YOUR PROBLEMS & OUR SOLUTIONS Index
Problems related to water quality and drinking water
What are drinking water standards?
Isn’t bottled water better than tap water?
How much water does a person use each day?
Why does tap water often smell like chlorine?
What are pathogens? How they can be removed?
What are sources of bacteria in drinking water?
What are the diseases caused by various bacteria and viruses?
What dangers can there be in drinking water other than microorganisms?
What are drinking water standards? Go to Top
Drinking water standards for packaged and non packaged water are as follow:
Sr. No.
Impurity
Non Packaged
Packaged
IS desirable limit (As per IS 10500)
USEPA Maximum contaminant level
WHO guideline value
IS desirable limit (As per IS 14543:2004)
1
Colour, Hazen units 5
NA
15 true colour units
2
2
Odour
Agreeable
3 threshold odour number
Not offensive
Agreeable
3
Taste
Agreeable
NA
Not offensive
Agreeable
4
Turbidity, NTU
5
5
5
2
5
Dissolved solids, mg/l 500
500
1000
500
6
Total hardness, mg/l (as CaCO3) 300
NA
500
NA
7
Ca, mg/l
75
--
--
75
8
Mg, mg/l
30
--
--
30
9
PH value
6.5 – 8.5
6.5 – 8.5
6.5 – 8.5
6.5 – 8.5
10
Manganese, mg/l
0.1
0.05
0.1
0.1
11
Chlorides, mg/l
250
250
250
200
12
Sulphates, mg/l
200
250
400
200
13
Nitrates, mg/l
45
10
10
45
14
Fluorides, mg/l
1.0
2.0
1.5
1.0
15
Phenolic compounds, mg/l 0.001
0.001
0.001
0.001
16
Mercury, mg/l
0.001
0.002
0.001
0.001
17
Cadmium, mg/l
0.01
0.005
0.003
0.01
18
Selenium, mg/l
0.01
0.05
0.01
0.01
19
Arsenic, mg/l
0.04
0.01
0.01
0.05
20
Cyanide, mg/l
0.05
0.2
0.1
Absent
21
Lead, mg/l
0.05
0.015
0.01
0.01
22
Zinc, mg/l
5
5
3
5
23
Anionic detergents, mg/l 0.2
--
0.2
0.2
24
Total pesticides, mg/l 0.0005
0.0005
0.0005
0.0005
25
Total bacterial count, CFU/ ml --
Not more than 500
--
100 at 200C
20 at 370C
26
Total coliform per 100 ml (including Fecal coliform & E-coli) Absent
Absent
Absent
Absent
27
Viruses (Enteric)
Absent
Absent
Absent
Absent
Isn’t bottled water better than tap water? Go to Top
Now-a-days, many people worry about the quality of tap water because of increased incidents of water borne deceases. Bottle water is one alternative for people on move for safe drinking water. However, studies have indicated that consumer may end up drinking water that is dirtier then they can get from their taps. To be safe, consumers who buy bottled water should determine whether the company that supplies them with water is certified by BIS (Bureau of Indian Standards) and lives up to the testing requirements of drinking water.
Just as tap water can vary by location, the content of bottled water varies from bottler to bottler. Some of the highest quality bottled water is produced by reverse osmosis (RO) filtration, which typically reduces impurities by 95 percent or more.
One alternative of getting safe water is to have tap attachment -Suraksha or POU unit.
How much water does a person use each day? Go to Top
In India, the average water use is around 145 litres a person each day with the following break up.
Water usage Quantity (lpcd)
Drinking 3
Bathing 30
Toilets/Flushing 45
Laundry 30
Kitchen/ Dish washes 22
Leakages 15
Total 145
Why does tap water often smell like chlorine? Go to Top
To remove bacteria from drinking water and to protect it from re-contamination during distribution, municipal treatment plants add chlorine during treatment. Chlorine is a very effective disinfectant, which is used to kill any harmful bacteria that might be present in the water source. Generally, around 0.2 mg/l of free residual chlorine is maintained for complete disinfection. The residual chlorine gives rise to chlorine smell to the tap water. When one's tap water smells like chlorine it does not mean a danger to the people that drink it. Chlorine levels used in drinking water are not high enough to form a serious threat to anyone's health.
Isn’t my municipal water treated?
Many municipalities treat water with clarification, filtration and chlorine to kill bacteria. But their goal is to only meet minimum drinking water requirements. Many times, water gets re-contaminated during distribution through long pipe line net work. To eliminate common water contamination problems, an in-home water treatment system is often necessary.
Water is hard when it contains minerals such as magnesium and calcium. If you have hard water, you may see staining on your sinks, tubs, showers and clothing; and build-up on your glassware. Hard water can produce a rock-like scale that builds up in pipes, dishwashers, water heaters, ice machines and other appliances. This scale can also reduce water flow and clog valves and vents to create maintenance problems and reduce service life.
You may also notice less lather from your shampoo and soap and a filmy feeling on your skin. All of these are symptoms of the need for softened water.
How to make water soft? Go to Top
Water can be made soft by removing the ions that cause the water to be hard, in most cases calcium and magnesium ions. Iron ions may also be removed during softening. The best way to soften water is to use a water softener unit and connect it directly to the water supply. A water softener is a unit that is used to soften water, by removing the minerals that cause the water to be hard.
The first step to improving your family’s water is to identify your specific problem. Are there reddish-brown iron stains in your sink, shower or tub? Does your bathtub have a hard water ring? Does your water look dirty or cloudy? Does it smell sometimes? For these and other common problems, Ion Exchange can conduct in-home water tests and recommend the perfect solution.
What are pathogens? How they can be removed? Go to Top
Water can be contaminated micro-biologically by pathogens. Main pathogens in water can be in the form of Protozoa, Bacteria and Viruses.
Protozoa cysts are the largest in drinking water, and are responsible for many of the waterborne disease cases The two most common protozoa pathogens are Giardia lamblia (Giardia) and Cryptosporidium (Crypto). Protozoa are responsible for many cases of amoebic dysentery. Protozoa cysts range is size from 2 to 15 µm (a micron is one millionth of a meter), but can squeeze through smaller openings. In order to insure cyst filtration, filters with a absolute pore size of 1µm or less should be used.
Bacteria are single celled microorganisms, which lack well defined nuclear membranes and other specialized functional cell parts. They are so small, that humans cannot visualize them. We can only see them through microscopes, by which the cells are greatly enlarged. Bacteria are smaller than protozoa and are responsible for many diseases such as typhoid fever, cholera, diarrhea, and dysentery. Pathogenic bacteria range in size from 0.2 to 0.6 µm, and a 0.2 µm filter is necessary to prevent transmission.
Viruses are the 2nd most problematic pathogen, behind protozoa. As with protozoa, most waterborne viral diseases don't present a lethal hazard to a healthy adult. Waterborne pathogenic viruses range in size from 0.020-0.030 µm, and are too small to be filtered out by a mechanical filter. All waterborne enteric viruses affecting humans occur solely in humans, thus animal waste doesn't present much of a viral threat.
There are various methods of removing microorganisms. They include boiling,
Chlorination systems-
Iodine based resin systems-
RO systems-
UF systems, etc.
What are sources of bacteria in drinking water?
Human and animal waste, Seepage from septic tanks and Floodwater runoff, etc.
What are the diseases caused by various bacteria and viruses? Go to Top
Waterborne diseases
Viruses
Diseases
Hepatitis virus
Jaundice
Poliomyelitis
Polio
Rotavirus
Gastroenteritis Dysentery
Bacteria
Diseases
Vibrio cholerae
Cholera
Shigella spp
Dysentery
Salmonella
Typhoid
Is boiling water enough for safe drinking? Go to Top
Boiling is one guaranteed way to purify water of all pathogens. Most experts feel that if the water reaches a rolling boil it is safe. A few still hold out for maintaining the boiling for some length of time, commonly 5 or 10 minutes, plus an extra minute for every 1000 feet of elevation. If one wishes to do this, a pressure cooker would allow the water to be kept at boiling with out loosing the heat to evaporation. One reason for the long period of boiling may be to inactivate bacterial spores (which can survive boiling), but these spore are unlikely to be waterborne pathogens.
Boiling is very costly method of treatment as it needs 1 kg of wood to boil 1 liter of water. Hardwoods and efficient stoves would improve on this. Also it is very inconvenient way of treating as one need to wait again for the water to cool. Regardless of the method, heat treatment does not leave any form of residual to keep the water free of pathogens in storage.
What dangers can there be in drinking water other than microorganisms? Go to Top
Besides microorganisms, there are several problems that can endanger the quality of drinking water. A number of these problems are summed up here.
Fluorine is very common element, found in earth’s crust. Fluoride also enters in the aquatic system in the dissolved form through industrial discharge form through aluminium industries, phosphite industries, coal plants etc. Higher concentration in drinking water can affect the health adversely. The World Health Organization (WHO) guideline for fluoride is 1.5 mg/liter in drinking water. As per IS 10500 standard the desirable limit for fluoride is 1 ppm and permissible limit is 1.5 ppm in drinking water. Ion Exchange has fluoride removal resin and activated alumina based Fluoride Removal Units.
Iron is another common pollutant found in nature. Water percolating through soil and rocks, which dissolves iron, and subsequently enter to ground water supplies. High concentration of Iron cause reddish brown stains on laundry and household fixtures. Sometimes it may clog water distribution pipes. High level of iron can impart a bittersweet or metallic taste to drinking water. The drinking water standard for iron is 0.3 ppm as per USEPA(27TH May2003)) and IS 10500:1996 Ion Exchange developed Iron Specific Resin (ISR) media and De-ferrous unit to remove iron from water.
Arsenic contamination is a serious problem found in ground water in Eastern part of India (West Bengal) & Bangladesh. The normal concentration of arsenic is around 0.1 to 1.5 ppm. In most of the areas, concentration varies from 0.2 to 1.0 ppm. However permissible limits for drinking purpose is less than 50 ppb. The excess intake of arsenic leads to skin diseases like hyper pigmentation, keratoses melanomas that disfigure the skin like in leprosy. Ion Exchange developed
Arsenic Removal Units (ATU) for removing arsenic from drinking water.Nitrate in drinking water can cause cyanosis, a reduction of the oxygen carrying capacity of the blood. This is particularly dangerous to infants under six months of age. Ion Exchange has Nitrate removal resin for removing nitrates from drinking water.
Lead can enter the water supply as it leaches from copper pipelines. As the water streams through the pipes, small amounts of lead will dissolve in the water, so that it becomes contaminated. Lead is a toxic substance that can be quickly absorbed in the human systems, particularly those of small children. It causes lead poisoning.
What causes white deposit on showers and bathroom walls? Go to Top
Water contains many compounds. A few of these compounds are calcium and carbonate. Carbonate works as a buffer in water and is thus a very important component.
When calcium reacts with carbonate a solid substance is formed, that is called lime. This lime is what causes the white deposit on showers and bathroom walls and is commonly known as lime deposit. It can be removed by using a specially suited cleaning agent.
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