How water reaches Delhi homes - Explained

Delhi’s two main surface water sources are the Yamuna and Ganga which, officials said, account for around 90% of the water supply. The remaining is covered by ground water. Of the 10 treatment plants run by the DJB, the Sonia Vihar and Bhagirathi WTPs in East Delhi get raw water from the Ganga through pipelines stretching from Muradnagar in Uttar Pradesh, while eight others rely on the Yamuna and ground water supply. The process starts after raw water enters the treatment plant.

At Haiderpur, guards are on patrol near a Yamuna canal that supplies water to it to keep “miscreants” away. Inside, the water passes through four processes before it is released to the public. The first is pre-chlorination, which removes impurities at the start. In the next step, polyaluminium chloride and alum is mixed into the water to remove mud and dirt.

“Together they act as a coagulant, meaning they clump the suspended particles in the water so they can be removed in the clariflocculator,” the Haiderpur officer said. In a clariflocculator, which is a large round open tank, clumped particles settle at the bottom and are scraped away as sludge from an outlet below, while clear water is sent further and passed through sand and gravel filters.

An officer, who is part of the treatment operations team in the plant, keeps a register with a neatly drawn table of 13 columns for each parameter that is checked in the water on an hourly basis, before and after treatment, including turbidity, pH level and ammonia. A recent graduate assists the team in testing the water samples in a one-room laboratory.

The plant runs day and night, and staff keep changing every eight hours. The central lab in the plant, equipped with more advanced testing technologies, also checks raw and treated water quality against 30 parameters, with standards set by the BIS. “If any parameter is found to be higher than the standard, we have to make quick decisions. For instance, if ammonia is found to be high, then we either have to dilute raw water or shut production completely,” the officer said.

In the BIS report, all 11 water samples had failed in 19 parameters, including ammonia, turbidity and pH level. Paswan, who had released the report on November 16, had said in Parliament that water supplied by the DJB was not fit for drinking and had challenged Delhi Chief Minister Arvind Kejriwal for a retest. The CM, in turn, called the report false and politically motivated. At present, officials from both DJB and BIS have been appointed for a re-assessment.

Back at the Haiderpur plant, the “political situation” is mentioned occasionally and quickly shrugged off, but a certain pressure is apparent. “I can guarantee that the water which goes out to the public from here is safe for drinking,” the operations officer at the plant said, holding up clear water in his hand after it has passed through the sand and gravel filters.

The final treatment process is post-chlorination. “We add chlorine because… if there is any bacteria, virus or contaminant somewhere in the pipeline, the chlorine reacts with it and kills it after which its own presence is reduced,” said Ankit Srivastava, technical advisor to the DJB.

He said the presence of this “residual chlorine” is tested in about 500 water samples the DJB collects every day from its supply network across the city. If it is not found, then there’s a possibility of contamination somewhere in the pipeline. The samples are also tested against over 25 other parameters.

Waste treatment plants to homes
After water is treated in the plant, it is released into the DJB water pipeline network stretching over 13,000 km. It first reaches a primary underground reservoir (UGR), a reinforced concrete water tank of a large capacity where water is supplied 24×7. However, a DJB officer revealed that while changing pipelines a few years ago, around 200 direct consumer connections were found in between water treatment plants and the primary UGRs — something that is now prohibited. The department now keeps a track of the amount of water received and supplied with 2,200 flow meters installed across its network.

From the primary UGR, water is either supplied directly to colonies based on a fixed time schedule, or is sent to a secondary UGR and in rare cases, a tertiary UGR, which cater to single or a group of colonies. Together, there are nearly 500 UGRs in Delhi. The water pipelines pass in front of houses and it is the responsibility of consumers to apply to the DJB for a connection, officials said. A DJB engineer then assesses the site and recommends how the connection can be made with the help of a DJB licensed plumber.

The water department assesses the quality of water supplied to homes every day, in addition to around 1,500 samples tested at WTPs and of raw water sources. Between January and September 24, 2019, over 1.55 lakh samples were tested by the DJB, of which 2,222, or 1.43%, were found unsatisfactory. In October, more than 16,000 samples were tested, of which 3.98% were unsatisfactory. The DJB states that as per guidelines of the World Health Organisation (WHO) on drinking water quality, 95% of the overall samples assessed in a city have to pass the test. more  

View all 9 comments Below 9 comments
DJB is Delhi Jal Board - the august Organization which is responsible for supply of good clean drinking water in Delhi. They already have set standrards which is followed irrespective of whichever Government is ruling. So no Government can claim to either improve water supply...Unlike Uma Bharti of BJP who spent crores of rupees for Clean Ganga with no result to the extent that an exasperated Court asked her how long would she take and she decided to move on or move out. more  
Thanks for info,Sh.Anil Mehta! I might mention,that one UWR ( perhaps one of the 500 maintained by DJB in Delhi) in ‘C’ Block,Vasant Vihar,New Delhi,smells awfully from the internal road on which it is located.Even the outside storm drain along its boundary is filthy. It also gives unkempt,insanitary look. Such a UWR does not evoke confidence. Perhaps,supervisors & engineers do not visit to check the condition.Insufficient staff ,lack of oversight by their superiors are apparently the causes.The overload of maintenance work is apparently not brought up to the notice of the DJ BOARD headed by the CM himself. Remark applies to both water & sanitary responsibilities of DJB. Smells of overdomination of political issues over the technical & routine maintenance work,& poor voice of the engineers in the say of the DJB, in the board’s deliberation. more  
We can challenge Delhi water is not that safe despite all claims. more  
Whatever they say, i am ready to provide sample from my house with a challenge if any agency can prove it's safe for drinking. more  
Post a Comment

Related Posts

    • 7 b.1.1.7 cased jn Delhi now.

      Delhi today has reported 3 New cases of New Mutant corona Virus in last 24 hours. Total 7 people have been tested positive for New variant of corona Virus so far. Dont ignore...

      By Dipali Yadav
    • Urgent need to oppose decriminalisation of stubble burning

      The Government is seriously considering per media reports to agree to farmers demand that the farmers will not be penalised for stubble burning as mentioned under the ‘Commission for the Air ...

      By Vinita Agrawal
    • HSRP Plates

      I dont understand why Delhi Govt is being blamed for HSRP. Please know what HSRP is and why its needed. the Ministry of Road Transport and Highways (MoRTH) has mandated all vehicles to h...

      By Ruchika L Maheshwari
    • HSRP - How to apply

      How to apply for a HSRP and colour coded sticker? Step 1: The vehicle owner needs to log on to Step 2: Then click on the – High Security Registration Plate with...

      By Harish Randhawa
    • India under coronavirus:Furtive legislation

      Times-intolerably extended pseudo-interregnums if you will-such as these coronavirus times,are not the time for the Central government or state governments, to pass furtive legislation without pu...

      By Urvi Sukul Singh
    • HSRP harassment of people of Delhi

      The HSRP colour-coded sticker rule for Delhi/NCR is a total mess. No booking slots available at dealerships but Delhi Traffic Police is harassing commuters. Bulk of the blame lies with Delhi govt b...

      By Shivani Batra
    • Stray Dogs in North Delhi

      There is a dog menace is DLFCapitalGreens, attached. 15 to 20 stray dogs have gone on a rampage hitting and attacking children and senior citizens. Urgent neutering and vaccination of these dogs to...

      By Chitra Kumar
    • Clueless Delhi Transport Department

      Saying they had earlier asked people living in the national capital to get their high-security registration plates and colour-coded stickers affixed on their vehicles "without any delay" as vehicle...

      By Naina Mittal
    • Delhi case load again above 4000 today

      4,067 new COVID19 cases, 73 new deaths, 40,191 RT PCR tests. Farmers calling strike on December 8 and disrupting Delhi is not right from a Covid spread standpoint. Attached full report

      By Seema Mehra
    • Farmer Protest or CAS 2.0

      I cant differentiate. These protestors at ghazipur border seems more like mobs and not farmers. Not just a law & order risk but also covid wild spread. Delhi and many states innIndi...

      By Mala Sehgal
    • RT-PCR covid-19 test capped at 800

      RT-PCR test cost in Delhi for samples collected at collection sites/laboratories/hospitals cut to Rs 800 for samples collected through home visits, to Rs 1,200. These rates include all charges.

      By Shivani Batra
Enter your email & mobile number and we will send you the instructions

Note - The email can sometime gets delivered to the spam folder, so the instruction will be send to your mobile as well

Please select a Circle that you want people to invite to.
Invite to
(Maximum 500 email ids allowed.)