Assam’s rivers are turning into a dumping ground

Bharalu river of Assam remains one of the most polluted rivers in the state

Guwahati: While the Assam government is going all out to promote and project its abundant resources of water as a major mode of transport and trade, an assessment on polluted stretches on India’s rivers presents a rather sorry state of affairs so far as the state is concerned.

A report by The Hindu citing a Central Pollution Control Board (CPCB) assessment on India’s rivers puts Assam on the second spot, just after Maharashtra, in the list of the most polluted river stretches in the country.

While Maharashtra accounts for 53 polluted river stretches, Assam features 44 such stretches. The assessment further mentions that Assam, Maharashtra and Gujarat alone account for 117 of the total 351 polluted stretches. Not just this year, Assam has made it to the dubious list even in 2015 in which the CPCB placed Assam at the second position with 28 stretches, Manipur with 12, Meghalaya with 10 and Nagaland with three.

As per reports, the CPCB assessment, which is yet to be published, states a considerable increase in the number of polluted river stretches from 310 in 2015-16 to 351 for 2016-17, while the number of critically polluted stretches has gone up from 34 to 45 so far. The CPCB measures the pollution in the 445 river stretches by taking into account the Biochemical Oxygen Demand (BOD), which is the amount of dissolved oxygen, consumed by micro-organisms to decompose the organic matter present in water, an important indicator of organic pollution.

PCBA data shows a slightly different picture

Meanwhile, the Pollution Control Board of Assam (PCBA), the apex pollution control body in the state, shows a slightly different data from that of the CPCB. As per the PCBA, there are 31 polluted stretches on Assam’s rivers, instead of 44, as projected by the CPCB assessment for 2016-2017.

PCBA’s assessment grades 31 river stretches on the basis of the BOD, and it places six rivers on a priority grade 1 category, which include the Brahmaputra (from Kherghat to Dhubri), Bhogdoi (Jorhat to Duliajan) , Bharalu (Guwahati to Chilarai Nagar), Burhidihing (Margherita to Tinsukia), Deepar Bill (Deepar Bill to Guwahati ) and Digboi (Lakhipathar, Reserve Forest).

PCBA data shows 31  polluted river stretches in Assam

But whatever the actual number may be, even if it is 31, if we are to believe the PCBA figures, what cannot be denied is that Assam has been holding the dubious distinction for two consecutive years now. This calls for some serious intervention by the state to ensure that the precious water resource does not get polluted beyond repair, just like the case of the Bharalu river.

Speaking to EastMojo, Rafiqua Ahmed, chief environmental scientist, PCBA, said: “The CPCB ranks river water on the basis of two parameters, i.e, BOD and Fecal Coliform bacteria, and it is on this basis that they have identified the stretches. But Assam’s river stretches are not as polluted as the CPCB data shows, as sometimes episodic pollution can be confused with the regular pollution level. If a sample is collected while the episodic pollution level is high due activities such as excreta discharge, the pollution may appear high, but such is not the case all the time.”

Pollution along river stretches has been primarily attributed to sewage discharge

What is causing such high pollution levels

Talking about the source of pollution in the rivers of Assam, Ahmed said, “Untreated domestic sewage discharge is a major source of pollution which increases the BOD due to the organic load in the river. But Assam still does not have a sewage treatment plant (STP) to treat the sewage water before it is discharged into the river system. Unplanned drainage system is another major obstacle in tackling the pollution in the river water. She further added, “Bharalu river is almost on the verge of becoming a dead river due to such sewage discharge.”

Despite such high levels of pollution in its river system, Assam does not have a single STP or Effluent Treatment Plant (ETP) to treat the harmful chemicals and bacteria released from domestic households as well as industries such as Coal India, Bharat Petroleum Corporation Ltd, among others.

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