Trading in 'unsafe' drinking water, especially bottled water, continues unabated in the country mainly due to lax monitoring and supervision by the authorities concerned.
As a result, such unrestricted supply and use of bottled drinking water has put public health at great risk, according to health experts and consumer rights activists.
According to experts, about a thousand unregistered companies sell substandard drinking water in the capital alone without any treatment or part-filtration due to people's unawareness and negligence of the regulators concerned.
Health experts said drinking contaminated water for a longer period of time could cause chronic diarrhoea, cholera, dysentery, typhoid, headache, nausea, stomachache, fever, etc.
A study conducted by a team of researchers from the state-run Bangladesh Agricultural Research Council (BARC) in 2017 found coliform bacteria in 97 per cent of so-called filtered water supplied in jars to households, shops and offices in and around the capital.
When contacted, lead researcher of the study and a director of BARC Dr Md Monirul Islam said, "Though the study was conducted in 2017, I don't think water quality has improved since then, as the authorities concerned took no effective measures in this regard."
The study traced the harmful microbes in the contaminated drinking water to wastewater leaking from sewer lines.
The water samples tested in the study found a higher level of total dissolved solids (TDS) and acidity and alkalinity known as pH in bottled water.
The level of total coliform in these samples was 1,600mpn (most probable number) per 100 millilitres. The presence of both should be zero in bottled water, Dr. Islam said.
Coliform acts as catalysts for creation of pathogens that cause long-term diarrhoea, headache, nausea, stomachache, fever and cold, besides weakening immunity, experts say.
Dr. Islam warned that the 20-litre plastic jars used for supplying bottled water were not of food-grade which was posing a further threat to public health, causing serious illnesses like cancer.
He said people below five years old and above 60 could suffer from a haemolytic uremic syndrome, which affects blood and blood vessels, destroying blood platelet, leading to a low red blood cell count, or anaemia and kidney failure.
According to a report of World Health Organization (WHO), at least 45,000 children under five in the country die of waterborne diseases every year.
Bangladesh Standards and Testing Institution (BSTI) has set the standard of water commercially supplied for drinking, but the business of water is continuing without proper monitoring.
BSTI only conducts drives when rights bodies or consumers raise concerns over contaminated water as regular monitoring on different water bottling companies hasn't been seen that much.
When contacted, a director at BSTI Food & Bacteriological Division told the FE that a shortage of manpower was the biggest constraint towards monitoring illegal water bottling companies.
"BSTI has only three magistrates responsible for overseeing the quality of around 184 products under different categories at field level and they sometimes bust unauthorised water bottling plants," he said seeking anonymity.
BSTI also has other departments to oversee the quality of products by testing samples. But unauthorised companies were not submitting samples for testing, he said. "This is why it is quite difficult to stop such water plants."
He also blamed unethical practice of business and lack of people's awareness behind a boom in trading in substandard water.
Visiting an unregistered water bottling plant in the city's Tejgaon, this correspondent saw two workers filling plastic jars with water from an age-old water purifier machine.
The water bottling plant did not have any chemist nor any testing lab to measure water quality, one of the workers said, adding that the plant was pumping up groundwater through a deep tube-well.
Seeking anonymity, the plant owner told the FE that his company had not registered with BSTI. Even he did not get the water quality tested.
"I am supplying water to tea-stalls, small restaurants, shops and offices for last three and a half years but nobody ever complained about water quality," he said.
When asked about obligation of the government approval and testing facilities at the plant and BSTI, he said, "If water supplied by WASA is tested, it would be found undrinkable. But the authorities only punish us, not them (WASA)."
According to the BSTI data, there are about 300 registered companies in the country which are authorised to produce plastic bottles, jars and other containers for bottled water.
The testing authority has no data on unauthorised water bottling plants.
The BSTI in 2018 examined bottled drinking water of 15 companies after a High Court order and found five below standard.
In response to some queries from the FE about adverse effects of drinking unsafe water, a three-member panel of ICDDR,B has jointly responded.
The panel included Associate Scientist (research) of Laboratory Sciences and Services Division of ICDDR,B Dr Zahid Hayat Mahmud, Project Coordinator of Infectious Disease Division of ICDDR,B Dr Md Mahbubur Rahman, and Emeritus Scientist of Environmental Microbiology Laboratory of ICDDR,B Dr Md Sirajul Islam.
They said water could be contaminated physically, chemically, biologically and radiologically from different sources.
Each of these factors could lead to a variety of health consequences, they said. Chemical contamination could cause skin diseases, imbalance in blood pressure, while heavy metal contamination could cause cancer, cardiovascular complications, kidney damage, etc., they added
Some of most commonly reported problems linked to waterborne diseases included gastrointestinal problems, diarrhoea, cholera, dysentery, typhoid, nausea, intestinal or stomach cramping, and dehydration, among others, they added.
Boiling water is the easiest way to purify the liquid at a minimal cost which is sufficient to kill pathogenic bacteria, viruses and protozoa. Chlorination is the most cost-effective approach while treatment through potash alum can also be a good and affordable option.
But if water is physically, chemically or radiologically contaminated, then it requires other costly treatment options.
Referring to Sustainable Development Goal (SDG)-6 that targets to "ensure availability and sustainable management of water and sanitation for all", the ICDDR,B scientists said out of the six targets under this goal five were related to water and without addressing water issues, it would be impossible to achieve SDG-6.
Terming access to clean water one of the fundamental rights of citizens, Consumers Association of Bangladesh (CAB) President Ghulam Rahman said people had been buying contaminated water at higher prices in Dhaka from both government and private suppliers.
"Primarily, the liability goes to DWASA as the state body is failing to supply quality water to its customers," he said. Many people were relying on unregulated jar water companies as they were finding WASA water not safe to drinking without filtration or boiling, he added.
WASA must separate its water and sewer lines in a bid to prevent contamination of piped water at the supply stage, he said.