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27 April 2018

Water Quality Testing

Author/Compiled by
Beat Stauffer (seecon international gmbh)
Dorothee Spuhler (seecon international gmbh)
Executive Summary

In many parts of the world, water is not safe enough to drink. There are basic qualitative observations that quickly determine if water is not safe to consume. However, there are also many “invisible” substances that must be tested for professionally to identify the contaminants and to figure out how the specific polluted water can be purified. Testing can be done in the field with portable test kits or mobile laboratories. Water samples can also be collected and sent to a professional laboratory.

Advantages
Provides clean water and protects human health
Many types of equipment are easy to handle and provide quick results
Disadvantages
Equipment can be expensive
Some parts of the testing kits and laboratories are very sensitive and must be handled carefully
Needs trained labourers or even experts
In Out

Precipitation, Freshwater, Treated Water

Precipitation, Freshwater, Drinking Water, Treated Water

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Introduction
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Drinking water can come from different sources depending on where we live in the world. Three sources that are used to collect drinking water are:

Water is in continuous movement on, above, and below the surface of the earth. As water is recycled through the earth, it picks up many things along its path. Water quality will vary from place to place, with the seasons, and with the various kinds of rock and soil it moves through.

For the most part, it is largely natural processes that affect water quality. For instance, water moving through underground rocks and soils may pick up natural contaminants, even with no human activity or pollution in the area. In addition to nature's influence, water is also polluted by human activities, such as open defecation, dumping garbage, poor agricultural practices, and chemical spills at industrial sites (see also water source protection).

Even though water may be clear, it does not necessarily mean that it is safe for us to drink. It is important for us to judge the safety of water by taking the following three qualities into consideration (see also pathogens and contaminants):

  1. Microbiological – bacteria, viruses, protozoa, and worms
  2. Chemical – minerals, metals and chemicals
  3. Physical – temperature, colour, smell, taste and turbidity

Safe drinking water should have the following microbiological, chemical and physical qualities:

  • Free of pathogens
  • Low in concentrations of toxic chemicals
  • Clear
  • Tasteless and colourless (for aesthetic purposes)

When considering drinking water quality, microbiological contamination is the main concern in most cases since it is responsible for the majority of illnesses and deaths related to drinking unsafe water. Learn more about water purification.

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Basic design principles
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Qualitative observations

The first step to check water quality can be done by very simple observations:

Water Observations

Possible Contaminants

Foamy

Detergents

Black in colour

Manganese, bacterial growth

Brown, yellow or reddish in colour

Iron

Dark brown or yellow in colour

Tannins and pigment from leaves and back

White deposits or scale

Hardness, dissolved metals

Earthy, fishy, muddy, peaty odour

Organic matter, algae, bacteria

Rotten egg odour

Hydrogen sulphide

Chlorine odour

Chlorine residual from water treatment process

Bitter or metallic taste

pH, zinc, copper

Qualitative observations. Source: CAWST (2009)

Portable testing kits

Analyses for many physical, chemical and microbiological contaminants can be carried out in the field or in a temporary laboratory using specifically designed products that are portable and relatively easy to use. A significant advantage of field analysis is that tests are carried out on fresh samples whose characteristics have not been contaminated or otherwise changed as a result of being stored and transported over long distances (CAWST 2009). Read more about the specific test kits in CAWST (2009).

 How to choose a portable test kit. Source: WAGTECH (n.y.)

How to choose a portable test kit. Source: WAGTECH (n.y.)

Portable water quality test kits should have the following characteristics (CAWST 2009):

  • Easy to use with simple instructions
  • Small and easy to transport
  • No restrictions on air transport
  • Fast results
  • Limited requirement for distilled or deionised water
  • Dilution not necessary
  • Does not require calibration
  • Robust (limited effects from UV light,shock,humidity or temperature)
  • Can test several parameters
  • Easy to repair or replace
  • Limited consumables or consumables are easy to obtain

Mobile laboratories

 These durable 4-wheel vehicles can be equipped with numerous applications, e.g. water &environmental monitoring, materials testing or health clinics. Source: WAFTECH (n.y.)

These durable 4-wheel vehicles can be equipped with numerous applications, e.g. water & environmental monitoring, materials testing or health clinics. Source: WAGTECH (n.y.) 

Water and environmental surveys frequently require the analysis to be carried out in remote areas. The use of a well-equipped mobile laboratory is often the ideal solution. More and more, they are becoming widely used, especially in developing countries where accurate results are required quickly, usually in areas where no fixed laboratory facilities exist (WAGTECH n.y.).

Laboratory Testing

Water quality testing can also be carried out in a laboratory. This method requires facilities, trained technicians, equipment and other supporting materials. Laboratory testing can be useful if you are only taking a small number of samples and your project is located close to an urban area where a laboratory is present (CAWST 2009).

Advantages

Limitations

Controlled environment

Relatively expensive

High level of precision and accuracy

Requires trained and skilled technicians

High level of quality assurance

Usually located in urban areas, may require samples to be transported over long distances

More consistent results

Some laboratories may have very limited options of test methods

More samples can be processed in a shorter time

Summary of advantages and limitations of laboratory testing. Source: CAWST (2009)

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Cost considerations
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Portable kits

Depending on the manufacturer and funding, portable tool kits can be very pricey for local organisations or NGO’s.

Mobile laboratories

Government agencies and research centres responsible for monitoring and water quality testing sometimes use mobile laboratories for periodic water quality testing. The vehicle is usually the most costly piece of equipment (CAWST 2009).

Laboratories

The initial costs to equip a laboratory are very high. The cost of a laboratory sample tests varies depending on the following parameters:

  • Geographical location of the laboratory
  • Types of chemical or biological contaminants
  • Quantity of sample tests
  • Accuracy and precision level required

The costs are usually reduced as the numbers of tests increase.

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Operation and maintenance
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Trained people can perform qualitative observations and tests with the help of portable tool kits. Laboratory work (mobile or immobile) must be carried out by experts. The equipment must be cleaned and maintained after being used. Instructions of the manufacturers must be considered.

Applicability

The techniques described above can be applied in every part of the world. The technique used depends on location, needs, and duration of the water-testing programme. It is important that programmes are planned carefully and executed in a serious manner to avoid failures.

Library References

The Definitive Guide to Portable Water Testing

This short form catalogue focuses entirely on the Wagtech manufactured range of portable water quality testing equipment. This comprehensive range of products offer testing options across a wide range of applications and parameters. These products contain a whole host of innovative features and cutting edge technology.

WAGTECH (n.y): The Definitive Guide to Portable Water Testing, Thatcham: Wagtech International Ltd URL [Accessed: 28.10.2012]
Further Readings

Sick Water? The central role of wastewater management in sustainable development

This book not only identifies the threats to human and ecological health that water pollution has and highlights the consequences of inaction, but also presents opportunities, where appropriate policy and management responses over the short and longer term can trigger employment, support livelihoods, boost public and ecosystem health and contribute to more intelligent water management.

CORCORAN, E. ; NELLEMANN, C. ; BAKER, E. ; BOS, R. ; OSBORN, D. ; SAVELLI, H. (2010): Sick Water? The central role of wastewater management in sustainable development, A Rapid Response Assessment. United Nations Environment Programme (UNEP), UN-HABITAT, GRID-Arendal URL [Accessed: 05.05.2010]

Water Quality Parameters & Indicators

Water quality determines the ‘goodness’ of water for particular purposes. Water quality tests will give information about the health of the waterway. By testing water over a period of time, the changes in the quality of the water can be seen. Parameters that may be tested include temperature, pH, turbidity, salinity, nitrates and phosphates. An assessment of the aquatic macro-invertebrates can also provide an indication of water quality.

MCCAFFREY, S. ; (n.y): Water Quality Parameters & Indicators, Gunnedah: Namoi Councils Water Working Group URL [Accessed: 28.10.2012]

The Hydrogen Sulphide (H2S) Paper-strip Test

The aim of this report is to provide information on the scientific basis, manufacture and use of the H2S paper strip test in the Pacific Islands. Suggestions are given on how the test could be utilised for rural, outer island and community-based water quality monitoring.

MOSLEY, L.M. ; SHARP, D.S. ; (2005): The Hydrogen Sulphide (H2S) Paper-strip Test, Suva: SOPAC URL [Accessed: 28.10.2012]

Arsenic in Drinking Water

The acute toxicity of arsenic at high concentrations has been known about for centuries. It was only relatively recently that a strong adverse effect on health was discovered to be associated with long-term exposure to even very low arsenic concentrations. Drinking water is now recognised as the major source of human intake of arsenic in its most toxic (inorganic) forms.

PETRUSEVSKI, B. ; SHARMA, S. ; SCHIPPERS, J.C. ; SHORDT, K. ; (2007): Arsenic in Drinking Water, Delft: IRC International Water and Sanitation Centre URL [Accessed: 28.10.2012]

UNICEF Handbook on Water Quality

This handbook is a comprehensive a new tool to help UNICEF WASH field professionals, but it will also be useful to other UNICEF staff and for partners in government, other external support agencies, NGOs and civil society. The handbook provides an introduction to all aspects of water quality, with a particular focus on the areas most relevant to professionals working in developing countries. It covers the effects of poor water quality, quality monitoring, the protection of water supplies, methods for improving water quality, and building awareness and capacity related to water quality.

UNICEF (2008): UNICEF Handbook on Water Quality, New York: United Nations Children's Fund (UNICEF) URL [Accessed: 30.03.2010]

Home Water Testing

Should I have my water tested? The answer to this question depends on several factors. It concerns your health and the health of your family, so you need to know some basic facts.

U.S. EPA (2005): Home Water Testing, Washington DC: United States Environmental Protection Agency (U.S. EPA) URL [Accessed: 28.10.2012]

The Definitive Guide to Portable Water Testing

This short form catalogue focuses entirely on the Wagtech manufactured range of portable water quality testing equipment. This comprehensive range of products offer testing options across a wide range of applications and parameters. These products contain a whole host of innovative features and cutting edge technology.

WAGTECH (n.y): The Definitive Guide to Portable Water Testing, Thatcham: Wagtech International Ltd URL [Accessed: 28.10.2012]

Guidelines for Drinking-water Quality, Fourth Edition

This volume of the Guidelines for Drinking-water Quality explains requirements to ensure drinking-water safety, including minimum procedures and specific guideline values, and how those requirements are intended to be used. The volume also describes the approaches used in deriving the guidelines, including guideline values. It includes fact sheets on significant microbial and chemical hazards.

WHO (2011): Guidelines for Drinking-water Quality, Fourth Edition, Geneva: World Health Organization (WHO) URL [Accessed: 08.08.2011]

Toolkit for monitoring and evaluating household water treatment and safe storage

In order to develop effective mechanisms to encourage and sustain correct use of household water treatment and safe storage (HWTS), there is a need to monitor and evaluate uptake. The Toolkit provides an overall framework for this. One of the key features is the presentation of 20 harmonized, global indicators to assess correct and consistent use of household water treatment and safe storage by those most at risk.

WHO ; UNICEF (2012): Toolkit for monitoring and evaluating household water treatment and safe storage, Geneva: World Health Organization URL [Accessed: 08.11.2012]

Rapid assessment of drinking-water quality

This handbook describes the methods and procedures of the Rapid assessment of drinking-water quality (RADWQ) applied by WHO and UNICEF to explore the quality of drinking-water from "improved" sources in five countries. The handbook is for adoption by any authority or institution that wants to prepare a snapshot of the quality of "improved" sources of drinking-water, as a first step towards strengthening drinking-water quality regulations.

WHO ; UNICEF (2012): Rapid assessment of drinking-water quality, A handbook for implementation. Geneva: World Health Organization URL [Accessed: 08.11.2012]

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