Two projects to clean Yamuna at Okhla Barrage, a riverine stretch plagued by heavy froth formation, have yet to move forward.Get breaking news anytime, anywhere. Download the TOI app now!Delhi. A new 124 MGD sewage treatment plant at Delhi's Okhla will cost Rs 1,161 crore. Another Rs 1,041 cr will upgrade 8 existing STPs, increasing their combined capacity from 78.2 MGD to 140.8 MGD.