New Delhi, Aug 8 (PTI) Delhi Jal Board Vice-Chairman Saurabh Bharadwaj on Monday directed officials to expedite the work of laying sewer lines in unauthorised colonies in the capital, a major component in the city government"s plan to clean the Yamuna to bathing standards by 2025.According to government data, 725 of the 1,799 unauthorised colonies in the city have been connected to the sewer network so far, and work is on in another 552.At a review meeting, DJB officials informed Bharadwaj that 16 of the 18 major drains discharging into the Yamuna have been trapped.The meeting also focused on eliminating the challenge of wastewater from sewers entering the storm water drains and polluting freshwater sources.All sewers which enter the storm water drains are being trapped and connected to the DJB"s sewer network.Work on 52 of the 59 such points has already been completed and the rest will be done by August-end, officials said.Bharadwaj also asked the officials to expedite the work on 299 water bodies and nine lakes that are being redeveloped by the DJB. He directed the department to take help from experts in the project. PTI GVS IJT