Water Security

As of now, around 60% of Bangladesh does not have access to clean water.[1] Water in Bangladesh is becoming dangerous to drink due to two different factors: high arsenic concentrations and high salinity. Salt has recently become a more evident problem as storm surges bring saltwater inland and contaminate groundwater.[2] Due to climate change, the probability of storm surges is increasing, thus this problem will only be exacerbated in the future.[3]

Arsenic is naturally occurring in the groundwater of Bangladesh, and poses a myriad health risks when ingested such as increased propensity to bladder, skin, lung, kidney and liver cancer and neurological diseases.[4] Currently, a large part of Bangladeshi people rely on tube wells for their drinking water as there are around 7 to 11 million tube wells in the country.[5] Of these, around half have been found to contain dangerous amounts of arsenic at over 50 micrograms per Liter. Although some tube wells that go deeper into the ground have less arsenic than shallow wells, not all have been studied.[6]

Source: Scientific & Academic Publishing[9]

Methods for desalination, such as distillation, where one purifies water through heating and cooling, and reverse osmosis,a process in which water is passed through a membrane that filters the salt out, are effective in removing all impurities from the water but are also costly to implement. Yet, large-scale desalination projects have been implemented in countries such as Israel. These projects must be backed by the government due to their expensive nature, but their benefit can be worth it. Looking at Israel’s recent construction of a large scale desalination plant, one can see the scope of costs and effectiveness. The plant, called Sorek, cost around 500 million dollars to build and produces about 627,000 cubic meters of pure water per day at a cost of around 58 cents per 1,000 cubic meters.[7] Thus, in one year this plant can produce around 229 million cubic meters of water. In 1990, around 1.8 billion cubic meters of water were consumed by Bangladeshi people for domestic use.[8] When we look at the percentage of people each of these plants can serve, we see that around 13% of Bangladeshi people could be provided clean water for domestic use at annual running costs of $132,820.

Source: Sorek Stands Tall[10]

Furthermore, since sea water levels continue to rise, location is important in deciding where to construct these plants. On the east side of Bangladesh there are areas where altitude reaches to 30 meters above sea level,[11] thus constructing at or above these heights can eliminate the threat of flooding and damaged machinery. However, it would also be imperative to choose a height where the seawater can be pumped in without expending excess energy.

Source: TES[12]

One other option for clean water is treating the river water that flows in from India, yet this is not as complete of an option as desalination plants for two reasons. Firstly, rivers in Bangladesh have been decreasing in flow rate throughout the dry seasons for the past 30 years[11] , thus it would put strain on available water in rivers and possibly affect the fish in the waters on which people depend on for food. Second, the increasing salinity intrusion as far as 100 km inland[12] means that these plants will soon have to filter out salt as well, meaning the costs would be the same for less future benefit.

By Alejandro Miranda

 

References

  1. (2017) Water in Crisis Bangladesh. Thewaterproject. Retrieved from https://thewaterproject.org/water-crisis/water-in-crisis-bangladesh
  2. Mimura, N, Hay, J. (2005) “Sea Level Rise: Implications for Water Resources Management” Mitigation and Adaptation Strategies for Global Change.
  3. (October 2017) “Global Warming and Hurricanes” Geophysical Fluid Dynamics Laboratory, NOAA.
  4. Naujokas, M., Anderson, B. Ahsan, H. et al. (2013) “The Broad Scope of Health Effects from Chronic Arsenic Exposure: Update on a Worldwide Public Health Problem” Environmental Health Perspectives.vol. 121.
  5. Uddin, R., Huda, N. (May 2011) “Arsenic Poisoning in Bangladesh” Oman Medical Journal.
  6. Flanagan, S. Johnston, R., Zheng, Y. (2012) Arsenic in tube well water in Bangladesh: health and economic impacts and implications for arsenic mitigation. World Health Organization.
  7. Talbot, D. (2017) “Megascale Desalination” MIT Technology Review. Retrieved from https://www.technologyreview.com/s/534996/megascale-desalination/
  8. (1990) Water Resources and Freshwater Ecosystems. Wayback Machine Internet Archive. Retrieved from https://web.archive.org/web/20050103091457/http://earthtrends.wri.org:80/text/water-resources/country-profile-14.html
  9. Panda, B. (2015) Danger of Arsenic Poisoning. Scientific & Academic Publishing.  Retrieved from http://article.sapub.org/10.5923.c.ije.201501.11.html
  10. (2017) Sorek Stands Tall. Retrieved from http://article.sapub.org/10.5923.c.ije.201501.11.html
  11. Islam, R. (February 2016) The high cost of low water flow in Bangladesh. thethirdpole.net. Retrieved from https://www.thethirdpole.net/2016/02/08/the-high-cost-of-low-water-flow-in-bangladesh/
  12. (2017) The consequences of climate change. TES. Retrieved from https://ih-igcse-geography.wikispaces.com/7.10.+The+consequences+of+climate+change