NEW DELHI: The Centre approved on Monday seven projects, worth nearly Rs 425 crore, under its ambitious ongoing river cleaning programme.Besides new sewage infrastructure projects, the fresh approvals include a research work to study nonpurefying properties of ‘Gangajal’ (Ganga water) — considered ‘holy’ by Hindus.The study will, in fact, be an extension of an ongoing research carried out by the National Environment Engineering Research Institute (NEERI) to identify special properties of the river’s waters.The research will cover study of both water and sediments, especially in the upper reaches of the Ganga.“This research would focus on finding out the science behind these special properties in order to formulate a strategy to retain these characteristics”, said an official note of the Union water resources ministry.All these projects were approved by an executive committee of the National Mission for Clean Ganga NMCG ), a central body which approves all projects up to Rs 1,000 crore under the Namami Gange programme. The Mission has earmarked Rs 4.96 crore for the research study to understand the nonputrefying properties of the river Ganga.The six sewage infrastructure related projects, approved on Monday, include three projects each for Uttar Pradesh and Bihar.In UP, these projects are aimed at creation of sewage treatment capacity of 29 million litres per day (MLD), at Unnao (13 MLD), Shuklaganj (6 MLD), and Ramnagar(10 MLD) at a total cost of over Rs 238 crore.In Bihar, these projects will create additional sewage treatment capacity of 27 MLD at Sultanganj (10 MLD), Naugachia (9 MLD) and Mokama (8 MLD). “All the six projects will be provided with ‘operation and maintenance’ cost for 15 years by the central government”, said the ministry in a statement.The projects at Unnao and Sultanganj will be taken up under hybrid annuity-based PPP model in which 60% of the capital cost will be paid to the contractor over a period of 15 years on the basis of his work performance on the achievement of desired norms of treated waste water.