The direct treatment of Njunangar stream leading to river Pampa using Ferrous Chloride procured from an Aluva-based private company has kicked up a controversy with various experts as well as environmentalists expressing serious concern over the river water pollution owing to largescale discharge of heavy metals like Cadmium, Zinc, Nickel, Chromium and a heavy concentration of iron into the river that houses a number of drinking water supply schemes in its downstream reaches.

Travancore Devaswom Board has been carrying out the direct water treatment in the Njunangar stream with technical guidance and expertise from the State Pollution Control Board (PCB) since the past two years in an effort to reduce coliform bacteria count in river Pampa.

However, many experts, including those attached to PCB, have strongly criticised the use of Ferrous Chloride procured from a private company situated on the banks of Periyar in Aluva for the river treatment.

Mr. Eloor Purushan, environmental activist who was in the forefront of the historic agitation against the discharge of Ferrous Chloride into river Periyar, alleged that the chemical used in Njunangar was a

by product or ‘waste’, which the private company used to drain into the Periyar earlier. The private company is engaged in the manufacture of Synthetic Rutile in which Ferrous and Ferric Chlorides are obtained as heavily contaminated by products, says he.

River Treatment

The river treatment system consists of three earthen bunds across the Njunangar. In the first segment, the coagulants, lime and ferrous chloride, are added and allowed to stand. The waste settles as sludge. The clear overflow is aerated in the next segment and released for discharge.

The sludge generated is discharged into small pits in the adjoining forests. But due to the nature of the terrain, the pits get filled quickly and overflow back into the river and thus the system fails, according to a senior engineer attached to the PCB.

The drinking water standards for iron (without conventional treatment, but after disinfection) is 0.3 mg per litre. But, if there is a conventional treatment followed by disinfection, the maximum permissible iron content is 50 mg per litre. Permissible standards for lead and cadmium are 0.1 mg/ltr and 0.01 mg/litre respectively.

However, the discharge of these toxic materials into river Pampa, through Njunangar, is said to be far exceeding all its permissible limits, ultimately posing alarming health risk to the population in its downstream reaches up to Kuttanad, opined the PCB expert on conditions of protecting his anonymity.

According to Mr. N.K. Sukumaran Nair, Pampa Parirkashana Samti general secretary, the unscientific river treatment without conducting any environment impact study posed a potential public health hazard to the population in the downstream reaches of Pampa.

Even the Legislative Committee on Environment chaired by Rajaji Mathew Thomas too have recently expressed concern over the direct river treatment without conducting proper studies, Mr. Nair said.

Erumely experiment

Close on the heels of the Njunangar experiment, the TDB and PCB are planning the same direct treatment system, using the same ‘chemicals’, for treatment of the canal, Ambalam-thodu pass, by the Erumely Sastha Temple during the ongoing pilgrim season.

Ambalam-thodu empties out into river Manimala, leaving a number of pumping stations of Kerala Water Authority in its downstream reaches exposed to serious contamination, alleged Dr Thomas P. Thomas, academic and Mr. V.N. Gopinatha Pillai, Manimalayar Samrakshana Samiti general secretary.

Periyar revolt

Mr. Purushan said the phenomenon of Periyar river turning red in Edayar area in Ernakulam district was due to indiscriminate discharge of chemicals from the private industrial unit, earlier. However, the chemical company had to stop discharging its hazardous ‘waste’ into Periyar, following public protest, later.

Ironically, instead of discharging the waste into Periyar, the company is now trying to dump the same into rivers Pampa and Manimala in the name of river treatment, he alleged.

Assembly panel’s concern

The question on the toxicity of the present river treatment system was raised by the Legislative Committee on Environment too during its sitting at Pampa on November 18.

It is noteworthy to mention that Ferric Chloride from the same company is used for sewage treatment at TDB’s sewage treatment plant at Cheriyanavattom near Pampa.

Though the chemical is reportedly obtained from the Alwaye company free of cost, the contractor who runs the TDB plant has quoted a very high price for the chemical, alleged Mr. Gopinatha Pillai.

Even the PCB has failed to initiate any scientific study in this regard for reasons best known to the authorities concerned. Environmentalists also demanded an enquiry into the whole matter.