“No yardstick to measure ecological flow of river” by Binay Singh, Times of India
Singh, B. “No yardstick to measure ecological flow of river.” The Times of India. 22 September 2011.
No yardstick to measure ecological flow of river
By Binay Singh
September 22, 2011
VARANASI: Only an integrated and holistic policy can come to the aid of the Ganga as there is a dire need to maintain its ecological flow. Expressing this view, BD Tripathi, an expert member of the National Ganga River Basin Authority (NGRBA), also says that the government should think seriously about rescheduling the criteria regarding the discharge of wastewater in rivers or surface waters as well as increasing the ecological flow of the rivers.
Tripathi, a noted environmentalist and professor at Banaras Hindu University (BHU), has been made chairman of the committee to co-ordinate research projects on the Ganga pollution control and river basin management under joint collaboration of National Ganga River Basin Authority (NGRBA) and Central Pollution Control Board (CPCB). He is also the founder coordinator of the Centre for Environmental Science and Technology (CEST) of BHU.
“According to the Indian standard for discharge of wastewater in surface waters, the sewage having biochemical oxygen demand (BOD) level of 30mg/l can be discharged into the rivers,” he told TOI. “The rational behind it is that the wastewater would be diluted to the permissible limit of BOD (3mg/l) in the rivers,” he said adding that it was supposed that the pollutants would get diluted in the flow of rivers. But, how can it be possible when the flow of rivers is decreasing gradually. “There should be an integrated and holistic planning and policy to maintain the ecological flow of river. Unfortunately, the country does not have a river policy,” he said.
The report, ‘Monitoring of Indian Aquatic Resources’, of the Central Pollution Control Board also suggests that an assessment of flow and wastewater load is necessary. The data on the dependable flow of the Ganga in Varanasi (1959-2008) shows that the average flow is less than 1200 m3/s during lean periods. This indicates that certain periods of monsoon show higher degree of peak flow, which is around 2781160 m3/s during the rest of the time. The data pertaining to dependable flow of the Ganga at Kanpur (1959-2008) indicates that the average flow is less than 1000 m3/s during lean period. This also indicates a higher degree of flow during certain periods of monsoon, while the flow during rest of the time is around 90386 m3/s. The data on the dependable flow of the Ganga at Allahabad (1970-2008) indicates that the average flow is less than 1000 m3/s during lean periods. This indicates that certain periods of monsoon show higher degree of peak flow, while during the rest of the time, the peak flow is around 279997 m3/s. A comparison of the flow data in Kanpur, Allahabad and Varanasi reveals a similar trend in the flow. However, the flow in Kanpur during the lean period is almost half of that in Allahabad and Varanasi, thus conferring a critical status on Kanpur with respect to water quality management.
The report further suggests that an assessment of flow and wastewater is necessary. It is to be borne in mind that unabated discharge of treated sewage, even if after 100 per cent treatment, with BOD level of 30 mg/l, cannot bring the water to bathing quality level in lean season river flow. In order to achieve the goal it is important that minimum flow throughout the year is maintained to support eco-system in general and all forms of aquatic life in particular and ultimately maintain the wholesomeness of water bodies. “Since there is no specific criteria of water flow in rivers due to lack of a national river policy, the issue of minimum ecological flow is still a matter of debate,” said Tripathi adding that it was impossible to control the pollution in rivers without maintaining the required flow of water.
It its latest report on pollution abatement measures, the ministry of environment and forests points out that the Central Pollution Control Board (CPCB) is monitoring water quality of rivers at 1085 locations covering 383 rivers in terms of Dissolved Oxygen (DO), Bio-chemical Oxygen Demand (BOD) and Fecal Coliforms. Based on BOD levels, 150 polluted river stretches have been identified by the CPCB. The CPCB has identified BDO criteria is exceeding 30mg/l. It exceeds in all occasions in all 35 stretches of different rivers including Ganga. The criteria between 20-30 mg/l is exceeding at 15 stretches while criteria between 10-20 mg/l is exceeding at 26 stretches. At 38 places BDO criteria remains Between 6-10 mg/l while While 36 stretches have BDO criteria between 3-6 mg/l.
According to the report, the rivers in the country are polluted by the discharge of treated and untreated municipal wastewater and industrial effluents. Out of the total measurable pollution in the rivers from various point sources, 75% is accounted for by municipal sewage from towns located along the banks of the river and remaining 25% is accounted for by industrial effluents. In case of municipal wastewater, it is estimated that Class-I cities (498) and Class-II towns (410) generate more than 38254 million litres per day of sewage per day against which the treatment capacity exists only for about 11787 million litres per day of sewage. Thus there is a large gap between generation and treatment of municipal sewage in the country. Until the entire sewage generated is comprehensively tackled, the problem of pollution in rivers cannot be satisfactorily resolved.
The Ganga Action Plan (GAP) was launched in 1985 and was later expanded to include other major rivers under NRCP. Pollution abatement schemes undertaken include interception, diversion and treatment of sewage, low cost sanitation works. An expenditure of Rs 4,729 crore has been incurred and sewage treatment capacity of 4,417 million litre per day (mld) has been created so far under these plans. The Central Government has constituted the National Ganga River Basin Authority (NGRBA) in February, 2009 as an empowered authority for conservation of the river Ganga by adopting a holistic approach. The NGRBA has decided that under Mission Clean Ganga, it will be ensured that by the year 2020, no untreated municipal sewage and industrial effluents flow into Ganga.