Talk about Delhi and it’s unlikely that the thought of Yamuna won’t cross your mind. But the image of the river that flashes up is not a pleasant one. Before entering the national capital, it is noticeably clearer and beautiful. As soon as it approaches the doorsteps of the city, the river is greeted and flooded with industrial pollutants, raw sewage and toxic waste.
Despite several measures, talks, and initiatives, little has been achieved by the state governments on keeping the Yamuna clean. Over the last few years, the situation has only deteriorated instead of getting better. “The river in the last few years has become more polluted. It is a collective failure of all the bodies and governments,” said Bhim Singh Rawat, a Yamuna activist and member of South Asia Network on Dams, Rivers and People (SANDRP).
In May, the Yamuna Monitoring Committee had asked the Central Pollution Control Board (CPCB) and Delhi Pollution Control Committee (DPCC) to conduct tests to ascertain if the water quality in the river had improved during the lockdown. The committee said there was a five to six times increase in freshwater availability downstream of Wazirabad during April, which helped in dilution of the pollution caused by wastewater from major drains like Najafgarh and Shahdara.
The CPCB had also reported that freshwater availability in Yamuna increased more than fivefold downstream of Wazirabad during the lockdown. The DPCC report, based on samples collected at nine stations along the river and 20 stations on the drains, said BOD (Bio-Chemical Oxygen Demand) concentrations had improved from 20 to 33 per cent at ITO, Nizamuddin, Agra Canal Jaitpur, Okhla Barrage (upstream) and Okhla.
Chronology of promises
In 2020, Delhi Chief Minister Arvind Kejriwal announced that his government was making a concrete plan to clean Yamuna and reduce its pollution by 90 per cent by 2023. The revival mechanism revolved around four major tenets. First, Delhi government would set up a modern technology plant to treat around 150 MGD (million gallons per day) of polluted water coming from Haryana and Uttar Pradesh by natural wetlands and aeration method. Second, wastewater in small or big drains be tapped into Sewage Treatment Plants (STPs). Third, steps be taken to improve the quality of existing STPs, including upgrading equipment and using innovative processes. Fourth, sludge and septage from septic tanks across the city to be collected by Delhi Jal Board and reused in bio-gas plants to generate electricity and gas.
In February this year, Water Minister Satyendar Jain claimed that the clean Yamuna project would be completed in three years. In April, Kejriwal expressed unhappiness over delays of various projects related to the cleaning of Yamuna. Cleaning of the river was one of the major poll promises made by the ruling party before the 2020 Assembly elections.
In June, Jain said that the government’s ambitious project to present a cleaner Yamuna is on track despite some slowdown due to the pandemic. Jain said that to curb pollution in the river, the government had already banned the sale, storage, transportation and marketing of soaps and detergent not conforming to latest BIS standards. The primary reason behind the formation of toxic foam in Yamuna is high phosphate content in the wastewater because of detergents used in dyeing industries, dhobi ghats and households, according to officials.
How to achieve goal
The DJB claimed to be on a war footing to ensure this. The department has taken up several measures. According to officials, Delhi at the moment has four major sources of pollutants affecting Yamuna — Sewage Treatment Plants (STPs), untreated water from unauthorised colonies, sewer water from authorised colonies and interstate factors involving Uttar Pradesh and Haryana.
To treat sewage water at STPs, the DJB is adopting a five-step method of intervention so that the water quality is improved. Dosing of coagulant: In this, alum is used to remove suspended solids in the STPs because at present, the solids getting dissolved is 60 per cent and with the use of alum, it will be 80 per cent. Increasing Aeration Capacity: Many existing STPs are old. The particles supposed to be treated as per the National Green Tribunal are currently not designed. Restructuring is being done so that these can treat BOD and ammonia as well.
Implementing Plastic Media: This method helps improve the efficiency of STPs. It basically acts as a house for growing bacteria that makes the water cleaner. The more bacteria, cleaner the water. In most cases, it is the last stage in the pretreatment of water for removal of un-dissolved impurities prior to treatment by Ion Exchange or Reverse Osmosis.
Disk filters: This is constructed by using numerous flat, grooved disks stacked tightly on top of each other and contained inside a casing. Water flows into the filter casing, surrounds the stacked disks and is forced through the grooves by pressure, removing the filtered material. It’s a weave of cloth that physically removes suspended solids. This help removes ammonia and maintain the NGT water parameter.
Incineration: This is high-temperature burning (rapid oxidation) of waste, also known as controlled-flame combustion or calcination. It is a technology that destroys organic constituents in waste materials. New techniques are developed for this process, used as energy-generating methods. The ash is used to make bricks.
“Our target is zero waste STPs. And that is going to serve a double purpose. With these methods, the water will be clean and sent to different lakes, horticulture centres, where clean water can be utilised. The extra clean water is to be reused,” said Ankit Srivastava, Advisor of DJB. “In areas with unsewer lines in unauthorised colonies, we are installing lines on a war footing which will be achieved in three years. Like in East Delhi, there is 100 per cent sewer, but there is no connection and therefore the wastewater is flowing through the drains and ultimately ending up in the Yamuna. The DJB has taken a policy to provide household sewer connections and the cost to be born by the state government. It is to be applicable in both authorised and unauthorised areas,” Srivastava added.
As far as the interstate factor goes, Delhi is receiving 105 MGD from Gurgaon via Najafgarh drain and 50 MGD from Uttar Pradesh via Shahdara drain. “To treat the water coming from Haryana, we are using in-situ treatment — sewage treated inside drains so that the water travels and gets cleaned up. Of this 105 MGD, 90 MGD is at Badshahpur drain where in-situ is already implemented and rest from drain number 6 which comes from Narela and is treated at Narela STP. So if we have an STP nearby, we are trapping the drain water there and cleaning it. Where this is not possible, we are going for the in-situ method,” said Srivastava.
“There are four main drains in Delhi meeting at the Yamuna — Najafgarh, Supplementary, Barapullah and Shahdara. Now, we have started drain tapping. So far we have provided 1.25 lakh sewer connections in the city. In the case of Barapullah, we are drain tapping and sending to Okhla STP,” the advisor explained.
As per the DJB official, industrial pollution is not a major factor for pollution of Yamuna as it is less than 10 per cent. “Where the pollutants are first getting mixed with Yamuna water, there it has some visibility, But as soon as it flows further, it gets diluted. Wherever we need to recycle the water, we are going for ozonation technology. It is the latest technology which breaks down pesticides and kills viruses. All these are going on simultaneously. We are in the process of sending out tenders.”
Is enough being done?
Rawat said that earlier, several promises had been made but none kept. “It is not possible to clean Yamuna. Don’t know how much has been achieved. Sewage flow is a major problem. There is no proper tracking, not even the control boards are serious about the measures,” the activist mentioned.
In 2018, a two-member YMC, comprising former Delhi Chief Secretary Shailaja Chandra and former expert member of the Tribunal BS Sajwan, was set up by NGT. The committee which got dissolved in January had submitted reports containing details of progress, or lack of it, on compliance with the directions of the NGT and also made recommendations for rejuvenating the river.
One of the crucial steps taken by YMC in 2018 was to suggest that the Central Water Ministry get a study done to assess the environmental flow (e-flow) required in the river between Haryana’s Hathnikund and Delhi’s Okhla.
“The Committee didn’t have authority to command and take action against violations, but only review and apprise implementation of the directions issued by the NGT and submit reports for issuance of directions. Reviving a river not only requires measures for pollution abatement but, more importantly, certain minimum flow in the river called the environmental flow.
A National Institute of Hydrology study made certain recommendations. The Central government, in consultation with stakeholder states, has to collectively address this. Also, sewage from 1,799 unauthorised colonies is a major issue” said Sajwan, who was a member of the committee.
