The Department of Health and Environmental Control shall make such investigations as it deems necessary to determine which persons or which of the parents, guardians, trustees, committees or other persons or agencies legally responsible therefor are financially able to pay the expenses of the care and treatment, and may contract with any person or agency for the care and treatment of any person to the extent permitted by the resources available to the Department. The Department may require any county or State agency to furnish information which would be helpful to it in making the investigations. In arriving at the amount to be charged, the Department shall have due regard for the financial condition and estate of the person, his present and future needs and the present and future needs of his lawful dependents, and whenever considered necessary to protect him or his dependents, may agree to accept a sum less than the actual cost of services. No person shall be deprived of available health services solely because of inability to pay. No fees shall be charged for services which in the judgment of the Department should be made freely available in order to protect and promote the public health.