Yamuna pollution: ‘Just 9 of 35 sewage plants along river in sync with norms’
The analysis of data showed that the non-compliance of such a large percentage of STPs means only 145 million gallons per day (mgd) or 27.3% of the 530mgd sewage treated is non-polluting
Only nine out of 35 sewage treatment plants (STPs) currently comply with the appropriate standards of 10:10 for biological oxygen demand (BOD) and total soluble solids (TSS) in the Yamuna, officials from the lieutenant governor’s office have said, citing data from different agencies involved in the clean-up of the river.
This was revealed at a meeting held between the Raj Niwas officials and those from Delhi’s environment department, the Delhi Pollution Control Committee (DPCC) and the Delhi Jal Board (DJB) on Saturday, people aware of the matter said.
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The analysis of data based off a presentation made by DPCC, DJB and the environment department, shared by Raj Niwas officials, showed that the non-compliance of such a large percentage of STPs means that only 145 million gallons per day (mgd) or 27.3% of the 530mgd sewage treated at these STPs is non-polluting.
“Delhi generates 768mgd of sewage every day. The STPs in Delhi have the installed capacity of treating 530mgd. However, these STPs function at just 69% of their installed capacity and hence, effectively, only 365mgd of sewage is treated every day,” an official said.
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A DPCC official, part of the meeting, said a detailed action plan to trap sewage has already been prepared, with agencies working to meet these timelines. “The increase in BOD is down to the sewage being released. Once completely trapped, it will dip significantly,” the official said.
LG House officials also noted that as per the data, pollution levels in the Yamuna today have risen considerably since 2014 in terms of BOD in the river.
The Yamuna enters Delhi at Palla, snakes through the city, and exits it from the Okhla barrage. According to the data shared by Raj Niwas officials, the BOD level of the Yamuna at Palla in 2014 was at an acceptable limit of 2mg/l -- as opposed to national standards of 3 mg/l or less -- and increased to 32mg/l as the river exited the Capital.
However, in 2023, while the BOD level at Palla remained the same, it spiked to 56mg/l at the Okhla barrage, the data showed.
“While in 2014, the BOD at ISBT, just after the Najafgarh drain falls into Yamuna, was 26, in 2017, this rose to 52 and remains at a high of 38 even today,” said an LG house official.
This continued rise in pollution has largely been attributed to pollution from the Najafgarh drain, which is yet to be tapped despite directions from the National Green Tribunal (NGT) and the Supreme Court.
Najafgarh drain accounts for 68.71% of the waste water being discharged into Yamuna, followed by the Shahdara drain which accounts for 10.90% of discharge, data shared in the meeting shows. If both these drains were tapped completely, then the sewage flowing into the Yamuna will drop considerably, officials added.
“This year-on-year rise in pollution has been consistent since 2014, with the only exception being 2019, when Haryana – which was undertaking repair of the Yamuna Canal -- released more than four times water into Yamuna from the Hathni Kund barrage. The same resulted in pollutants getting washed downstream,” the official said.
On January 9, the NGT had formed a high-level committee headed by the LG to oversee all progress related to the clean-up of the Yamuna, and to ensure that timelines for completion of work were met.
The DPCC, in its latest progress report on the clean-up of the Yamuna made public on January 9, revealed that 171mgd of sewage flowed untreated into the Yamuna within the borders of the national capital in December 2022, and to fix this, existing STPs will be upgraded and new STPs are to be constructed, taking Delhi’s sewage treatment capacity to 925.5mgd by December 2023.
DJB vice-chairman Saurabh Bhardwaj said the water utility is already working towards these legacy problems facing the Capital, and has awarded contracts for the upgradation of almost all major STPs in the city.
“All the works are expected to be completed by the end of December 2023. Further, we have issued showcause notices to private operators running the STPs, as well as to executive engineers in case of DJB-operated plants where deficiencies have been found. The projects are also facing difficulty as all payments for DJB were stopped for six months due to obstacles created by the finance department.” Bhardwaj said, noting that this may delay the timelines of ongoing works.
“We expect and request the LG to take action against the erring officers of department of finance,” he said.
Activist Manoj Misra, who is the convener of the Yamuna Jiye Abhiyan (YJA), said efforts to revive and clean the river are welcome, but the Yamuna requires a committee in which its members can spend their entire time dedicated to its clean-up.
“The Yamuna Monitoring Committee (YMC), which was headed by retired expert members, was also fulfilling this purpose, but it was dissolved by the NGT. While this new committee can fulfil a similar role in terms of the power granted by the NGT, its members will not be able to dedicate their entire workload to the Yamuna, as they will also be dealing with other issues concerning the city,” he said.
