NEW DELHI : Conversion of waste into wealth can generate Rs 10 lakh crore per annum for the Indian economy Road Transport and Highways Minister Nitin Gadkari said today."Conversion of waste into wealth could be an economy of Rs 10 lakh crore in India," Gadkari said while addressing the India Economic Summit here.At a session on 'Building Blocks for Infrastructure Development', the minister said innovation and technology is needed to harness India's huge liquid and solid waste.He cited the example of how India's largest sewage treatment plant is being set up at Mathura to purify sewage from the town and neighbouring Vrindavan and put the treated water for use at Indian Oil Corp 's ( IOC ) Mathura refinery.Listing steps to augment infrastructure, the minister said a number of expressways are being planned and he was hopeful that Eastern Peripheral Expressway to decongest Delhi will be ready in a record about 400 days.Similarly, work is likely to start on Vadodara-Mumbai Expressway while length of the National Highways is being increased to 2 lakh km from the present 96,000 km.Stressing on development of waterways, Gadkari said tenders would be floated soon to begin work on 36 waterways.Replying to a query that construction of barrages on Ganga would hinder flow of water, the minister said this was not correct.At the same time, he stressed that shifting the cargo to waterways from highways would result in savings in logistics cost which in turn would boost the economy.Gadkari said India has been working to improve its reputation with investors by tackling historical problems.