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With water quality where does the buck stop ?

April 17, 2012

http://www.youtube.com/watch?v=FVMdq5Qn2io

The blame game apparently has begun when accusations of bad quality water being supplied in several areas and causing sickness is being reported. What is the water quality to be ensured by any supplier of drinking water ? The water has to meet BIS-10500 norms. These constitute physical, chemical and biological standards with more than 30 parameters.  Unfortunately these are not legally binding norms but just standards. How does a water utility ensure that the water is potable ? Typically any water utility reduces physical turbidity through a filtration process and then doses the water with enough chlorine to kill bacteria. It then ensures that there is residual chlorine when the water reaches the consumer. Typical numbers are 2 mg/litre after 30 minutes of chlorination and 0.2 mg/litre after 24 hours of chlorination. Since the water supply is typically limited and usually more than 24 hours in cycle utilities absolve their responsibility the moment the water enters the premise. Water in sump tanks or overhead tanks is the responsibility of the consumer. Caveat Emptor is the motto.

 Most water utilities do not have any treatment against chemical contamination and rely on the fact that surface water sources do not have chemical contamination. In small and medium towns where the source is groundwater there is generally no treatment against such chemical contaminants as Nitrates, Fluorides and salts.

So what can be done? The only solution to no contamination of water in piped utilities is a 24/7 pressurized supply. This is the only way that it can be ensured that no sewage contamination enters pipes when there is no flow. All utilities must design systems for 24/7 supply. Secondly they must all be legally bound to supply BIS 10500 water. This should also be the norm for commercial water supply through private tankers for domestic purpose. Otherwise the water supplied should clearly specify that it is non-potable water. Water sourced by consumers directly through bore-wells, open wells and rainwater harvesting systems is the responsibility of the consumer and should be frequently checked for potability. Chlorine dosing and checking for residual chlorine is easy and every consumer wo is concerned should learn how this is done and check the water regularly.

Households who can afford it can and do take recourse to end of the pipe treatment systems such as filters, R.O. systems etc.  In the end while the blame games continue the consumer is wisest who has taken all precautions.

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One comment

  1. Very important issue.

    Something with great potential that I suspect no one has tried is a VEGETATED SAND FILTER at the home to treat drinking water and eliminate biological and chemical contamination (including the poisonous chlorine that has been added for our “protection”). What I am referring to more specifically is a subsurface, vertical-flow artifical wetland, which could be on the roof of a house, between storage tanks (and municipal water lines) and the faucets in the house.

    The substrate for these marsh plants would be sand or something similar … and many people would be concerned that pathogens could come on it, but it could first be thoroughly washed, even boiled, baked, and/or amply exposed to the sun in thin layers.

    I encourage you to google “root zone treatment” to delve into the ample scientific support for the purification potential of plant roots and the beneficial bacteria that live around them. This has also been shown to very effectively neutralize pH.

    Most commonly, fast-growing marsh grasses are used that are adapted to having their roots in standing water and therefore pump oxygen into their roots (since roots also need to breathe) and part of the oxygen comes out into the water around the roots, thus oxygenating it for free, with the plants working with solar energy.

    One general rule is to dimension the system such that water spends 3 days in the system. This could thus constitute a significan part of the storage system.

    Let me know if I can be of any help on this.



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