Most states and countries have a listing of standard items for checking initially, and to some degree it may depend on the source of the waters, well water from a confined aquifer is different from a relative pristine forest or a stream with a variety of land uses and industries nearby.  I am attaching a really good document on drinking water relative to forests and grasslands, many good papers.  Even forest wilderness may have some things to check, but with any open system, there can be issues without proper treatment.  As you may have heard from the Flint, Michigan issues, pipes that deliver water may also have impacts.  

I forgot to add, years ago we had directives to conduct a sanitary survey of domestic surface water sources to help identify potential pollution sources or problems that needed to be considered.  This was before many of the remote sensing tools we might consider today such as land use, but it really helps to review on the ground the specifics of surface water sources and know the contributing drainage area, be aware of what is going on.  Individuals and communities that rely on surface waters or shallow wells need to know the risks and to be aware of changes, increased potential for contamination during storms, hot periods when animals frequent open water sources, etc. 

It depends on which country's drinking water standards you wish to follow. However mostly United states which is more or less WHO standards are copied by most countries of the world.

Dear Susan Verghese,

It depend on many factors (cost, existence pollutant and...), but usually used the WHO parameters.

Dear Susan

What sort of water you have to examine? If you examine ground water then you must need base line data of the area and you will check the parameters such as TDS, TSS, Turbidity, ALKALINITY, EC, Majors anions and cations, Heavy metals, but if you examine lake water you may also check DO, BOD, E.Coli, COD, F.Coli.

With Regards

Dear Susan,

The answer is not easy but usuall when I have to analyse some water sample I need to know: which kind of water I have:underground or surface water, if is possible to be some source of impurification.How many parameter you need to analyze? Depends by law from one country to another,but parameter like: pH, hardness sometimes TSD is compulsory! Other parameters: COD especial for surface water, the biogenic elements ammonia, nitrite compulsory for underground water, nitrates for surface water.this parameter give s you clue if the water is or not impurificates with organic matters. It doesn't mean that intermediate elements we cannot find in surface water if are around a source of impurification that why I look for them. The hardness and pH can show you the presents of  calcium, magnesium in different form, so I look for this parameters. Analysing chloride you discover if the water is salty or potassium chloride give s you the high results on this parameter! The iron, sulfates are other parameters! Underground water has a high degree oh mineralisation! Of course it is important to make a bacteriological exam: quantitative and qualitative .I the area is different and exist some other source of impurification I have to take in account this aspects. 

r

I think what is needed is to meet the drinking water standard of your country. Not all countries have the same requirements, either indicators or maximum permissible concentrations thereof.

I hope these considerations will be helpful for you.

Dear Susan Verghese

It depend on he area standard in each country. The country have different standards.

all cations and anions and PH-EC-COD-BOD- TDS, TSS, Turbidity, ALKALINITY, DO, E.Coli, F.Coli, heavy metals, pesticides-refractory pollutants, etc.

Regards

There are extremes in water quality sources that exist, and even fluctuations in an individual source that could be of concern.  In S. Oregon and N. California mountains, I used to drink directly from mountain streams or springs with no problems. but that could have been a mistake.  I had an excellent well in Oregon, some of the best water of my life.  But in S. Carolina, the well I have is high in iron and potentially subject to pollution on a rural urban interface.  A couple months ago, some Turkey Vultures on migration spent a few weeks roosting at night in vicinity of my well.  I drove them off a few nights and they came back again and again.  My water is treated in several ways to take care of iron and reverse osmosis for drinking.  Even with that, we also buy some drinking water.  Whether open or well water, there remains a degree of risk, testing or not.  We need to test to make sure that there are no geological or existing pollution sources, but users must be diligent in recognizing any changes in clarity, smell, etc. and conditions especially when using surface waters.  Even in community treated and managed systems, a break in a water line will mean boiling water until they sanitize the lines and storage tanks. 

There are extremes in water quality sources that exist, and even fluctuations in an individual source that could be of concern.  In S. Oregon and N. California mountains, I used to drink directly from mountain streams or springs with no problems. but that could have been a mistake.  I had an excellent well in Oregon, some of the best water of my life.  But in S. Carolina, the well I have is high in iron and potentially subject to pollution on a rural urban interface.  A couple months ago, some Turkey Vultures on migration spent a few weeks roosting at night in vicinity of my well.  I drove them off a few nights and they came back again and again.  My water is treated in several ways to take care of iron and reverse osmosis for drinking.  Even with that, we also buy some drinking water.  Whether open or well water, there remains a degree of risk, testing or not.  We need to test to make sure that there are no geological or existing pollution sources, but users must be diligent in recognizing any changes in clarity, smell, etc. and conditions especially when using surface waters.  Even in community treated and managed systems, a break in a water line will mean boiling water until they sanitize the lines and storage tanks. 

 Dear Susan Verghese,

It depend on the country standards and water use. U can follow the attachment for your reference.

http://www.mblabs.com/html/services/drinkingwater.htm

http://kmam.moh.gov.my/public-user/drinking-water-quality-standard.html

http://www.who.int/water_sanitation_health/dwq/gdwqvol32ed.pdf

To assess the Water Quality there are more than hundreds of parameters to be tested... 600 plus..  I think it is ridiculous to suggest testing all the parameters.. 

So it all depends on source of water whether river, pond, hill stations or near to municipal dump yards, industrial area etc... So also hard-water or fluoride or as enriched area... 

So the best way is to test for E Coli and taste, odour, colour are basics...

PLUS

Common sense in assessing water Quality.

Ensure enough oxygen is and no bacteria..  

"Potable" water historically has meant free of human pathogens. Since its impossible to monitor water for all pathogens (protozoa, bacterial, virus) in a cost-effective, credible, and timely manner (before water is consumed), indicators of possible presence of pathogens are used.   Escherichia coli is the best indicator now and probably forever.  There are cost-effective, rapid (

Hi,Thank very much for information

regards

susan verghese p

Physical, chemical and biological parameters in water  must be within the permissible limit of potable water. Permissible limits are well defined and known. 

Hi,

There are many physical parameters ( pH, conductivity, ....) Chemical (COD, BOD 5, minerals salts,) biological (micro pathogens count). Regarding the standards, in principle, you should see your national regulations! 

May be you can enjoy with this WHO paper! 

It depends on the source of water and the region you consume water from but in general, you have 2 types of contaminants one of them is concerning water potability and that doesn't affect the human health but the other type is concerning human health as its concentration if exceed a certain value will cause harm to human health and from it cyanide, NO2, Arsenic also biological aspects must be of a major concern in the water quality issues as it cause server symptoms in very little time and there is a guideline for water quality standards prepared by the world health organization that may be your guide in detecting the most common issues related to the type of water you use.

I would want these tests done before consuming any water: 1. Inorganic Contaminants, 2. Volatile Organic Compounds (VOC's), 3. Nitrate, Nitrite, 4.Perchlorate, 5. Radionuclides, 6. Secondary Contaminants, 7. Synthetic Organic Contaminants (SOC's),  8. Giardia/Cryptosporidium, 9. Total Coliform /E.Coli. The list of these parameters can be found on the EPA and/or any State DEP site.

There are national standards for most Countries for the potability of water. However,  the quality of water can be described as physical, chemical and biological parameters that affect survival,reproduction, growth and fitness of water for consumption. Hence, the parameters required depend on the aims and objectives of the research, and the geological properties as well as the anthropogenic and natural activities around your sampling area.

Basically and practically it must accomplished the criteria of th WHO and if there is any other local regulation in your country.

http://www.who.int/entity/water_sanitation_health/publications/dwq-guidelines-4/en/index.html

The WHO guidelines are thorough but ominous.  Think simple.   For drinking water - appropriate treatment processes to match source water quality,  a chlorine-based disinfection residual, integrity of the distribution system.  Monitor for E coli.   The science is settled on which water treatment process work.

Hi Susan

There are key parameters that you must check in case of drinking water such as chlorine residual, ecoli, turbidity, EC/TDS, chloride, sulphate, iron, manganese, nitrates.

Apart from key parameters measured above,  you can also check  other parameter based upon the  activities that  are sorrounded within the water catchment areas/water sources, for example if the water catchment area/water source is sorrounded by industry  or agricultural activities, then check other parameters e.g heavy metals, pesticides,  fertilize products etc.

chanzi, h

There are Several parameters that can be considered important for deciding if the water is potable.  Depending on source of water. But most important parameters which are generally tested for surface and ground water in India are 

Turbidity, Fluoride, pH, Total Hardness, Alkalinity, Acidity, TDS, Chlorides, Cynide, Nitrates, e-coli, and Chlorine if you are checking Municipal water. If you are analyzing surface water which might have possibility of receiving industrial effluents, it is important to test most of the trace elements, metals etc.

if you are going for simple field testing of water, you will find required things on attached link. 

hope it will help.

kunal

www.waterclues.com

Madam, based from WHO standard, there are four general parameters to consider for potability of water such as microbial, radiological, chemical, and physical quality. In most cases Microbial, chemical and physical quality are usually used unless there is known radioactive presence within the area where the source of water is located. The World Health Organization has released the fourth edition of drinking water standard available for free in their website. I hope this helps