Water Quality | What is Water Quality & How do we measure it

What is water quality and how do we measure it?

Pure water has no electrical charge. Hence its conductivity is very high. However, most water has impurities in it. These impurities are organic and inorganic compounds. These impurities cause the water to have increased conductivity that can be measured. Water quality is measured by how much Total Dissolved Solids [called TDS] per liter of water contains. The only true of measuring this is by evaporating 1 liter of water and weighing the solids left behind. This is impractical.

It is possible to estimate the Total Dissolved Solids in water via an indirect method that is very easy to implement and is the world standard. Water contains different ions of the impurities [e.g. Ca, K, Na, Mg, etc.]. By measuring the electrical conductivity [micro Siemens] of water we can estimate the TDS of water. Since different elements have different charges, it is necessary to convert the electrical conductivity reading to TDS applying a converting factor. The most commonly used conversion factors used are:

1: 0.5 to 0.57 by using a standard KCL Potassium Chloride solution

2: 0.47 to 0.5 by using a standard Nacl Sodium Chloride solution

3: 0.65 to 0.85 442TM solution by Myron L Company. This solution mimics the properties of natural waters like in lakes/wells etc.

The Electrical conductivity readings are also temperature compensated. 

The important thing is to note the relative readings of TDS rather than absolute values.  

TDS bot measures coverts the measurement to TDS in a non-linear way as would occur in nature

 Common solids found in water [both useful and harmful]

Water is very effective at dissolving substances.  After filtration microscopic materials are still present water, some of which can be potentially harmful in high doses.

Some believe that the presence of minerals in the water they consume is good; others realize that the health risk posed by drinking water with unwanted TDS is not worth it. Everything that consumes, uses or lives in water is affected by TDS, for better or for worse.

TDS are commonly found in tap or well water because a combination of leaves, silt, plankton, industrial waste and sewage gets into the water supply, as well as runoff from road salts used during the winter, and from fertilizers and pesticides used in agricultural areas. Lead and copper particles can also get mixed into water supply as the liquid travels through pipes, and water may come into contact with inorganic materials, such as rocks or the air, which can infuse calcium bicarbonate, nitrogen, iron phosphorous and sulfur into water, along with other minerals.

Combinations of these materials can form a residue of salts – compounds that contain both a metal and a nonmetal, which, when dissolved in water, usually form ions. Ions consist of cations (positively charged ions) and anions (negatively charged ion). Essentially, the TDS concentration measurement is the sum of the cations and anions found in water.

Pesticides, heavy metals and human and animal waste and other pollution can infiltrate a water supply before it is treated and it can be difficult for authorities to ensure that drinking water is totally fit for consumption by the time it gets to the tap.

 A region’s industrial and agricultural practices, geological make up, and weather patterns often determines which contaminants make their way into source water – the body of surface or ground water from which drinking water supplies come from.

 Common chemical contaminants include arsenic, radon, lead and nitrates. These contaminants can cause health problems, from short term discomfort such as nausea and stomach aches, to much more serious, even fatal, ailments including developmental problems as well as cancer.

 Ingesting microbes in water can induce nausea, fever, diarrhea and dehydration, and long-term exposure to microbes can cause rashes, heart disease, diabetes, cancer, along with a number of immune, neurological, developmental and reproductive problems. The most common microbial contaminants include: E. coli, Cryptosporidium, Giardia and Salmonella.

 Sometimes, even the chemical by-products from the water treatment can contaminate the drinking water delivered to residential homes that it is meant to purify. Treatment processes are sometimes ineffective and the chemicals used to remove certain contaminants can create chemical by-products that pose a threat to human health. Risk varies from person to person and depends on the dosage, pre-existing health conditions, age, pregnancy or the strength of one’s immune system.

 Source: http://action.psr.org/site/PageServer?pagename=Safe_Drinking_Water_main

Water borne diseases:

Second only to air, water is the most important thing in the world. Water has the power to give and take life. Water has always been the breeding grounds for diseases. With the historically recent increase in waste and pollution that is produced on a daily basis, the amount of diseases and harm that water can bring to us is increasing drastically.

The most important thing to note is that these diseases cannot be seen in water; they are invisible to the naked eye. It is for this reason that it is very important to filter or purify water. For example, decreasing the amount of total dissolved solids (TDS) in water to 0 ppm will decrease the possibility of contracting diseases. This can be done with various methods, such as the use of reverse osmosis (RO) and de-ionization (DI) systems.

Diarrheal disease accounts for 4.1% of the daily global burden of disease. An estimated 1.8 million people die of diarrheal diseases every year. 88% of diarrheal diseases are caused by unsafe or untreated water use or consumption. The following is a list of the many diseases that are linked to untreated water and its symptoms.

·         Botulism – Clostridium botulinum bacteria – gastro-intestinal food/water borne; can grow in food

·         Campylobacteriosis- fever, abdominal cramps, and mild to severe diarrhea. Diarrhea can lead to dehydration, which should be closely monitored. Signs of dehydration include: thirst, irritability, restlessness, lethargy, sunken eyes, dry mouth and tongue, dry skin, fewer trips to the bathroom to urinate

·         (http://www.kidshealth.org/parent/infections/stomach/campylobacter.html”)

·         Cholera – Vibrio cholerae bacteria – gastro-intestinal often waterborne

·         Chronic granulomatous disease – caused by the Mycobacterium marinum infection and localized in skin, frequently occurred with aquarium keepers [3].

·         Diarrheal disease due to E. coli.

·         Dysentery – Shigella/Salmonella bacteria – gastro-intestinal food/water

·         Legionellosis – cause Pontiac fever and Legionnaires’ disease

·         Leptospirosis- The illness typically progresses through two phases:

·         The first phase of nonspecific flu-like symptoms includes headaches, muscle aches, eye pain with bright lights, followed by chills and fever. Watering and redness of the eyes occurs and symptoms seem to improve by the fifth to ninth day.

·         The second phase begins after a few days of feeling well. The initial symptoms recur with fever and aching with stiffness of the neck. Some patients develop serious inflammation of the nerves to the eyes, brain, spinal column (meningitis), or other nerves. Right upper area abdominal pain may occur. Less common symptoms relate to disease of the liver, lungs, kidneys, and heart. (http://www.medicinenet.com/leptospirosis/article.htm)

·         Otitis externa- or swimmer’s ear usually starts out as a nagging itch, brought on by a softening of the protective lining of the ear canal. However, it can blossom into as painful an infection as you will ever experience.
(http://www.healthscout.com/ency/68/524/main.html)

·         Typhoid – Salmonella typhi bacteria – gastro-intestinal water/food borne

·         Vibrio illness caused by the bacteria of Vibrio vulnificus, Vibrio alginolyticus and Vibrio parahaemolyticus commonly found in seafood and recreational water [4].

·         Adenovirus infection – its serotypes are typically waterborne [5].

·         Astroviruses- gastroenteritis, predominantly diarrhea
(http://www.nlv.ch/Astrovirus/Astrofactsheet.htm)

·         Caliciviruses- diarrhoea or vomiting lasting 1-4 days (incubation period 1-2 days). The most frequent source of infection appears to be contaminated food/beverages – may cause up to 90% of food-related gastroenteritis outbreaks.
(http://www.microbiologybytes.com/virology/Caliciviruses.html)

·         Circoviruses – its human form of Transfusion Transmitted Virus found in feces, saliva, skin and hair [2]

·         Coronaviruses – cause SARS and excreted in the feces [2]

·         Enteric Adenoviruses- most commonly cause respiratory illness; however, depending on the infecting serotype, they may also cause various other illnesses, such as gastroenteritis, conjunctivitis, cystitis, and rash illness. Symptoms of respiratory illness caused by adenovirus infection range from the common cold syndrome to pneumonia, croup, and bronchitis.
(http://www.cdc.gov/Ncidod/dvrd/revb/respiratory/eadfeat.htm)

·         Hepatitis A – Hepatitis A virus – gastro-intestinal water/food borne

·         Parvoviruses – associated with Gastroenteritis [2].

·         Picobimaviruses – associated with Gastroenteritis in AIDS patients, children and elderly [2].

·         Polio – polioviruses – gastro-intestinal exposure to untreated

·         Polyomaviruses – its human form of JC virus cause Progressive multifocal leukoencephalopathy and detected in sewage [2]

·         Small Round Structured Virus- also known as “Winter vomiting disease” the most common cause of infectious gastroenteritis
(http://www.hpa.org.uk/infections/topics_az/norovirus/menu.htm)

·         Hay fever – a part of disease rate is associated with the high frequency of swimming pool attendance in childhood [6]

·         Meningitis

·         Trihalomethanes – a byproduct of chlorinated water which will cause bladder cancer through inhalation and dermal absorption during showering, bathing, and swimming in pools [7].