M.C. Mehta vs Union of India & Others.

1.Case Title and Citation  

M.C. Mehta vs Union of India & Others.  

Equivalent citations include AIR 2002 SC 1696, 2002 4 SCC 356. 

2.Court Name and Bench  

Supreme Court of India  

Bench: B.N. Kirpal, V.N. Khare, Ashok Bhan JJ. 

3.Date of Judgement  

5 April, 2002. 

4.Parties Involved  

Petitioner: M.C. Mehta  

Respondent: Union of India and Others. 

5.Facts of the Case  

This case addresses the persistent air pollution in Delhi primarily caused by vehicular  emissions. Despite existing legislation, the lack of effective enforcement resulted in hazardous  air quality. The Supreme Court had issued several orders since 1986, seeking measures to  reduce pollution, including mandating lead-free petrol, lowering sulphur content in diesel and  phasing out diesel buses in favour of those running on CNG. Implementation delays and  repeated requests for extensions by the authorities frustrated the Court’s orders. 

6.Issue Raised  

The primary issue was the non-compliance with Supreme Court directives to phase out  polluting diesel buses and convert/commercial vehicles to clean fuels such as CNG in Delhi.  The question arose whether administrative reasons justified the delay sought by the  government and bus operators. 

7.Arguments of the Parties

• The Union of India contended that there was a shortage of CNG and that transitioning all  commercial vehicles to CNG immediately would disrupt public transport. 
• The petitioners and other stakeholders maintained that the CNG supply was not actually  insufficient for the transport sector and that the protection of public health should take  precedence over administrative and economic difficulties. 
• The government further argued that emission norms and not mandating a particular fuel  (such as CNG) would suffice, but the Court found this argument unconvincing given the history  of non-compliance with norms. 

8.Judgement / Final Decision  

The Court dismissed the application for further time, reaffirmed the mandate for CNG  conversion and issued detailed directions. These include urgent phasing out and replacement  of diesel buses, imposing penalties on non-compliant bus operators, prioritising CNG  allocation to the transport sector and extending the shift to other polluted cities. Applications  by the Union of India for more time were dismissed with costs. The Delhi government and  other authorities were instructed to ensure compliance and file further reports. 

9.Legal Reasoning / Ratio Deciendi  

The judgement relied heavily on constitutional duties under Articles 39(e), 47 and 48A,  imposing obligations on the State to protect health, improve public health and preserve the  environment. The Court highlighted the ‘precautionary principle’ and ‘polluter pays principle’  as the cornerstones of environmental law. The Bench noted that the State must prevent  environmental degradation and public health risks and that administrative or economic  concerns cannot override these constitutional mandates. Compliance with emission norms  alone was deemed insufficient, citing persistent poor air quality as evidence of enforcement  failure. The decision emphasised prioritising public health over economic interests and the  State’s responsibility to implement clean fuel solutions without delay. 

10.Conclusion 

The Supreme Court’s decision is a landmark in Indian environmental jurisprudence,  reinforcing the judiciary’s proactive role in protecting the right to a clean environment. The  Court placed the onus on government agencies to prioritise the health of citizens and strictly  enforce orders to curb pollution, specifically by phasing out diesel buses in favour of CNG,  imposing penalties on violators, and extending clean air initiatives to other critically polluted  cities.