Thursday, May 1, 2014

India - Water Contamination - Schoolkids on Guwahati fringes drink acidic water

GUWAHATI: In an alarming find, the state public health and engineering department (PHED) and an NGO said schoolchildren in the tribal belt along the outskirts of the city have been consuming water, which is highly acidic in nature and unfit for drinking. The source of the water for these children is a well.

A little over five per cent of the samples were found to contain iron above the permissible limit of 0.3 mg/l. The survey pointed out that long time consumption of water with a high concentration of iron could lead to liver diseases. The test was conducted to ascertain the availability of pure drinking water to the students in the Rani-Deepor Beel-Gorchuk belt bordering Meghalaya by NGO Eco Concept in collaboration with PHED.

Apart from the high pH value, the survey also found the levels of hardness, turbidity, residual chlorine, iron and bacteria high in the water. Of the 1,052 water samples tested across 129 villages, 202 or 19.20% were found to have pH above 7 while 33 samples or 3.13% had pH above 8.5 limits, which is considered unsuitable for drinking. "The pH value is a measure of the intensity of alkali or acid in water. A high value of pH hastens scale formation in water-heating apparatus and reduces the germicidal potential of chlorine. A pH level below 6.5 leads to corrosion in pipes thereby releasing toxic metals," the report said. Only 549 samples or 52.18% of the total samples were found to have pH levels within permissible limits of 6.5 to 8.5 pH. Absolutely pure water has a pH value of 7.0.

Four different schools were selected for the tests on different days. The samples were taken to the school by students from their homes. Free chlorine concentration (0.1-0.4 ppm) is usually maintained in municipal water. Only 222 samples tested had free chlorine concentration. Use of proper chemicals in the water source can improve the quantity of free chlorine concentration in water, which is essential for good health.

On the other hand, 90 samples had a turbidity range of 10 Nephelometric Turbidity Unit and 56 samples had turbidity of 25 NTU. The report said samples above 10 NTU should be filtered before consumption. Samples in 96 containers tested positive for bacterial contamination. Gorchuk had the highest number of samples testing positive for bacterial contamination followed by Pamohi.

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Publication Date: 30 April 2014

1 comment:

  1. It is alarming to notice that school children are affected by improper water treatment management. Research resources in our country do not focus on finding solutions for such perennial public issues. In turn this has been taken as the subject for voluntary services. Efforts taken by NGOs are highly commendable considering the severity of such problems.

    Chlorine dosages and management will vary with the specific purpose. Our water management authorities should have close vigilance on the application and maintenance of water treatment systems. It is recommended that water leaving a treatment plant be tested at least daily for both chlorine residual and turbidity. This never happens in the history of our water management. We need to incorporate stringent design protocols and change the operation methodology based on history of events. Chlorine demand has to be worked out to find out the appropriate level of chlorine dosage. Excessive chlorination is often mistaken for highly effective disinfection action. Maintenance of right level of residual chlorine is mandatory for efficient control over water contamination. At the same time this shouldn’t affect other water quality parameters and materials that we use for water distribution. Corrosion of water distribution materials is one of the leading causes for contamination of water.