NATURAL RESOURCES DEVELOPMENT COLLEGE
WATER ENGINEERING DEPARTMENT
GROUNDWATER ASSESMENT
FINAL PROJECT REPORT
STUDENT ID: WE/17/30 | COURSE: WE 300 | DATE: 04/01/22
DECLARATION
I hereby declare that this work is a product of my own research efforts, undertaken under
the supervision of _________________ and has not been presented anywhere for the award
of a diploma. All sources have been duly and appropriately acknowledged.
Author
Name: ______________________ Signature ______________ Date: ________________
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CERTIFICATION
This is to certify that this report has been examined and approved for the award of the
diploma in Water Engineering at Natural Resources Development College.
External Examiner
Name: ______________________ Signature ______________ Date: ________________
Supervisor
Name: ______________________ Signature ______________ Date: ________________
Head of Department
Name: ______________________ Signature ______________ Date: ________________
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ACKNOWLEDGEMENT
I have taken efforts in this project. However, it would not have been possible without the
kind support and help of many individuals. I would like to extend my sincere thanks to all
of them.
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SUMMARY
Groundwater is the most reliable source for drinking water supply. hence, access to safe
water is a fundamental human need. I took interest in assessing the groundwater quality
for roads board area because of the following factors;
i.
Shallow water table which makes it easy for stormwater runoff / surface water
to interfere with ground water
ii.
Separation distances between wells and potential sources of contamination
which increases the level of vulnerability to contamination
The focus of the assessment was mainly on biological parameters and the study provides
treatment and management strategies to promote safe drinking water.
Laboratory Tests Conducted
•
pH test with phenol red.
•
Total Hardness with EDTA
•
Membrane Filtration
Results
Results from this study generally indicate that most water parameters complied with the
Zambian Bureau of Standards (ZABS) drinking water guideline values. However,
biological parameters which include total coliform and E coli did not meet ZABS guideline
values for drinking water although water supplies from these wells will not affect the health
of the consumers
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TABLE OF CONTENTS
Introduction………………………………………………………………...1
Literature Review……………………………………………………….….2
Study Area……………………………………………………......................3
➢ Geographical Description
➢ General Description
➢ Excreta Disposal
➢ Sample Collection
Methodology……………………………………………………..................5
➢ Ph Test with Phenol Red
➢ Total Hardness – Titration Method with EDTA
➢ Membrane Filtration
Analysis & Results………………………………………………………...11
➢ Lab report
➢ Analysis
Discussion…………………………………………………………….……12
➢ Treatment
➢ Separation Distances Required
➢ Investigative analysis of Shallow Water Tables & Groundwater Flow
Conclusion…………………………………………………………………15
References……………………………………….………………………...16
LIST OF FIGURES
Figure
Page
1
Study area
03
2
Sampling points
04
3
Storage of samples
04
4
Lab Report
10
5
Shallow water table
13
6
Well recovery
13
7
Plastic septic tank
14
8
Lined pit latrine
14
9
Well lining
14
INTRODUCTION
Groundwater is the most important source of fresh water supply for domestic, agricultural
and industrial purposes in the Eastern part of Zambia. In most cases, little or no treatment
is required prior to consumption as compared to surface water sources. But due to increase
in population, industrialization, utilization of composts in farming and other man-made
actions, groundwater is being polluted more than ever before. This makes it necessary to
access its quality in terms of chemical, physical and biological parameters.
1
LITERATURE REVIEW
Water is essential for life and for all economic activities. It is used for domestic, industrial
and agricultural purposes. Having sufficient water in sufficient quantity and quality
contributes to maintaining health. The availability of water of good quality is essential to
prevent diseases and to improve the quality of life. The use of water increased due to
increasing in human population and activities. Groundwater is one of the important
components in development of any area. It is the major potable, agricultural and industrial
source of water. In 2003, it was estimated that groundwater holds nearly 50% of the
drinking water supply, 40% of the demand for industrial water, and 20% of the water used
for irrigation. Globally, more than a third of water used by humans comes from
groundwater. In rural areas, the ratio is higher: more than half of all drinking water
worldwide is supplied from groundwater. Groundwater pollution can also result from
innumerable common practices, such as the use of fertilizers and pesticides as well as
disposal of human, animal and agricultural waste. Globally, many researchers have
conducted a study on the quality of groundwater and pollution sources affected by the
industrial and natural process. This concept has been developed from the vulnerability of
groundwater, which is therefore the most important part of the assessment of the risks of
groundwater contamination. Quality changes of surface water, such as rivers or lakes, may
be due to contamination of groundwater. In the past two decades, awareness of
groundwater pollution and contamination has been grown up. Groundwater contamination
effects becomes widely. Seven million people of United States drink contaminated water
yearly. The contaminated water which caused by vomiting, rash, hepatitis, diarrhea closed
all around the US beaches. Ground water pollution can lead to poor drinking water quality,
loss of water supply, degraded surface water systems, high cleaning costs, rising costs of
alternative water supply and / or potential health problems. The objective of this study is
review researches of groundwater pollution and contamination as well as pollution types
and the effects of groundwater contamination and pollution on public health. Some of
groundwater detection and remediation methods will be discussed in this review.
2
STUDY AREA
Geographical Description
Roads Board area is located on the Eastern part of Zambia under UTM Zone 36 Southern
Hemisphere and lies between (457649.02 m E, 8493700.69 m S) and (456496.50 m E,
8493443.75 m S). Covers an area of about 360 538 square meters. Below is the aerial view
of the area.
Figure 1 Study Area
General Description
The area has an approximate number of 500 of households and according to my research,
more than 80% depend on groundwater for fresh water supply.
Excreta Disposal.
Exposal of excreta in Roads Board area is mainly through pit latrines with a limited use
of flushing toilets.
3
Sample collection
The water samples were collected from three (3) different wells at random and due to the
fact that the groundwater table is shallow, sample collection was successfully done by
lowering a container about 30cm below the water surface and scooping up the water. The
scooping action ensures that no external water enters the sample container.
Figure 2 Sampling Points
Storage of samples
Although recommendations vary, the time between sample collection and analysis should,
in general, not exceed 6 hours, and 24 hours is considered the absolute maximum. It is
assumed that the samples are immediately placed in a lightproof insulated box containing
melting ice or ice-packs with water to ensure rapid cooling.
Figure 3 Storage of samples
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METHODOLOGY
Total Hardness – Titration Method with EDTA
Calcium hardness is the measurement of dissolved calcium in hot tub or pool water. Total
hardness, which is measured by different test kits, measures both the calcium and
magnesium present in water.
Items to collect
Description
Quantity
Black T Hardness Indicator Powder Pillow
1
Hardness 1 Buffer Solution
2ML
EDTA Titration Cartridge
1
Titrator
1
Delivery tube for Titrator
1
Graduated cylinder
1
Water, deionized
Varies
Test Procedure
1. Select a sample volume and titration cartridge from the table above.
2.
Insert a clean delivery tube into the digital titration cartridge. Attach the cartridge to
the Digital Titrator.
3. Hold the Digital Titrator with the cartridge tip up. Turn the delivery knob to eject air
and a few drops of titrant. Reset the counter to zero and clean the tip
4. Use a graduated cylinder or a pipet1 to measure the sample volume from Table 1 on
page 3.
5. Pour the sample into a clean, 250-mL Erlenmeyer flask.
5
6. If the sample volume is less than 100 mL, dilute to approximately 100 mL with
deionized water.
7. Add 2 mL of Hardness 1 Buffer Solution.
8. Swirl to mix.
9. Add the contents of one Black T Hardness Indicator Powder Pillow.
10. Swirl to mix.
10. Put the end of the delivery tube fully into the solution. Swirl the flask. Turn the knob
on the Digital Titrator to add titrant to the solution. Continue to swirl the flask. Add
titrant until the color changes from red to pure blue. Record the number of digits on the
counter.
11. Use the multiplier in Table 1 on page 3 to calculate the concentration. Digits used ×
digit multiplier = mg/L (or Gdh) total hardness as CaCO3.
PH test with Phenol Red
The test was done by using a tablet reagent containing a precise amount of phenol red.
Phenol red reacts in water at different pH values over the range 6.8 – 8.4 to produce a
distinctive range of colors from yellow to red.
Membrane Filtration
Coliforms, Total and E. coli
Total coliforms are a group of bacteria commonly found in the
environment, for example in soil or vegetation, as well as the intestines of
mammals, including humans. Total coliform bacteria are not likely to cause
illness, but their presence indicates that your water supply may be vulnerable
to contamination by more harmful microorganisms. Escherichia coli (E.coli)
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is the only member of the total coliform group of bacteria that is found only
in the intestines of mammals, including humans.
The Membrane filtration method provides a direct count of bacteria in water based on
the development of colonies on the surface of the membrane filter. A water sample is
filtered through the membrane which retains the bacteria. After filtration, the membrane is
placed on a selective and differential medium and incubated.
Items to collect
Description
Quantity
Broth ampule, m-ColiBlue24
1
Sterile buffered dilution water
1
Membrane filter, 0.45 micron
1
Petri dish with absorbent pad, 47-mm
1
Filtration apparatus with aspirator or pump
1
Forceps, sterilized
1
Incubator
1
Microscope, low-power
1
Pipet(s) for dilution or for sample volumes less than 100 mL, if necessary
1
Sample Volumes
Use a sample volume that is applicable to the sample type. For samples with a low level of
bacteria such as finished, potable water, use 100 mL of sample. Use less sample for nonpotable water or water that contains more bacteria.
7
When the approximate bacteria level is unknown, analyze three different sample
volumes. Use the results from the sample volume that shows approximately 20 to 200
colonies for each membrane filter.
When the sample volume is less than 20 mL (diluted or undiluted), add 10 mL of sterile
buffered dilution water to the filter funnel before the vacuum is applied. The additional
dilution water helps to apply the bacteria equally across the membrane filter.
\
Sample Dilution
Dilute samples that contain a high level of bacteria so that approximately 20 to 200 bacteria
colonies grow on the membrane filter. Use the steps that follow to make serial dilutions of
the sample.
1.
Wash hands thoroughly with soap and water.
2.
Invert the sample container for 30 seconds (approximately 25 times).
3.
Open a bottle of sterile buffered dilution water.
4.
Use a sterile pipet to add 11 mL of sample into the dilution water bottle.
5.
Put the cap on the dilution water bottle and invert for 30 seconds (25 times). This is a
10x dilution (sample is diluted by a factor of 10).
6.
Add 11 mL of the 10-fold dilution to another dilution bottle (100x dilution). Mix well.
7.
Add 11 mL of the 100-fold dilution to the third bottle (1000x dilution). Mix well.
8.
If necessary, continue to dilute the sample.
Membrane filtration test procedure
1.
Invert one m-ColiBlue24 broth ampule 2 to 3 times. Open the ampule. Lift the lid of
a petri dish and carefully pour the contents equally on the absorbent pad.
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2. Set up the membrane filtration apparatus. Use sterile forceps to put a membrane filter
in the assembly. Make sure that the grid side is up.
3. Invert the sample or the diluted sample for 30 seconds (25 times) to make sure that the
sample is mixed well.
4. Pour or use a pipet to add the sample into the funnel. If the volume is less than 20 mL,
add 10 mL of sterile buffered dilution water to the funnel
5. Apply the vacuum until the funnel is empty. Stop the vacuum.
6. Rinse the funnel with 20 to 30‑mL of sterile buffered dilution water. Apply the vacuum.
Rinse the funnel two more times.
7. . Stop the vacuum when the funnel is empty. Remove the funnel from the filter
assembly. Use sterile forceps to lift the membrane filter.
8. Put the membrane filter on the absorbent pad. Let the membrane filter bend and fall
equally across the absorbent pad to make sure that air bubbles are not caught below the
filter.
9. Put the lid on the petri dish and invert the petri dish.
10. Incubate the inverted petri dish at 35 ± 0.5 °C (95 ± 0.9 °F) for 24 hours.
11. Remove the petri dish from the incubator. Use a 10 to 15x microscope to count the
number of bacteria colonies on the membrane filter. Interpret and report the coliform
results.
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ANALYSIS & RESULTS
Lab Report
Figure 4 Lab Report
Analysis
All the water samples tested positive for total coliform and only sample 1 and 2 tested
positive for fecal coliform. The intensity of fecal coliforms indicate that the water may
contain disease causing bacteria. The pH ‘s of all the samples were found to be within the
permissible limits. However, the total hardness was unusually high.
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DISCUSSION
Coliform Bacteria – Total Coliforms & E. coli
Total coliforms are a group of bacteria commonly found in the environment, for example
in soil or vegetation, as well as the intestines of mammals, including humans. Total
coliform bacteria are not likely to cause illness, but their presence indicates that your water
supply may be vulnerable to contamination by more harmful microorganisms.
In water, coliform bacteria have no taste, smell, or color. They can only be detected
through a laboratory test.
Acceptable Concentration for Drinking Water = none detectable per 100 mL
The main source of pathogens in drinking water is through recent contamination
from human or animal waste, from
• Leaky or improperly treated septic and excreta disposal through unlined pit latrines
• Leaching of animal manure
• Stormwater runoff
Health Risks
The health effects of exposure to disease-causing bacteria, viruses, and parasites in
drinking water area varied. The most common symptoms of waterborne illness include
nausea, vomiting, and diarrhea. Infants, the elderly, and those with compromised immune
systems may suffer more severe effects. In extreme cases some pathogens may infect the
lungs, skin, eyes, nervous system, kidneys, or liver and the effects may be more severe,
chronic, or even fatal. You should not assume that your water is safe to drink just because
it has not made you sick in the past. If bacteria are present in your water, there is a risk that
it could make you ill.
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Treatment
Bacteria cannot be removed from water with pitcher-type carbon filters. Bacteria can be
removed by keeping water at a rolling boil for at least one minute. Effective treatment
methods for microbial contamination include
Boiling
To kill microorganisms, you must keep water at a rolling boil for at least one minute. Water
can be boiled either in a pot or kettle on a stove, in a microwave oven, or in an electric
kettle without an automatic shut-off.
• Permanent point-of-entry disinfection units, which can use
- Chlorine
Separation Distances Required.
Source of Potential Contamination
Type of Well
pesticide or fertilizer storage tank (less
Distance from Well
Dug well
15 m
Dug Well
30m
Public roads
All well
10m
Septic Tank
Dug well
10m
Liquid waste collection facility
Dug well
45m
than 1500 gallons
animal shelter or yard and feed storage
facility
The separation distances required are usually never met in most pre-urban areas due to
uncontrolled settlements.
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Investigative analysis of shallow water tables & groundwater flow
Shallow Water Table
The water table is the surface where the water pressure head is equal to the atmospheric
pressure. Shallow water table means a median depth of six metres and less to the
underground water table and this is the condition for roads board residence. The
groundwater in areas with such a condition is highly vulnerable to contamination.
Pathogens that may contaminate the water are most likely to come from stormwater runoff,
unlined pit latrines or leaky septic and it is evident that the major contributing factor to
contamination in roads board area is the present shallow table. See figure 4 below.
Figure 5 Shallow Water Table
Groundwater Flow
Normally groundwater flows down a gradient with gravity as the major driving force.
The flow usually gets disturbed by excess withdraw. As the well is recovering, the water
flows into the well from all directions forming a radio like pattern. See figure 5.
Figure 6 Well Recovery
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Investigative analysis of shallow water tables & groundwater flow
Conclusion
From the illustrations above, we note that, even when the separation distance required
between the well and source of contamination is met, groundwater still stands greater
chances of getting contaminated.
How can we safeguard groundwater in areas with shallow water tables?
We can successfully safeguard groundwater by the adaptation of the following.
1. Use of plastic septic tanks
Plastic septic tanks are watertight and are
immune to water-based corrosion. They are
also rust-resistant. Plastic tanks are less prone
to cracking since plastic is flexible, and thus
a plastic septic tank does not crack as much as
a cement septic tank.
Figure 7 Plastic Septic Tank
2. Construction of lined pit latrines
When properly built and maintained, pit
latrines can decrease the spread of disease by
reducing the amount of human feces in the
environment from open defecation. This
decreases the transfer of pathogens from
feces to groundwater.
Figure 8 Lined Pit Latrine
3. Raising well lining above land surface
This
prevents
stormwater
runoff
from
interfering with groundwater. Stormwater
runoff is generated from rain that flows over
land or impervious surfaces, such as paved
streets, parking lots and building rooftops.
14
Figure 9 Well Lining
CONCLUSION
Results from this study generally indicate that most water parameters complied with the
Zambian Bureau of Standards (ZABS) drinking water guideline values. However,
biological parameters which include total coliform and E coli did not meet ZABS guideline
values for drinking water although water supplies from these wells will not affect the health
of the consumers.
Remarks
Long term deterioration of water quality may lead to more costly water treatment.
There is need to;
I.
Formulate adequate community-based sensitization awareness campaign
programs on; for instance, pathways of pathogens into water supply sources and
what methods, at house hold level may be used to treat and safeguard water.
II.
III.
Have controlled settlements.
Do away with the use of unlined pit latrines.
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REFERENCES
1. Standard operating procedures for basic laboratory tests (Eastern Water &
Sanitation Company) 2020
2. Palin test (Rapid response portable water quality laboratory) 2013
3. Water supply (WE 251) lecture module (2020) by O. Mulenga (Natural Resources
Development College)
4. Hach Company/Hach Lange GmbH, 2007–2015.
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