New Delhi: Delhi continues to face a significant gap in sewage treatment, with 249 million litres a day (MLD) of sewage remaining outside the treatment system and 12 of the city’s 22 sewage drains still untapped, two amici curiae have told National Green Tribunal (NGT).The report, by advocates Katyayni Chaubey and Vikrant Badesra, also raises questions on Delhi Jal Board’s (DJB) claim of over 91.5% STP utilisation. The report says the claim is not corroborated by the high pollution level in Yamuna.The observations by the amici were filed in an ongoing matter concerning compliance with Municipal Solid Waste Management Rules, 2016, and other environmental issues.The observations, dated Sept 16, deal with liquid waste management in Delhi and rejuvenation of Sahibi river , which is called the Najafgarh Drain in Delhi.It notes that Yamuna’s pollution is relevant to the proceedings because the river is the ultimate recipient of all the liquid waste generated in Delhi.Delhi generates 3,636 MLD of sewage. Although, sewage treatment plants (STPs) under DJB have an installed capacity of 3,702 MLD, only 3,387 MLD of that capacity is utilised. This leaves a gap of 249 MLD. Of the STPs, 29 comply with DPCC standards, and seven are non-compliant, the report said.The observations also flagged that 12 untapped sewage drains carry part of a combined flow of 5,196.44 MLD of sewage through 22 drains. The amici curiae said this results in the direct and continuous discharge of untreated sewage into receiving waterbodies. Ten stormwater drains are also being used for sewage disposal.The report also highlighted the sewage connection gap. Against the target of 40 lakh household sewer connections, only 23.5 lakh have been achieved, leaving 16.5 lakh households without connections. Delhi govt had earlier set June 2028 as the deadline to connect these households.The findings linked the deficiencies to the continuing poor condition of Yamuna. It recorded that water-quality analysis disclosed high BOD, nil dissolved oxygen and alarmingly high fecal coliform.“This is difficult to reconcile with the respondent’s claim of 91.5% STP utilisation, and suggests either under-performance of commissioned STPs, unaccounted or illegal discharge bypassing the treatment chain, or discharge through the 10 stormwater drains and 12 untapped sewage drains,” the report said, stressing that the matter requires examination.The amici sought, among other measures, a firm action plan for tapping the untreated drains, disclosure of the seven non-compliant STPs and their parameters of non-compliance, and a plan for the proposed 600-tonne-per-day sludge management capacity for 26 STPs currently without functioning sludge-management facilities.The observations also proposed a joint Delhi-Haryana-Rajasthan mechanism for the rejuvenation of the Sahibi river, along with the interception of sewage, restoration of its natural channel, removal of encroachments and continuous water quality monitoring. The note said the Najafgarh drain is, in effect, the degraded course of Sahibi and has become heavily polluted through the disposal of untreated sewage, solid waste and effluents.
