Monday, March 31, 2008

EUTROPHICATION IS KILLING RANCHI PONDS.

EUTROPHICATION IS KILLING RANCHI PONDS.
by
DR. Nitish Priyadarshi

This are the pictures of local ponds situated in the Ranchi city, capital of Jharkhand State of India. Quality of water has been badly affected due to Cultural Eutrophication. This is the sad examples of aging of the existing ponds. All these ponds are undergoing siltation process. Also affected with sewage, domestic waste, detergent and oil and grease addition.
After becoming the capital there is a rapid increase in population, urbanization and industrialization which has lead to severe problems waste management in the city.
Due to Eutrophication and siltation and zero oxygen level there is always a foul smell from these water bodies. Now in most of the ponds there is a scarcity of fishes and other aquatic animals.
Due to less oxygen level there is always a threat of growing of pathogenic microbes, viruses, protozoa and bacteria etc. on the sewage products in the ponds. It may result into spread of fatal water-borne diseases such as polio, dysentery, typhoid, viral hepatitis etc. all these poses great threat to local poor people who unknowingly use this water for domestic purpose especially for washing clothes and bathing.
Most of the ponds are filled with water hyacinth. Water hyacinth mats degrade water quality by blocking photosynthesis, which greatly reduces oxygen levels in the water. This creates a cascading effect by reducing other underwater life such as fish and other plants. Water hyacinth also reduces biological diversity, impacts native submersed plants, alters immersed plant communities by pushing away and crushing them, and also alter animal communities by blocking access to the water and/or eliminating plants the animals depend on for shelter and nesting.
Algae was also found in surface waters of some of the ponds especially in the center of the city. Though algae help in water purification by removing carbon dioxide and adding oxygen during photosynthesis but they are harmful to health. Algae are considered to be indirectly responsible for gastroenteritis. Accumulation of dead planktons in sand filters offers a substrata for the growth of Pseudomonas which causes gastroenteritis troubles. Algae poison is considered to be one of the most virulent poison which produces cirrhosis of the liver. It also reduces the resistant power against the diseases in man. Dead algae form a mat on the surface of the water and act as a oxygen barrier.

Eutrophication in Ranchi generally speeds up in rainy season when high influx of water from the surrounding brings good amount of sediments, with domestic and small scale industrial wastes and other nutrient rich particles.
Most of the ponds now in Ranchi city is affected with Eutrophication phenomenon posing threat to the life of the ponds. It is not only the growth of water hyacinth or the Algae which are creating problem. But with the addition of nutrient reach sediments the problem is increasing many fold.
All these natural and man made ponds earlier helped in ground water recharging of the Ranchi plateau. Ranchi faces acute water crisis during summer season. Ground water gets depleted and well go dry. Earlier these ponds helped to maintain the ground water and well water level. But now due to siltation and Eutrophication ground water recharging has been stopped forcing most of the people to thrive on contaminated pond water during peak summer season. Even two dams situated around Ranchi city is also contaminated. Water supplied from these dams to the residential and commercial buildings are not safe for drinking. Every year in Ranchi district several people especially children die due to water borne diseases.
If proper steps are not taken up timely the problem is definitely going to multiply in the coming future.

Dr. Nitish Priyadarshi
geologist
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