NGT committee grades Chandapura lake water Class-E, says can be used for irrigation, industrial cooling

“However, the dissolved oxygen (DO), chemical oxygen demand (COD) and biochemical oxygen demand (BOD) levels of the Mastenahalli, Kachanayakanahalli and Chandapura lakes were very low, indicating anaerobic/anoxic conditions. The bore well samples collected show higher levels of nitrate (NO3). In some cases, higher levels of the ammonia and sulfate and hardness were also found. This indicates that the bore well samples should be treated before using it for drinking purposes. Few of the drain samples feeding the Chandapura lake show high levels of COD. In drain water samples, zinc and iron were found, again indicating the presence of industrial effluents,” the report stated.

It is important to note that the Mastenahalli, Kachanayakanahalli lakes meet the Chandapura lake and are equally polluted.

The committee in its report has also stated that sewage generated in the municipal limits of Chandapura is also being discharged into the lake directly or indirectly through the drain and except for private residential apartments, there is no common Sewage Treatment Plant (STP) to treat sewage.

The NGT’s suo moto cognizance came after a report by The Indian Express — Lakes of Bengaluru: Industrial effluents, raw sewage; stinky tale of Chandapura lake — published on November 21.

It is important to note that the Mastenahalli, Kachanayakanahalli lakes meet the Chandapura lake and are equally polluted.

It constituted a seven-member joint committee of the Central Pollution Control Board (CPCB), Karnataka State Pollution Control Board (KSPCB), Indian Institute of Science (IISc), State Environment Impact Assessment Authority (SEIAA), National Wetland Authority, State Wetland Authority and the District Magistrate, Bengaluru to ascertain the facts with regards to the violation of the buffer zone and solid waste management guidelines at Chandapura lake.

“Out of four samples, the drain sample collected at Hargadde was having colour contamination as is evident in the photograph and the sample also has organic solvent odour, which was indicating the characteristics of effluent from the pharma industry. From the preliminary investigation, it is apprehended that there may be a chance of illegal discharges from industries or pilferages from the tankers carrying trade effluents from the pharma industry using 2,4 dichlorophenol as a raw material,” the report stated.

The team suggested the District Magistrate (Bengaluru Urban) and local bodies to carryout mapping in the Chandapura lake catchment area to identify all the drains carrying mixed effluents and entering the lake and to take immediate steps to control the discharge of untreated effluents into the drains. “To follow-up with the Govt of Karnataka to expedite the approval of DPR and allocation of land for setting up of STPs in the catchment area,” the report read.

Social activist and former Army veteran Captain Santhosh Kumar, who was the first to have raised an alarm over the worsening condition of the Chandapura lake, said, “There are several other lakes in Anekal which require equal attention. The NGT has acknowledged the entry of sewage into the lake and this puts the local bodies in the dock. Fortunately, the deputy commissioner (Bengaluru Urban), J Manjunath, has swung into action and got the encroachment evicted.”