Water, a renewable resource, dissolves nutrients and transfers them to cells, regulates global temperature, supports structure and removes waste products. Natural stores of water in hydrological cycle are oceans 97.41%, ice caps and glaciers 1.9%, ground water 0.5%, soil moisture 0.01, lakes and river 0.009% and atmosphere 0.0001%. In this planet, 97.5% water is saline where only 0.03% is pure to drink. Climate change, sea-level rising and global warming is changing the total global picture and it is true that third world countries are unable to face these emergency rather than first world countries.

Setting the Scene

"Water quality" is a technical term that is based upon the characteristics of water in relation to guideline values of what is suitable for human consumption and for all usual domestic purposes, including personal hygiene. Components of water quality include microbial, biological, chemical, and physical aspects.

Microbial Aspects: Drinking water should not include microorganisms that are known to be pathogenic. It should also not contain bacteria that would indicate excremental pollution, the primary indicator of which are coliform bacteria that are present in the feces of warm-blooded organisms. Chlorine is the usual disinfectant, as it is readily available and inexpensive. Unfortunately, it is not fully effective, as currently used, against all organisms.

Biological Aspects: Parasitic protozoa and helminths are also indicators of water quality. Species of protozoa can be introduced into water supply through human or animal fecal contamination. Most common among the pathogenic protozoans are Entamoeba and Giardia. Coliforms are not appropriate direct indicators because of the greater resistance of these protozoans to inactivation by disinfection. Drinking water sources that are not likely to be contaminated by fecal matter should be used where possible due to the lack of good indicators for the presence or absence of pathogenic protozoa. A single mature larva or fertilized egg of parasitic roundworms and flatworms can cause infection when transmitted to humans through drinking water. The measures currently available for the detection of helminths in drinking water are not suitable for routine use.

Chemical Aspects: Chemical contamination of water sources may be due to certain industries and agricultural practices, or from natural sources. When toxic chemicals are present in drinking water, there is the potential that they may cause either acute or chronic health effects. Chronic health effects are more common than acute effects because the levels of chemicals in drinking water are seldom high enough to cause acute health effects. Since there is limited evidence relating chronic human health conditions to specific drinking-water contaminants, laboratory animal studies and human data from clinical reports are used to predict adverse effects.

Physical Aspects: The turbidity, color, taste, and odor of water can be monitored. Turbidity should always be low, especially where disinfection is practiced. High turbidity can inhibit the effects of disinfection against microorganisms and enable bacterial growth. Drinking water should be colorless, since drinking-water coloration may be due to the presence of colored organic matter. Organic substances also cause water odor, though odors may result from many factors, including biological activity and industrial pollution. Taste problems relating to water could be indicators of changes in water sources or treatment process. Inorganic compounds such as magnesium, calcium, sodium, copper, iron, and zinc are generally detected by the taste of water, and contamination with the oxygenated fuel additive MTBE has affected the taste of some water.

State of Water Bodies in Bangladesh

Our water body is being polluted by agricultural pollutants, industrial effluents, different rivers are losing their life, climate change affects the water table, policy is failing to manage this public goods; on the other side, corporate elites are trying to use this gap as their interlude of profit. Nowadays, local, national and international companies are doing their water business in our country. After all, quality and access of pure water is lessening day by day due to the rapidly growing population; industrial contamination; slumization; improper use of agricultural synthetic chemicals and pesticides; indiscriminate disposal of municipal wastes, poorly designed flood control and water supply systems, drainage and irrigation works, lack of adequate regulatory measures and institutional setup for proper monitoring and control.

Asian water development outlook, 2016 mentions; 80% wastes are dumping into river in Bangladesh. Water security index indicates Bangladesh is 44th out of 48 countries. Around 250 industries are discharging chemical pollutants into Buriganga and Sitalakkha River. Every day four thousand tons of solid waste and 22,000 tons of tannery waste mixes with water in Buriganga River. Different industries and their contribution to pollution in Dhaka are: Pulp and paper - 47.4%; pharmaceuticals - 15.9%; Metals -14%; Food industry - 12.1%; Fertilizers/pesticides - 6.6%.

In urban areas, the groundwater laced with harmful chemicals may then be supplied to urban dwellers who are unknowingly exposed to health hazards. Sewages are discharging directly into the rivers and low-lying part around the urban areas. In Dhaka, 20 canals have lost her life out of 43. Heavy metals − copper, iron, lead, nickel is distressing the BOD, COD, DO, TDS, PH of water. Different projects were taken to recovery the present situation of canal and pond in Dhaka city. Such as, dredging Buriganga River by WASA, digging the Dhaleshwari, Pungli-Bangshi and brings water through Jamuna to meet the demand of Buriganga River. But the projects could not see the light of a day. Eutrophication and bacterial content in lakes and rivers are also high. This is a threat to the health of urban dwellers as river water is also supplied by the "Water Supply and Sewerage Authority" for drinking and other purposes. This is happening in all cities of Bangladesh. Reduction of 'river water flow due to siltation' is increasing salinity at coastal areas. Unplanned shrimp farming creates more salinity affecting the agricultural land and water quality particularly in Khulna, Satkhira and Bagerhat districts.

Arsenic Poisoning in Ground Water of Bangladesh

Arsenic concentration in natural water varies widely depending on the sources of water, sources of As and local conditions. Arsenic concentration in rivers water is low, between 0.1 to 2.0 mg/l, but polluted river water can have higher concentration of As. High As concentrations are found in some alkaline closed-basin lakes due to high evaporation and geothermal inputs.

In Bangladesh and West Bengal, alluvial Ganges aquifers used for public water supply are polluted with naturally occurring arsenic, which adversely affects the health of millions of people. The arsenic derives from the reductive dissolution of arsenic-rich iron oxyhydroxides, which in turn are derived from weathering of base-metal sulphides.

As many as a million water wells drilled into Ganges alluvial deposits in Bangladesh and West Bengal may be contaminated with arsenic. Measured arsenic concentration reached up to 1,000 g/l, which is above limit set for drinking water in Bangladesh (50 g/l) or that recommended by the World Health Organization (10 g/l). Consumption of this contaminated water has led to widespread death and disease. Arsenic has been reported to derive from the oxidation of arsenic rich pyrite in the aquifer sediments as atmospheric oxygen invades the aquifer in response to a lowering of the water level by abstraction.

The arsenic rich groundwater is mostly restricted to the alluvial aquifers of the Ganges delta. The source of arsenic rich iron oxyhydroxides must therefore lie in the Ganges source region upstream of Bangladesh. Weathered base-metal deposits are known to occur. The Ganges basin, so weathering of these arsenic rich base metal sulphides must have supplied arsenic rich iron oxyhydroxide to downstream Ganges sediments during Late Pleistocene - Recent times. The arsenic-rich iron oxyhydroxides are now being reduced, causing the present problem. Reduction is driven by concentration of sedimentary organic matter of up to 6%.

Action Plans of Government in Bangladesh

The Government of Bangladesh, in its 'Action Plan for Poverty Reduction', has clearly stated that to ensure 100% access to pure drinking water across the country. But the practical scenario is different where the people are affected by large amount of water impurities.20 million people are suffering from Arsenicosis, keratosis, melanosis, and karato-melanosis (diseases of poor). That means 12.5 % of our total population. 43 thousand people are dying every year owing to consumption of impure water.

According to the water policy 1998, environmentally sound water management is suggested in utilization and development of water resources, construction of irrigation networks and embankments, dredging of water courses and in taking measures against river pollution. Environmental impact assessment is required before undertaking projects related to water resources development and flood control measures. The current scenario is not clear as people are deprived to access germ-free water. The 'right to flow' of rivers is affected. It meets the effective demand for criminalization of not only politics but also economics. Consequently, it is a truth-seeking deficiency of a state.

Constraints to Afford Pure Drinking Water in Bangladesh

The human rights challenge of provisioning of germ-free water in Bangladesh is a challenge from the viewpoints of both constitutional and justifiable rights. From that standpoint, heavy metal-free water for the citizens should view as public goods. But there are some financial, technical and social constraints. Govt. should overcome the financial constraints through effective water budget, providing incentives for raising water use efficiency, rights to water through abstraction charges, power sharing strategy among administrative actors, policy formation and implementation strategy etc. It is important to resolve all technical constraints to accelerate the filtering process of heavy metals (nickel, lead, chromium, arsenic, cadmium) from impure water, emphasize surface water for irrigation and industry, engineering process of water supply and distribution, raising supply efficiency by having buried and plastic pipes in case of ground water, effluent treatment plant (liquid wastes, hard materials), sanitation, immunization and maternal health related issues. Similarly we have to address the social constraints (cropping pattern and diversification, patriarchy, climate, geographic variability, vulnerability and occupational structure) through communities 'knowledge attitude practice' towards life and livelihood.

Concluding Remarks

In our country bottled water is also not safe to drink, studies mention. We have to initiate sustainable policy regarding water resources to provide pure water for all in Bangladesh.

The Writer is an Environment Analyst and Associate Member, Bangladesh Economic Association