The Chairman of the Rangamati Hill District Council, Ching Kew Roaza has underscored the need for setting up biogass plants in Chittagong Hill Tracts to check depletion of forests, biodiversity and development of environment. Terming them as vehicles of technology transfer and motivation, her urged the participants of the seminar "on expansion of Biogas technology' to create awareness among the people and motivate them in setting-up biogas plants to protect the environment.