More than 20 mega-dams are being constructed or planned on Burma?s major rivers, including the Salween and Irrawaddy, by multinationals without consulting local communities, a wide range of NGOs charged in a statement Friday. In addition, the group charged, mining, oil and gas projects are creating severe environmental and social problems. Several papers are to be delivered on Sept. 18 in an all-day seminar in Bangkok on the impact and consequences of overseas investment in large-scale projects in Burma that say as many as 30 companies from China alone are investing in dam projects on the two rivers.