In 1994, BRPL authorities prepared a feasibility report for setting up of the hydrotreatment plant (Anon., 1994a). Also, earlier in 1991, Department of Chemical Engineering, University of Roorkee undertook a comprehensive environmental impact assessment study of Bongaigaon Refinery and Petrochemicals Limited. These reports were of immense help in providing the much needed information on the project profile and the project environment. Discussions with the naturalists of various NGO groups and the scientific community in educational and scientific institutions also proved useful in compilation of the information on ecological aspects of the proposed site. All the information sources were of great help in collating the information on site characteristics prior to any field based studies.

Detailed maps of the project area were obtained from the office of the Divisional Forest Officer, Aie Valley Forest Division, Bongaigaon and the office of the Principal Chief Conservator of Forests, Assam State Forest Department, Guwahati. These maps provided the basic references for locating the sites for field observations.