Alappuzha, Kottayam stretches of Vembanad Lake choked by sewage pollution, says PCB

A report submitted to the green tribunal says faecal coliform exceeds permissible limit, while the oxygen content is below the desired limit

Goshree bridge stretch of the ecologically-vulnerable Vembanad Lake is among the spots where faecal contamination has exceeded the permissible limits, indicating discharge of untreated sewage into the waterbody. | Photo Credit: Vibhu H

Dumping of untreated sewage has impacted the ecosystem along the Alappuzha and Kottayam stretches of Vembanad Lake, according to the Kerala State Pollution Control Board. (PCB)

Testing of water samples collected from the monitoring stations in Alappuzha showed high values of faecal coliform than the permissible limit (desirable) of 500 MPN/100ml, indicating discharge of untreated sewage into the lake, which is considered one of the critically vulnerable coastal areas in the country by the Ministry of Forest, Environment and Climate Change. The dissolved oxygen content is below the limit (5 mg/l) at certain points, said a report submitted by the board before the National Green Tribunal in the case related to the worsening pollution of Vembanad Lake.

Fertilizers, pesticides

With an increase in the number of houseboats catering to backwater tourism, a commensurate waste management facility is yet to be developed. Intensification of agriculture and use of high yielding varieties of rice has also led to increased use of fertilizers and pesticides, which may ultimately reach the lake, it said.

On the action taken against violators, the board stated that it had imposed a penalty of ₹90.45 lakh on houseboat owners for not complying with the norms. Action is being taken through Port Officer, Alappuzha, to find out unauthorised houseboats. The waste from peeling sheds is another major issue affecting the ecological condition of the lake along its Alappuzha stretch, it said.

Industrial units

The board stated that periodic inspections are being held to check dumping of untreated sewage and effluents from industrial units near the Meenachil and Muvattupuzha rivers as it will eventually reach Vembanad Lake. The analysis report of the samples taken for the period 2019-2021 from the monitoring stations in the Kottayam stretch showed faecal coliform levels above the permissible limits at the monitoring stations in Meenachil and Muvattupuzha rivers.

The report said that the local bodies along the Vembanad Lake have not yet taken the board’s authorisation for solid waste management. The panchayats and municipalities have also not yet set up scientific waste management facilities, it said.