Drinking Water Standards

Introduction

Drinking-Water Standards (DWS) are quality conditions set for drinking water that must be encountered by International Drinking Water Standards (IDWS). Every person should have the right to clean as well as safe drinking water. However, human activities, as well as certain environmental elements, have polluted this existing natural resource. A secure water system is the foundation of a healthy economy, but it is severely undervalued in many parts of the globe. Numerous health organisations have mentioned certain specifications for drinking water considering the adverse effects of this scenario on human health.

What is Potable Water?

It is defined as water that is safe to drink and can be used in the kitchen. It is appropriately filtered as well as treated, then it is finally free of all contaminants as well as harmful bacteria. Water can be purified using a variety of methods, including UV-filtered water purifiers, reverse osmosis, and so on. Raw water is water that is not safe to drink or fit for drinking as well as comes from sources such as rivers, lakes, & groundwater. Factory water cannot be regarded as potable, which is why most of the households prefer to boil or filter water before actually drinking it. Non-potable water can taste just like drinkable water, but it can lead to complications in health.

Different Methods to Make Potable Water

• Filtration − It is extremely useful in the purification of water. In general, there are 2 types of filters commercially available. A few rely on carbon filters to eliminate bacteria, while others use chemicals such as iodine to desalinate water. Filters are very bulky & therefore must be replaced regularly. They are also very costly.

• Distillation is the process of boiling water & accumulating the vapour while abandoning the bacteria & contaminants behind. Distilled water is 1 of the purest forms of water; the household distillation system removes 98 percent of contaminants as well as produces water that is purer than that from filters.

• Boiling is the simplest way to purify water. It neutralises most viruses as well as bacteria in the supply, but it is incapable of removing all heavy pollutants.

• Reverse Osmosis − It removes most pollutants from water by forcing it via a semipermeable membrane under pressure. This technique is used by water purifier industries & for seawater cleansing.

Benefits

• Saliva aids digestion & keeps the mouth, nose, as well as eyes moist. It can also help to prevent tooth decay if ingested instead of sweetened beverages.

• It distributes oxygen throughout the body.

• Blood is composed of more than 90 percent water & transports oxygen throughout the body.

• It improves the health and appearance of the skin.

• Dehydration makes the skin more susceptible to skin problems & premature wrinkling.

• It also plays a role in the synthesis of hormones but also neurotransmitters. Prolonged dehydration can impair thinking as well as reasoning abilities.

• It maintains the temperature of the body.

• When the body has insufficient water, heat storage rises as well as the person becomes less able to endure heat strain.

• If temperature stress arises during the workout, having lots of water in the body may decrease physical strain.

• It is essential to the digestive system. Water is required for the bowel to function correctly.

What are the properties of Drinking Water?

• Water is a chemical substance with the chemical formula H₂ O, consisting of 1 molecule of water made of 2 H-atoms covalently bonded to a single O-atom.

• Amphoteric Nature: An amphoteric chemical is 1 that can act as both an acid as well a base. Water is neither acidic nor basic, even though it serves both features. It acts as a base for acids that are more powerful than water. It also acts as an acid against bases that are more powerful than it.

Property	Value
Appearance	Colourless, odourless & tasteless liquid
Structure	Hexagonal
Density	$\mathrm{1\frac{gm}{cc}}$
Viscosity	0.89 cP
B.P.	$\mathrm{100^\circ C}$
F.P.	$\mathrm{0^\circ C}$

International Standards for Drinking Water

• Fluoride deficiency leads to dental decay in individuals. Water fluoridation is a technique that guarantees the managed addition of soluble fluoride to the water supply to raise its concentration to 1 ppm. Even so, excessive fluoride results in tooth mottling as well as bone defects.

• Lead (Pb): Plumbing fittings, water supply pipes and other items contain lead (Pb). Excess lead has neurological consequences & can endanger the health of infants as well as pregnant women. It can also harm the kidneys, liver including other organs. As a result, the permissible limit for lead concentration is only 50 ppm.

• Sulphate is frequently used to regulate algae in water supply system pipes. Mines also discharge them into the water. Some sulphates are extremely water-soluble. As a result, they may still be present in water upon treatment. Even though it is safe at low concentrations, if it surpasses 500 ppm in water, it can lead to diarrhoea, gastrointestinal problems, certain laxative effects, as well as dehydration.

• Nitrates are found in fertilisers. They can reach surface & groundwater from agricultural areas. The digestive system is harmed when the concentration of nitrates in water increases by 5 ppm. It also induces methemoglobinemia, also known as the blue baby syndrome.

Conclusion

The WHO issued International Standards of Drinking Water (SDW) as a set of guidelines that aim to facilitate water supply officials in the removal of harmful substances from water as well as the inclusion of essential mineral elements in the appropriate amounts. Colourless, odourless, flavourless, as well as turbid drinking water, is safe & clean. Drinking water must be free of illness-causing pathogens & harmful chemicals, as well as contain adequate amounts of essential elements.

FAQs

1. Which element is the most dangerous for water contamination?

Lead (Pb) is the most toxic water contaminant because it causes Pb poisoning. Prolonged exposure to high-lead water can result in developmental problems, stomach pain, as well as neurological changes. When found in excess doses in the body, it leads to death.

2. What exactly do you mean by TDS? How is it calculated?

TDS is an abbreviation for Total Dissolved Solids. It is described as the no. of dissolved solute particles in each volume of solvent. TDS is a sample calculated as $\mathrm{TDS=\frac{[(A-B)✕ 1000]}{mL}}$ (where A is the weight of dried residue + dish and B is the weight of empty dish)

3. How do Arsenic & other heavy metals enter water supplies?

Arsenic (As) can be found in both merged as well as free forms in nature. It can be found in rocks such as oxide, sulphides, nitrites, & other similar compounds in their combined state. Arsenic or other elements access the deeper layers of soil as well as gather in the groundwater's water table during the weathering & leaching processes.

4. WHO has not established strict guidelines for which factors or substances are present in water?

There are no strict WHO guidelines on how much iron, sulphate, zinc, as well as dissolved oxygen, is safe. However, high iron (Fe) and zinc (Zn) concentrations can cause a variety of health issues.

5. What exactly does hard & soft water mean?

Hard water is water that does not lather with soap, whereas soft water does. Hard water cannot be used for washing or bathing while soft water can.