Ganges River question The Ganges River shown in Figure 457 h

Ganges River question

The Ganges River, shown in Figure 4.57, has an annual average flow rate of 12,105 m3/s. The average temperature of the Ganges River was reported to be 24.68C. The Ganges has become contaminated with raw sewage and industrial waste, so that the dissolved oxygen in the river upstream of sewage discharges is 4.6 mg/L. Suppose that the raw sewage that is untreated flows into the Ganges at a rate of 460 m3/s, the temperature is 258C, and the dissolved oxygen in the sewage stream is completely depleted (i.e., DO 0). How would you develop a plan for improving water quality in the Ganges River? 90\" 90 5 STAN 00 kn CHINA BHU NDIA G.aga. Bana Bay of Bengal 20 Figure The Ganges River Basin Source: Based on Rahaman, M.M. (2006) The Ganges water conflict: A comparative analysis of the 1977 Agreement and the 1996 Treaty

Solution

Ganges, the holiest river of India is 2500 kms long binding 5 different states of India and has a huge cultural and spiritual signifincance. The Ganga River Basin is home to more than 600 million Indians which is the highest number of people supported by any river in the world. However, this huge population has made the Ganges one of the most polluted rivers in the world. Despite this iconic status and religious heritage, the Ganges today is facing formidable pollution pressures and associated threats to its biodiversity and environmental sustainability. Increased dumping of human waste, as well as industrial waste, is noted as the most common form of pollution of the river. The studies indicate that a large proportion of pollution load in the river came from the municipal wastewater generated in twenty-five Class I towns located on the banks of the Ganges, each with a population exceeding 100,000. It constituted around 75% of the pollution from all point-sources. Remaining 25% of the pollution from point-sources was mainly due to untreated industrial effluent. Therefore, emphasis is to be given on interception and diversion of wastewater and its treatment in Sewage Treatment Plants, before discharging into river.

The data given are -

Annual average flow rate = Qr = 12105 m3/sec

DO in the river upstream of the sewage discharge = DOr = 4.6 mg/l

Flow rate of raw sewage flowing into the river = 460 m3/sec

DO of the mix is given by ( Qr x DOr + Qsewage x DOsewage ) / (Qr + Qsewage) which according to the question gets depleted completely and one can observe the amount of sewage that is being dump in the river every day.

Improving the water quality in Ganges can be initiated by preparing a plan, that guides investment and choices. An obvious focus to be given on the critically polluted stretch and the plan should prioritize the pollution hot spots and the investments with the greatest impact.Scarce resources must be allocated to investments with the highest returns. The paucity of credible and reliable water quality data on the Ganges must be rectified. The global experience shows that we need good data, including, for example, on the share of point source versus non-point source pollution and on the share of the pollution-load generated by cities versus industries. In Ganges, real-time water quality monitoring would provide a baseline from which to measure improvements and inject transparency in reporting. Then, leadership, autonomy, and professional management are needed.

The plan can consist of following important strategies -

Interception and diversion (I&D) of sewage, reaching the Ganges river.

Installing treatment facilities to treat the intercepted sewage.

Providing facilities of Low Cost Sanitation at community and individual levels at identified locations

Installation of Crematoria (electric as well as wood based improved crematoria)

River Front Development including bathing Ghats

Afforestation

Public awareness and participation

The global experience shows that, as an implementation task, river-cleaning should be de-linked from line ministries charged with policymaking and regulation and given, instead, to smaller, professionally managed river basin organizations. Cities need to be strengthened as ultimately they will be the custodians of the assets being created: sewerage networks, treatment plants, riverfront development schemes, and solid waste management systems. Many cities in the Ganges basin are particularly weak, with limited financial powers, weak revenue generation, and poorly managed utilities. In addition to current strategies, such as the piloting of 10-year Design Build Operate contracts to improve sustainability, one way forward is to partner a Ganges rejuvenation programme with a smart cities programme, and to pick a few iconic cities in which to pilot reforms, cluster investments, and show results. The Ganga’s constituents are its inhabitants, its champions, its religious leaders, its elected representatives, and all the people who value it as a cleaner river. People must be part of development and every successful clean-up programme has tapped this crucial resource. This is worth investing in. Regular reporting on goals and on progress, reaching out to youth and schools, encouraging participation in water quality testing and social audits, and promoting behaviour change are all examples of how far reaching this can be. Riverfront development—including ghats, parks, and other public spaces—is also critical, bringing people closer to water and increasing their affiliation and respect for its cleanliness and flow. Rejuvenation requires equal attention to quality and quantity. The old adage that “the solution to pollution is dilution” is partly true. This begs a basin-scale plan in which inter-sectoral trade-offs are analyzed and water is allocated according to greatest need and societal values. Today, 90% of the water is used for irrigation at some of the lowest productivity levels in the world. Much could be achieved by improving agricultural efficiency and reallocating water to higher value uses, including river health. This is particularly important for a large and complex water system that is highly seasonal with 90% of rainfall generated in three months and with a long lean season of slow run-off and marginal glacier melt.