An increase in discharge of sewage from cities and towns has resulted in the deterioration of water quality in the Periyar, according to the Kerala State Pollution Control Board.
The worsening water quality has been detected along the three river stretches that include Idukki, Idukki-Ernakulam border (Neriamangalam) to Aluva and Mangalapuzha branch in Thrissur district and Aluva to Eloor ferry, covering industrial areas in Eloor, Edayar and Kalamassery.
All results, except a few, are showing that the worsening of water quality is due to sewage intrusion particularly from cities and towns. Certain drains carry severely polluted wastewater from identified discharge points from town areas and unidentified sources in industrial areas, especially the Eloor-Edayar stretch, said an updated status report on the condition of the Periyar filed before the National Green Tribunal.
The coliform content, indicating faecal contamination, was higher than the permissible limits owing to sewage intrusion into the river. But the levels of biological oxygen demand and the coliform count were within the limits along the main stream of the river, it said.
The findings revealed that small and medium industries located along the identified stretches may be resorting to unauthorised discharged into the river. These units were found not having effluent treatment plants as prescribed by the board. However, the report claimed that the industrial units that had installed effluent treatment plants were found complying with the standards stipulated by the board.
The issue of unauthorised discharge from industrial units has been placed before the government. A study is under way to install a common effluent treatment plant in Edayar industrial area. The Kerala Water Authority has been entrusted with the execution of the project.
The board said that it was awaiting guidelines from the Central Pollution Control Board for fixing the environment compensation on local bodies in Idukki district that failed to comply with the Solid Waste Management Rules, 2016. On the delay in the completion of the final draft of the Periyar Rejuvenation Action Plan, officials cited that some more time was needed as personnel entrusted with the task were middle-level officers lacking powers to give administrative sanction for projects.
