onsite water quality monitoring training guide · 2019-02-28 · this training guide aims at...
TRANSCRIPT
2016
Onsite Water Quality Monitoring Training Guide
MINISTRY OF HEALTH
Environmental Health Section Directorate of Disease Surveillance Control
and Research
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ACKNOWLEDGEMENTS
This Training Guide was compiled and developed by Evans Tembo [i.e. holder of MSc Env.San
(Universiteit Gent, Belgium), MSc Public Health (Leeds Beckett University, UK), BEng.Env.Eng (CBU),
PGDip. IWRM (UNZA) and CME (Chainama College of Health Sciences)] for the Ministry of Health.
The Training Guide was primarily prepared for Environmental Health Technologists and Laboratory
Technician who would wish to be involved in Onsite Drinking Water Quality Monitoring (ODWQM)
both for rural water and urban water supply in Zambia FOR enhanced water security.
Funding for formulation of the original Training Guide was provided for by Oxfam through the Peri-
Urban water and sanitation project which Village Water is implementing in Chawama and George
compounds of Lusaka, Zambia.
Last but not the least, the pivotal role played by the Director Dr. E. Chizema, Mr. Mate the Deputy
Director - Disease Surveillance Control and Research and the Chief Environmental Health Officer Mrs.
F. Mwale of the Ministry of Health Headquarters in the adoption of the Village Water – Onsite Water
Quality Monitoring guide to be used by the environmental health personnel in Zambia.
For any technical clarification the author can be contacted on:
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Contents
ACKNOWLEDGEMENTS .............................................................................................................................................. 1
TRAINING GUIDE INTRODUCTION ............................................................................................................................. 3
Rationale ................................................................................................................................................................. 3
Aim …………………………………………………………………………………………………………………………………………………………… 3
Course Objectives ................................................................................................................................................... 3
UNIT 1: INTRODUCTION TO WATER SUPPLY .......................................................................................................... 4
1.0 Introduction ............................................................................................................................................... 4
1.1 Benefits from Improved Water Availability ............................................................................................... 4
1.2 Adequacy of supply .................................................................................................................................... 5
UNIT 3: WATER ASSOCIATED DISEASES ................................................................................................................. 7
3.0 Introduction ............................................................................................................................................... 7
3.1 Water-borne diseases ................................................................................................................................ 7
3.2 Water-based Diseases ................................................................................................................................ 8
3.3 Water-washed diseases ............................................................................................................................. 9
3.4 Water related insect vector diseases ......................................................................................................... 9
UNIT 4: CATEGORIES OF WATER QUALITY PARAMETER ...................................................................................... 11
4.0 Introduction ............................................................................................................................................. 11
4.1 Categories of water quality parameters .................................................................................................. 11
4.1.1 Physical or aesthetic parameters; ........................................................................................................... 12 4.1.3 Radiological Characteristics ..................................................................................................................... 14 4.1.4 Microbial Contamination ........................................................................................................................ 15
UNIT 5: ONSITE WATER QUALITY MONITORING USING WAGTECH .................................................................... 17
5.0 Introduction ............................................................................................................................................. 17
5.1 Features .................................................................................................................................................... 17
5.2 Water Sampling ........................................................................................................................................ 19
5.3 Water Analysis using WAGTECH .............................................................................................................. 19
5.3.1 Analysis of physical parameter ............................................................................................................... 19 5.3.2 Analysis of chemical parameters............................................................................................................. 20 5.3.3 Analysis of microbiological parameter .................................................................................................... 20 5.4 Interpretation of water quality data ........................................................................................................ 20
5.4.1 Steps to Interpret Results ............................................................................................................................ 20
UNIT 6: SANITARY INSPECTION ............................................................................................................................ 22
6.0 Introduction ............................................................................................................................................... 22
6.2 Sanitary inspections .................................................................................................................................... 22
6.3 Functions of sanitary inspection report forms............................................................................................ 23
APPENDIX: FORMS USED IN SANITARY INSPECTION OF WATER POINTS ................................................................ 25
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TRAINING GUIDE INTRODUCTION
Rationale
The World Health Organisation estimates that 94% of diarrhoeal cases are preventable through
modifications to the environment, including interventions to increase the availability of clean water,
and to improve sanitation and hygiene. In addition, a 2005 systematic review concluded that
diarrhoeal episodes are reduced by 25% through improving water supply, 32% by improving sanitation,
45% through improved personal hygiene.
While the world may be currently on track to meet the target in terms of numbers of sources
constructed, it may not be on track if the quality of water in new sources is not fully taken into account
(WHO/UNICEF, 2010). Thus, many more people than estimated may drink unsafe water from improved
sources. At current rates of progress, in sub-Saharan Africa (including Zambia) the water target will not
be met until 2035, based on trends in the (WHO/UNICEF, 2008).
For Zambia, the problem of drinking water contamination in rural and peri-urban areas is being
compounded by unplanned settlement, insufficient number of improved water sources, overcrowding,
poor sanitation and indiscriminate dumping of solid, hence the need to carryout onsite drinking water
quality monitoring.
Aim
This training guide aims at introducing EHTs and Community Volunteers to some basic understanding
of onsite water quality monitoring using WAGTECH POTALAB, water sources, diseases associated poor
water quality management and the various sanitary inspection options for water points.
Course Objectives
At the end of the training, the participants should be able to:
i) Explain the meaning of safe water,
ii) Distinguishing between improved water sources and unimproved water sources,
iii) Identify the link between water supply, sanitation and health,
iv) Describe the faecal oral transmission pathway,
v) Practically demonstrate how to analyse physical parameters in drinking water using WAGTECH
POTALAB,
vi) Practically demonstrate how to analyse chemical parameters in drinking water using WAGTECH
POTALAB,
vii) Practically demonstrate how analyse microbiological parameters in drinking water using
WAGTECH POTALAB
viii) Conduct sanitary inspection on water points effectively,
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UNIT 1: INTRODUCTION TO WATER SUPPLY
1.0 Introduction
Water is essential for life, health and human dignity. In extreme situations, there may not be sufficient water
available to meet basic needs, and in these cases supplying a survival level of safe drinking water is of critical
importance. In most cases, the main health problems are caused by poor hygiene due to insufficient water and
by the consumption of contaminated water with feacal matter.
The World Health Organisation (WHO) defines safe water as “drinking water which does not cause any negative
health effects during its lifetime usage”. Furthermore, safe water is three characteristics namely;
i. Sufficient quantity meaning that the community should have enough water for drinking and household
needs,
ii. Good quality meaning that water should not be contaminated with feaces and other chemicals,
iii. Accessibility meaning that a person should be able to collect 20 litres of within 500 meters distance of
30 minutes time.
1.1 Benefits from Improved Water Availability
There are a number of potential benefits to improved access to water supply, in addition to the reduction of
disease. The reasons that many communities give for placing a high priority on improved water supply usually
relate to benefits other than health. These benefits are of particular importance to women. A closer, cleaner
source of water can produce immediate and far-reaching improvements on women's lives;
a. Convenience; Most people, when identifying improved access to water as a priority, are thinking of
convenience. Everybody wants water as close as possible to their home, simply because it is more
convenient. As such, convenience is as important a consideration as health benefits. In some societies and
situations, convenience is also related to the security of women: water closer to home can minimize the
chances of abduction or assault.
b. Time Saved; Women and girls can spend many hours a day collecting water from distant sources and thus
the time saved by having a safe water source closer to the household can be very significant. The time
saved is used for much needed leisure or, possibly (but not necessarily) activities relating to improved
child care, or economic production. Less time spent fetching water is one less possible excuse for not
allowing girls to attend school.
c. Energy Saved; Studies have shown that women who walk long distances to collect water can burn as much
as 600 calories of energy or more per day, which may be one third of their nutritional intake. Closer
sources of water can thus improve the nutritional status of women and children (and hence health and
wellbeing).
Q;- Is mineral water safe water..????
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d. Money Saved; In many communities, especially in poor urban areas, households continue to have to buy
water from vendors, often at exorbitant rates. Such direct financial costs can absorb up to 30 percent of
total household cash income. Measures that improve the availability of water reduce its cost and are
therefore of direct benefit to families, and particularly to women, who are often responsible for finding
the funds to pay for water.
e. Prevention of Injury; When girls are forced to carry heavy loads of water over large distances, there is a
danger of lasting spinal column and pelvis injury and deformations. Closer water sources minimize this.
1.2 Adequacy of supply
The performance of a community water supply system can be determined by looking at critical factors which are
used to assess the a the adequacy of water supplied to a given community. In Zambia, NWASCO has developed
national strategies for the surveillance and quality control of water supply.
In undertaking an assessment of the adequacy of the drinking-water supply, the following basic service factors
of a drinking-water supply should normally be taken into consideration:
These usually include:
i. Quality: the proportion of the population using water from different levels of drinking-water supply.
ii. Coverage: the percentage of the population that has a recognizable (usually public) water-supply
system.
iii. Quantity: the average volume of water used by consumers for domestic purposes (expressed as litres
per person per day).
iv. Continuity: the percentage of the time during which water is available (daily, weekly or seasonally).
v. Cost: the tariff paid by domestic consumers.
Key indicators of water quantity and accessibility include;
Average water use for drinking, cooking and personal hygiene in any household is at least 15 litres per
person per day.
The maximum distance from any household to the nearest water point is 500 metres.
Queuing time at a water source is no more than 15 minutes.
It takes no more than three minutes to fill a 20-litre container.
Water sources and systems are maintained such that appropriate quantities of water are available
consistently or on a regular basis.
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UNIT 2: DRINKING WATER SOURCES
2.0 Improved water supply technologies.
Household connection
Public standpipe
Borehole
Protected dug well
Protected spring
Rainwater collection
Unimproved water supply technologies:
Unprotected well
Unprotected spring
Vendor-provided water
Bottled water
Tanker truck provision of water.
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UNIT 3: WATER ASSOCIATED DISEASES
3.0 Introduction
Improper care of water can result in reduction in quality and quantity from source to point of use leading to
poor health for the consumers. Many of these problems are related to health, in terms of diseases suffered, and
to finance, in terms of money spent on health care (Table 1). There four different categories of water associated
diseases.
3.1 Water-borne diseases
Water-borne diseases are diseases that are caused when water contaminated with faeces is consumed. Drinking
water can be contaminated with feacal matter which contains disease causing pathogens (viruses, bacterial,
helmiths and protozoa) in various ways and at various stages of the water chain (Figure 1):
When we don’t dispose of refuse containing excreta properly, rain washes it into our water sources;
Feacal matter can be transport by water from a pit latrine to a shallow well;
Faecal matter that is left exposed on the ground can also be washed into our water sources; and
Flies land on exposed faecal matter and carry the faeces to our water and food if not stored properly.
Examples of water-borne disease are cholera, diarrhoea, amoebic dysentery, typhoid, etc. Water-borne
diseases, like cholera, and dysentery all have a common symptom in addition to other symptoms of these
diseases. The common symptom is known as diarrhoea and so these diseases are jointly known as ‘diarrhoeal
diseases’.
The major method of preventing water-borne diseases is by preventing faeces from coming into contact with
food and water.
1 Gram of Excreta can contain-------->
Excreta: No. 1 Enemy! (Curtis, 98)
Selection of remedial measures for water-borne diseases; Most sanitation related diseases (water-borne
diseases) are caused by poor sanitation, which essentially means that germs in faeces need to get to a person’s
mouth, and be ingested, for the infection to occur.
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3.2 Water-based Diseases
These are the diseases caused by infective agents that rely on vectors that live in water for their transmission;
examples are schistosomiasis or bilharzias, guinea worm, among others.
Schistosomiasis (Bilharzia);- This is caused by a type of worm, which has to develop in a snail which breeds in
vegetation in slow moving or stagnant water bodies. Human beings are infected when they bathe, wash in such
polluted waters e.g. dams, rivers and streams. The worms are able to burrow through the skin and get into the
blood system. It is possible, although less common to contract schistosomiasis by drinking contaminated water.
The most important measures to prevent schistosomiasis are:
restraining oneself on swimming in stagnant/ponding water;
avoiding contact with untreated water;
boiling, filtering or chlorine or iodine treatment of water;
improvement and increase of access to safe water and sanitation services; and
promoting hygiene education.
Figure 1: Feacal Oral Diagram (Sari & Ari, 2006)
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3.3 Water-washed diseases
These diseases are contracted when people in an overcrowded situation also use less water and neglect
personal hygiene as a result of the considerable effort to obtain water. Examples of this group of diseases are
trachoma and scabies.
Trachoma;- This is an external eye disease, which left untreated, will cause blindness. There are cycles of
infection and re-infection.
The most important measures to prevent trachoma include:
improvement and increase of access to sufficient quantity of water for personal hygiene;
promoting hygiene education; and
facial cleanliness;
Scabies; - This is a skin disease, which is highly contagious i.e. it spreads easily and usually more than one person
in the house is affected. It is caused by small mites under the skin.
The most important measures to prevent scabies include:
adequate water for personal hygiene;
improvement and increase of access to safe water and sanitation services;
washing up with hot water and soap and thereafter with acaricide mite wash; and
disinfection and wash of contaminated(by mites) clothes and bed linen.
3.4 Water related insect vector diseases
These diseases are caused by vectors which require water for them to complete their metamorphosis (i.e. life
cycle). For example Malaria is caused by a plasmodium which is carried by female mosquitoes which breed in
water.
Figure 2: female mosquito
This can be prevented by clearing the
surroundings and proper surface water
management. Refer also to Table 1 for a
summary of different types of water
associated diseases
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Table1: Disease Transmission Mechanisms (UNICEF, 1999)
Transmission Mechanism
Diseases (examples) Preventative Strategy
Water-borne diseases Diarrhoea, Cholera, Typhoid, Dysentery
- improve water quality - prevent casual use of other unimproved sources
Water-washed diseases Roundworm (Ascariasis), Trachoma,
- improve water quantity - improve water accessibility - improve personal hygiene
Water-based diseases Bilharzia (Schistosomiasis), Guinea worm (Dracunculiasis)
- decrease need for water contact - control snail populations - improve water quality
Water-related Insect Vector diseases
Malaria, River Blindness (Onchocerciasis), Sleeping Sickness (Trypanosomiasis)
- improve surface water management - destroy breeding sites of insects - decrease need to visit breeding sites - remove need for water storage in the home or
improve design of storage vessels
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UNIT 4: CATEGORIES OF WATER QUALITY PARAMETER
4.0 Introduction
Drinking water, or potable water, is defined as having acceptable quality in terms of its physical,
chemical, bacteriological and acceptability parameters so that it can be safely used for drinking and
cooking (WHO, 2004). Water quality parameter are simply things which can contaminate water
thereby making it unfit for human consumption.
WHO provide the drinking water quality guidelines to all the countries to guide them with the
allowable limits of water contaminants (parameters). While Zambia Beaure Standard (ZABS) has
provided for the national drinking water quality standards in the ZS 190 document by taking a leaf from
WHO guidelines.
These requirements cover the basic hazards of contaminated water to human health and the
distribution infrastructure:
It should be acceptable to the consumer. Bad taste or colour, or unpleasant odour can cause a
user to choose an alternative source;
It should be free from disease-causing organisms;
It should be free from toxic chemicals;
4.1 Categories of water quality parameters
Substances that change the quality of water as it moves over or below the surface of the earth may be
classified under four major headings.
i. Physical: Physical characteristics are related to the quality of water for domestic use and
are usually associated with the appearance of water, its color or turbidity, temperature,
taste, and odor.
ii. Chemical: Chemical differences between waters are sometimes evidenced by their
observed reactions, such as the comparative performance of hard and soft waters in
laundering.
iii. Radiological: Radiological factors must be considered in areas where there is a possibility
that the water may have come in contact with radioactive substances.
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iv. Biological: Biological agents are very important in their relation to public health and may
also be significant in modifying the physical and chemical characteristics of water.
4.1.1 Physical or aesthetic parameters;
This includes the following:
Turbidity; Water that is not clear but "dirty," in the sense that light transmission is reduced, is
considered turbid. Turbidity can be caused by many materials. In the treatment of water for
drinking purposes, turbidity is of great importance, first because of aesthetic considerations,
second because pathogenic organisms can hide on (or in) the tiny colloidal particles and third
because hydrophobic (water hating) substances like organochloride pesticides can cling on the
surfaces of the colloids and this can lead to the formation chlorine by-products during
chlorination.
Color and Odor; Color and odor are both important measurements in water quality. Along with
turbidity they are called physical parameters of drinking water quality. Color and odor are
important from the standpoint of aesthetics. If water looks colored or smells bad, people
instinctively avoid using it, even though it might be perfectly safe from the public health aspect.
Both color and odor may be and often are caused by organic substances such as algae or humic
compounds.
Solids; In discussion of water treatment, both dissolved (Total Dissolved Solids - TDS) and
suspended materials (Total Suspended Solids – TSS) are called solids. These solids can be
further sub-divided in volatile and fixed solids.
Temperature; The most desirable drinking waters are consistently cool and do not have
temperature changes of more than a few degrees. Groundwater and surface water from
mountainous areas generally meet these criteria. Most individuals find that water having a
temperature between 10 °C and 15°C is most palatable.
4.1.2 Chemical Contamination
Assessment of water quality by its chemistry includes measures of elements and molecules dissolved
or suspended in water. Chemical measures can be used to directly detect pollutants in drinking water.
Most chemicals from water sources are of health concern in humans as a result of exposure through
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drinking. Commonly measured chemical parameters include arsenic, cadmium, calcium, chloride,
copper, fluoride, total hardness, nitrate, and potassium (refer to WHO Drinking water quality
guidelines vol. 3 and ZS 190).
pH; The pH of a solution is a measure of hydrogen ion concentration, which in turn is a measure
of its acidity. Pure water dissociates slightly into equal concentrations of hydrogen and hydroxyl
(OH-) ions. An excess of hydrogen ions makes a solution acidic, whereas a dearth of hydrogen
[H+] ions, or an excess of hydroxyl [OH-] ions, makes it basic.
Arsenic; Arsenic is a semi-metal that is used as a rat poison. In humans, it is essential in small
quantities for the integrity of the immune system, skin and the hair. The concentration of
arsenic in unpolluted water is less than 0.01 mg/l. It leads to skin lesions, sensory loss in the
peripheral nerves and gastrointestinal symptoms when found in increased concentrations
above 0.5 mg/l in ground water.
Cadmium; Cadmium is a highly poisonous metal, used for the protection of metals from
corrosion. The concentration of cadmium in unpolluted water is normally 0.01 mg/l. Elevated
concentrations exceeding 0.05 mg/l found in ground water can lead to nausea, vomiting,
diarrhoea, kidney damage and bone pains.
Calcium; Calcium is an alkaline earth metal that reacts with water to form calcium hydroxide. It
is essential for the building and maintenance of healthy bone structure. It is normally less than
10 mg/l in rainwater or soft water. High calcium concentration above 10 mg/l leads to the
development of kidney stones in sensitive people.
Chloride; Chloride is the negatively charged component of table salt. Its high concentrations
impart a salty taste to water and accelerate corrosion of metals. In fresh water, its
concentration is less than 10 mg/l. Health effects such as nausea and vomiting may occur at
concentration above 1200 mg/l in sensitive individuals.
Fluoride; Fluoride is an element needed during tooth formation for the hardening of the tooth
enamel. The concentration of fluoride in unpolluted water is 0.1-0.3 mg/l. Prolonged intake of
fluoride (>1.5 mg/l) can damage the skeleton, cause brittle bones, lead to crippling and lead to
coloration of the teeth (i.e. fluorosis).
Nitrate; Nitrate is the end product of oxidation process between ammonia and nitrite, and it is
needed as a plant nutrient. It is produced by the decay of plants, animals and human waste.
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Nitrate concentration is usually less than 2 mg/l in unpolluted water and more than 20 mg/l in
polluted water. Increased nitrate concentrations lead to tiredness; failure to thrive in sensitive
people and infants, and causes blue baby syndrome in newly born babies due to lack of oxygen.
Total Hardness; Total hardness is calculated as calcium and magnesium concentrations
expressed as mg/l calcium carbonate. Total hardness indicates whether the water is soft or
hard, and it relates to the ease or difficulty of lathering of soap. Increase in total hardness (>300
mg/l) leads to scaling problems in pipes.
Potassium; Potassium is an alkali metal, which is regarded as an essential dietary constituent.
Exposure to increased concentration (>100 mg/l) of potassium leads to disruption of heart and
muscular function, irritation of the mucous membranes and also causes nausea and vomiting.
Alkalinity; A parameter related to pH is alkalinity, or the buffering capacity (i.e. ability to resist
change in pH) of the water against acids. Water that has a high alkalinity can accept large doses
of an acid without lowering the pH significantly. Waters with low alkalinity, such as rainwater,
can experience a drop in the pH with only a minor addition of hydrogen ion. In natural waters
much of the alkalinity is provided by the carbonate/bicarbonate buffering system. Carbon
dioxide (CO2) dissolves in water and is in equilibrium with the bicarbonate and carbonate ions.
4.1.3 Radiological Characteristics
The development and use of atomic energy as a power source and mining of radioactive materials (e.g.
uranium mining in Siavonga and Lumwana in Zambia) have made it necessary to establish limiting
concentrations for the intake into the body of radioactive substances, including drinking water. The
effects of human exposure to radiation or radioactive materials are viewed as harmful and any
unnecessary exposure should be avoided.
Humans have always been exposed to natural radiation from water, food, and air. The amount of
radiation to which the individual is normally exposed varies with the amount of background
radioactivity. Water of high radioactivity is unusual. Nevertheless, it is known to exist in certain areas,
either from natural or man-made sources.
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4.1.4 Microbial Contamination
Microbial contamination refers to waterborne microorganisms (pathogen) from human and animals’
feacal wastes. These wastes contain a wide range of bacteria, viruses, protozoa and helmiths that may
be washed into drinking water supplies. A drop of feacal matter can contain millions of
microorganisms, which degrade the aquatic environment and constitute a health risk due to the
introduction of pathogenic microorganisms that cause water-borne diseases.
i. Viruses: (0.02 – 0.2 microns) smallest, most complex – requires a host cell to replicate.
Examples of the diseases include; influenza, hepatitis A.
ii. Bacteria: (0.2 - 5 microns), most prevalent micro-organism. Examples of the diseases include;
cholera, typhoid.
iii. Protozoa: (4 - 20 microns), may be able to form cysts that can stay alive without hosts and in
harsh environments. Examples of the diseases include; malaria, amoebiasis.
iv. Helminths: (40 – 100 microns), worms & parasites which derive sustenance at the host’s
expense. Examples of the diseases include; tapeworm, guinea worm.
Figure 3: Size comparisons
Helminths
Helminths
Bacteria
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Unlike physical and chemical parameters which are tested directly, the testing of microbiological
pathogens (viruses, bacteria, protozoa and helminthes) is quite different. Microbiological pathogens
are analysed indirectly by testing for the indicator microorganisms whose presence who indicate feacal
contamination of drinking water which in return indicate the likelihood of the actual microbiological
pathogens to be found in water.
Indicator microorganisms are measured in CFU/100 ml. CFU stands for colony forming unit.
The reasons for using bacterial indicator microorganism include the following;
• They are cheaper,
• They are easier to perform,
• They give faster results, and
• They do not require highly trained personnel even community volunteers can be trained to do
the testings.
Indicator Organisms; Organisms, whose presence indicate likely occurrence of waterborne pathogens:
Ideal indicators should fulfill several criteria:
• Always be present when pathogens are present;
• Share similar persistence and growth characteristics;
• Exist in larger concentrations for easy detection;
• Detection tests should be relatively simple, inexpensive;
• Detection tests should detect indicator org. only;
• Detection tests should be applicable to all types of water.
Two common indicator microorganisms are;
• Total Coliforms; these group of bacterial can originate both from the environment
(surrounding) and the feaces.
• Feacal Coliforms; these group of bacterial can only originate the small intestines there by very
good indicator of the presence of feaces. An example of this group is the Escherichia coli (E.
coli).
Feacal
contamination Pathogen Diseases Indicator
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UNIT 5: ONSITE WATER QUALITY MONITORING USING WAGTECH
5.0 Introduction
Onsite water quality monitoring is the most suitable and cost effective method of drinking water
testing and that it gives rapid results. To this end, there a number of technologies being applied in
carrying out onsite water testing. These include the use of Delaguar and Wagtech POTOLABs. This unit
explores the use of WAGTECH POTALAB.
The WAGTECH POTALAB is an advanced portable water quality laboratory for the long term monitoring
and surveillance of a wide and varied range of water quality parameters. This fully digital system
provides rapid and highly accurate results. The kit also reduces the reliance upon costly lab-based
analysis for advanced levels of monitoring.
5.1 Features
• Digital twin chamber incubator, featuring automatic timer and LCD display with maximum
capacity of 50 microbiological tests – allows simultaneous incubation of both faecal & total
coliforms.
• Separate hand-held digital meters for pH/mV, Conductivity/TDS & Turbidity.
• Direct-reading Digital Photometer for testing up to 40 different chemical parameters.
• Arsenator digital arsenic testing device, the world’s first low-cost field instrument capable of
measuring arsenic do wn to ppb levels. ppb means parts per billion.
• Supplied with consumables to carry out 200 microbiological tests.
• Supplied with reagents to carry out a minimum 200 tests each of Ammonia, Arsenic, Free and
Total Chlorine, Fluoride, Nitrites and Nitrates.
• All components housed in a single, lockable, water-proof aluminium carry case.
• Dimensions – 600 x 350 x 450mm (H x W x D)
• Weight – 25kg
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5.2 Water Sampling
Water sampling is the initial step of water quality testing which needs to be undertaken with caution in order to
collect a representative sample more especially when dealing microbiological water sample.
Sampling for physical and chemical parameters; Normally, plastic sampling bottles (1 litre) are used to collect
water directly from the water point. This to consider may include the following;
• Label the bottle before taking a water sample,
• Indicate the time for sampling,
• Do not touch the inside of the bottle,
• Sampling can then be followed by the onsite rapid analysis of the desired parameters,
Sampling for microbiological parameters; This is the very crucial in order to avoid the recontamination of the
collected sample. This to consider may include the following;
• Flame the water point to kill the pathogen at the opening of the water point (e.g. tap or borehole),
• Allow water to run for a minute and the collect your water sample using sterlised glass bottles,
• Do not rinse a sterlised bottle,
• Do not put the bottle cap on the ground while sampling,
• All the glass bottle to be filled to slightly over half to leave the air space which will allow the pathogens
which require oxygen to survive up to the actual analysis.
5.3 Water Analysis using WAGTECH
For the detailed procedures for the analysis of physical, chemical and microbiological parameters refer to the
WAGTECH Lab manual provided with the equipment.
5.3.1 Analysis of physical parameter
The following parameters can be analysed as showed in the table.
# Name of the physical parameter Name of the WAGTECH instrument
1 Electrical conductivity Conductivity/TDS Meter
2 Total dissolved solids (TDS) Conductivity/TDS Meter
3 Temperature pH/Temp Meter
4 Turbidity Turbidity Meter
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5.3.2 Analysis of chemical parameters
The following parameters can be analysed as showed in the table.
# Name of the physical parameter Name of the WAGTECH instrument
1 Arsenic Digital Arsonator
2 Ammonia 7500 Photometer
3 Free Chlorine 7500 Photometer
4 Total Chlorine 7500 Photometer
Fluoride 7500 Photometer
5 Nitrates 7500 Photometer
6 Nitrates 7500 Photometer
7 And many more depending on the availability of the reagents
7500 Photometer
5.3.3 Analysis of microbiological parameter
Microbiological parameters are analysed by the membrane filtration (MF) using the potable incubator and other
accessories for the same analytical method.
I wish to recommend that the present and absence (P/A) test be incorporated in the training so that the trained
Community Volunteers and EHTs can only do quantitative test of Total Coliforms on the suspected water points
to serve on the time and resources.
5.4 Interpretation of water quality data
They are three basic approaches to interpreting water quality monitoring results
i. Comparison
– Compare measured values to WHO Guidelines or ZABS national standards,
ii. Trend
– Compare results over time and/or location,
iii. Scientific/statistical
– Academic or scientific research
5.4.1 Steps to Interpret Results
1. Collect data sheets
2. Check data sheets
3. Choose an appropriate analysis
• Comparison
• Trend
• Scientific/statistical
4. Compare data to objectives
5. Report results
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Table 2: of the WHO guidelines and ZABS drinking water quality standards
No. Parameter Unit of measurements WHO / ZABS Limit for
drinking water
Physical Parameters
1 Electrical Conductivity mMhos/cm 1500
2 Total Dissolved Solids mg/l 1000
3 Turbidity NTU 5 / 15
4 Colour CTU 15
Chemical Parameters
1 Nitrates mg/l 10.0
2 Arsenic mg/l 0.05
3 Fluoride mg/l 1.5
4 Lead mg/l 0.05
5 Chloride mg/l 250
6 Total Hardness as CaCO3 mg/l 500
7 Iron mg/l 0.3
8 Manganese mg/l 0.1
9 DDT µg/l 1.0
10 pH - 6.5- 8.5
11 Residue Chlorine mg/l 0.2
Microbiological Parameters
1 Total coliforms CFU/100ml Absent in 100ml
2 Feacal coliforms CFU/100ml Absent in 100ml
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UNIT 6: SANITARY INSPECTION
6.0 Introduction
Water frameworks refer to the strategies or plans instituted to minimise the contamination of water
points with microbiological pathogens and thereby reduce on the outbreak of water-borne diseases. In
doing this, a number of steps are followed with the first step being a community survey. A community
survey or community field appraisal is an evaluation of all the factors and resources (physical and
human) that affect the water-supply service, sanitation, and environmental health of a community
(WHO, 1997). Such field appraisal should be conducted by the local authority office under the RWSS
and should include the following four components:
Basic data on water-supply and sanitation facilities with which to update the inventories (refer
also to the community appraisal forms). The water-supply data (and, in some circumstances,
sanitation data) are ideally the responsibility of the RWSS unit to confirm the information
submitted in the application form for a water point.
Sanitary inspection (comprising sanitary inspection of the water points and water quality
analysis).
6.2 Sanitary inspections
A sanitary inspection is an on-site inspection and evaluation of all conditions, devices, and practices in
the water-supply system that poses an actual or potential danger to the health and well-being of the
consumer. It is a fact-finding activity that should identify system deficiencies - not only sources of
actual contamination but also inadequacies and lack of integrity in the system that could lead to
contamination.
The primary focus of sanitary inspection is ensuring there is no feacal contamination of drinking water
at the source or household level. The health risks associated with the contamination of a water point
are categorised in to three namely (WEDC, 2002 :56);
i. Hazard factors; these are factors from which contamination may come from and are the
sources of faeces in the environment. Examples include pit latrines, sewer, animal husbandry,
solid waste dumps,
ii. Pathway factors; are those factors which do allow microbiological pathogens to get into water
supply, but are not a source of microbiological contamination. Examples include leaking pipes,
eroded catchment, areas or damaged protection works, and
iii. Indirect factor; are factors which enhance the development of pathway factors, but do not
allow either water directly into the water source nor are a source feaces. Examples include lack
of fencing, faulty surface water diversion, or poor drainage of waste water from the source.
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6.3 Functions of sanitary inspection report forms
In order to have more reliable sanitary inspection results, standardised forms have been designed for
various water points (copies of these forms to be availed in class). Each form has questions which are
scored and the total score is interpreted as high risk, medium risk or as low risk with respect to the
ability to cause diseases.
Inspection forms should provide a simple and rapid means of assessing and identifying hazards
associated with water-supply systems. Wherever sanitary inspections are carried out, there will
inevitably be a variety of systems to consider, and a decision must then be made on whether to
attempt to produce a single inspection form that deals with all types of system or to produce a series
of forms, each of them with dealing with a different type. Some of the information that it may be
useful to include on one inspection form may already have been collected for inventory purposes.
Again, a decision must be made on how much of this kind of detail is appropriate to include.
The inspection form should include at least a checklist of the components of the water supply from
source to distribution and incorporate all the potential points where hazards may be introduced. Any
problems identified during the inspection should be highlighted so that a report may be provided
directly to the community and copies forwarded to both supply agency and health authority (WHO,
1997).
The sanitary inspection report serves the following functions:
• identify potential sources and points of contamination of the water supply;
• quantify the hazard (hazard score ) attributable to the sources and supply;
• provide a clear, graphical means of explaining the hazards to the operator/user;
• provide clear guidance as to the remedial action required to protect and improve the supply;
• provide the raw data for use in systematic, strategic planning for improvement.
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Reference
Gaur R.C,. (2008). Basic Environmental Engineering: New Age International (P) Ltd., Publishers
A community Guide to environmental Health, 2008 (www.hesperian.org)
Hans-Joachim Mosler (2012): A systematic approach to behavior change interventions for the water and
sanitation sector in developing countries: a conceptualmodel, a review, and a guideline, International Journal of
Environmental Health Research,DOI:10.1080/09603123.2011.650156
Howard, A.G (2002): Water Supply Surveillance: A reference manual, WEDC, Loughborour University, UK
Jagadishwar BARUN, (2010): Household Latrine Options for Rural Hills of Nepal: SNV
Kamal Kar and Robert Chambers (2008):Handbook on Community-Led Total Sanitation (ISBN 978-0-9550479-5-
4), Plan - Uk
Sari Huuhtanen and Ari Laukkanen, (2006): a guide to sanitation and hygiene for the working in developing
countries: TAMPERE POLYTECHNIC - University of Applied Sciences Publications
To link to this article: http://dx.doi.org/10.1080/09603123.2011.650156
Training Manual on Hygiene and Sanitation Promotion and Community Mobilization for Volunteer Community
Health Promoters (VCHP)
UNICEF, (2007): Trainers Participatory Hygiene and Sanitation Promotion Manual, Kaduna
UNICEF, (1997): Towards better programming: Sanitation Handbook
UNICEF, (1999): A water handbook: Toward better programming, New York
WHO, (1997): Guidelines for drinking-water quality.—2nd ed. Geneva
WHO, (1987): Technology for water supply and sanitation in developing countries, Geneva.
WHO. (1998). PHAST Step-by-Step Guide: A Participatory Approach for the Control of Diarrhoeal Disease.
Geneva
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APPENDIX: FORMS USED IN SANITARY INSPECTION OF WATER POINTS
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