The county commissioners of a county of the fourth, fifth, sixth, seventh or eighth class may, and for the purpose of protecting and promoting the welfare of children and youth, shall, provide child welfare services designed to:
(1) keep children in their own homes;
(2) prevent neglect, abuse and exploitation;
(3) help overcome problems that result in dependency, neglect or delinquency;
(4) provide in foster family homes and child-caring institutions adequate substitute care for any child in need of substitute care; and
(5) upon the request of the court, provide services and care for children and youth who have been adjudicated dependent, neglected or delinquent.