Bengaluru: Three days after a worker went missing inside the Balagere sewage treatment plant (STP), rescue teams said thick layers of silt, sludge, plastic waste, and accumulated sewage have emerged as the biggest obstacles to the search operation.Officials said the missing worker, Akhilesh, a 30-year-old from Bihar, is believed to be inside one of the STP’s circular compartments with an approximate radius of 10-11 metres and a depth of 13 metres. However, nearly 3-4ft of the structure is covered with accumulated silt, making the search extremely difficult. “The tank has three compartments. One contains a large quantity of plastic and floating waste, another has sewage water and sludge, while a significant portion is covered by silt deposits. We’ve already searched the compartments by cutting through the concrete slabs and are rechecking them,” a rescue officer said.Officials said heavy rain on Saturday led to the fresh accumulation of water inside the tank, forcing teams to undertake de-watering operations once again before resuming the search.Another major challenge has been breaking through the thick concrete slabs covering the compartments. Rescue personnel said the slabs are nearly 1.5ft thick, requiring extensive cutting before teams can gain access to the chambers below. Multiple openings have been created across the structure to facilitate the search.Rescue personnel are also battling hazardous conditions inside the STP. Before entering any chamber, teams are required to test for poisonous gases such as hydrogen sulphide and carbon monoxide. Officials said oxygen levels inside the structure are being continuously monitored before personnel are allowed to descend into the compartments. According to officials, the oxygen percentage in the compartments is below 19%.The prolonged operation has also raised questions about maintenance of the STP. According to fire and emergency services personnel, silt in STPs is generally expected to be removed once every two years. “We were told that a private company visited the plant and submitted a quotation for silt removal just a week ago,” a rescue personnel said.However, BWSSB officials were unavailable for comment on the matter.Akhilesh and Akilan, a mechanical supervisor from Tamil Nadu, fell into the plant Thursday evening while inspecting it. Akilan’s body was recovered early Saturday, while the search for Akhilesh continues.
