National Acid Precipitation Assessment Program  In United States federal environmental legislation, the National Acid Precipitation Assessment Program (NAPAP) was authorized by Congress under the Acid Precipitation Act of 1980 (P.L. 96-294, Title VII) because of concern that acidic deposition might contribute to adverse effects on aquatic systems; agriculture; forests; fish; wildlife and natural ecosystems; materials such as metals, wood, paint and masonry; and public health and welfare. Congress also expressed concern over the potential impact from long-range transport on national and international policy. Congress further directed that a comprehensive 10-year research plan be developed and guided by an Interagency Task Force consisting of representatives of 12 agencies, the directors of four National Laboratories, and four presidential appointees. Operational management evolved to a six-member Joint Chairs Council consisting of the Administrators of the National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency (EPA); secretarial officers of the Departments of Agriculture, Energy and Interior; and the Chairman of the Council on Environmental Quality. Other program managers include a Director for Research for executive functions, Task Group leaders reporting jointly to the Director of Research and their agencies for Coordination of research in each major subject area, and two committees composed of the Director of Research and senior representatives of the Joint Chairs Council’s agencies, i.e., the Interagency Science Committee and the Interagency Policy Committee. According to the Congressional mandate, the research was to include programs for:  Other responsibilities of NAPAP include coordination and communication of the Federal program related to acidic precipitation and cooperation with international, private, and State organizations engaged in similar research. The legislation also required reporting of results and recommendations to the Administration and Congress by the issuance of Annual Reports. Federal agencies responded to the Act by conducting a vigorous research and development program coordinated by NAPAP. The NAPAP Interim Assessment was issued on September 17, 1987. A major assessment was issued in 1990. Following the 1990 renewal and expansion of the Clean Air Act, resources devoted to NAPAP declined. National Acid Precipitation Assessment Program: Interim Assessment: The Causes and Effects of Acidic Deposition, issued September 17, 1987