Ganga the holiest of the rivers of India, has served as the cradle of Indian Civilization. Several major pilgrim centers have flourished on its banks for centuries and millions of people come to bath in the river during various religious festivals. The Ganga in its 2525 Km stretch passes along 27 big cities, each with a population more than 100,000 and 73 small towns, each with less than 100,000 populations. Most of these cities and towns are either only partially skewered or do not have any sewage system at all.
Hence, every day about 1 million m3 of wastewater flows through open drains (nalahs), directly into the river, without any treatment.
In addition, the Ganga basin is extensively cultivated and about 47 percent of the total irrigated area of the country is located in the Ganga Basin. Three fourths of annual rainfall in the Ganga Basin, occurs only in the four-month period from June to September.
Hence, during the lean season, in the upstream, more than 80-90 percent of river flow is directed by two major canals for irrigation purpose. Over a period of time, all these activities have resulted in severe pollution, particularly in certain specific stretches of the river, where BOD levels of 10-15 mg/1 are often observed.
In 1984, the Central Pollution Control Board completed a comprehensive pollution inventory study on identification and quantification of all major pollution sources. Based on the results of this study and recognizing the importance and need for preserving the Ganga River water quality, Government of India launched the Ganga Action Plan in the year 1985.
Immediate reduction of pollution load and established of self-sustaining wastewater treatment plants are the two major objectives of the first phase of the Action plan. Accordingly, following components have been identified:
- Renovation of existing trunks sewers
- Construction of interceptors to divert the sewage flow
Renovation of existing sewage pumping stations and construction of new sewage pumping stations and sewage treatment plants, with emphasis on resource recovery, e.g., energy, recovery, to operate the treatment plants, and use of treated waste water for irrigation.
- Low cost sanitation programmes
- Construction of electric crematoria
- River front facilities and related improvements
In the first phase, 262 different schemes, within the overall framework of the components listed above, have been taken up for the 27 big cities, since they alone contribute to more than 70 percent of the population load. Total cost of these 262 schemes has been estimated as Rs. 2,600 million rupees.
In addition, an inventory of industrial units discharging waste into the river was carried out. As a result, 68 units were identified as gross polluters, who discharge more than 1000 kilo-litters of wastewater per day. All these units were directed to construct wastewater treatment plants and to comply with the water pollution control act.
The over all objective of the Ganga Action Plan is to achieve the bathing water quality standard of D.O. (dissolved oxygen) of 5 mg/1 minimum, and BOD of 3 mg/1 maximum, over the stretch of his river. In order to assess the impact of Ganga Action Plan, regular water quality monitoring is carried out at 27 different locations, starting from Rishikesh to Ulberia. In these locations, 42 different physico-chemical parameters are being monitored once in a month.