New Delhi, March 26 -- The Delhi Jal Board (DJB) underestimated the capital's overall sewage generation by nearly a fifth, compromising efforts to clean the Yamuna, shows data from a Comptroller and Auditor General (CAG) report that examined the utility's functioning from 2017 to 2022. It warned that without realistic sewage figures, an effective treatment plan to reduce the pollution load on the Yamuna-where all sewage is discharged-would remain elusive. Citing "anomalies in the estimation of sewage generated in Delhi," the report noted that according to the Delhi Pollution Control Committee (DPCC), the total water flow to the Yamuna differs from DJB's data. A March 2022 DPCC report estimated outfall into the Yamuna at 892.22 million gallons per day (MGD), including 155 MGD of sewage received from Haryana and Uttar Pradesh. The DJB, meanwhile, estimated that 594.25 MGD of sewage generated in Delhi ends up in the river. "Thus, there is a clear gap of 142.97 MGD in the sewage/waste-water generation estimates of DJB and that of DPCC," the report concluded. The CAG also found that none of the 56 new sewage treatment plants (STPs) proposed during Phase-II of the DJB's Sewage Master Plan (2017-2021) materialised. The deadline for achieving standards for existing STPs was April 2018, yet of the 35 functional STPs as of March 2022, only 10 were designed as per DPCC parameters. "The objective of restoring the Yamuna waters to bathing standards could not be achieved as under-treated effluent was continuing to be discharged into the river," it noted. CAG noted that during joint inspections of 22 STPs between April and December 2022, auditors noticed that DJB was monitoring only dissolved oxygen, biochemical oxygen demand, and total suspended solids. "This is not only in violation of the orders NGT but also the Yamuna waters cannot be restored to bathing standards without monitoring the FC levels... regular monitoring of FC level in treated effluent emanating from all STPs' were not being done even till December 2023," it noted. A DJB official, who asked not to be identified, said several plants are very old and treatment norms have become stricter over the years. "DJB is undertaking a phased action plan to upgrade old STPs and nine more will be revamped under the project. New STPs could not be set up due to acute shortage of land during that period," the official said, adding that sewage generation continues to be estimated on 80% of water supplied....