Ground Water Pollution By Agriculture and Pesticides

Introduction
- Pollution can be defined as the change of physical, chemical and biological properties of water, restricting or preventing its use in the various applications.
- Water is polluted artificially by human activities or naturally due to salt water intrusion and others without human intervention. In the new reclaimed lands, agricultural and industrial activities may create different sources of pollution.
Agricultural impacts on water quality
- Tillage/ploughing
- Fertilizing
- Manure spreading
- Pesticides
- Irrigation
How Pesticides Get Into Groundwater
- Practices of users
- Water (or lack of) on site surfaces
- Chemical nature of pesticide
- Type of soil at release site
- Location of groundwater
- distance from surface
- geological formation above it
Groundwater Contaminations Due to Practices of Pesticide Users
Ø Not following label directions
Ø Overdosing (it’s illegal!)
Ø Application method
Ø Back-siphoning
Ø Storage close to water*
Ø Mixing/cleaning sites*
Ø Improper disposal
Advantages of Pesticides
- Save human lives (malaria, bubonic plague, typhoid fever)
- Increase food supplies (even now 55% of world’s potential food supply is ‘lost’ to other species)
- Increase profit for farmers
- They work fast
Disadvantages of Pesticides
- They accelerate the development of genetic resistance to pesticides by pest organisms
- They can put farmers on a financial treadmill
- Some kill natural predators and parasites that control ‘pest
Nutrients
Farmers apply nutrients such as phosphorus, nitrogen, and potassium in the form of chemical fertilizers, manure, and sludge.
Ground Water Pollution by Nitrogen Compounds
Nitrate Health Risks
- Methemoglobinemia = “blue baby syndrome”
- NO2- combines with Hemoglobin, blocking oxygen transport (thus the blue color)
Removal of Nitrogen
Phosphorus
Fertilizers usually contain Phosphorus in the form Phosphate.
Other sources of Phosphate producing can be animal manure, detergents and some other natural sources.
Major points on groundwater pollution
Groundwater Pollution by Organics
Organic Compounds in Groundwater
References
http://krishisewa.com/articles/2011/gwp_nfert.html Date:22-8-2011
http://www.fao.org/docrep/w2598e/w2598e04.htm#agricultural impacts on water quality Date 25-8-2011
CENTRAL POLLUTION CONTROL BOARD (CPCB)(MINISTRY OF ENVIRONMENT AND FORESTS)
www.cpcb.nic.in Date:23-8-2011
http://krishisewa.com/articles/2010/biofert.html Date:25-8-2011
http://water.epa.gov/learn/training/wacademy/webcasts_index.cfm Date:28-8-2011
CGWB and CPCB (2000), Status of Ground Water Quality and Pollution Aspects in NCT-Delhi, January 2000 Date:24-8-2011