The Environmental Protection Agency's (EPA) inhouse library systems fall into two principle categories: basic library inventory systems and literature retrieval systems. Currently, the library network supports three inventory systems: the journal system; the hard bound book system; and the circulation system. At the same time, five efforts are under way in the area of literature retrieval: (1) a system involving bibliographic information concerned with the health aspects of pesticides; (2) a similar application in the area of air pollutants and their effects on vegetation and animals; (3) a system covering a collection of international environmental reports pertaining to national environmental policies and laws; (4) an EPA reports system using master files provided by the National Information Service (Department of Commerce); and (5) an EPA document control system which monitors documents not covered by other library applications. Each of these systems generates comprehensive computer outputs meeting the total needs of the data managers as well as the daily user. (WCM)