GROUNDWATER CONTAMINATION POSES SERIOUS HAZARDS

 

 

 Groundwater is India's lifeline, meeting 85% of rural drinking water needs and 60% of agricultural requirements. However, its contamination poses severe environmental and health hazards. Groundwater contamination refers to the introduction of pollutants into aquifers, making the water unfit for consumption and other uses. The issue is exacerbated by over-extraction, poor waste management, and a lack of effective regulation. 

Current Situation

According to the Central Ground Water Board (CGWB), around 70% of India’s groundwater is contaminated, with regions across states showing high levels of fluoride, arsenic, nitrates, and heavy metals.

India is the largest consumer of groundwater globally, with about 87% of groundwater used for irrigation and 11% for domestic purposes. However, groundwater quality is deteriorating due to various natural and anthropogenic factors:

• Extent of Contamination: The Central Ground Water Board (CGWB) reported that 20% of groundwater samples in India exceed permissible pollutant limits.
• NITI Aayog Report (2018): India is facing the worst water crisis in its history. Groundwater levels are depleting while contamination rises.
• Regional Overview:
  • Arsenic: Found in the Ganga-Brahmaputra plains, affecting states like West Bengal, Assam, Bihar, and Uttar Pradesh.
  • Fluoride: High concentrations in Rajasthan, Telangana, Karnataka, and Andhra Pradesh.
  • Nitrate: Detected in groundwater in Punjab and Haryana due to overuse of chemical fertilizers.
  • Heavy Metals: Lead, chromium, and cadmium from industrial effluents in Gujarat, Maharashtra, and Tamil Nadu.
• Drinking Water Crisis:
  • The Comptroller and Auditor General (CAG) reported that in 256 districts, groundwater contamination exceeds permissible limits for drinking water.

Data:

• Fluoride: Over 66 million people in 200 districts are at risk of fluorosis.
• Arsenic: Affects more than 40 million people in the eastern regions.

Reasons for Groundwater Contamination

A. Natural Factors

1. Geological Sources:
   • Arsenic occurs naturally in sedimentary rocks in the Ganga-Brahmaputra basin.
   • Fluoride-rich minerals are found in the aquifers of Rajasthan and Telangana.
2. Saline Intrusion:
   • Over-extraction near coastal areas leads to seawater intrusion.

B. Anthropogenic Factors

1. Agricultural Practices:
   • Overuse of chemical fertilizers and pesticides leads to nitrate leaching into aquifers.
   • In Punjab, nitrate levels in groundwater exceed WHO guidelines (50 mg/liter).
2. Industrial Pollution:
   • Discharge of untreated effluents by industries containing heavy metals (lead, chromium).
   • Example: Gujarat Industrial Development Corporation (GIDC) areas report chromium levels above safe limits.
3. Urbanization and Waste Management:
   • Leakage from unlined sewage systems contaminates aquifers.
   • Municipal waste dumping leads to heavy metal leaching.
4. Mining and Industrial Activities:
   • Open cast mining and improper waste disposal in states like Odisha and Jharkhand.

Case Study:

• Arsenic in West Bengal:
  • Over 83 blocks in 8 districts are severely affected.
  • The contamination originates from alluvial deposits and is aggravated by groundwater extraction.

Effects of Groundwater Contamination

A. Health Impacts

1. Fluorosis:
   • Long-term consumption of fluoride-contaminated water leads to skeletal deformities and dental issues.
   • Over 5 million people in Rajasthan suffer from fluorosis.
2. Arsenicosis:
   • Causes skin lesions, cancers, and neurological effects.
   • Affects over 1 million people in Bihar and West Bengal.
3. Blue Baby Syndrome:
   • High nitrate levels cause oxygen deprivation in infants.
   • Reported cases in agricultural belts of Punjab.

B. Environmental Effects

• Degradation of Aquatic Ecosystems:
  • Polluted groundwater seeps into rivers and lakes.
• Loss of Biodiversity:
  • Heavy metal contamination affects aquatic flora and fauna.

C. Economic and Social Costs

• Healthcare Burden: Increased expenditure on diseases caused by water contamination.
• Impact on Livelihoods:
  • Farmers suffer due to decreased agricultural productivity caused by soil salinization.
  • Example: Luni River Basin in Rajasthan reports a loss of arable land due to saline water use.

Steps Taken

A. Policy and Legislation

1. The Environment Protection Act, 1986:
   • Regulates industrial waste discharge.
2. Water (Prevention and Control of Pollution) Act, 1974:
   • Focuses on controlling water pollution in rivers and groundwater.
3. Groundwater Management Regulations:
   • States like Maharashtra and Punjab have laws to regulate groundwater extraction.

B. Government Schemes

1. National Aquifer Mapping Program (NAQUIM):
   • Maps 25 million hectares of aquifers to assess water quality.
2. Atal Bhujal Yojana (2020):
   • Promotes sustainable groundwater management through community participation.
3. Jal Jeevan Mission (2019):
   • Aims to provide safe drinking water to rural households.
4. Namami Gange Program:
   • Focuses on cleaning rivers and restoring groundwater quality in the Ganga basin.

C. Technological Solutions

1. Defluoridation Plants:
   • Installed in fluoride-affected villages.
2. Reverse Osmosis (RO) Plants:
   • Used to treat water in arsenic- and heavy-metal-affected areas.

Challenges

1. Governance Issues:
   • Overlapping responsibilities between the Central and State authorities.
   • Weak enforcement of laws.
2. Technological Barriers:
   • High cost of advanced technologies like RO plants.
3. Awareness:
   • Lack of awareness among rural populations about contamination risks.
4. Overexploitation:
   • Over-reliance on groundwater for irrigation and urban use.

Way Forward

A. Policy Recommendations

1. Strengthen Monitoring:
   • Equip the Central Pollution Control Board (CPCB) with advanced tools.
2. Legislation:
   • Enact stricter penalties for industrial polluters.

B. Sustainable Practices

1. Organic Farming:
   • Reduces dependence on chemical fertilizers.
2. Water-Efficient Irrigation:
   • Techniques like drip and sprinkler irrigation minimize water usage.

C. Community Engagement

• Awareness Drives:
  • Educate people about the health impacts of contaminated groundwater.
• Community-Led Initiatives:
  • Involve locals in aquifer recharge and water conservation efforts.

D. Technological Advancements

• Nanotechnology and Bioremediation:
  • Use microorganisms to treat groundwater contamination.

E. Research and Collaboration

• Establish research centers focused on groundwater contamination.
• Collaborate with global organizations like UNICEF and WHO for expertise.

Case Studies

Success Stories:

1. Rajasthan’s Fluoride Mitigation Program:
   • With defluoridation plants and awareness campaigns, villages in Rajasthan have significantly reduced fluoride levels in water.
2. Namami Gange Program:
   • Reduced pollution and improved groundwater recharge in the Ganga basin.
3. Gujarat's RO Plants:
   • Ensured safe drinking water in heavily industrialized areas like Ankleshwar.

Conclusion

Groundwater contamination is a multifaceted challenge with severe implications for health, environment, and economy. A multi-pronged approach combining policy, technology, public participation, and sustainable practices is essential. Protecting this invaluable resource is not just an environmental necessity but a critical step towards sustainable development.