Less polluted river sections but the worst sections unchanged
Photo used for representation purposes only. | Photo Credit: The Hindu
The number of polluted reaches in India’s rivers has fallen from 351 in 2018 to 311 in 2022, though the number of most polluted reaches remains largely unchanged, according to a report by the Central Pollution Control Board (CPCB) of India. November but made public this week.
The CPCB network monitors water quality at 4,484 locations in 28 states and seven union territories, including rivers, lakes, streams, drains, and canals.
Biochemical oxygen demand (BOD) that exceeds 3.0 mg/l (milligrams per liter) is identified as contaminated sites. Two or more polluted sites identified in a river in a continuous sequence are considered as a “polluted river reach”. A BOD less than 3 mg/L means that the section of the river is suitable for ‘Open Air Bathing’.
In addition, the sections with a BOD greater than 30 mg/L are considered ‘Priority 1’, that is, the most contaminated and, therefore, in need of the most urgent remediation. There are five such categories with ‘Priority 2’ indicating a BOD of 20-30 mg/L and ‘Priority 5’ indicating 3-6 mg/L. The success of river cleanup programs is measured by the number of stretches that go from 1 to 2, from 2 to 3 to 5 (requiring the least action) are also reduced.
In 2018, when the CPCB published its report (after analyzing sections in 2016 and 2017), there were 45 sections categorized as Priority 1, 16 as Priority 2, 43 as Priority 3, 72 as Priority 4 and 175 as Priority 5. The last report counts 46 in P1, 16 in P2, 39 in P3, 65 in P4 and 145 in P5. All the improvements, therefore, occurred in stretches of rivers that required relatively minor intervention.
“No change/slight change in the Priority I and II category of polluted river reaches indicates that more stringent actions are required for the control of organic pollution from various point sources of pollution, including the development of infrastructure and its proper operation to the treatment of residual waters before the discharge in the container bodies of water”, observes the report of the CPCB.
While Gujarat and Uttar Pradesh had the maximum number of ‘Priority 1’ river reaches (6), Maharashtra had the maximum number of polluted river reaches i.e. 55, followed by Madhya Pradesh (19), Bihar (18 ), Kerala (18), Karnataka (17) and Uttar Pradesh (17).
Following a report published in the hindu In 2018, the National Green Court had issued orders for the CPCB and the Jal Shakti Ministry to monitor the river pollution and ensure that all acts of river pollution were addressed. Each State had to ensure that at least a section of the river was “restored” to the extent that it was at least suitable for bathing. States were also ordered to implement ‘Action Plans’ detailing how they were addressing different stretches of their rivers.
Responding to questions about the status of river pollution abatement efforts by states, Minister of State Prahlad Patel (Jal Shakti) said that pollution abatement works had been implemented on 36 rivers in 80 cities, spread across 16 states of the country at a total sanctioned cost of ₹6,248.16 crore, and a wastewater treatment capacity of 2,745.7 million liters per day (MLD) has been created. “Under the Regime of the Central Sector of gange namami program, 406 projects including 176 projects for sewage treatment of 5,270 MLD and a sewerage network of 5,214 km have been sanctioned at a cost of ₹32,898 crore against which a treatment capacity has been created so far of wastewater of 1,858 MLD,” he said in a statement.
The CPCB in its report added that the overall decrease in the net number of identified polluted river reaches, which have shown an improvement in water quality, “could be attributed” to the efforts made for the development of infrastructure for water management. residuals, management of industrial effluents, waste management and application of regulations for the prevention and control of pollution in rivers.