40 crore litres of untreated sewage daily: A peril for port city

Highlights:

• Lack of sewage management contaminates rivers and groundwater
• CWasa plans a centralised sewerage system by 2030
• Diseases from sewage exposure spread quickly, causing health risks
• Untreated sewage harms fish and aquatic ecosystems

Chattogram city is facing a dire environmental and public health crisis as huge amounts of untreated sewage are released into its drains and canals daily.

Experts say a lack of proper sewage management has led to the indiscriminate discharge of sewage into various watercourses, including drains and canals, worsening the contamination of rivers like the Karnaphuli and Halda and, ultimately, the Bay of Bengal.

Additionally, a significant quantity of sewage permeates the ground, contaminating groundwater sources as well. This rampant sewage contamination presents a serious hazard to aquatic life and public health.

According to Chattogram Wasa (CWasa), the city currently produces around 40 crore litres of untreated sewage per day, which could increase to about 51.5 crore litres by 2030.

It may be noted, though, that CWasa claimed to have formulated a master plan for the centralised sewerage system in 2017 to mitigate the crisis. The plan is expected to be completed by 2030.

Public health expert Dr Somen Palit said that diseases involving sewage can have instant effects on the human body and see a quick spread of bacteria. "Raw sewage poses three main health risks such as viruses, bacteria and parasites," he told TBS.

"Viruses can cause gastroenteritis, which can be mistaken as the stomach flu. This virus can cause diarrhea, abdominal pain, cramping, nausea, and excessive vomiting. Another virus, poliomyelitis can cause temporary or even permanent paralysis. Symptoms such as sore throat, fever, nausea, vomiting, constipation and abdominal pain are common," he added.

"Bacterial infections can occur due to exposure to sewage if left untreated and uncleaned. Infections can become blood borne which can then turn into life-threatening issues. One bacterial infection known as Campylobacteriosis can cause bloody stool, fever, cramping and vomiting," he further said.

"A more common bacterial infection related to sewage exposure is E coli, which can develop into the fatal hemolytic uremic syndrome, eventually turning into kidney failure or even death if it is not addressed properly. Symptoms with E coli include nausea, vomiting, abdominal pain and fever among other related issues," Dr Palit also said.

Dr Mohammad Muslem Uddin, professor in the Department of Oceanography at Chattogram University, said, "The presence of untreated sewage in aquatic environments has significant implications for fish health and productivity, potentially leading to a decline in fish populations and affecting fisheries and aquaculture operations."

He stated that proper sewage treatment and pollution control measures are essential to mitigate these impacts and safeguard fish populations and aquatic ecosystems.

According to experts, sewage refers to wastewater generated from households, businesses and industries, containing a mixture of water and various contaminants, including human waste, soaps, chemicals and other debris.

Additionally, sewage may contain solid waste such as plastics, paper and other materials which can entangle marine animals, block sunlight from reaching underwater plants and degrade habitats.

Urban planner and engineer Subhas Barua said a comprehensive sewage management system plays an indispensable role in envisioning a modern city. Reflecting on the establishment of Chattogram Wasa six decades ago with the dual mandate of supplying potable water and developing a sewage system, Barua lamented the prolonged inaction in implementing the latter.

He said although there have been some recent small-scale efforts, it is crucial to expand this initiative citywide. Barua emphasised the urgent need to connect the whole city to a sewage system to reduce pollution significantly and make Chattogram a modern, eco-friendly city.

According to the sewerage master plan of CWasa, to treat the city's sewage six treatment plants and two faecal sludge treatment plants will be set up.

Maksud Alam, chief engineer of Chattogram Wasa, told TBS, "We hope that the tender process will be done by June 2024 and the construction of the full sewerage management system will be completed by 2030."

"Around 75% of houses will be connected to the sewerage treatment plants. The remaining 25% will be outside the plants due to narrow roads. For this, two faecal sludge treatment plants will be set up," he said.