The Different Types of Water Quality Parameters and WHO Standards

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Water Quality Parameters

water Quality, Have you ever wondered what different parameters are important

to measure? What do they all mean? What do they look like on a chart?

This article will introduce you to some of the major water quality parameters that are

used to measure water quality and will help you learn how they can be

used to monitor and improve water quality in your area. It will also tell

you what standards have been established by WHO, as well as why it’s

important to meet them, so that you can ensure the health

of your watershed.

Natural Mineral Waters

Natural Mineral Waters


Mineral water that originates from a natural source has to meet strict

criteria laid down by WHO to ensure its safety, in particular, that it is free

from harmful microorganisms. For example, total coliforms and fecal

coliforms are not permitted at any level (in 1 ml sample). Also known

as drinking waters or table waters, they include spring waters (flowing

water from natural springs), carbonated mineral water, aerated mineral

water (carbon dioxide added), and still mineral water. Total dissolved

solids are not to exceed 1000 mg/L. Sulfate levels should not exceed 250 mg/L

for both potable uses as well as for some industrial uses such as brewing beer.

Calcium hardness should be 100–500 mg/L.

Water Quality

Drinking-Water with added Fluoride


Research has demonstrated that low levels of fluoride are beneficial for

children’s teeth, reducing tooth decay by up to 40%. In areas where tap

water is not fluoridated, studies show a higher incidence of tooth decay in

children. As a result, many countries have instituted programs that add

small amounts of fluoride to tap water or salt. Research shows no

difference in bone health between those who live in communities with

fluoridated water and those who do not. Furthermore, recent studies

show no risk to bone strength from consuming modest amounts of fluoridated

water during infancy. For adults over 25 years old, even larger quantities are

safe for daily consumption for life—thereby reducing dental cavities

without harm to bones.

Nitrate and Nitrite (used for preservation)

Nitrate and Nitrite (used for preservation)

Nitrate and Nitrite (used for preservation)


Nitrate and nitrite are also used for preservation. In other words, it helps

inhibit or slow down bacterial growth. Adding too much nitrate can have

a negative effect on fish; however, nitrites do not cause any harm to fish in

low concentrations (less than 0.05 ppm). While nitrogen plays an important

role in aquatic ecosystems, there is a direct correlation between increased

levels of nitrogen in water systems and eutrophication (water plants

growing like crazy).

pH value

pH value


pH stands for the potential of hydrogen, and it is a measurement used

to indicate acidity or alkalinity in water. Pure water has a pH value of 7; if your pH

is lower than 7, you have an acidic solution; if your pH is higher than 7, you

have an alkaline solution. The more acidic (or basic) a substance is, the more

hydrogen ions are present in that solution. In pure water, there are equal

amounts of hydroxide ions and hydrogen ions present. When the value

changes either way from pure water we call it as having acidity or alkalinity

respectively. These two things make up our ph scale on which we measure

how acidic or how basic a fluid is.

pH measuring

Arsenic and Lead

Arsenic and lead


As a rule, cyanide in water should be below 0.5 μg/L (0.005 mg/L) to avoid

toxicity to aquatic life; at that level mortality is 100% if an organism is

exposed to 1 μg/L (0.001 mg/L) for 24 hours or even less. The threshold level in

surface waters is 0.2 μg/L (0.0002 mg/L). In drinking water,

it should be below 0.01 ppm,

while wastewater treatment plants can accept levels

up to 5 ppm without

significant effects on purification processes or organisms living

within them.[citation needed]

Free Cyanide in water (used for mining or manufacture)

Free Cyanide

Usually, it’s found in low levels, but cyanide is lethal in even very small amounts.

If your local water source comes from a well, talk to your municipality

about buying a filter to remove toxins. Even if you use city water, which

has higher quality standards, there are several things you can do to improve

its purity. Filtration systems remove heavy metals, chlorine and other elements

that can build up inside your pipes. There are some basic tests you can do at

home (like testing for lead content), which will let you know if any filters need

replacing; many kits start around $20-$30 on Amazon or at big-box stores like

Lowe’s or Home Depot.

Cadmium, Mercury, Thallium, Chromium VI compounds.


The Tolerable Weekly Intake (TWI) or Provisional Tolerable Monthly Intake (PTMI)

is expressed in milligrams per kilogram body weight per week. The TWI/PTMI can

be exceeded if no other source of exposure to that contaminant is present. To

make sure that the TWI/PMI will not be exceeded, it is necessary to take

into account all sources of exposure: food, drinking water, and any non-dietary,

non-occupational exposure. This can be achieved by performing a risk

assessment using standard modeling software such as ERICA or STOWA. As part

of an assessment, it is recommended to also consider taking maximum

admissible concentrations for relevant environmental

media into account.

Learn More.

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