Health Desk---- May 20, 2016: The entire volume of faecal sludge in the country is released directly into the environment with only a tiny fraction effectively treated in the capital, Prof Muhammad Ashraf Ali of Buet said at a discussion on Thursday.
As a result, it is mixed with the rain, which is otherwise pure natural water, and domestic wastewater and contaminates the rivers, canals, wetlands and the ecology, causing serious hazards to public health and environment, he said.
With the mostly-non-functional 882km sewer line covering only four million people and the lone wastewater treatment plant in Pagla in the capital, the rest are covered by septic tanks and pour flush latrines, he said.
But innumerable households, including the posh areas of the capital's Baridhara, Banani and Gulshan, have not installed properly designed septic tanks and connected their sewage pipes to the storm drainage network that eventually carries the untreated faecal sludge (human excreta) to rivers and water bodies, the professor said.
Rain Forum, WaterAid Bangladesh, International Training Network Centre of Buet and EQMS consulting firm jointly organised the discussion on "sustainable urban domestic wastewater management" at The Daily Star Centre.
Citing the World Bank findings, Prof Ali said that due to inadequate sewers, faecal sludge of only 2 percent of the Dhaka city population is treated properly. Also, faecal sludge management of the septic tanks is not done scientifically and safely, he added.
In absence of the proper pit-emptying service, the sludge is often drained into surrounding low-lying wetlands and water bodies, he said.
Col Kabirul Islam, head of the environment, water resources and coastal engineering department of the Military Institute of Science and Technology (MIST), said the domestic wastewater volume must be reduced through segregation, and the highly contaminated water should be treated, letting less polluted water into the environment.
Hasin Jahan, country director of Practical Action, who moderated the discussion, said domestic wastewater should be reused through segregation.
Prof Ishrat Islam, head of the urban and regional planning department at Buet, said the precious rainwater was being lost in absence of a rainwater harvesting system.
Rain Forum President Syed Azizul Haq said segregation and reuse of domestic wastewater must be incorporated in the plumbing of any building.
“We have been clamouring for a rainwater harvesting guideline since 2010 but the government is yet to finalise it,” he said.
Dhaka must be decentralised because any utility service system is sure to collapse in a neighbourhood with an excessive concentration of population, he said.