What are we Drinking- The quality of water?

An average human requires drinking 2-4 liters of water daily to maintain a healthy lifestyle, but is the water we are drinking healthy? Before answering this question, let us look at few unique properties of water. Water is known as a universal solvent as it is capable of dissolving the highest number of substances, without changing its composition. It is this unique property of water that makes it a life-giver, all living organisms rely on water to carry all the nutrients throughout their body. But the fact that water is a universal solvent also means that it can dissolve a large number of pollutants in it as well. This means that the water can be a life-giver or a slow poison based on its quality.

In the past few decades, with the increase in industrialization and rapid urbanization, we have seen a drastic decrease in the quality of water across the globe. Almost all the water resources have been contaminated by one or more pollutants.

Even the underground water, which is generally considered to be a safe source of water, has begun showing the sign of hazardous pollutants like arsenic, fluorine, etc. as per a report by WHO, Globally, at least 2 billion people use a drinking water source contaminated with feces, while every year almost 485,000 deaths, are directly attributed to diarrhea caused by drinking contaminated water. While many people suffer from chronic diseases related to water pollution. The problem of contaminated water is even worse in developing countries, especially African and south Asian countries, where almost all sources of water have some form of contaminants present.   

Water Quality standards

Now, know that we know the risk associated with water, the next question that comes into a person’s mind is, how safe is the water that I drink? How can one check the quality of water? And what are the perimeters/standards of drinking water? The answers to these questions are relatively simpler, as all the nations as well WHO have set their own standard for drinking water. And the government bodies have to ensure that the water supplied to the house met these standards. Although in some countries like India, most of the people still rely on groundwater sources and need to be careful about the water parameters. Below is the list of water standards for general parameters.

ParameterWHO standardIndian Standard
color15TCU5 TCU (max limit)
Taste and OdourAcceptable to consumerPleasant
Turbidity5 NTU1 NTU
TDS1000 mg/l500 mg/l
Total HardnessNR200 mg/l
Sulphates250mg/l200 mg/l
MagnesiumNR30 mg/l
Nitrate50 mg/l45 mg/l
Chloride250mg/l250 mg/l
Fluoride1.5mg/l1-1.5 mg/l
CalciumNR75 mg/l
AlkalinityNR200 mg/l
E.coliundetected in 100 ml sampleundetected in 100 ml sample

Table 1 water quality standards (WHO and India Standard) (*NR: Non-regulated)

Consequences of poor quality water

The consequences of using bad quality water, are not just limited to health but are just as wide as the scope of uses of water.  Poor quality water can cause both direct as well as indirect losses. In terms of direct loss, Bad water quality can cause various chronic and acute diseases, damage crops, death of fishes as well as animals, while indirect damages include,  poisoning of the food chain, structural damage, and boiler damage, etc.

Below is a list of various undesirable effects that can be caused due to water pollutants

Table 2 various water pollutants, their sources, and their effect

Status of Water quality in India

Water pollution is a major concern in India. Almost all Indian rivers are polluted, while as per a report almost 80% of freshwater sources are severely polluted and needs thorough treatment before they can be used for drinking purpose. Underground water, is the other major source of potable water in India, contributing to almost 90% of the total water supply in rural areas. But recently many aquifers are becoming unfit for drinking purposes due to overexploitation as well as illegal dumping of wastewater into the ground.

As per Composite Water Management Index (CWMI) 2018 of Niti Ayog, 70% of the Indian water supply is contaminated. While Globally India is ranked 120th out of 122 countries in WaterAid’s water quality index. According to World Bank, approximately 21% of diseases in India are caused due to poor quality of water, also each year approximately 1.5 million children below 5years of age, losses their life due to water-borne diseases, Even in many big cities like Delhi, Kolkata, Chennai, and Mumbai, etc. where there is proper water treatment facility and water is supplied by municipalities, people are still advised to install home water filters, or boil the water before drinking. This is because, even though the high-quality water is supplied into the pipe by treatment plants, quality starts declining rapidly as the water travels through the trunk mains to service reservoirs, due to old pipes and improper management of the supply chain.   

Sources of water pollution:

Water quality is affected by various sources, which are classified as point, nonpoint, and transboundary sources.

It is estimated that in India 26900 million liters of wastewater is generated daily, out of which only 26% of wastewater is treated before disposal. As a result, most of the wastewater is directly disposed of (mostly into rivers) polluting the freshwater sources. As per an estimate by the Centre for Science and Environment, 1ltr of wastewater can pollute 5-8ltr of freshwater. Amongst the various types of sources, some industries/ activities contribute more heavily towards water pollution, with domestic sewage contributing 75-80% of total wastewater by volume. Although in terms of pollutant concentration, discharge from industries and agricultural sectors are much more lethal.

The quality of water that we are drinking may not be as transparent as it looks, with the consequences of drinking contaminated water being as high as loss of life. Giving the poor water quality we must be cautious about what we drink. And yet despite the severity of the problem, 67% of Indian households still do not employ any kind of treatment for their drinking due to lack of awareness, which results in a high child mortality rate in India. It is high time that government, local bodies, as well as every single educated person, need to feel obliged to spread awareness amongst the people around him/her.