Water Conservation

The arsenic contamination of drinking water is highest in Kolkata, West Bengal.

Ultra-violet water purification is the most effective method for disinfecting bacteria from the water. Ultra-violet rays penetrate harmful pathogens in water and destroy illness causing micro- organisms. This is extremely efficient in eliminating their ability to reproduce. UV systems destroy 99.99% of harmful micro-organism without adding chemicals or changing water's taste or odour. Hence, option (a) is the correct answer.

Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from water. Water filtration can be done in many ways like- through temperature, ultraviolet rays and radioactive ions, oxidation of chemicals using a compound of ozone, Iodine and Chlorine. Cloramine (NH₂Cl) and Chlorine dioxide (CIO₂) are also used for water purification.

The removal of sand from the riverbed increases the velocity of the flowing water with the distorted flow- regime eventually eroding the river banks. Sands acts like a sponge which helps in recharging the water table. Its progressive depletion in the river is accompanied by declining water tables in the nearby areas. The sand acts as an efficient filter for various pollutants and thus maintains the quality of water in rivers and another aquatic ecosystem.

Due to the scarcity of water in the desert, in some plants, leaves are modified to reduce water loss. Hard and waxy leaves help to minimise water loss through diffusion. Water loss is also prevented in the form of gummy substance in leaves minimising the surface area to volume ratio. Thorns have a high surface area but they help in water conservation. They also help in condensing moisture from the air which then drips to the ground and is absorbed by the roots.

National Lake Conservation Plan (NLCP) is a centrally sponsored scheme exclusively aimed at restoring the water quality and ecology of the lakes in an urban and semi-urban area of the country. The objective of the scheme is to restore and conserve the urban and semi-urban lakes of the country degraded due to wastewater discharge into the lakes and other reasons, through an integrated ecosystem approach. The Sukhna Lake in Chandigarh, Bhoj in Madhya Pradesh and Pichola Lake in Udaipur, Rajasthan have been declared a Wetland covered under National Lake Conservation Plan. Chilika lake in Odisha is not covered under NLCP list.

National Lake Conservation Plan was launched in June, 2001 as a centrally sponsored scheme. This plan included 58 lakes of 14 states by December, 2009. The list included Bhimtal and Ooty. Since Ooty was a part of the project from the begininng, it is Bhimtal which was included recently.

Launching a new initiative named 'Hariyali' the Prime Minister said under watershed management, villagers can take up many small works to conserve water for drinking. irrigation, fisheries and afforestation. This would not only add "Hariyali" to the rural landscape but also create new employment opportunities for the rural poor.

The 'Central Ganga Authority' was constituted in February, 1985 under the aegis of former Prime Minister Rajiv Gandhi. In September, 1995 its name was changed to "National River Conservation Authority."

The 'Central Ganga Authority' was constituted in February, 1985 under the aegis of former Prime Minister Rajiv Gandhi. In September, 1995 its name was changed to "National River Conservation Authority."