Sabarna Roy

Wastewater Generation and Treatment – Present Status in India  

From day one, in India we did not integrate wastewater projects with water supply projects. The reason being: water is a service provided by the Government that is politically sensitive to win elections. The over-arching thought is: wastewater projects have no produce; it is only to be disposed of. With development of technology and acute water crisis setting in, some people have gradually come to understand that transmission and treatment of wastewater leads to recycle and reuse of watering specific applications including agriculture, horticulture and generation of power from sludge compost. This understanding is yet to percolate to the citizens of the nation whereby people demand wastewater projects in the same manner as they demand water supply projects so that politicians and policy makers are bound to integrate the two and implement sustainable projects for the long term with lower Carbon Footprint.

The Government of India has now given major focus towards treatment, recycle and reuse of sewage/wastewater/greywater.

Broad status as on date in India:

1.Sewage Generation61,754 MLD
2.Sewage Treatment Capacity22,963 MLD
Untreated Sewage38,791 MLD

Break-up between Metropolitan Cities, Class-I Cities and Class-II Towns:

1.Sewage Generation15,644 MLD
2.Sewage Treatment Capacity8,040 MLD
Untreated Sewage7,604 MLD

Status of Sewage generation and Treatment Capacity of Class-I Cities [on River Ganga]:

1.Sewage Generation2,601 MLD
2.Sewage Treatment Capacity1,192 MLD
Untreated Sewage1,409 MLD

Status of Sewage generation and Treatment Capacity of Class-II Towns [on River Ganga]:

1.Sewage Generation122.0 MLD
2.Sewage Treatment Capacity16.4 MLD
Untreated Sewage105.6 MLD
Sewage generation in balance Class-I Cities35,558 MLD
Sewage generation in balance Class-I Towns2,697 MLD
Total38,255 MLD
Sewage Treatment Capacity14,907 MLD
Untreated Sewage23,348 MLD

The Order of the National Green Tribunal regarding Effluent Discharge Standards for Sewage Treatment Plants dated April 30, 2019 and further updated on May 8, 2019 lays down much more stringent Standards of Discharge compared to the earlier Standards stipulated by Central Pollution Control Board and therefore, calls for adoption and integration of new technologies in the country with low life cycle cost, which is clearly mentioned in the Order. The concluding paragraph of the Order, point no. 14, states as follows: –

Accordingly, we accept the report of the Expert Committee with the modification that the standards recommended for Mega and Metropolitan Cities will also apply to rest of the country. We also direct that the standards will apply not only for new STPs but also for existing/under construction STPs without any delay and giving of seven years’ time stands disapproved.

Industry also creates substantial effluent and now if we look at this sector specifically, we will find that the effluent generation is in the tune of 500 MLD. A break-up is given below: –

Sector specific industrial waste-water generation Type of IndustryTotal UnitsEffluent Generation (MLD)
Chemical2797.8
Distillery3537.0
Food, Dairy & Beverage226.5
Pulp & Paper67201.4
Sugar6796.0
Textile, Bleaching & Dyeing6311.4
Tannery44222.1
Others4128.6
Total764501

The National Green Tribunal constituted an Expert Committee comprising the nominees from IIT Kanpur, IIT Roorkee, NEERI and CPCB which was to give its report after examining the best available technologies and best practices and after referring to the Experts study on the subject particularly CPCB Report on “River Stretches for Restoration of Water Quality, 2014-15” and the order of this Tribunal on the subject of polluted river stretches dated 20.09.2018 in Original Application No. 673/2018 in the matter of News item published in “The Hindu” authored by Shri Jacob Koshy titled “More river stretches are now critically polluted : CPCB”. The Tribunal also directed stay of operation of the Notification dated 24.11.2015 issued by Ministry of Environment, Forest and Climate Change (MoEF&CC) and application of pre-revised standards till further orders.

In view of all matters examined before the Expert Committee and severity of depletion of aquatic resources vis-a-vis the financial aspects related to conveyance and treatment of water/sewage the Committee recommended that the effluent discharge for STPs to be as follows:

Sl. No.IndustryParametersStandards (Applicable to all mode of disposal)
1234
Sewerage Treatment Plants (STPs)Mega and Metropolitan CitiesClass I CitiesOthersDeep Marine Outfall
pH5.5-9.05.5-9.05.5-9.05.5-9.0
Bio-Chemical Oxygen Demand (BOD)10203030
Total Suspended Solids (TSS)20305050
Chemical Oxygen Demand (COD)50100150150
Nitrogen Total1015
Phosphorus Total (For Discharge into Ponds, Lakes)1.01.01.0
Fecal Coliform (FC) (Most Probable Number per 100 millilitre, MPN/100 ml)Desirable – 100
Permissible – 230
Desirable – 230
Permissible – 1000
Desirable – 1000
Permissible – 10000
Desirable – 1000
Permissible – 10000

Note:

  1. Mega-Metropolitan Cities have population more than 1 crore, Metropolitan Cities-Population more than 10 Lakhs and Class-1Population more than 1 Lakh.
  2. All value in mg/l except for pH and Fecal Coliform.
  3. These standards will be applicable for discharge into water bodies as well as for land disposal/applications.
  4. These Standards shall apply to all new STPs for which construction is yet to be initiated.
  5. The existing/under construction STPs shall achieve these standards within 07 years from the date of notification.
  6. In case where the marine outfall provides a minimum initial dilution of 150 times at the point of discharge and a minimum dilution of1500 times at a point 100m away from discharge point, then norms for deep sea marine discharge shall be applied.
  7. Reuse/Recycling of treated effluent shall be encouraged.
  8. State Pollution Control Boards/Pollution Control Committees may make these norms more stringent taking into account the local conditions.

It is important at this stage that the state Government, the industry and the people should rise up to the occasion of handing wastewater in a smart and intelligent manner so as to reduce the acute water scarcity on a sustainable basis.

Source: indianinfrastructure.com

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