There is hereby authorized to be employed by the child support unit of the state department of public welfare such other, investigative, technical, secretarial and supportive staff as may be necessary for the proper and necessary implementation of the requirements of Public Law 93-647, 93rd Congress, and any amendments adopted thereto applicable to said program as provided under Sections 43-19-31 through 43-19-53; said positions shall be subject to the merit system's rules and regulations and their salaries shall be fixed in such amounts as the state department of public welfare may deem proper.