Bangladesh's journey with water has been fraught with many challenges. However, despite all the setbacks, huge achievements have been made – including the fact that the country successfully reached the Millennium Development Goal for water – a point we need to keep in mind during the long journey ahead to the Sustainable Development Goals.

In the past, a large part of Bangladesh's population obtained most of their drinking water from surface water sources, such as ponds and rivers. As a result, there were widespread deaths from diarrheal diseases such as cholera due to the presence of microbiological pathogens in surface water sources. 

In the 1970s, there was a campaign led by UNICEF to promote tubewells throughout the country. They provided an easy solution to obtain drinking water that was not contaminated with pathogens. This campaign was highly successful and by the early 1990s, millions of tubewells were installed across rural areas of Bangladesh, providing drinking water for over 90 percent of the population. These were mainly shallow tubewells, i.e. they pulled up water from shallow aquifers. During this time, there was a significant decline in deaths from diarrheal diseases in the country, both due to availability of safe water as well as the use of oral rehydration solution.

However, this apparent success also had a major downside. A growing number of people were starting to be diagnosed with symptoms of arsenic poisoning. Large-scale water quality screenings took place, and widespread arsenic contamination of groundwater was discovered. It was found that arsenic levels in shallow aquifers were much higher than permissible limits, with highest concentrations in the central and southern rural areas of the country. 

Since then, much effort has been taken at the policy level to combat this issue. The government established policies and strategies such as the National Policy for Safe Water Supply (1998), National Water Policy (1999), National Policy for Arsenic Mitigation (2004) and the Water Safety Framework (2011). Efforts have also been taken at the implementation level, with the provision of deep tubewells and other arsenic-free safe water options by the government and various NGOs. However, it is important to note that many people still continue to be exposed to unsafe levels of arsenic and the issue still needs stronger focus and attention. 

Bangladesh has since made significant progress in improving the water and sanitation situation. Access to improved drinking water sources is at 87 percent nationally, according to the WHO/UNICEF Joint Monitoring Programme. However, arsenic remains a critical issue and in the years that followed, many more new challenges started to arise. 

As the sanitation coverage of the country increases (61 percent nationally), an increasing amount of faecal sludge is filling up latrine pits and septic tanks. In Bangladesh, a very small percentage of faecal sludge is managed and treated properly. As an example, only 22 percent of Dhaka city's population is covered by the sewerage network. In areas that are not covered by a sewerage network, such as most rural and peri-urban areas, much of the faecal sludge gets discharged into storm water drains, canals and other open water bodies, resulting in biological contamination of surface water. 

The rising sea level due to climate change has led to the intrusion of saline water into the surface water and groundwater along the coastal belt. High salinity levels have been shown to have negative impacts on health, such as hypertension, especially in pregnant woman among who risk of gestational hypertension and pre-eclampsia becomes higher.  

Of course, water is not just used for drinking, but also for other domestic purposes and by other sectors, such as agriculture and industry. In fact, in Bangladesh, usage patterns show that 96 percent of water is used for agriculture, three percent for domestic use and one percent for industrial use. Of the total water consumed for these various purposes, 69 percent comes from groundwater sources. Thus, depletion of groundwater sources is occurring at an alarming rate. In fact, in 2011, The Daily Star reported that the groundwater level in the capital dropped by six metres within a seven-year period. The rate of depletion is much faster than the rate of groundwater recharge, and this can lead to further salinity intrusion.

In Bangladesh, various authorities are responsible for the different aspects of the water sector. For example, the Bangladesh Water Development Board (BWDB) is responsible for water resource management, and the Water Supply & Sewerage Authorities (WASAs) and Department of Public Health Engineering (DPHE) are responsible for water supply and sanitation. Moreover, coordination between the drinking water, agriculture and industrial sectors need to be strengthened further. A greater level of integration is needed to overcome issues of overuse, increase efficiency of water use in agriculture and industry, and for the treatment and reuse of wastewater. 

What remains to be done? 

We need to continue strengthening collaboration between different government bodies and between government organisations and other implementers. With increasing population growth and therefore increasing demand, there is a need to increase sustainable domestic and international financing in the water sector. Many people are still living under the poverty and extreme poverty lines, and many reside in hard-to-reach areas, thus remaining outside of service coverage. We have to ensure that their needs and demands are also met, through appropriate approaches and financial mechanisms.  

Wastewater treatment services have to be improved, and the root causes behind pollution of surface water sources need to be reduced. Improvement of surface water quality will help slow down the depletion of groundwater sources. Multi-sectoral engagement is crucial for the improvement of water use efficiency, especially by the agricultural sector. 

We need to continue investing time, efforts and resources to achieve universal and equitable access. It is important to understand that support is needed across the spectrum, including raising awareness (and demand) in the community; strengthening the supply chain; ensuring inclusion of the poor and those in vulnerable situations; addressing the concerns of women and girls and empowering them to meaningfully take part in decision-making; mobilising service providers and creating linkages between them and the community; and investing in research to develop sustainable context-specific technologies.

In the government's Perspective Plan of Bangladesh 2010-2021: Making Vision 2021 a Reality, water is addressed as a truly cross-cutting issue, the importance of which is mentioned in the plans for almost every sector, including agriculture and rural development, industrial development, regional cooperation, transport and communication, climate change mitigation, and sustainable development. This is a very important step towards greater integration and coordination, and its practical implementation will help us achieve our own national goals, as well as Sustainable Development Goal 6 to ensure availability and sustainable management of water and sanitation for all. 

The writer is the director of communicable diseases and water, sanitation and hygiene (WASH), BRAC. He is an adjunct professor of James P. Grant School of Public Health at BRAC University.