"Formal investigation" means those activities conducted by Department investigative staff necessary to make a determination as to whether a report of suspected child abuse or neglect is indicated or unfounded. Those activities shall include: an evaluation of the environment of the child named in the report and any other children in the same environment; a determination of the risk to such children if they continue to remain in the existing environments, as well as a determination of the nature, extent and cause of any condition enumerated in such report, the name, age and condition of other children in the environment; and an evaluation as to whether there would be an immediate and urgent necessity to remove the child from the environment if appropriate family preservation services were provided. After seeing to the safety of the child or children, the Department shall forthwith notify the subjects of the report in writing, of the existence of the report and their rights existing under the Act in regard to amendment or expungement. [325 ILCS 5/3] (R300)(P 383)