Lakes of Bengaluru: Industrial effluents, raw sewage; stinky tale of Chandapura lake

However, untreated effluents from industries continuously enter stormwater drains and flow into the lakes of Anekal. There are around 195 red category industries in the Jigani-Bommasandra area which include drug manufacturing companies, electroplating, powder coating, pickling, heat treatment, galvanizing, casting, lead-acid battery manufacturing, used oil reprocessing, lead smelting and chemical industries.

Untreated effluents from industries continuously enter stormwater drains and flow into the lakes of Anekal. (Express Photo)

Chandapura lake, Anekal taluk (Bengaluru Urban)

Built during the Chola dynasty to meet the drinking and domestic requirements of the local village settlers, Chandapura lake is now being choked by rapid encroachments and industrial effluents, like its upstream feeder lake — Kachanayakanahalli lake, which featured in the first part of this series.

The industrial effluents from Kachanayakanahalli lake drain into Chandapura lake without being treated. It also receives raw sewage from Chandapura town through the stormwater drains.

The lake is spread over 7.2 acres in Heelalige village and 17.27 acres in Chandapura town. Out of the total 24.27 acres, nearly two acres of the lake in Chandapura town has been encroached by construction activities.

The buffer zone of the lake has been encroached by a government hospital and local shops. The fence around the lake has been broken and garbage is littered on its boundaries.

A resident Murali P recalls swimming in Chandapura lake during his school days. “The lake, three decades ago, was pristine. My friends and I used to swim and drink water without any fear of getting sick. Today, the stench emanating from the lake will not let you even stand near the lake,” he said.

There are around 195 red category industries in the Jigani-Bommasandra area. (Express Photo)

Former army veteran and social activist Captain Santhosh Kumar pointed out that there is no Sewage Treatment Plant (STP) for the lake.

“The condition of the lake has worsened due to encroachment, dumping of sewage and industrial effluents. The state pollution board in a showcause notice to the Hennagara panchayat has stated that the water quality index is unsatisfactory and the water from this lake connects to other downstream lakes,” he said.

In a letter written a few months ago to former chief minister B S Yediyurappa, the retired army official had said that if the government fails to take steps to restore the lake, it would turn into another Bellandur and Varthur lake – which are now best known for the toxic foam that occasionally brims over from the lake to the streets of east Bengaluru.

According to Dr TV Ramachandra from the Centre for Ecological Sciences at the Indian Institute of Science (IISc), the sustained inflow of sewage into the lakes contaminates the groundwater in the region.

There are numerous water tanker lorries supplying water directly from bore wells next to the lake to consumers in Bengaluru for domestic needs. There are water packaging industries in Bommasandra that supply water to the entire city. IISc in its report on water quality in the lakes has warned about the deteriorating water quality in Anekal.

The sewage-laden stormwater drains flowing between the lakes in Anekal also pass through many farms and vegetable plots where farmers grow produce and supply it to the local market.

“There is no buffer zone between Jigani – Bommasandra industrial area and the adjoining residential areas. The area is so packed that the compound wall of an electroplating company could be shared by residential houses. These industries are supposed to hand over the effluents to Common Effluent Treatment Plant (CETP) after pre-treatment,” Kumar lamented.

A Karnataka State Pollution Control Board (KSPCB) official acknowledged that industrial waste is the major reason behind the pollution of the lakes. “We have tested the water quality of Yarandahalli lake which is upstream of Chandapura lake. Yarandahalli is severely polluted and the same water passes through Kachenayakanahalli lake and then to Chandapura lake. The water from Chandapura lake then connects to Muthanallur and finally into Bidaraguppe lake,” he added.

A fresh survey of the lake and its current has been recommended by the KSPCB but it is yet to be done.