The National Green Tribunal has rejected a notification issued by the Ministry of Environment, Forest & Climate Change in which it significantly relaxed sewage treatment norms in the country. The tribunal then prescribed stringent norms for sewage treatment in the country, on the basis of a report of an expert committee, and directed the ministry to issue a fresh notification within a month’s time.
The principal bench of the NGT, led by Chairperson Adarsh Kumar Goel, passed the order on April 30, acting on a petition moved by one Nitin Deshpande.
The order is significant at a time when Gujarat is planning to use treated wastewater as an alternative source in order to reduce dependence on groundwater and the Narmada.
The environment ministry has been prescribing effluent discharge standards for Sewage Treatment Plants (STPs) in the country since 1986 in notifications under the provisions of Environment Protection Rules. In November 2015, the ministry issued a draft notification which proposed stringent sewage treatment norms on what could be the acceptable levels of Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), total Nitrogen, Ammoniacal Nitrogen, total Phosphorus and fecal Coliform in water.
Since 1986, the sewage treatment norms for BOD (mg/l) stood at <30, for COD (mg/l) <250, TSS (mg/l) <100, total Nitrogen (mg/l) <100, Ammoniacal Nitrogen (mg/l) <50, whereas no limit was fixed for total Phosphorus, which is measured in mg/l, and fecal Coliform measured as MPN/100 ml — Most Probable Number per 100 ml. The ministry in its November 2015 draft notification proposed to be make the norms significantly more stringent at such levels as BOD <10, COD <50, TSS <20, total Nitrogen <10, Ammonical Nitrogen <5 and fecal Coliform at <100.
However, in October 2017, the ministry issued a notification in which all the norms were drastically relaxed — BOD at <30, TSS at <100 and fecal Coliform at <1000 — with no limit included for COD, total Nitrogen, Ammoniacal Nitrogen and total Phosphorus.
This led to a challenge to the notification before the NGT. The tribunal then rejected the notification and ordered the environment ministry to issue a new notification with norms prescribed by it as per recommendations of an expert committee that was formed by it during the course of the petition. The expert committee comprised nominees from IIT Kanpur, IIT Roorkee, NEERI and Central Pollution Control Board.
The Committee recommended norms that were almost identical to those that proposed by the ministry in its November 2015 notification.
In its order, the NGT referred to a report it received from Central Pollution Control Board (CPCB) and observed, “The report noted the current status of water quality of rivers that flow in India and the fact that 323 river stretches, out of 351 rivers, were polluted. There was need for revised standards for BOD and COD with a view to protect the water quality of the rivers/streams. There was also a need for revised standards for TSS, for Nitrogen (Ammonia & Nitrates) and Phosphorus and for Fecal Coliform.”
Commenting on the need to have a stringent norm for Fecal Coliform (FC), the NGT said, “Relaxing FC poses risk to downstream cities/town/villages that rely on drinking water sources on the same water body in the case of rivers. It appears quite reasonable to say that FC standards be prescribed to 100 MPN/100 ml, considering its impact on human health in general and (poor) readiness of Indian wastewater sector to handle the same…”
The NGT order states, “The greatest benefit of these standards is to achieve all-purpose non-potable reuse quality effluent. Each STP (Sewage Treatment Plant) is to be treated as a source of water for reuse and recycling, helping in mitigating drought/climate change in the country. It will also reduce exploitation of groundwater reserves and dependency on rainfall which has become quite unpredictable in the past few years.”
Will switch to new norms: GPCB
Sewage treatment plants in Gujarat function as per norms prescribed by the environment ministry in October 2017. When contacted, Secretary of Gujarat Pollution Control Board K C Mistry said, “Yes, the 2017 notification has been set aside. We will be issuing instructions to all authorities that run the plants to follow the new norms. Plants in the pipeline will comply with the new norms.”