers and duties as it considers advisable. The collection and deportation counsel or any of the assistants may administer oaths, take affidavits and testimony, examine public records, and subpoena witnesses and the production of books, papers, records, and documents material to any matter of proceeding relating to payments for the cost of maintenance. The department shall encourage agreements or settlements with the liable person, having due regard to ability to pay and the present needs of lawful dependents.