Assam's lifeline, the mighty Brahmaputra, could be turning into a threat to life along the river that it supported all along. Its waters are muddy and black. The culprit is Siang river that originates in the Tibetan Glaciers and meets the Brahmaputra in Assam and there are fears it is getting worse. A little over ten days after a test of a water sample from the river indicated that its turbidity was way over the safe limits for human consumption and set alarm bells ringing, NDTV got the Siang water samples tested at the prestigious IIT-Guwahati.