Secondary contamination worsening water crisis

Secondary contamination worsening water crisis
MD FIROJ ALAM

After detection of arsenic in the ground water in Bangladesh the coverage for safe water has dropped to 74 per cent from its previous coverage of 97 per cent. We do not know for sure how safe is this 74 per cent too! Finding the decreased mortality rate from water borne diseases we jump to a conclusion that water and sanitation situation of this country must have improved. We also prove it statistically by showing the data of increased numbers of physical installation of the water points and sanitary latrines. However, we do not have any authentic data on how many people actually suffer from water borne disease. The cause of less death is possibly because of improvement in the efficiency of management, not necessarily because of increased physical facilities. Increasing the coverage by constructing new water sources is never meaningful unless the quality of water is also ensured. To calculate the safe water coverage, we just show the ratio of the users and water points. We simply divide the population by the water points and report the coverage rate. According to the National Policy for Safe Water Supply and Sanitation 1998, 50 persons or 10 households is a standard coverage for a tube well. It means every water source we consider as safe. In reality is it true?In Bangladesh there are seven main types of improved sources for water: tube-well, ring-well, rain water harvesting system, gravity flow system [in Chittagong Hill Tracts], pond-sand filter, infiltration gallery and piped water supply systems for the urban areas. Water that comes from these sources, the general people considers it as safe. And, our estimation to show the coverage rate is also based on that assumption. A big flaw in it is; water of each and every water point has the risk of getting contaminated either at its very source or outside of the source in the process of collection, transport, storage and consumption. Even if the source is safe originally, there are possibilities of getting contaminated at any time if the principle of water safety plan is ignored. Contamination once the water has left the source is termed here secondary contamination. Secondary contamination occurs in three forms: chemical, physical and microbial. All these three are hazardous for health, but the third one is the riskiest because of its endemic trend and quick effects on human health. There is a permissible limit up to which the chemical and physical contamination is considered as safe for human health. For example as per the WHO guideline the safe limit for arsenic, fluoride and iron is 0.01, 1.5 and 0.3 respectively. But, for microbial contamination it is zero, means even the presence of a single pathogen in 100ml sample water is risky for human consumption! We are getting report of diarrhoea disease outbreak everyday from every corner of the country — village, towns and cities. Why? Despite having water from tube-well/ ring-well/rain water harvesting system/ gravity flow system/pond-sand filter, infiltration gallery/ piped water supply systems people are getting sick everyday because of this secondary contamination. Pathogens come in our safe water sources from human and animal faecal matters. In tube-wells it leeches down to the water layer mainly through latrines pits when the rules for safe distance between latrine and water points is not maintained. Tube-wells having no sanitary seal at the base of the pumps are also having the high risk of getting contaminated by pathogens. Same is the reason for ring well. Rain – water harvesting systems become risky due to lack of proper maintenance of the catchment roof, pond sand filter fails to produce pathogen free water if the pond and filter-bed are not properly maintained. Unhygienic situation in the spring catchments areas is the main reason for presence of pathogens in the water of the Gravity Flow Systems, and the pipe water get easily contaminated because of the leakages in the supply pipe networks. In addition, the unhygienic process of collection, storage, transport and use are the common cause of making safe water unsafe and applicable for all the sources mentioned.Safe water is a must for each and every human being. But, for a poor country like Bangladesh it is almost impossible to carryout regular water testing and treating the water at sources and ensures safe water for its population.There are 11 water quality testing laboratories in Bangladesh, both government and private owned. However, if we consider that, there are over ten million tube-wells alone located throughout the country, and then it is evident that testing all water facilities is unfeasible. It is simply impossible, in terms of time and resources to keep these water points under surveillance by government or any agencies to monitor water quality. Perhaps this is one of the reasons why Bangladesh to date still has not taken any initiative to establish any water quality surveillance system. We cannot ignore our responsibility to ensure that people have safe water and therefore need to develop a system, which does not require physical water quality testing. But, how? My suggestion is to impart knowledge to the people on how to keep “safe water” safe. By reducing secondary contamination routes and ensuring regular maintenance, water remains safe, free of pathogens and other contaminants, at the source and throughout the collection, transportation and use stages. This approach of keeping water safe is popularly known as water safety plan. Agencies that are working to provide safe water in Bangladesh can be benefited by adopting water safety plan in their implementation strategy. Route for Secondary contamination: The following scenes are very common in Bangladesh. Users believe that they are getting safe water, but in fact they are not. These kinds of practices place high risk on water supplies, Water has the potential of becoming contaminated with pathogens like bacteria, viruses and protozoa leading to water borne diseases.
[The writer is a Project Officer working for Water and Environmental Sanitation with UNICEF )]

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