BACTERIAL CONTAMINATION OF DRINKING WATER IN RURAL GHANA
Katherine Tracy Parker
B.S., Harvey Mudd College, 2000
THESIS
Submitted in partial satisfaction of
the requirements for the degree of
MASTER OF SCIENCE
in
BIOLOGICAL SCIENCES
at
CALIFORNIA STATE UNIVERSITY, SACRAMENTO
FALL
2011
BACTERIAL CONTAMINATION OF DRINKING WATER IN RURAL GHANA
A Thesis
by
Katherine Tracy Parker
Approved by:
__________________________________, Committee Chair
Robert Metcalf, Ph.D.
__________________________________, Second Reader
Susanne Lindgren, Ph.D.
__________________________________, Third Reader
Enid Gonzalez, Ph.D.
___________________________
Date
ii
Student: Katherine Tracy Parker
I certify that this student has met the requirements for format contained in the University
format manual, and that this thesis is suitable for shelving in the Library and credit is to
be awarded for the thesis.
_________________________, Graduate Coordinator
Susanne Lindgren, Ph.D.
Department of Biological Sciences
iii
_________________
Date
Abstract
of
BACTERIAL CONTAMINATION OF DRINKING WATER IN RURAL GHANA
by
Katherine Tracy Parker
The disease burden from the lack of biologically safe water to drink has been
observed in Ghana, where shallow hand-dug wells, deep-drilled boreholes, and other
point sources constitute the rural drinking water supply. The low-cost, easy-to-use
“Portable Microbiology Laboratory,” containing both a Colilert field test for the presence
or absence of E. coli, as an indicator of fecal contamination, and a Petrifilm field test to
enumerate E. coli colony forming units, was used to classify the disease risk of 146 rural
drinking water point sources and 21 household water storage units in two districts of
Ghana from "low" to "very high," in accordance with World Health Organization
standards.
The results showed that drinking water from 85% of boreholes was low risk of
disease, while only 6% of water from hand-dug wells and other surface point sources was
low risk of disease. This verified the strategy of the Ghana government of constructing
boreholes to improve the safety of drinking water for the rural population. Use of the
Portable Microbiology Laboratory to test water stored in homes, which had been obtained
from the nearby borehole, showed generally higher disease risk in the home-stored water
than in the water directly from the borehole. The results also demonstrated variations in
iv
the disease risk by region and changes in the disease risk for particular point sources over
a relatively short period of time.
This study demonstrated the effectiveness of the water tests in the Portable
Microbiology Laboratory in rural Ghana to rapidly identify drinking water sources that
had a high risk of disease.
___________________________, Committee Chair
Robert Metcalf, Ph.D.
___________________________
Date
v
ACKNOWLEDGMENTS
Many thanks to Gabriel M. Nartey, Gershon Hiamadey, and the members of the
Suhum District Water and Sanitation Team who provided transport via governmentissued motorbike, translation, community connections, and valuable insights. Their
support made testing in the Suhum District possible.
Similarly, testing in the Nanumba District was only able to occur because of the
transport, translation, community connections, and commitment to community
improvement of Abu Mutaru Abass, who served as an Area Coordinator for Guinea
Worm Eradication.
Theo Mensa, who is an engineer for the Eastern Region Water and Sanitation
Team, provided access and information that substantially furthered my understanding, as
did Charlotte Engmann, an engineer working out of CWSA headquarters.
Hospital personnel graciously provided, and I much appreciated, the Monthly
Out-Patient Morbidity Returns for the Suhum-Kraboa-Coaltar District Hospital in the
Eastern Region of Ghana, for the period of January to December 2005 and January to
September 2006.
Joseph Ampofo generously shared his experience in water testing in Ghana and in
the current practices and procedures of the country's national laboratory for biological
water quality assessment.
vi
The faculty and staff at the University of Ghana, Legon were dedicated to
providing a rich learning environment. Special thanks to Irene Odeti, who expertly
facilitated my presence in Ghana in an exchange between California State University,
Sacramento and the University of Ghana, Legon. Professor F.K.E. Nunoo in the
Department of Oceanography and Fisheries provided expert advice and guidance for this
research effort while I was in Ghana and gave helpful comments on early drafts.
vii
TABLE OF CONTENTS
Acknowledgments.............................................................................................................. vi
List of Tables ...................................................................................................................... x
List of Figures .................................................................................................................... xi
INTRODUCTION .............................................................................................................. 1
Context of the Study ....................................................................................................... 1
Water Surveillance .......................................................................................................... 2
E. coli Direct Testing as an Indicator of Water Quality ................................................. 7
Water Safety Plan ......................................................................................................... 13
Objectives ..................................................................................................................... 15
MATERIALS AND METHODS ...................................................................................... 18
Study Sites and Sample Collection ............................................................................... 18
Colilert Defined Substrate Medium (10 ml test)........................................................... 19
E. coli Count Petrifilm (1.0 ml test) .............................................................................. 21
Visual Sanitation Survey of Boreholes ......................................................................... 22
Statistical Analysis ........................................................................................................ 22
Quality Assurance ......................................................................................................... 23
RESULTS ......................................................................................................................... 25
Contamination Levels in Hand-dug Wells and Other Shallow Sources ....................... 27
Contamination Levels in Boreholes .............................................................................. 33
Visual Sanitation Survey of Boreholes ......................................................................... 39
viii
Novel Testing Method for 100 ml Samples .................................................................. 39
Independence of Well Sources Within a Community................................................... 42
Comparison of Boreholes and Hand-dug Wells ........................................................... 42
Comparison of Disease Risk Across Geographical Variation ...................................... 45
Comparison of Disease Risk Across Seasonal Difference ........................................... 45
Contamination Levels in Household Water Storage Units ........................................... 48
DISCUSSION ................................................................................................................... 53
Point Sources ................................................................................................................ 55
Comparisons ................................................................................................................. 61
Application of Findings ................................................................................................ 72
APPENDICES .................................................................................................................. 80
Appendix A. Management of the Rural Water Supply in Ghana .................................... 81
Appendix B. Water Facilities Monitoring Sheet for WatSans .......................................... 86
Appendix C. Survey of Point-Source Water Supply ........................................................ 89
Literature Cited ................................................................................................................. 91
ix
LIST OF TABLES
Table 1. Determination of WHO disease-risk categories for drinking water and
correlation of Colilert and E. coli count Petrifilm results with risk
categories. ....................................................................................................... 11
Table 2. Test results for drinking water from shallow, hand-dug wells. ..................... 30
Table 3. Test results for drinking water from open water sources............................... 32
Table 4. Test results from boreholes in the Suhum District during the short rainy
season (October). ............................................................................................ 35
Table 5. Test results for boreholes in the Nanumba District during both the dry
(March) and rainy (June) seasons. .................................................................. 36
Table 6. Comparison of disease-risk level of water sources within and between
communities. .................................................................................................. 43
Table 7. Comparison of WHO disease-risk levels in paired water test results for
boreholes in the Nanumba District during two seasons, dry and rainy. ......... 47
Table 8. Water test results from household storage units in the Nanumba District,
rainy season. ................................................................................................... 50
Table 9. Order of magnitude change comparison of contamination levels in
households to the contamination level at the nearest borehole. ..................... 52
x
LIST OF FIGURES
Figure 1. Using the Portable Microbiology Laboratory in Ghana. ................................... 26
Figure 2. Surface and shallow water sources at each WHO disease-risk level in the
Suhum District. .................................................................................................. 31
Figure 3. Comparison of boreholes by region and season at each WHO disease-risk
level. ................................................................................................................... 38
Figure 4. Comparison of boreholes at each WHO disease-risk level for various score
ranges on the sanitation survey. ......................................................................... 40
Figure 5. Comparison of Colilert test results from 10 ml and 100 ml borehole samples. 41
Figure 6. Comparison of boreholes and hand-dug wells in the Suhum District at each
WHO disease-risk level. .................................................................................... 44
Figure 7. Comparison of boreholes at each WHO disease-risk level in the Nanumba
District during two seasons, rainy and dry......................................................... 46
Figure 8. Comparison of closest boreholes and household drinking supplies in
Nanumba District (rainy season) at each WHO disease-risk level. ................... 51
Figure 9. A University of Ghana teaching assistant talks to a group of school children
about the importance of proper well maintenance. ............................................ 71
Figure 10. The District Water and Sanitation Team can simultaneously take a variety
of measurements and perform maintenance on a borehole. ............................... 75
xi
1
INTRODUCTION
Context of the Study
The international community well recognizes the importance to public health of
sufficient quantities of safe drinking water. The United Nations emphasizes the
importance in declaring 2005-2015 the International Decade for Action: Water for Life.
Similarly, Target 7.C of the Millennium Development Goals of the United Nations is to
“halve, by 2015, the proportion of the population without sustainable access to safe
drinking water and basic sanitation.”
Worldwide, approximately 2.6 billion people do not have access to improved
sanitation and approximately 900 million people are without improved drinking water
sources (40). The lack of safe water contributes to the approximately 4 billion cases of
diarrhea and about 1.8 million deaths every year in developing countries (40). Of these
deaths, 90% are of children under five, which accounts for about 19% of total child
deaths (4, 32). The global disease burden from diarrhea in developing countries has also
been observed in Ghana, where this study is focused (Suhum-Kraboa-Coaltar (Suhum)
District Hospital, personal communication).
For rural and small-town communities in Ghana, the responsibility for promoting
and sustaining a safe water supply is delegated to the Community Water and Sanitation
Agency (CWSA). The CWSA coordinates the construction of community-owned and
managed sources of drinking water in rural areas. (For further background, see Appendix
A.) These are “point sources” and primarily take the form of boreholes, which are deep-
2
drilled wells (50 to 120 m) with an attached hand-pump. Some communities also have
alternative point sources available, such as shallow, cement-lined, hand-dug wells (10 to
30 m, with or without a pump), rainwater collection systems, and ponds that are seasonal
or year-round. The testing of biological water quality in such point sources and how that
testing relates to the public safety policy of CWSA to drill boreholes in replacement of
alternative sources of rural drinking water is the context of the study addressed by this
paper.
Water Surveillance
Since the 1880s when cholera, typhoid and bacterial dysentery (shigella) were
demonstrated to be caused by pathogenic bacteria, microbiological quality has been
recognized to be one of the characteristics that is important to a community’s drinking
water supply. In addition to the microbiological quality, indicators that are important in
the surveillance of water to ensure that it meets the needs of the community include: (1)
per person daily quantity used, (2) the reliability of the supply, (3) the cost, and (4) the
percentage of the population with access (16). The CWSA periodically, though
infrequently, studies water usage and collects information on all of these indicators
except for microbiological quality. “District Water and Sanitation Teams” in the CWSA
Eastern Region, for example, as part of their management responsibilities in partnership
with village-level water and sanitation committees (WatSans), use a “Water Facilities
Monitoring Sheet for WatSans” to collect data on indicators one through four for
boreholes and hand-dug wells with hand-pumps and rainwater catchments (Appendix B).
3
The CWSA data collection for microbiological water quality in Ghana, however, is
limited by the availability of laboratory facilities that can perform traditional monitoring
tests and by the cost and time involved in transporting samples. These are major
limitations, which lead to few tests and long intervals of time between microbiological
testing. This is an unfortunate circumstance for the health of rural communities in Ghana
insofar as reducing the risk of waterborne diseases. Studies have found that the
microbiological quality of water can vary significantly over short periods of time and
therefore water should be monitored frequently to ensure low disease risk to the
community using the supply (1, 16).
Concern about Fecal Contamination of Drinking Water. Microbiological
pathogens that are transmitted by the fecal-oral route, especially those originating from
human feces, are of particular concern for water quality surveillance programs focused on
public health. Fecal-oral pathogens can be transmitted from the excreta to the mouth via
water, flies, hands, or food (16). Bacteria that cause fecal-oral infections include
Campylobacter jejuni (dysentery), Escherichia coli (diarrheal infection or dysentery),
Shigella spp. (dysentery), Salmonella spp. (acute diarrheal infection), Salmonella typhi
(typhoid fever), Yersina enterocolitica and Y. pseudotuberculosis (acute diarrheal
infection), and Vibrio cholerea (cholera).
Studies have shown that diarrheal disease in developing countries can be reduced
in occurrence by 20% through increased water availability, which provides the
opportunity for increased effective hand washing (32). Furthermore, improved drinkingwater quality can lead to a reduction in occurrence of adult diarrhea by 15% and up to a
4
40% reduction for infant diarrhea when provided in conjunction with appropriate sewage
disposal (32).
In addition to bacterial pathogens, viruses transmitted in fecally-contaminated
water are well recognized as agents of diarrheal disease and mortality (16). Of particular
concern for children is Rotavirus, which is the number one cause of diarrheal disease and
infant mortality in developing countries today. Viruses such as Hepatitis A and E (fever
and jaundice) and Norwalk agent are also spread by fecal contaminated water. Several
protozoa are the cause of fecal-oral infections, including Entamoeba histolytica
(protozoal diarrhea), Giardia lamblia (protozoal diarrhea), and Cryptosporidium parvum
(protozoal diarrhea).
Water Testing Policy in Ghana. Testing drinking water for biological quality is
essential in providing information about disease risk and when disinfection methods are
needed to protect public health. What, though, is the optimal frequency of such testing for
the protection of public health? The CWSA policy at the time of this study only
recommended the microbial testing of two boreholes per district every year. In the Suhum
District of Ghana's Eastern Region, for example, there are 181 boreholes located in 98
communities. The CWSA policy results in testing only one percent of the Suhum District
sources each year, a frequency that presents three questions of adequacy: (1) Will testing
a well once per year ensure the quality of the water for the entirety of the year? (2) Will
testing only 1% of the water point sources in a district ensure the quality of all the
sources in the district? (3) Will testing only two sources give a sufficient picture of the
situation in the district to validate that the policy is effective in meeting its goals?
5
More extensive testing, it would appear, is not a CWSA priority for public health.
Why? A major reason water quality testing is sometimes given lower priority in public
health discussions in developing countries (far behind HIV/AIDS, malaria, and
tuberculosis discussions, e.g.), is the perception of limited availability of modern and
efficient water testing procedures. Unfortunately, the procedures and equipment most
widely known to be available, as discussed further below, are obsolete or cumbersome.
History and Development of Water Testing. The general importance of water
quality and testing to insure good water quality has long been established. In the 1880s,
typhoid fever, cholera, and bacterial dysentery (Shigella sp.) were discovered to be
caused by bacteria entering water from fecal contamination, which lead to a general
recognition of the importance of water testing to public health. Because testing directly
for all pathogens is impractical, microbiologists sought a universal microbial indicator of
fecal pollution and identified Escherichia coli (E.coli) as the best indicator (10, 12, 14,
35).
E. coli were acknowledged as the best indicator of recent fecal contamination
because it is universally present in large numbers in the feces of humans and warmblooded animals; it does not multiply once it leaves the body and enters water; it survives
in water and is removed from water in a manner similar to waterborne pathogens; and it
is relatively easy to detect (10, 12, 14, 35). Thus, the WHO established that the presence
of E. coli provides conclusive evidence of recent fecal pollution and therefore E. coli
should not be present in drinking water (39).
6
Measurement of Indicator Bacteria. There are two general types of
bacteriological assessment of water quality, quantitative and qualitative. In the
quantitative method, the number of bacteria is expressed as colony forming units (cfu)
per volume of water. This term comes from counting the number of colonies that grow
either on a membrane filter or in a Petri plate. The qualitative option is to report the
presence or absence (P/A) in a set volume of water, typically 10 ml or 100 ml. A P/A test
can also be used to estimate the microbial concentration (cfu per volume) using multiple
and varying sample volumes (typically nine tubes: three dilutions in triplicate). This is a
maximum likelihood analysis method and is reported as a Most Probable Number
(MPN).
Thermotolerant Coliform Test. A century ago, there was no simple test
specifically to identify E. coli. Substitute tests were developed based on the ability of E.
coli to produce gas from lactose at 44-44.5°C. This test was first called the fecal coliform
test. (Although E. coli is a coliform bacterium, the term “coliform” as used in this paper
will refer to coliforms other than E. coli.) The fecal coliform test was later renamed the
thermotolerant coliform test, as some coliform bacteria besides E. coli, particularly
members of the genus Klebsiella, may also produce gas from lactose at this elevated
temperature. Klebsiella grow in the environment and are not indicators of fecal pollution.
Because of this ambiguity in interpretation of test results, the thermotolerant test is not
considered today to be a definitive measure for the presence or absence of E. coli without
follow-up confirmation (12, 22, 35). WHO regards the thermotolerant test as a less
7
reliable, but acceptable, index of fecal pollution when specific testing for E. coli is not
performed (39).
In the rare occasions when water testing is performed in Ghana, and in most other
developing countries, the thermotolerant test is performed. This requires an autoclave to
sterilize the lactose containing tubes used in the test, incubators at 35°C and 44° or
44.5°C, and trained personnel. Where field-testing kits are available, such as Oxfam’s
Del Agua unit, Wagtech Potatest, or the ELE Paqualab, they are expensive, bulky and
cumbersome. They can be transported by car or truck, but not by motorbike. Not only do
they require extensive media preparation and in-field disinfection supplies, they also
require battery power to run the incubator, which is not available in most rural areas of
Ghana.
E. coli Direct Testing as an Indicator of Water Quality
In the 1980s, advances in the understanding of genomic type bacteria of the
family Enterobacteriacia led to the discovery that E. coli, but not other coliforms,
contained the constitutive enzyme β-glucuronidase. This discovery enabled direct testing
for E. coli in water, which makes the inexact coliform and thermotolerant coliform tests
obsolete. The new tests, including Colilert and Petrifilm, discussed below, detect and
enumerate E. coli easily, rapidly, cheaply, and independently of an equipped laboratory
(1, 7, 11, 13, 15). Because of these advances, neither coliforms nor thermotolerant
coliforms, the older targets of testing, are now considered to be acceptable substitute
indicators for E. coli (22).
8
P/A Testing for E. coli with Colilert. In 1987, IDEXX Laboratories, Inc.
(Westbrook, Maine) introduced the Colilert test, where MUG (4-methyl-umbelliferyl-βD-glucuronide) is the substrate for glucuronidase and is hydrolyzed to the fluorescent 4methyl-umbelliferone (MU) and glucuronide, which E. coli uses as an energy source for
growth (12). The Colilert test also contains the substrate ONPG (o-nitrophenyl β-Dgalactopyranoside), for the β-galactosidase enzyme present in all coliform bacteria. This
is hydrolyzed to release the yellow o-nitrophenyl (ONP). Environmental coliforms will
only turn the Colilert tests yellow, whereas E. coli will also cause a blue fluorescence
when a long-wavelength ultra-violet (UV) light shines on the sample. After approval by
the U.S. Environmental Protection Agency (EPA) and international organizations, the
Colilert test has come to be used in over 90% of all U.S. state labs and more than all other
methods combined in the U.S., Canada and Japan drinking water markets (20). In the
U.S., a 100 ml Colilert P/A test is most often performed on treated drinking water, as
U.S. drinking water standards are based on the absence of any coliform bacterium in 100
ml (42). When the Colilert method was first introduced, it came in a small test tube to
which 10 ml of water was added. This was because the EPA standards at that time (1988)
were for no coliform in 50 ml of water and inoculation of five 10 ml P/A tubes could
provide some information on the extent of coliform contamination in a 50 ml sample. In
1989, when the EPA standard shifted to no coliform in 100 ml, use of the Colilert shifted
from the 10 ml P/A to a 100 ml P/A snap-pack of reagents. Fortunately, however, IDEXX
still produces the 10 ml P/A test.
9
Enumeration of E. coli with Petrifilm. In the U.S. food industry, the most widely
used test to detect E. coli in foods is the E. coli Count Petrifilm, developed by the 3M
Company (St. Paul, Minnesota). In this test, approved by the Food and Drug
Administration (FDA), a violet-red bile medium contains the glucuronidase substrate
BCIG (5-bromo-4chloro-3-indolyl-β D Glucuronide). One ml of a food dilution is added
to a circle of dried nutrients, which is then covered with a transparent plastic film and
incubated for up to 24 hours at 35°C. If E. coli bacteria are present, a blue colony will
develop, as BCIG is hydrolyzed to release the insoluble blue BCI. Gas bubbles also form
around the E. coli and other coliform colonies, as lactose in the medium is fermented to
acid and gas. Although the E. coli Count Petrifilm was not intended to be used for
drinking water in the U.S., because it samples only 1 ml and not 100 ml, it has been
effective in detecting E. coli in raw water sources where E. coli concentrations are >1/ml
(26, 33, 36).
Determination of WHO Categories for Risk of Disease from Water Using the
Colilert and Petrifilm Tests. The WHO standard for a very low risk of disease using a
P/A test of E. coli in water intended for human consumption is “A” (Absent, zero
tolerance) in 100 ml of water. This is also the drinking water standard in developed
countries with chlorinated water systems (42). However, because the great majority of the
rural water supply, especially in developing countries, is not chlorinated and has
widespread occurrence of fecal contamination, other disease-risk categories are also
included in the WHO standards: low, moderate, high, and very high (37). WHO suggests
10
that the tolerable risk levels need to be set for each country based on goals to make
progressive improvements in the water supply (39).
By combining the results of the 10 ml Colilert P/A test with the results of the 1 ml
Petrifilm test, four WHO disease-risk categories can be determined based on differences
in E. coli concentrations (Table 1). The quantity of 10 ml for the Colilert P/A test is
important, as it distinguishes water that has a low disease risk from water that does not
have a low disease risk. The quantity of 1 ml tested by the Petrifilm is important to
identify high- or very-high-disease-risk water sources.
The combination of Colilert and Petrifilm tests cover a four-log difference in E.
coli counts, which would be challenging for a single test to cover. These are low, < 1 cfu
in 10 ml; moderate, 1-10 cfu in 10 ml; high, 1-10 cfu in 1 ml; and very high, >10 cfu in 1
ml. To be precise, the most favorable category is not designated "safe" or "zero" presence
of E. coli or waterborne pathogens, but "low disease risk” (16).
11
Table 1. Determination of WHO disease-risk categories for drinking water and
correlation of Colilert and E. coli Count Petrifilm results with risk categories.
Disease-risk Level
Low
Moderate
High
Very High
E. coli in sample
< 1 cfu per 10 ml
1 – 10 cfu per 10 ml
1 – 10 cfu per ml
> 10 cfu per ml
Colilert MUG +
+
+
+
# Blue Colonies + gas
on Petrifilm
0
0
1 – 10
> 10
12
The Portable Microbiology Laboratory. In order to test water at its source, the
Colilert tubes and Petrifilms are combined with sterile plastic pipettes and collecting
bags, and a hand-held, long-wave UV light to form a “Portable Microbiology
Laboratory” (27, 28). As the tests are stable at room temperature, no special storage
conditions are required and materials for 25 of each test can be included in a one-gallon
plastic bag.
The Portable Microbiology Laboratory is suited to identifying and enumerating
both E. coli and coliforms in ranges of concentrations similar to what have been found in
other studies in Ghana, without needing to guess at concentrations before sampling (2,
29). For example, a study of three rivers in Ghana, using thermotolerant by membrane
filtration, resulted in a range of 66 to 1848 cfu/100 ml (2). Although the low counts could
be detected filtering 100 ml, direct testing of water from the most contaminated sources
would result in a clogged filter. Dilutions would have to be made so that the amount of
source water actually filtered was only 1-5 ml. By using the combination of Colilert and
Petrifilm tests, results with a similar level of detail could be obtained with direct testing
for E. coli and without guessing about dilutions to filter.
Because the Colilert and Petrifilm tests are ready to use with the addition of
water, they are practical to use in the field. As E. coli counts need to reach approximately
106 to form a visible blue colony on Petrifilm and about 107/ml to give a MUG positive
test in Colilert, a single E. coli cell in these tests would have to double 20-24 times,
respectively, to reach these levels. As E. coli grows most rapidly at body temperature of
near 35°C, if ambient temperatures are <30°C and results are desired within 12-18 hours,
13
one can incubate Petrifilm and/or Colilert tubes on one's body. In addition, the simplicity
of performing these tests and interpreting the results creates the possibility of involving
community members in testing their water sources.
Water Safety Plan
WHO Guidance. The primary aim of the WHO Guidelines for Drinking Water
Quality is the protection of public health. In order to implement the guidelines within a
national context, WHO also recommends each nation develop a Water Safety Plan and
has published guidelines for such a plan that outline a disease-risk management
framework (38). The need for, and practice of, water testing in order to monitor effective
treatment practices in pipe distribution systems is well established. However,
microbiological testing is rarely employed in systems where individual families access
water from a point source.
In order to meet health-based targets in point source supply areas, the first goal is
usually to improve access and quantity of water available, so that all communities meet
intermediate access service levels (17). According to the most recent WHO and UNICEF
statistics, only 74% of the rural population of Ghana has access to "improved" sources of
water that include both boreholes and hand-dug wells (40).
In a point-source system, a Water Safety Plan should include “health outcome
targets” that are set at the national level. However, “performance targets” of a particular
point source that are of concern to the local community are not necessarily within the
14
scope of priorities at the national level, but should be monitored by the community
operator (39).
The Portable Microbiology Laboratory is a combination of effective tests that is
particularly suited to several steps in the development of a Water Safety Plan for point
sources. WHO has developed a model water safety plan for monitoring and verifying
boreholes fitted with a hand-pump (38). Within the framework of a Water Safety Plan,
microbiological testing of point sources can serve three purposes: (1) system assessment
as a baseline to set policy, (2) community-based self-monitoring and management of
sources, and (3) verification/validation of policy and surveillance (38).
Community-based Monitoring. The role of water-quality monitoring within
WHO’s model Water Safety Plan for boreholes is relegated to a community operator. In
Ghana, this was primarily the role of the WatSan committee, with mobilization and
assistance from the CWSA officers. With regard to microbiological testing, the WHO
model plan has the community operator check on a monthly basis for leaching of
microbial contaminants into the aquifer by verifying that there is no source of fecal
material within the setback distance. In the areas of this research, where sanitation
facilities were largely non-existent, this would include establishment of a well-marked
fecal-free zone. Enforcement of a policy to maintain animals at a safe distance and
prevent human free-range defecation within that zone, as well, would then be within the
ability of the community operator. Thermotolerant coliform microbiology testing is
prohibitively expensive and technologically impossible to do in this context. However,
use of the Portable Microbiology Laboratory, in conjunction with regular sanitary
15
inspection, would enable the community operator to monitor the community water
sources and to share the results of these tests with the community. The community would
then have evidence-based microbiology upon which to self-identify sources of
contamination and take corrective action.
Suitability for Community-managed Water Supplies. The rural water supply
systems in Ghana fall under the classification of “community-managed supplies.”
Community-managed water supplies include simple piped systems and a variety of point
sources such as boreholes, dug wells and protected springs. This range of water sources
poses a problem for surveillance using traditional methods, because the dispersed nature
of these small-scale water supplies increases the cost of surveillance.
Taking all of the foregoing into consideration, then, and in particular the context
of advances in water testing technology and concern about public health in the
developing world relative to biologically safe drinking water, and being mindful of WHO
guidance and the governmental infrastructure in Ghana, this author developed some
hypotheses for study.
Objectives
I hypothesize that the Ghana Community Water and Sanitation Agency (CWSA)
is meeting its mandate of providing low-disease-risk drinking water (defined here as a
tolerable disease-risk level of no E. coli in 10 ml of water) through the construction of
boreholes. I have five subsidiary hypotheses.
16
(1) There will be a lower level of E. coli contamination in boreholes than in handdug wells and open sources.
(2) There will be a lower level of E. coli contamination in boreholes during the
dry season than during the wet season.
(3) There will be a lower level of E. coli contamination in boreholes in the
Northern, arid region (Nanumba District) than in the Southern, tropical region
(Suhum District).
(4) There will be a lower level of E. coli contamination in boreholes not
associated with risk factors.
(5) There will be a lower level of E. coli contamination in boreholes than in
household storage units for water.
A further goal of this study is to evaluate the effectiveness of the Portable
Microbiology Laboratory and to share these methods with governmental agencies that are
involved in water quality and with non-governmental organizations (NGOs) that sponsor
drinking water projects.
This research has several original components. Ghana government agencies that
have responsibility for water-quality monitoring rarely perform any tests in rural areas,
and the tests they do perform are the inexact and cumbersome thermotolerant tests. My
project is the first extensive use of the Portable Microbiology Laboratory in rural Ghana,
and the first attempt to involve community members in Ghana in the testing of their water
sources. This study has introduced Ghana government agencies to innovative methods for
testing E. coli in water in rural areas. The demonstration in this study of the usefulness
17
and practicality of the Portable Microbiology Laboratory may encourage adoption of
these tests by government agencies, leading to significant improvements in public health
in Ghana.
18
MATERIALS AND METHODS
Study Sites and Sample Collection
The two study sites for this research were the Suhum-Kraboa-Coaltar (Suhum)
District, Eastern Region, Ghana and the Nanumba-North (Nanumba) District, Northern
Region, Ghana. The Suhum District is located at latitude 6 N. in a moist, semideciduous forest, Celtis-Triplochiton Association, and partially includes a rain forest
transition zone. The Nanumba District is located at latitude 9 N. in the Guinea Savannah
Woodland. Twenty-five communities were selected in each district. All available
(functioning) point sources of water in each community were sampled, typically one to
four point sources per community. Point sources included boreholes (deep drilled wells
with hand pumps, >50 m), shallow hand-dug wells (<30 m) with and without hand
pumps, a rainwater collection system, and ponds. Additionally, two rivers used as water
sources were also tested as shallow, open sources. An emphasis was placed on sampling
boreholes. Flaming was not used to sterilize the pump outlet, because the desire was to
know the quality of water being collected by the users. For wells with bucket retrieval, a
sterile, 4 oz. stand up Whirl-Pak (Nasco, Modesto, California) was filled from the bucket
typically used by the community for this purpose, or by lowering the Whirl-Pak on a rope
into the well. In the Suhum District, 33 samples from unique boreholes were collected
during the short rainy season (October). In the Nanumba District, samples were collected
from 47 unique boreholes, twice from each of 32 point sources, including 40 samples in
the dry season (March) and 39 samples in the rainy season (June). One sample from the
19
drinking water supply in the household closest to the primary point source was tested in
each community in the Nanumba District during the rainy season. The household closest
to the borehole was chosen to be tested in an attempt to limit the impact of introducing
water from multiple sources into the storage unit, which could have residual impact on
water quality.
Colilert Defined Substrate Medium (10 ml test)
The detection of coliform and E. coli in 10 ml and 100 ml samples was performed
using the Colilert Defined Substrate Medium (IDEXX Laboratories, Westbrook, Maine).
The Colilert media contains no organic sources of nitrogen and only two carbon sources
as energy (ONPG and MUG), which discourages the growth of most heterotrophic
bacteria.
The enzyme -galactosidase for metabolizing lactose is an inducible enzyme
produced by all coliform bacteria, including E. coli. This enzyme also hydrolyzes the
colorless carbon source Ortho-nitro-phenol-β D-Galactopyranoside (ONPG) into the
sugar galactopyranoside (G) and o-nitrophenol (ONP), which has a bright yellow color
(11). The yellow color indicates the presence of coliforms.
The enzyme -glucuronidase is constitutively expressed by greater than 95% of
all E. coli strains, and can hydrolyze the colorless carbon source 4-methyl-umbelliferone
β-D-Glucuronide (MUG), forming the fluorescent product 4-methyl-umbelliferone (MU)
and a sugar (11). MU fluoresces under UV light (340 nm). E. coli is the only coliform
that constitutively produces β-glucuronidase, although strains of bacteria in the genus
20
Salmonella, Aerococcus, Bacillus and Klebsiella have also been shown to have βglucuronidase activity (6).
When grown in Colilert media, a pure culture of E. coli will first consume the
MUG, causing the tube to fluoresce, and then consume the ONPG, causing the tube to
turn yellow. Without E. coli, or when a different coliform dominates in a mixed culture,
the β-D-galactopyranoside will be consumed first, causing the tube to appear yellow
before it fluoresces.
Glass tubes, pre-dispensed with Colilert media from the manufacturer, were
marked to indicate a 10 ml volume of water. Water collected in the sterile Whirl-Pak was
immediately transferred to the glass tubes using a sterile pipette. The tube was then
incubated against the body of the author (approximately 37C). After 16-24 hours, the
tube was checked for the presence of E. coli, as indicated by fluorescence when a longwave, battery-operated UV light was shown on it.
If the 10 ml sample were negative for ONPG and/or MUG, the 10 ml was
transferred to the reserved 90 ml sample in the sterile Whirl-Pak. The Whirl-Pak was
placed in a black bag in the sun for 18 hours. This provided a test for the presence or
absence of E. coli in 100 ml, the standard for very-low-disease-risk or treated water. The
method of testing 100 ml was developed by the author in the field and has several
limitations, discussed supra in a section on quality assurance, that place it outside of the
guidelines provided by the manufacturer.
21
E. coli Count Petrifilm (1.0 ml test)
E. coli Count Petrifilm (3M Microbiology Products, St. Paul, Minnesota) was
used for detection of coliform and E. coli in 1 ml of water. In references hereafter, the
Petrifilm test is referred to as the 1.0 ml test and the above described Colilert test is
referred to as the 10 ml test.
The E. coli Count Petrifilm includes violet-red bile nutrients that consist of
lactose, a tetrazolium indicator for gram-negative bacteria, and a glucurondiase indicator
(BCIG, 5-bromo-4 chloro-3 indolyl-β D Glucuronide) to identify E. coli. Non-E. coli
coliform bacteria appear as a red colony surrounded by a gas bubble, which is formed
from the fermentation of lactose. Among the coliform bacteria, only E. coli constitutively
express β-glucuronidase and can hydrolyze BCIG to form the blue precipitate BCI. Thus,
the E. coli appear as a blue colony surrounded by a gas bubble.
In the Petrifilm test, after removing the film from the foil packet, the pack was resealed with masking tape to prevent moisture from entering. Immediately after collection
of water from the source using a Whirl-Pak, the E. coli Count Petrifilm was inoculated
with one ml of water from the Whirl-Pak, using a sterile pipette. The water was
distributed over the circle of nutrients using a plastic spreader and allowed to solidify for
one minute. The Petrifilm was placed between two pieces of thin, firm cardboard to
prevent bending. The stacks of up to 16 Petrifilm were incubated on the body of the
author (approximately 37C) for up to 24 hours.
Additional supplies for the Portable Microbiology Laboratory include a sterile 4oz Standup Whirl-Pak (Nasco, Modesto, California) to collect a water sample, an
22
individually wrapped, 3.5 ml graduated, sterile pipette (Evergreen Scientific, Los
Angeles, California), and a battery-operated, long wavelength UV lamp (Spectronics
Corp., Westbury, New York).
Visual Sanitation Survey of Boreholes
At each borehole, a visual sanitation survey of the point source was conducted
and recorded according to standard guidelines (16). At least one community person was
surveyed for demographic information about usage of the water source and for his or her
opinion of the water quality. A priority was placed on interviewing a local representative
of CWSA followed by an adult individual from among those (principally women) who
used the point source.
A blank survey can be found in Appendix C. An additional question regarding the
erosion level was added after the first round of testing, when a chance observation of
erosion was linked with contamination.
A score was given to each borehole based on the number of points of concern (014) identified (Appendix C). The boreholes were grouped into three levels of concern
based on their score: 0-3 (lowest concern), 4-6, or 7-9 (highest concern).
Statistical Analysis
The results of the Colilert and Petrifilm tests were combined and interpreted to
assign each source with a disease-risk level (Table 1). For various groupings of sources, a
count of the point sources with each disease-risk level was compiled. A Chi-square test
23
for goodness of fit was used to determine if, for a particular source type, such as
boreholes, the range of contamination varied from a random (even) distribution among
the disease-risk categories of low, moderate, high, and very high. A Chi-square test of
association was used to compare pairs of groupings such as boreholes/hand-dug wells,
rainy/dry seasons, or north/south regions. The test was to determine if the pairs of
groupings were meaningfully associated with any variation in the range of contamination.
Microsoft Excel was used for all statistical analysis. The statistical significance level used
was 0.05.
Quality Assurance
Manufacturer guidelines for the Colilert test state that after 28 hours of incubation
the compounds for suppression of non-coliform bacteria are less effective. Negative
results can be confirmed after 28 hours; however, positive results should be considered
tentative and the sample should be retested. Because of the difficulty and time involved
in the collection of each sample, tubes that appeared positive after 28 hours, and thus
constituted tentative results, were not retested. Because incubation temperatures may not
have been consistent, growth rate may have been lower than under manufacturer
guidelines, therefore, tentative results were noted during the initial data collected, but
reported as negative in the results of this study.
Additionally, a few samples tested positive for MUG but negative for ONPG
within the 28-hour incubation time. E. coli constitutively produces β-glucuronidase, but
can be induced to produce β-galactosidase when all of the MUG sugar has been
24
consumed. Therefore, a sample that is predominantly E. coli and has few or no other
coliforms will fluoresce before it appears yellow. However, the tube will eventually turn
yellow and, according to manufacturer guidelines, this should occur within 28 hours.
Samples that fluoresced within 28 hours but showed yellow after more than 28 hours
were considered tentative but negative for E. coli; samples that fluoresced within 28
hours but never turned yellow were considered an anomaly and not considered positive
for E. coli.
Significant limitations occur with the 100 ml adaptation of the Colilert test. No
follow-up testing to confirm these results against standard and approved methods was
done. Because these 100 ml samples were incubated without temperature control and
contained diluted nutrients, potential false negatives could occur. The average ambient
temperature in Ghana is 26°C. Seasonal ranges for the regions where testing took place
are as follows: the range near Accra (closest major city to Suhum District) in October is
22-30°C, the range near Tamale (closest major city to Nanumba District) in March is 2437°C, and in June is 22-31°C. Potential false positives also could occur with this method
(and are perhaps more likely) because inhibitors of non-coliform growth may be
insufficient.
In the Nanumba District during the second testing phase (June rainy season), the
100 ml sample was inoculated simultaneously with the 10 ml sample using the amount of
reagent from a 10 ml tube. While this version is superior because it avoids the breakdown
of inhibitors that occurs after 28 hours, according to the manufacturer, it is still limited by
the factors noted above.
25
RESULTS
In order to evaluate the relative disease risk of boreholes as compared to hand-dug
wells in Ghana, I tested samples from boreholes, hand-dug wells and other sources in two
regions of the country during two seasons. The results set forth extend to new data points
beyond what Ghana’s rural water agency (CWSA) has obtained in the past in its
recommended routine of testing two boreholes per year in each district using the
thermotolerant test. The Portable Microbiology Laboratory used in this study enabled the
collection of this new data and allowed for community participation (Figure 1).
26
Figure 1. Using the Portable Microbiology Laboratory in Ghana. District Water and
Sanitation Team member Gabriel M. Nartey uses a sterile pipette to transfer possibly
contaminated drinking water from a borehole in Aponopono, Suhum District to the 10 ml
Colilert tube in his left hand. The red 1 ml Petrifilm and Whirl-Pak are resting on the
head of the borehole pump.
27
Contamination Levels in Hand-dug Wells and Other Shallow Sources
To evaluate the disease-risk level of hand-dug wells and other open sources, I
tested their bacterial contaminations levels. I obtained 33 samples from hand-dug wells in
the Suhum and Nanumba districts (Table 2). In the Suhum District, these consisted of 22
samples from open hand-dug wells and eight samples from hand-dug wells with pumps.
In the Nanumba District, the samples consisted of three from open hand-dug wells and
one from a hand-dug well with a pump. E. coli and coliforms were consistently detected
in drinking water from hand-dug wells using the Petrifilm and Colilert tests.
Specifically, E. coli and coliforms were detected in all 22 open hand-dug wells in
the Suhum District in both 10 ml and 1.0 ml tests (Table 2, Figure 2). E. coli were
detected on the Petrifilm tests at rates of contamination between 1 and 60 cfu/ml of water,
which is equivalent to a World Health Organization disease-risk level of high or very
high (Table 1). As would be expected, more non-E. coli coliform than E. coli were
counted in 31 of 34 sources, which confirms the benefit of using the testing method that
evaluates specifically for the presence of E. coli. Two of the hand-dug wells (Siriki and
Otwebediadua #1) had more than twice as many E. coli as coliforms (Table 2).
In all, eight hand-dug wells with a pump were tested in Suhum; coliforms were
detected in both 10 ml and 1.0 ml samples (Table 2, Figure 2). E. coli were detected in a
1.0 ml sample in four of the eight hand-dug wells with pumps (50%). In the 10 ml
samples, E. coli were detected in six of the hand-dug wells with pumps (75%). One handdug well with a pump where E. coli were not detected had been recently chlorinated
(Gabriel M. Nartey, Suhum District Water and Sanitation Team, personal
28
communication). High levels of environmental coliforms were detected in all hand-dug
wells both with and without a pump.
In addition to the samples of drinking water from hand-dug wells, the study
obtained six samples from other open sources (Table 3, Figure 2). In Suhum, the study
obtained one sample from a rainwater collection system (positive for E. coli in a 10 ml
sample, moderate disease risk). The study obtained one sample from an open stream
(positive for E. coli in a 1.0 ml sample, high disease risk). In the Nanumba District, E.
coli colonies were detected in 1.0 ml samples in three of the four open sources (two lakes
and a river), which were therefore classified as high disease risk.
While low disease-risk drinking water was detected on occasion from shallow,
hand-dug wells (based on the WHO disease-risk levels), a majority of the sampled handdug wells and other open water sources had high and very high disease-risk levels. A
Chi-square goodness-of-fit test (2) statistically confirmed the observation. The Chisquare test confirmed an uneven (different from random) distribution of the total number
of hand-dug wells (with and without pumps) in the Suhum District at each disease-risk
level: two wells were low disease risk; two were moderate disease risk; 14 were high
disease risk, and 11 were very high disease risk (Figure 2, 2=14.4, p<<0.001).
The Chi-square test cannot be used meaningfully on the data from the hand-dug
wells with pumps alone, because while it meets a requirement for the average expected
frequency of at least 2.0, Koehler and Larntz suggest that the total number should be
greater or equal to 10, and the study tested only eight hand-dug wells with pumps (21).
29
The WHO disease-risk level observations from the few available samples of open
water sources other than hand-dug wells (two at moderate disease risk, four at high
disease risk) suggest that the disease risk of these other open sources being contaminated
may be similar to the pattern found for hand-dug wells. It may be that the majority of
open sources are high disease risk. However, beyond this general suggestion, the study
collected insufficient data to make a statistical analysis of whether the six open sources
tested were more or less risky than other point sources.
A Chi-square test combining the observations from all these surface and shallow
point sources (hand-dug wells with and without pumps, rainwater collection, dammed
lakes, and rivers) produced results consistent with the previous suggestion that all of
these sources trend towards higher levels of contamination. Statistically, they are also
unevenly distributed (Figure 2, 2= 19.8, p<0.001).
30
Table 2. Test results for drinking water from shallow, hand-dug wells.
Community
Source1
Petrifilm
Colilert
Suhum District
Nsuta Wawase
Okanta
Kwabena Kumi
Adarkwa
Siriki
Otwebediadua #2
Ntunkum
Jato Kudzi
Akorabo
Manfe Nkwata
Amenhia
Amede
Wekpeti
Ali
Kaponya
Nkwata Anoma
Otwebediadua #1
Sawa
Amenhia
Nanumba District
Bimbla D Section
Bimbla Imam
Chiriloyili
1
Coliform
(non-E. coli)
E. Coli
ONPG
MUG
HDW2
HDW
HDW
HDW 1
HDW 2
HDW 3
HDW
HDW 1
HDW 2
HDW
HDW
HDW 1
HDW 2
HDW 3
HDW 4
HDW 5
HDW 6
HDW
HDW 1
HDW 2
HDW
HDW
HDWp3 1
HDWp 2
HDWp
HDWp
HDWp 1
HDWp 2
HDWp
HDWp
TNTC4
20
TNTC
7
30
9
10
10
51
9
51
43
+
17
+5
+
+
7
+
22
32
+
+
2
41
5
8
2
12
TNTC
11
5
61
3
1
1
20
3
58
8
12
28
2
5
9
15
2
1
7
1
14
TNTC
0
0
3
0
17
0
1
88
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
HDW 1
HDW 2
HDWp
HDW
1
17
0
TNTC
0
0
0
8
WHO
Disease-risk
Level
Very High
High
Very High
High
High
High
Very High
High
Very High
High
Very High
Very High
High
High
High
Very High
High
High
High
High
Very High
Very High
Moderate
Low*6
High
Moderate
Very High
Low
High
Very High
Moderate/Low
Moderate/Low
Moderate/Low
High
Source (e.g., 1, 2, or 3) references the first, second, or third site tested in the community identified.
HDW = open, shallow, hand-dug well with bucket retrieval. 3HDWp = well capped with a pump.
4
TNTC = too numerous to count, assumed >100 cfu.
5
+ (on Petrifilm) = coliform colonies were detected but not counted.
6
Low* = sample was also MUG negative in 100 ml, indicating very low disease risk.
2
31
100%
Percentage of wells tested
90%
80%
2
9
11
70%
High Disease
Risk
2
60%
Very High
Disease Risk
50%
40%
30%
2
14
2
2
2
12
20%
10%
0%
Hand-dug wells
without pumps
Moderate
Disease Risk
Low Disease
Risk
Hand-dug wells with
pumps
All hand-dug wells
with and without
pumps
Hand-dug wells in the Suhum District
Figure 2. Surface and shallow water sources at each WHO disease-risk level in the
Suhum District. The number in each column section represents the number of sources at
each WHO disease-risk level.
32
Table 3. Test results for drinking water from open water sources.
Community
Source
Petrifilm
Colilert
Coliform
(non E. coli)
E. coli
ONPG
MUG
+
+
WHO
Disease-risk
Level
Suhum District
Kwabena Kumi
Rain
2
0
Moderate
Kwabena Kumi
River
12
3
High
Bimbla Lake
Lake
11
3
High
Champa Dam
Lake
20
0
Moderate/Low
Gbeini Nakpa Dam
Lake
35
4
High
Yapala River
River
30
7
High
Nanumba District
33
Contamination Levels in Boreholes
To evaluate the disease-risk level of boreholes, I tested their bacterial
contamination levels. For drinking water from deep, drilled boreholes, both coliforms and
E. coli were detected using the Colilert and Petrifilm methodologies with 10 ml and 1.0
ml samples. The study obtained 112 samples from 80 boreholes. Of these, 33 of the
boreholes were from the Suhum District (Table 4) and 47 of the boreholes were from the
Nanumba District (Table 5).
E. coli were not detected in either the 1.0 ml or 10 ml samples in any of the 33
boreholes tested in the Suhum District (Table 4). E. coli were detected in a 1.0 ml sample
in one borehole at Karalga in the Nanumba District during the rainy season (Table 5). In
total, E. coli were detected in 10 ml samples in 10 boreholes from Nanumba (21% of the
samples from the district). The 10 ml sample testing detected E. coli in five boreholes
during the dry season (13% of Nanumba boreholes tested that season) and seven
boreholes during the rainy season (18% of Nanumba boreholes tested that season). Of the
10 Nanumba boreholes that tested positive for E. coli, two boreholes tested positive for E.
coli during both the rainy and dry seasons (Table 5).
Turning from detection of E. coli in the boreholes to detection of coliforms, the
Suhum District testing detected coliforms in 1.0 ml samples in four boreholes (12% of
the boreholes tested in the district) and in 10 ml samples in nine boreholes (27% of the
boreholes tested in the district) (Table 4).
Coliforms were detected in 1.0 ml samples in 15 Nanumba boreholes (32% of the
boreholes tested in the district). Of these 15 Nanumba boreholes, coliforms were detected
34
in seven (17.5%) during the dry season and nine (23%) during the rainy season.
Coliforms were detected in a 1.0 ml sample in one borehole during both seasons (Table
5). Coliforms were detected in 10 ml samples in 28 boreholes (60%) from the Nanumba
District. Of 28 boreholes, coliforms were detected in 12 (30%) during the dry season and
in 20 (51%) during the rainy season. Coliforms were detected in 10 ml samples from four
boreholes during both seasons (Table 5).
The trend among boreholes was to be low disease risk. This was statistically
confirmed with a Chi-squared goodness-of-fit test that showed that the number of
boreholes at each disease-risk level was unevenly distributed. In the Suhum district, 27
boreholes (82%) were very low disease risk, and six boreholes (18%) were low disease
risk (Figure 3, 2= 13.4, p<0.001). In the Nanumba District, the distribution of boreholes
among the various disease-risk levels followed a similar pattern during both the dry and
rainy seasons. In the Nanumba dry season, 31 boreholes (78%) were very low disease
risk, three (7.5%) were low disease risk, and six (15%) were moderate disease risk
(Figure 3, 2=44.5, p<<0.001). In the Nanumba rainy season, 27 boreholes (69%) were
very low disease risk, five (13%) were low disease risk, six (15%) were moderate disease
risk, and one (3%) was high disease risk (Figure 3, 2=50.9, p<<0.001). The distribution
of 72 independent borehole samples from both districts during the rainy season at each
disease-risk level was uneven, 63 were low (or very low) disease risk, six were moderate
disease risk, and one was high disease risk (Figure 3, 2=238, p<<0.001).
35
Table 4. Test results from boreholes in the Suhum District during the short rainy season
(October).
Community Source1
24 hr Petrifilm
Colilert
WHO
Coliform
E. Coli
ONPG
MUG
Disease
(non-E. coli)
Risk Level2
Omenako
Obretema
Krobomu
Aponopon
Nsuta Wawase
Suhum Tech
Ateibu
Okanta
Kwabene Kumi
Adarkwa
Ayisikrom
Kweadjo Owuo
Akote
Ntunkum
Abisim Dawa
Abisim Adjatey
Kwahia
Jato
Jato
Jato Kudzi
Akorabo
1
1
1
2
1
1
2
1
2
1
2
1
2
3
1
1
1
1
1
1
1
1
2
1
1
2
3
1
2
1
2
1
2
3
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
1
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
+
+
+
+
+
faint +
faint +
+
+
-
-
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low
Low*
Low*
Low
Low*
Low*
Low*
Low*
Low
Low
Low
Low*
Source (e.g., 1, 2, or 3) references the first, second, or third site tested in the community
identified.
2
Low* = sample was also MUG negative in 100 ml, indicating very low disease risk.
36
Table 5. Test results for boreholes in the Nanumba District during both the dry (March)
and rainy (June) seasons.
Community Source1 Season 24 hr Petrifilm
Colilert
WHO
Coliform
E.
ONPG MUG Disease(non-E.
coli
risk
coli)
Level2
Bimbla D Section
Bimbla Jekpafuri
Bimbla Badiligli
Bimbla Imam
1
2
1
1
1
Dakpam
2
1
2
Nabagnando
Chamba – Small
London
Gungunpaya
3
1
1
1
2
Jangbojado
1
Afayili Jayindo
#2
Afayili Jekodo
1
1
Chamba - police
2
3
1
Manchoni
1
2
Kpabi
3
1
2
1
Dry
Dry
Rainy
Rainy
Dry
Rainy
Dry
Dry
Rainy
Dry
Rainy
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
1
6
0
0
1
0
0
0
0
0
0
0
7
0
0
0
0
0
0
0
5
0
1
0
Dry
Rainy
Rainy
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Dry
Rainy
Dry
0
10
2
1
0
3
0
0
0
-
0
0
0
0
0
-
+
+
+
+
+
+
+
+
+
+
>24
+
+
+
+
faint +
+
+
+
faint +
faint +
+
-
Low*
Low*
Moderate
Low*
Low*
Low*
Low*
Low*
Low*
Low
Low
Low*
Low
Low*
Low*
Low*
Moderate
Low*
Moderate
Moderate
Low*
Low
Low*
+
+
+
faint +
-
Low
Low*
Low*
Low
Moderate
Moderate
Low*
Moderate
Low*
Low*
Moderate
Low*
Low*
Low*
Source (e.g., 1, 2, or 3) references the first, second, or third site tested in the community
identified.
2
Low* = sample was also MUG negative in 100 ml, indicating very low disease risk.
37
Table 5 continued.
Community Source1 Season
Pusuga
1
2
3
Demonayili
1
2
Chiriloyili
3
1
Gilisya
1
2
Kpaligaboni
1
Dipa
1
2
Gbeini Nakpa
1
Yapala
2
1
Chakosi / Jakpafoli 1
Karalga
Juo
1
Jua
1
Juasheya
1
Guidua #2
2
1
Guidua #1
1
1
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Rainy
Dry
Rainy
Dry
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Rainy
Dry
Dry
Rainy
Dry
Rainy
24 hr Petrifilm
Coliform
(non-E. coli)
0
0
2
1
1
0
2
+
4
3
0
14
-
E.
coli
0
1
2
0
-
Colilert
ONPG
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
MUG
+
+
+
+
+
-
WHO
Diseaserisk Level2
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Moderate
Low*
Low*
Low
Low*
Moderate
Low*
Low*
Low*
Low*
Low*
Low*
Low
Low*
Low*
Low*
Low*
High
Low*
Low*
Low*
Low*
Low*
Low*
Moderate
Low*
Moderate
Low*
Low*
Source (e.g., 1, 2, or 3) references the first, second, or third site tested in the community
identified.
2
Low* = sample was also MUG negative in 100 ml, indicating very low disease risk.
38
100%
Percentage of boreholes tested
90%
80%
33
1
6
34
6
32
High
Disease
Risk
70%
60%
Moderate
Disease
Risk
50%
40%
30%
Low
Disease
Risk
20%
10%
0%
Suhum District, Nanumba District, Nanumba District,
rainy season
dry season
rainy season
Boreholes by region and season
Figure 3. Comparison of boreholes by region and season at each WHO disease-risk level.
The number in each column section represents the number of sources at each WHO
disease-risk level.
39
Visual Sanitation Survey of Boreholes
In order to evaluate the correlation between established visual indicators of
contamination and the levels of E. coli in boreholes, I also performed a visual sanitation
survey. The visual sanitation survey identified possible sources of fecal contamination or
pathways for fecal contamination to enter the groundwater or point source. No borehole
scored more than nine out of 14 possible points. No correlation was found among the
distribution of boreholes at each WHO disease-risk level in these three levels of concern
(Figure 4).
Novel Testing Method for 100 ml Samples
During the sampling and analysis of the well water, it seemed possible to expand
the use of the Portable Microbiology Laboratory by adding an additional step to enhance
the sensitivity of the testing methods. To evaluate the samples further, therefore, I tested
for the presence or absence of E. coli in 100 ml of water as detailed in the Materials and
Methods section. With the addition of the 100 ml Colilert sample data, further
comparisons can cautiously be made, noting the limitations previously stated. Among 99
borehole samples that tested MUG negative in 10 ml samples, 85 (86%) were also MUG
negative in 100 ml samples (Figure 5).
40
20
18
18
1
16
Number of boreholes
High
Disease
Risk
3
14
13
12
10
2
8
9
6
7
6
4
2
3
Moderate
Disesae
Risk
Low
Disease
Risk
0
0-3
4-6
7-9
0-3
4-6
7-9
(low risk) (moderate) (high risk) (low risk) (moderate) (high risk)
Suhum
Nanumba
Visual Sanitation Survey Score for boreholes by district
Figure 4. Comparison of boreholes at each WHO disease-risk level for various score
ranges on the sanitation survey. The number in each column section represents the
number of sources at each WHO disease-risk level.
Percentage of boreholes tested
41
100%
90%
80%
70%
6
3
31
27
5
27
Low Disease
Risk (100 ml
MUG pos.)
60%
50%
40%
Very Low
Disease Risk
(100 ml
MUG neg.)
30%
20%
10%
0%
Rainy Season
Dry
Rainy
Suhum District
Nanumba District
Boreholes by distric and season that are MUG negative in 10 ml
Figure 5. Comparison of Colilert test results from 10 ml and 100 ml borehole samples.
The number in each column section represents the number of sources at each WHO
disease-risk level.
42
Independence of Well Sources Within a Community
For villages with multiple wells in the same village, I examined, with the
inclusion of the 100 ml data, how many villages had wells that were consistent and how
many villages had wells that differed in disease-risk level. Overall, more villages showed
variation (19 villages) between their sources than had the same quality in all wells (16
villages) (Table 6). Hand-dug wells and boreholes in the Nanumba District dry season
both had sources that ranged across four different disease-risk levels, and both of these
situations had more villages that showed variation. Boreholes in Suhum only spanned
two disease-risk levels and Nanumba (rainy season) spanned three disease-risk levels.
Also, these locations did not have as much variation within villages.
Comparison of Boreholes and Hand-dug Wells
I used a test of association (2) to compare various sources to each other. The
disease-risk category distribution for boreholes and hand-dug wells in the Suhum District
was significantly different, (Figure 6, 2=42.7, df=2, p<<0.001), with hand-dug wells
more often in the higher disease-risk categories than boreholes. Inclusion of the Nanumba
District data does not change these results. However, this study presents only the Suhum
District data in this comparison in order to avoid variability that might theoretically be
caused by differences in geography or season (though no such variability was in fact
observed).
43
Table 6. Comparison of disease-risk level of water sources within and between
communities.
Source
Same diseaseDifferent
risk level
disease-risk
level
Hand-dug wells
(7 communities, Suhum District, rainy season)
Boreholes
(8 communities, Suhum District, rainy season)
Boreholes
(11 communities, Nanumba District, dry season)
Boreholes
(9 communities, Nanumba District, rainy season)
Total
2
5
4
4
7
4
3
6
16
19
44
100%
Percengate of sources tested
90%
80%
33
11
70%
Very High Disease
Risk
High Disease Risk
60%
50%
40%
14
30%
Moderate Disesae
Risk
20%
10%
2
0%
2
Low Disease Risk
Boreholes
Hand-dug wells
Water source type in the Suhum District
Figure 6. Comparison of boreholes and hand-dug wells in the Suhum District at each
WHO disease-risk level. The number in each column section represents the number of
sources at each WHO disease-risk level.
45
Comparison of Disease Risk Across Geographical Variation
Disease-risk category distribution was significantly different for boreholes in the
two distinct geographical zones represented by the Suhum and Nanumba districts, with
boreholes in the Suhum District more consistently being low risk than boreholes in the
Nanumba District (Figure 3, 2=6.6, df=2, p=0.038). Only data from the rainy season in
Nanumba were used in order to hold constant for seasonal variation (though no such
variation could be confirmed by this study).
Comparison of Disease Risk Across Seasonal Difference
In order to evaluate the variation in disease-risk level over a three-month period,
dry and wet season paired samples were taken for 32 boreholes in the Nanumba District
(Figure 7). While there were more high and moderate disease-risk boreholes during the
rainy season than in the dry season, there was no significant difference between the
distribution of disease risk for the two seasons (Figure 7, 2=1.19, df=2, p=0.55).
A more detailed evaluation shows that 16% (5/32) of boreholes changed over this
three-month period: three boreholes increased from low to moderate disease risk and one
borehole increased from low to high disease risk (two orders of magnitude) from the dry
to the rainy season, while one borehole decreased from moderate to low disease risk from
the dry to the rainy season (Table 7). Two boreholes were moderate disease risk during
both seasons. Inclusion of the 100 ml data adds an additional five boreholes that changed
between low and very low risk from season to season, increasing the number of boreholes
that changed over the three months to 31% (10/32).
Percentage of boreholes tested
46
100%
1
90%
5
80%
70%
26
4
28
60%
High
Disease Risk
Moderate
Disease Risk
50%
40%
30%
Low Disease
Risk
20%
10%
0%
Rainy season
Dry season
Boreholes tested twice in the Nanumba District
Figure 7. Comparison of boreholes at each WHO disease-risk level in the Nanumba
District during two seasons, rainy and dry. The number in each column section represents
the number of sources at each WHO disease-risk level.
47
Table 7. Comparison of WHO disease-risk levels in paired water test results for boreholes
in the Nanumba District during two seasons, dry and rainy.
Community
Dry1 Rainy Order of magnitude change in
number of E. coli in sample2
Bimbla Imam Section
Dakpam
Nabagnando
Chamba – Small London
Gungunpaya
Jangbojado
Afayili Jekodo
Chamba - police
Manchoni
Kpabi
Pusuga
Demonayili
Chiriloyili
Gilisya
Kpaligaboni
Dipa
Gbeini Nakpa
Yapala
Karalga
Juo
Jua
Juasheya
Guidua #2
Guidua #1
1
Low*
Low*
Low
Low
Low*
Mod
Mod
Low*
Low
Mod
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low
Low*
Low*
Low*
Mod
Low
Low*
Mod
Mod
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low*
Low
Mod
Low*
Low*
Low*
Low*
High
Low*
Low*
Low*
Mod
Low*
Same
Same
Same
Same3
Same
+1
Same
Same3
Same3
Same
-1
Same
Same
Same
Same
Same
Same
Same
Same
Same3
Same3
-1
Same
Same
Same
Same
-2
Same
Same
Same
-1
Same
Low* = sample was also MUG negative in 100 ml, indicating very low disease risk.
The order of magnitude change reported in the column represents any difference in disease-risk
level from the dry season to the rainy season. Every disease-risk level change represents a 10-fold
change in the quantity of bacteria cfu in the sample.
3
Boreholes that are designated “Same3” met the tolerable disease-risk level of no E. coli in 10 ml
during both seasons, however, there was a disease risk change from very low to low or vice-versa,
as explained in footnote 1.
2
48
Contamination Levels in Household Water Storage Units
In order to evaluate the relative disease risk of water directly from the borehole
source as compared to water from the borehole after it has been placed in storage in
nearby homes, I tested the bacterial contamination levels in household storage units. Both
coliform and E. coli were detected in household water storage units using the Petrifilm
and Colilert methodologies. Twenty-three samples were taken from household water
storage units in the Nanumba District during the rainy season (Table 8). E. coli were
detected at 1.0 ml in 30% (7/23) of households, and at 10 ml in 74% (17/23) of
households. Coliforms were detected at 1.0 ml in 65% (15/23) of households and in all 23
households at 10 ml. The total number of household supplies at each disease-risk level
was unevenly distributed (Figure 8, 2=9.5, p=0.02).
Twenty-one paired samples of boreholes and the closest available household
water storage unit were taken. Disease-risk category distribution was significantly
different between the source boreholes and the household supplies for these paired
samples (Figure 8, 2=15.1, df=2, p=0.0005), with households having higher disease-risk
levels than boreholes.
A closer look, with the inclusion of 100 ml Colilert samples, shows that 14%
(3/21) of households maintained the same water quality in household storage as at the
source (one very low disease risk, two moderate disease risk), 29% (6/21) of households
were ten times more contaminated than the source (four changed from very low to low,
one changed from low to moderate, one changed from moderate to very high), 48%
(10/21) of households were two orders of magnitude more contaminated than the source
49
(seven changed from very low to moderate, two from low to high, one from moderate to
very high), and 10% (2/21) of households were three orders of magnitude more
contaminated than the source (very low to high disease risk) (Table 9). No household
improved the water quality from the source.
50
Table 8. Water test results from household storage units in the Nanumba District, rainy
season.
Community
24 hr Petrifilm
Colilert
WHO Disease-risk
Coliform
E. coli
ONPG
MUG
Level
Dakpam
Nabagnando
Chamba – Small
London
Gungunpaya
Jangbojado
Afayili Jayindo #2
Afayili Jekodo
Manchoni
Kpabi
Pusuga
Demonayili
Chiriloyili
Gilisya
Kpaligaboni
Dipa
Gbeini Nakpa
Yapala
Juo
Jua
Juasheya
Guidua #2
Guidua #2
1
(non E. coli)
TNTC1
26
2
1
0
TNTC
+2
32
+
6
+
14
21
TNTC
43
+
2
-
0
20
2
5
0
4
0
0
0
0
1
0
0
2
0
0
0
0
0
0
+
+
+
+
+
-
Moderate
High
Low
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
Moderate
Very High
High
High
Low
High
Moderate
Moderate
Low
Low
High
Moderate
Moderate
High
Low*3
Moderate
Moderate
Moderate
Moderate
Moderate
TNTC = too numerous to count, assumed >100 cfu.
+ (on Petrifilm) = coliform colonies were detected but not counted.
3
Low* = sample was also MUG negative in 100 ml, indicating very low disease risk.
2
Percentage of samples tested
51
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
4
6
High Disease Risk
17
10
5
Moderate Disease Risk
Low Disease Risk
Borehole
Household drinking
supply
Source and storage of water in the Nanumba District, rainy season
Figure 8. Comparison of closest boreholes and household drinking supplies in Nanumba
District (rainy season) at each WHO disease-risk level. The number in each column
section represents the number of sources at each WHO disease-risk level.
52
Table 9. Order of magnitude change comparison of contamination levels in households to
the contamination level at the nearest borehole.
Community
Level of
Level of
Order of
contamination in contamination in magnitude
borehole
household
change in
storage unit
number of E.
coli in sample1
Dakpam
Nabagnando
Chamba – Small
London
Gungunpaya
Gungunpaya
Jangbojado
Afayili Jayindo #2
Afayili Jekodo
Manchoni
Kpabi
Pusuga
Demonayili
Chiriloyili
Gilisya
Kpaligaboni
Dipa
Gbeini Nakpa
Yapala
Juo
Jua
Juasheya
Guidua #2
1
Very Low
Very Low
Very Low
Moderate
High
Low
-2
-3
-1
Very Low
Moderate
Low
Very Low
Very Low
Moderate
Low
Very Low
Very Low
Very Low
Low
Moderate
Very Low
Very Low
Very Low
Very Low
Very Low
Very Low
Moderate
Moderate
Very High
High
High
Low
High
Moderate
Moderate
Low
Low
High
Moderate
Moderate
High
Very Low
Moderate
Moderate
Moderate
Moderate
-2
-2
-2
-3
-1
-1
-1
-2
-1
-1
-2
Same
-2
-3
Same
-2
-2
-2
Same
The order of magnitude change reported in the column represents any difference in disease-risk
level from the dry season to the rainy season. Every disease-risk level change represents a 10fold change in the quantity of bacteria cfu in the sample.
53
DISCUSSION
The results of this study substantiated, using a new technique, the presence of the
fecal indicator bacterium E. coli in various point sources of drinking water in rural
Ghana. Further, the results verified the strategy of CWSA of providing low-disease-risk
drinking water (defined in this study and by WHO as free from E. coli contamination in
10 ml) through the construction of boreholes. Most of the samples taken from boreholes
in the two regions during various seasons (88%, 99/112) represented low disease risk, but
only 6% (2/34) of samples from hand-dug wells met this standard. This study concluded
that, in these regions of study in Ghana where almost no microbiological testing of water
had been performed up to this point, the prevalence and levels of E. coli were highest in
shallow, unprotected water sources and lowest in boreholes, which provide a deep source
of water. Only one borehole was identified as high disease risk (allowing for corrective
action). Among the 11 boreholes in the Nanumba District that were not low disease risk,
there was not a significantly greater number in the rainy or dry season. Eighty six percent
(20/23) of household storage units had higher levels of E. coli than the corresponding
borehole, suggesting that in addition to encouraging use of boreholes over hand-dug
wells, attention needs to be given to how households handle water.
Taking the results from this study as a snapshot of a water system composed of all
point sources examined, the data in this study could be used to validate the performance
of each district in meeting policy of the CWSA. Using “no E. coli in 10 ml of water” as
the tolerable risk level, all boreholes in the Suhum District met this standard, and the
54
district performance can be rated as excellent. For the Nanumba District, 76% (35/46) of
the boreholes met this standard, and the district performance can be rated as moderate.
I further demonstrated that use of the Colilert and Petrifilm tests enabled low-cost,
convenient, and efficient data collection and assessment of rural water sources. This
combination of drinking water tests in the Portable Microbiology Laboratory was
effective in establishing the prevalence and levels of contamination, in line with WHO
disease-risk classifications of low, moderate, high, or very high. The demonstrated
effectiveness of the testing techniques gives the CWSA, for the first time, a viable
opportunity to collect a substantial amount of data in order to set water policy guidelines
based on actual contamination rates.
The results from this study demonstrated changes in water quality over a short
period of time in boreholes (Table 7). Additionally, because a range of contamination
levels (including low, moderate, and high disease risk) were found in boreholes, it
appears that current CWSA policy for random sampling of two boreholes per district per
year is insufficient to monitor potential health risks or to set effective policy and to verify
its implementation. The Portable Microbiology Laboratory tests can be incorporated into
the ongoing work with communities of CWSA officers and provide timely (within 24
hours), comprehensible feedback to help the CWSA meet the minimum WHO monitoring
guidelines (39). In addition, with minimal training, the tests could also be performed and
interpreted by community members for self-monitoring, which is not possible with
current testing methods in Ghana (Figure 1).
55
WHO advocates a risk-assessment approach for water quality analysis. Risk
analysis combines the results of E. coli counts with a sanitary inspection (38). The
sanitary inspection consists of a visual analysis of factors affecting water quality and
needs no equipment. What has been missing in risk analysis surveys has been testing for
E. coli. The results of this study demonstrate that the Portable Microbiology Laboratory
tests can fill this missing link and enable CWSA to improve its detection and
management of health risks associated with drinking water.
Particularly in high disease-risk areas, relatively modest, incremental
improvements in water quality can result in substantial health gains (34). The Portable
Microbiology Laboratory is particularly suited to identify these high and very high
disease-risk sources and can be a helpful addition for establishing a baseline on which to
set water policy, for verification of water policy targets for point sources, and as a
component of community-based monitoring. Use of the Portable Microbiology
Laboratory can help CWSA in each of these three ways in improving its early detection
and management of health risks associated with contaminated drinking water.
Point Sources
Hand-dug Wells Without Pumps. The presence of E. coli in Portable
Microbiology Laboratory tests in all 22 open hand-dug wells in the Suhum District
indicates that drawing water from hand-dug wells poses a high (59%, 13/22) or very high
(41%, 9/22) risk of disease. Tests of open hand-dug wells in the Nanumba District during
the dry season showed that two of the three open hand-dug wells were negative for E.
56
coli at 1.0 ml. However, since the 10 ml Colilert test was not performed, it was not
determined if these sources were of moderate (Colilert MUG positive) or low disease risk
(Colilert MUG negative).
Poor hygiene practices and other conditions observed in a sanitary survey of open
hand-dug wells in the Suhum District may explain some of the high levels of E. coli in
samples from these sources. Despite the active involvement of staff from the Suhum
District in supporting the WatSan committees, I observed no consistent hygiene practices
by the majority of district communities to maintain their well quality. Almost all studied
communities, for example, used multiple buckets to fetch water from the wells, and these
buckets were on occasion observed dropping on the ground and in the dirt, such that the
well was repeatedly re-inoculated with environmental bacteria. The open wells were
commonly exposed to sunlight and algae growth was typically visible. In several
locations, community members complained of children’s negligent behavior, such as
throwing sticks into the well. One well that I observed had a dead frog floating in it.
Another source of contamination that could account for these high levels of E.
coli is from fecal sources transported through the ground water. Open defecation was
common in the villages sampled (personal observation). A number of the surveyed
community representatives complained of an increase in turbidity following even the
slightest rain, suggesting poor design or damage to the well casing that allowed ground
water fecal sources to contaminate the wells. These observed conditions and comments
were consistent with the pattern of classification in the study results for open hand-dug
wells in the Suhum District as high or very high disease-risk water sources.
57
In contrast to the Suhum results, two of the three open hand-dug wells tested in
the Nanumba district during the dry season had no E. coli colonies on the Petrifilm tests.
All of these open hand-dug wells in the Nanumba District were a significant distance
(more than 500 m) from any residence, which may have limited their exposure to fecal
contamination. These results show that there are instances where open hand-dug wells
can be classified as less than high disease risk and suggest a follow-up test that includes
the Colilert as well as the Petrifilm test.
Hand-dug Wells With Pumps. While four of the eight water samples from handdug wells with pumps indicated high or very high disease risk, the other four were
classified at much lower disease-risk levels. Investigation revealed a possible explanation
for the lower disease risk in some: recent chlorination. A non-governmental organization
(NGO) in the Suhum District was involved in well rehabilitation, including the capping
of hand-dug wells with pumps and performing shock chlorination to disinfect the water
(Gabriel M. Nartey, personal communication). Several of the hand-dug wells with pumps
had placards indicating this NGO was involved with their maintenance, and several local
WatSan representatives noted that their wells had been chlorinated within the last two
months. This study, though, was not extensive enough to demonstrate a pattern. Further
study would be needed to establish whether un-chlorinated, hand-dug wells with pumps
are generally high disease risk. In any event, the results show that a well maintained
hand-dug well with a pump does have the potential of achieving low-disease-risk water
quality.
58
Current CWSA policy is to work towards replacing all hand-dug wells with
boreholes and not make further attempts at improving hand-dug wells (Charlotte
Engmann, National CWSA engineer, personal communication). As a practical matter,
because of the cost and time involved, the replacement of substantially all the hand-dug
wells in Ghana with boreholes will likely take considerable time. In the interim,
monitoring the low-disease-risk hand-dug wells with a pump using the Colilert test can
provide evidence that the water source stays at a low-disease-risk level. If future Colilert
tests are MUG positive, additional Petrifilm tests could be performed to evaluate the level
of disease risk and re-assess mitigation options. Mitigation options to be considered,
other than construction of a new borehole, could include measures such as the addition of
pumps or periodic shock chlorination to improve quality.
Open Sources of Drinking Water. Six open sources including small lakes (three),
rivers (two) and a rainwater catchment (one) were also surveyed in this study. E. coli
were present in 1.0 ml testing (high disease risk) for five of the six sources. These results
are consistent with previously observed high levels of thermotolerant coliform in surface
supplies of water in areas with poor sanitation in Ghana (2, 29). One lake source was
classified as either moderate or low disease risk, because only the Petrifilm test was
performed, and coliforms but no E. coli were present on the Petrifilm.
Boreholes. The presence of E. coli at disease-risk classifications of moderate (12)
or high (1) in 13 of the 112 borehole samples contradicts the general confidence
expressed by staff of the CWSA that “boreholes are free from fecal contamination.” This
optimistic sentiment was also reflected at the community level, where surveyed members
59
consistently thought that borehole water was high quality, although sometimes they
complained of a stale or mineral taste. Testing these sources using the Portable
Microbiology Laboratory is a means to identify occasional high disease risk and also to
assure the community that even if the taste is different from surface water, there is a low
risk of disease from fecal bacteria.
The great majority of the boreholes tested (86%, 68/79) were consistently low
disease risk, though the testing revealed a range of disease risk among those tested
including low, moderate, and high. Overall, the success of the Portable Microbiology
Laboratory in revealing a range of risk validates the effectiveness of the Portable
Microbiology Laboratory in discriminating among the categories that WHO identifies as
relevant.
As a stand-alone assessment, the visual sanitation survey was insufficient as an
indicator of fecal contaminator, as some boreholes with the highest number of indicators
were still low risk when tested for the presence of E. coli. All of the boreholes with a low
number of indicators on the visual sanitation were also low risk based on the absence of
E. coli in 10 ml of water. Some risk factors were identified through the visual sanitation
survey for all boreholes that were moderate or high risk based on E. coli levels,
suggesting that the survey may be helpful with mitigation decisions even if it is
insufficient as a stand-alone indicator.
Boreholes (100 ml Adaptation). In developed countries where water is
chlorinated, drinking water standards are for no E. coli in 100 ml, signifying a very low
disease-risk level (42). As a side project with boreholes in the Suhum District, and again
60
in the Nanumba District during the dry season, I used a novel approach to look at 100 ml
samples. After 24 hours of incubation, I poured the MUG negative 10 ml contents into
the remaining 90 ml of the Whirl-Pak used to collect the water, which had been kept at
ambient temperature. I discovered that there was enough ONPG and MUG reagent in the
10 ml sample so that ONPG and MUG tests could be detected in the Whirl-Pak with 100
ml.
Following this observation, samples from the Nanumba District in the rainy
season were inoculated into Colilert simultaneously at 10 ml and 100 ml using the
amount of reagent present in a 10 ml tube in both cases. A cautious look at these
additional data from the Nanumba rainy season distinguishes between samples that are
low disease risk versus those that are very low disease risk (Table 5).
Most (86%, 85/99) of the samples that were low risk were also very low risk,
which further verifies the safety of boreholes (Figure 5). While I do not advocate the 100
ml Colilert adaptation used here for regular monitoring, it highlighted several advantages
of the 10 ml test in this situation. Since the limitations of this adaptation suggest that
there may be false positives, the percentage of boreholes that are also very low risk may
be higher. In addition to the difficulty of incubating a 100 ml test at any but ambient
temperature in the rural setting, the Colilert snap-pack for the 100 ml test is several times
more expensive than the 10 ml tube tests. Therefore, the additional cost and difficulty
associated with these tests may not warrant the small number of additional sites that are
identified with a slight increase in risk of disease.
61
Comparisons
Hand-dug Wells and Boreholes. While both boreholes and hand-dug wells
spanned a range of disease-risk categories, the majority of boreholes were low disease
risk, while the majority of hand-dug wells were high disease risk (Figures 2 and 3). When
a statistical comparison was made between samples taken from the Suhum District for the
two well types, the variation was great enough to show a statistical difference in the
comparison of the disease-risk category distribution for the hand-dug wells as compared
with the boreholes (Figure 6).
The test results using the Portable Microbiology Laboratory verified that in the
Suhum District, where there are both a large number of hand-dug wells and boreholes,
the boreholes are of superior quality (Figure 6). The data verified the public health policy
of constructing boreholes. Continued use of the Portable Microbiology Laboratory can
further verify that the substantial investment that has been made in Ghana and elsewhere
to construct boreholes is warranted by the low-disease-risk level of the water in the
boreholes.
Boreholes by Region. There were observed variations between the Suhum and
Nanumba districts that might account for the higher proportion of low disease-risk
boreholes in Suhum than in Nanumba (Figure 3). The most notable variation was the
different level of government attention and resources devoted to drinking water in each of
the districts. Other research in Ghana, similarly, has noted lack of government policy and
regulations and political neglect as factors in effective control of water contamination (3,
29).
62
The Suhum District had five full-time field officers assigned to water and
sanitation and three motorbikes for transportation within the district. The field officers
made regular visits to communities to meet with the village WatSan committees and,
simultaneously with this research, were in the process of conducting their own survey on
flow rate and village policies for collection of fees for maintenance of boreholes
(Appendix B). The WatSan committees appeared well organized and were easy to locate
in each community. Many communities had a local person trained in minor maintenance.
At one village, the local mechanic brought out his tools and demonstrated his pride in
being able to maintain the community pump. Three additional mechanics with greater
skills were available to fix pumps in the district for a small fee from the funds collected
by the village WatSan committee as part of its water management plan (household tax or
“pay as you pump”). While the majority of households did not appear to have access to a
latrine, there had been projects to provide latrines to a few households in the majority of
villages (Gabriel M. Nartey, personal communication).
During the period of my data collection, the Nanumba District was recovering
from a conflict between the three tribes that live within the district and a large part of the
governmental funds provided to the district were spent on supporting the military
presence that enforces the peace, rather than other government services such as sanitation
infrastructure. Additionally, the Nanumba District, by contrast with the Suhum District,
had only one full-time officer and a secretary for district water and sanitation. The visual
sanitation survey of boreholes in the Nanumba District identified fewer latrine
63
construction projects or households with even unimproved latrines than were reported in
the Suhum District (personal observation).
The minimal staff available to give attention to the maintenance of the Nanumba
water sources may explain the greater proportion of higher-disease-risk boreholes in the
district. In no Nanumba District village could I find a WatSan committee or anyone who
self-identified as being trained in health, sanitation or pump maintenance. In some of the
villages visited, I met with the Guinea worm volunteer whose responsibility was to
contact the local NGO if a potential case was spotted in the village. Villagers, on
occasion, expressed frustration to me in their attempts to receive outside assistance with
well maintenance. It was unclear if there were skilled mechanics available to visit such
villages, even if the community had funds available to pay for a mechanic. I visited one
community from the minority side during the war whose well had been vandalized during
the conflict. The well had the potential to be rehabilitated for far less than the cost of
digging a new well. However, the villagers expressed frustration that this rehabilitation
project, for whatever reason, was not carried out. Another community had its pump break
down shortly before my first visit, and it was still broken three months later during my
second visit. Villagers reported multiple visits by community members to the district
capital to request assistance. Political neglect and lack of governmental funding may be
the root causes of the poor community drinking water and sanitation infrastructure, which
has been reported in other studies of nearby districts (3).
The Nanumba District is one of the last remaining regions in Ghana with Guinea
worm disease as an endemic health problem. Construction of boreholes in the 1960s to
64
1990s played a role in reduction of this disease (18). Today, there is a large effort that is
being undertaken by the Carter Foundation to fully eradicate this debilitating waterborne
parasite, which enters a human who drinks untreated surface water containing the Guinea
worm larvae and causes a painful parasitic worm to erupt from the skin, usually in the
lower extremities (5). My research in this district was conducted with the assistance of a
staff member of the NGO that monitors for cases of Guinea worm and ensures
confinement of such persons until they are recovered. Because of the large size of the
Guinea worm, cloth filtration of drinking water has sometimes been advocated in regions
where this disease is prevalent (31). While this has been effective in reducing cases of
Guinea worm, it is not sufficient to make water safe to drink, because cloth filtration with
a mesh size of 20 by 20 m will not filter out bacteria or viruses (19). The Portable
Microbiology Laboratory tests can demonstrate to healthcare workers the need to respect
the risk of bacterial contamination while in the process of eradicating Guinea worm.
Continuing to advocate methods such as cloth filtration may lead to poor practices that
are difficult to correct later.
Boreholes by Season. The observation of changes in borehole water quality over
time supports the public health protocol for periodic testing of drinking water. The
majority (86%, 68/79) of boreholes tested in this study were low disease risk both times
they were tested. The identification of a few (11) boreholes in the Nanumba District that
had moderate and high disease risk confirms the need for periodic testing of each
borehole, not just a sampling of a few boreholes in the region.
65
There was no statistical difference between the distribution of disease risk in the
dry season and rainy season for boreholes in the Nanumba District. While four of the 32
boreholes that were tested twice showed an increase in the level of E. coli contamination
from the dry to the rainy season, one borehole showed a decrease in level of E. coli
contamination from the dry to the rainy season. Therefore, while this research does not
indicate a greater disease risk during a particular season, it does demonstrate that five of
the 32 boreholes (15%) changed in the level of E. coli contamination during the fourmonth period. Inclusion of the 100 ml data demonstrates that 10 of the 32 boreholes
(31%) changed during this period. Whether or not the changes in water quality in these
10 boreholes were due to seasonal factors or to other factors, the considerable percentage
that changed supports the policy of periodic testing.
One possible cause of the change in contamination levels over time in the
Nanumba District was the prevalence of animals at the boreholes. Large livestock near
the boreholes can occur in the Nanumba District during the dry season, when the cattle
herders flood the drainage channel for their cattle to use as a drinking trough (personal
observation). Use of the Portable Microbiology Laboratory in combination with an
inspection survey could help to sensitize the community to this disease risk. A future
study could look at both the quality of water inside the well as well as the water standing
in the drainage trough. Potential mitigations of this disease-risk factor exist, such as
channeling water to a separate area for use by the animals. Community engagement in
local health issues through a combination of using the Portable Microbiology Laboratory
66
and a routine sanitary inspection survey could raise awareness of the importance of
keeping animals away from the human source of drinking water.
Boreholes and Household Storage Units. Point-of-use water quality monitoring
is recognized, along with safe household water storage and treatment, as a means of
addressing post-collection contamination (30, 41). My study included household testing
on a one-time basis. The systematic meta-analysis of earlier studies of contamination
between source and point-of-use (household) by Wright et al. found that none of the
studies in high bacteria count locations used E. coli as an indicator, but instead used total
coliform or thermotolerant coliform (41). My study, by contrast, used E. coli as the
indicator to compare contamination between source and household, which has a stronger
link to public health. My study detected high coliform counts in many sources where E.
coli were not present. In other studies that only looked at thermotolerant coliform levels,
these non-E.coli coliform bacteria could give a false-positive indication of fecal
contamination.
Water from 78% (18/23) household storage units in Nanumba that were tested
was either moderate or high disease risk. This was a consistently higher disease risk than
the water from nearby boreholes. No household in this study had higher quality water
than at the point source. Various observed circumstances may explain the higher disease
risk. No household reported any use of water purification techniques, such as filtration,
except for limited use of boiling. The lack of household-level purification is consistent
with the same or higher level of disease risk that the test results revealed in households as
compared to the nearest borehole.Considering another possible factor, Wright et al. have
67
noted that transportation methods and storage are a concern for water quality in locations
where point sources are the primary source and water is not delivered directly to
households through pipes (41). The drinking water that was the subject of this study was
commonly transported from the point sources to the household storage units in metal or
plastic bucket-shaped containers of the size that women and girls of the region can carry
on their heads (personal observation). Once inside the house compound, the water was
stored in wide-mouth clay or concrete pots (often with a lid) holding 100-500 liters.
Water stored in such pots at the household level was used both for hygiene purposes and
also as a source of drinking water. Repeated dipping of hands or a shared cup is one
possible explanation for the increased contamination observed in households, as
compared to nearby boreholes.
Many families had multiple buckets for collecting and transporting water
(personal observation). Wright et al. also note the risks of contamination during such
bucket transport (41). I observed an anecdote of risky behavior myself. During one
village interview in my study, a group of women all stopped and put down their buckets
to participate in the testing and discussion about the household water. During this time, a
small child, perhaps 18-months old, had a diarrheal episode in the midst of the group. The
mother used a scrap of wood to scoop up the fecal matter and dirt and remove it a few
meters off into the bush. The mother then proceeded to wash the toddler’s behind by
repeatedly dipping her hand into the bucket used for transporting water from the point
source to her household. No one in the group acted as if this were behavior out of the
ordinary.
68
Many families reported using multiple sources of water to fill their household
storage units, even if they lived adjacent to the borehole. Reasons articulated for
accessing multiple sources included breakdown of the pumping mechanism, inadequate
water in the well to meet all needs, seasonality of the supply, or dislike of the taste of
certain water supplies (especially deep wells). The use of these multiple sources of water,
as well as lack of education regarding sources of disease, as evidenced by the observed
diarrheal episode, could account for the higher level of disease risk found in the
household supply than in the closest borehole in 15 (68%) of the 22 cases. These results
are consistent with other studies that have looked at the degradation of water quality from
the point source to the household (41).
Health Education. One of the goals of the CWSA is to promote proper hygiene.
Even if the water supply is of high quality at the source, it can become contaminated due
to poor handling and storage, which, as discussed, may account for the disease-risk
results addressed in the previous section.
The Portable Microbiology Laboratory can be used as part of participatory testing
to trace water quality from various sources available in the community through transport,
storage, household level purification, and, finally, consumption. Testing the water at
various stages along this path can provide evidence to identify water sources that are
moderate to very high disease risk and engage the whole community in discussing how
water sources get contaminated, how to treat contaminated water to make it safe to drink,
and how water sources with a low disease risk can be kept low risk.
69
In the last two years, I have led community workshops with this particular focus
in Cambodia, utilizing the perspective gained from this study. Workshops have extended
to information about the size of bacteria, how they grow, and germ theory of disease (28).
Through this use of evidence-based microbiology to test their source and household
water, community members can come to understand the health risks associated with safe
water handling. In the first session of a two-day workshop, participants identify, sample
and inoculate local water sources and household supplies into the two tests. Next,
participants use body-incubation methods on samples from their own water source.
Following the incubation period, participants meet again to interpret and discuss the
results from their personal water supplies. In this way, participants have knowledge of
their individual situation and can share this with their family and neighbors. Together
with a discussion of the germ theory of disease, the direct observation of growth of E.
coli colonies on the Petrifilm in some or all of the samples can lead to an effective
discussion of possible reasons for contamination and appropriate actions to correct the
problem.
Point-of-use water quality monitoring is recommended along with safe household
water storage and treatment as a means of addressing post-collection contamination (41).
The Colilert/Petrifilm method is uniquely adapted for use directly as part of such health
education programs to promote safe water handling. In this study, most of the household
samples taken in the Nanumba District were inoculated either by a community member
or by a child. This demonstrates that the technique for inoculating the sample can be
learned and implemented quickly. Community participation also provided an opportunity
70
for discussion about water storage, sanitation, and proper maintenance of the community
well. At one well that was tested in Ghana, a University of Ghana, Legon teaching
assistant utilized the results to explain to children the importance of keeping the apron of
the borehole clear of debris and not to abuse the pump mechanism, which causes
breakdowns (Figure 9).
71
Figure 9. A University of Ghana teaching assistant talks to a group of school children
about the importance of proper well maintenance.
72
Application of Findings
The ease of using the Portable Microbiology Laboratory and the ability to collect
and process the results rapidly by existing field staff and/or community members makes
the development of a Water Safety Plan that incorporates evidence-based microbiology
possible. The following sections address (1) system assessment as a baseline to set
policy, (2) community-based self-monitoring and management of the local water source,
and (3) verification/validation of policy and surveillance.
System Assessment and Cost Considerations. The CWSA plan of testing two
boreholes per district per year results in many boreholes in each district going untested,
because a typical district has many boreholes. There are on average more than 100
boreholes per district (8). WHO recommends testing of all boreholes in a district once
every three to five years in order to assess and validate policy (39). Assuming that the
national laboratory is used, which at the time of this study charged $25 per sample for a
thermotolerant coliform test, the current cost per district is $50 per year to test two
boreholes (Joseph Ampofo, Water Research Institute, Ghana, personal communication).
The cost of using the Portable Microbiology Laboratory is dramatically less,
approximately $2 per test. Without increasing the district cost, 25 boreholes could be
tested for E. coli using the 10 ml Colilert P/A test. For the average district, this frequency
of borehole testing would be in accord with the WHO recommendation of testing all
boreholes once every three to five years. This would be a definite improvement over the
current testing regime.
73
Transportation costs associated with testing in Ghana can also be reduced in
shifting away from the thermotolerant coliform test to the Portable Microbiology
Laboratory. The cost of transporting samples back to a central laboratory can be avoided.
The Colilert ingredients are premeasured as a shelf-stable dry powder into marked tubes
and can be distributed and stored for use in rural Ghana without refrigeration. The
Petrifilm test, too, is shelf stable and acceptable for distribution to rural areas. Unused
Petrifilm tests need to be stored in a resealed foil packet to prevent moisture damage; this
can be done with masking tape. Moreover, the testing in the field that is possible with the
Portable Microbiology Laboratory eliminates false negative results that may occur from
prolonged transport to a laboratory and delay in laboratory processing of the sample (6).
In summary, the Portable Microbiology Laboratory tests obtain better, more
timely data than the thermotolerant tests and at a lower cost. Plus, the results should be
more intelligible to the community, because of their timeliness and their graphical clarity.
That is, for example, a fluorescent blue color in the Colilert tube or a Petrifilm containing
blue colonies with gas from an on-the-spot test visually indicates the presence of E. coli
and an unsafe water source (intolerable disease-risk level). By comparison, a written lab
report, received a week or more later from a central laboratory of 50-500 thermotolerant
coliform per 100 ml, requires further interpretation.
Acceptance of the Portable Microbiology Laboratory. The Portable
Microbiology Laboratory is a kit that complements the current monitoring practices of
the CWSA. Biological testing is easily combined with other elements of pump
maintenance and testing. For example, District Water and Sanitation Team member
74
Gabriel M. Nartey was able to measure the depth of water in the borehole simultaneously
to my inoculating the Colilert sample, and to the area mechanic and District Water and
Sanitation Team member Gershon Hiamadey recording information about the pump flow
rate (Figure 10).
Portable Microbiology Laboratory supplies for an entire day fit in a small twoliter bag that easily can be carried while riding the standard issue CWSA motorbikes used
to visit the communities for other monitoring. The ease of body incubation of the
multiple samples taken each day eliminates the need for a bulky incubator powered by
the electricity that is scarce in rural Ghana. In my study, the ease of body incubation
attracted community volunteers in Ghana who participated in inoculation of the samples,
a similar circumstance to subsequent trials by the author in Cambodia, and to earlier trials
in Kenya and Tanzania (24, 25, 26).
75
Figure 10. The District Water and Sanitation Team can simultaneously take a variety of
measurements and perform maintenance on a borehole. From left to right, Gabriel M.
Nartey measures the depth of water in the borehole, Katherine Parker (kneeling)
inoculates the Colilert sample, and the area mechanic assists Gershon Hiamadey record
information about the pump flow rate. Women with water collection buckets in
background wait patiently.
76
Integration of Portable Microbiology Laboratory into Existing Surveillance.
WHO recommends the use of microbiological testing in conjunction with a sanitation
inspection survey to identify other disease-risk factors (39). In Ghana, though, the district
officers do not always have the ability to collect water samples and transport them to the
few regional laboratories in a safe and efficient manner that would allow for laboratorybased microbiological testing (personal observation). Therefore, up until now, it appears
that regular microbiological testing has not been included in surveys, because it is
seemingly impractical in terms of time and cost to conduct. However, this research
demonstrated that the Portable Microbiology Laboratory field kit for microbial testing
could be used in conjunction with other assessment surveys.
In the Eastern Region of Ghana, which includes the Suhum District, the District
Water and Sanitation Team currently visits all communities to conduct a management
survey of the borehole, monitor the flow rate, and maintain the pump, as part of its
surveillance of point source water supplies. The team members who accompanied me
rapidly learned the techniques involved to ensure sterile, microbiological quality and
were soon instructing members of the WatSan committee and even local children in how
to perform the tests.
Community-based Monitoring. The results presented here indicate that periodic
community-based testing of boreholes and hand-dug wells may be an appropriate level of
monitoring for this type of water source in Ghana. The Portable Microbiology Laboratory
is particularly suited to this because the community members themselves can perform the
tests. Having test results available to a local community with hand-dug wells creates
77
some options about actions that can be taken to provide low disease-risk water pending
the construction of boreholes. If an unacceptable risk level is identified with the Portable
Microbiology Laboratory, even with a borehole, immediate action can be taken. For
example, during my testing, when I identified one high disease-risk borehole, I was able
to provide chlorine tablets to the local contact for him to take back to the community for
an immediate shock chlorination treatment.
Once the community has done an initial assessment of all point sources with both
the Colilert and Petrifilm tests and identified all of the high and very high disease-risk
sources, it is not necessary to use ongoing monitoring for these high disease-risk sources.
Where possible, alternative moderate- or low-disease-risk sources should be identified for
use, or appropriate household-level purification and safe storage techniques should be
applied.
For sources that are generally low disease risk, such as the boreholes and some of
the hand-dug wells with pumps tested in this study, ongoing monitoring by the WatSan
committee using only the Colilert test has potential advantages to the community. Based
on the data collected, the community could be assured that the source was consistently
low disease risk. After confirmation by follow-up testing that any 10 ml Colilert sample
that was positive for E. coli were a true problem rather than an anomaly, 1 ml Petrifilm
tests could be used to determine the extent of the contamination and if significant
degradation to the well or borehole existed such that alternative sources should be sought
or household treatment like boil orders or other appropriate purification should be
implemented for water from this source for a period of time. In line with the CWSA
78
policy of shifting responsibility of monitoring the water supply from the CWSA to the
community, the Portable Microbiology Laboratory gives a low cost option for the
communities to take greater responsibility for water safety.
Validation of CWSA Policy. This study shows that the Portable Microbiology
Laboratory can be used to verify the policies set by the CWSA to focus on construction
of boreholes. For water systems that receive regular monitoring, WHO presents a grading
system for performance targets based on the percentage of samples from the system
classified to be below a tolerable risk level (typically negative for E. coli at 100 ml where
water is chlorinated) (39). WHO notes that developing countries may need to set
intermediate tolerable disease-risk levels during the period when the primary focus is on
improving access, such as low disease risk (negative for E. coli at 10 ml or the pre-1989
standard in the USA of negative for E. coli at 50 ml) (39). The 2001 WHO Guidelines lay
out clearly that no E. coli in 10 ml of water constitutes a low disease risk and thus is an
appropriate tolerable risk level (37). All boreholes in the Suhum District met this
standard, and the district performance can be rated as excellent. Seventy-six percent
(76%, 35/46) of the boreholes in Nanumba met this standard, and the district performance
can be rated as moderate.
The relatively low cost of testing associated with the Portable Microbiology
Laboratory, about $2/test, enables not just water systems but also point sources to be
tested more frequently. Frequent testing can allow for immediate identification of
problem sources for urgent action and also for standards to be set for individual point
sources. In addition to providing sufficient data so that, for the first time, the CWSA can
79
have an overall grade for different districts, the results presented in this thesis also
identified a high-disease-risk source for urgent action.
Use of the combination of tests in the Portable Microbiology Laboratory could
transform water testing in Ghana and bring its testing regime into substantial accord with
WHO testing recommendations (38). The portable testing provides simple, inexpensive,
and accurate results that correspond to the WHO disease-risk categories. The results of
this study identified water sources in all four WHO disease-risk categories of low,
moderate, high, and very high, indicating sensitivity of testing that corresponds to current
contamination levels. The testing can be used both to provide a baseline to set national
policies and strategies and for ongoing verification of quality. Furthermore, by involving
communities in the testing and interpretation of these results, progress can be made in
reaching goals for health education and improving domestic hygiene. The tests are
commercially available and could be integrated in Ghana into current water supply
surveillance practices to improve public health.
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APPENDICES
81
APPENDIX A
Management of the Rural Water Supply in Ghana
The Community Water and Sanitation Agency (CWSA) is currently part of the
Ghana Ministry of Works and Housing. In 1994, the National Community Water and
Sanitation Program was launched as a decentralized support structure to the District
Assemblies (area government units) in the provision of potable water and related
sanitation services to rural communities and small towns in Ghana. Later, by
Parliamentary Act 564 in December 1998, the CWSA was formally split from the Ghana
Water and Sewage Corporation (more recently known as the Ghana Water Company
Limited) and organized within the Ministry of Works and Housing (9). The CWSA
mandate is to the rural communities and small towns that account for about 70% of the
population of the country.
The head office for the CWSA is located in Accra. The CWSA functions in all ten
administrative regions of Ghana through regional offices. The Regional Water and
Sanitation Teams provide support to the District Assemblies to form and train District
Water and Sanitation Teams. CWSA operates in 128 districts and in 13,488 communities
(9).
External Support Agencies. In the urban sector, there has been a move towards
privatization of water. Privatization started with "structural adjustment" programs
initiated in 1983 and culminated in the introduction of foreign management support to the
Ghana Water Company Limited in 2006 (23). In the rural sector, by contrast, potential
profit margins for private investors are low. This is because there is a high cost to the
82
necessary investment and because low rural income levels require low water rates to be
charged (23). Provisioning of water to this sector has therefore become the responsibility
of the rural communities themselves, with financial and technical assistance from
“external support agencies,” which are foreign governments and non-governmental
organizations (NGOs) that provide aid (23). The key role of such external support
agencies is reflected in the country's national program for Community Ownership and
Management of the water and sanitation facilities. This program seeks to integrate the
assistance from external support agencies into building and maintaining locallycontrolled rural water supplies, which is different from the earlier approach of principal
reliance on the national Ghana Water and Sewerage Corporation (9).
CWSA Mandate. The specific function of the CWSA in the country's
organizational structure for providing rural water and sanitation service, as set forth in
Act 564, is to (i) promote the sustainability of a safe water supply and related sanitation
services in rural communities and small towns; and (ii) encourage the active involvement
of communities, especially women, in the design, planning, construction and community
management of water and sanitation projects. The CWSA is responsible for formulating
strategies for the mobilization of resources, providing technical assistance, and
coordinating with NGOs engaged in the development of water and sanitation projects and
hygiene education. It is also the role of the CWSA to “prescribe standards and guidelines
for safe water supply and provision of related sanitation services in rural communities
and small towns and support the District Assemblies to ensure compliance by the
suppliers of the services” (9).
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The CWSA outlines its four goals for the minimum basic service of a water
supply as: (1) it is protected year-round; (2) it provides 20 liters per capita per day; (3) it
is within 500 meters of families in the community, and (4) in the case of a borehole with
a hand-pump, it serves no more than 300 persons per outlet (9).
Village, Community and District Roles. Implementing the national policy for
Community Ownership and Management of water resources, the basic unit of the
community water supply program is the village Water and Sanitation (WatSan)
committee. Every village is required to have a WatSan committee with a constitution and
a chairperson, treasurer, secretary, hygiene officer, and caretaker. At least one leader
must be a woman; a woman as the hygiene officer typically fulfills this requirement (23).
The WatSan committee is required to contribute towards the capital cost of its facility at
the rate of 5% for communities and 2.5% for small towns and to pay the full operation,
maintenance, and repair cost (8). At the time of this study, the 5% share for a local
community came to $350 for a typical $7000 borehole. The fees that are intended to
cover these capital and operational costs are typically collected either through a monthly
tariff on each household, monthly tariff per person above 18, or through a “pay as you
fetch” tariff per bucket of water collected (Appendix B).
The District Water Sanitation Team directly supports the village WatSan. The
Team helps to coordinate additional services for the WatSan committee that are provided
through the private sector and external support agencies. These include prioritizing the
distribution of external support agency funding for the building of new water sources,
monitoring and interfacing with private contractors engaged in construction, and setting
84
guidelines on rates to be charged by the area mechanic (Gabriel M. Nartey, personal
communication).
Constructing Water Projects. In recent years, there has been a significant effort at
construction of new boreholes. WHO and UNICEF report the percentage of the rural
population having access to improved sources of drinking water in 2008 as having
increased to 3% piped on premises, 71% other improved sources (boreholes and handdug wells), and 26% with access only to unimproved sources (40). For example, in the
Eastern Region of Ghana, which is part of the study area here addressed, there have been
five construction phases for boreholes supported by various external support agencies.
These phases were "3000 Wells" (1978-1984) for 576 boreholes, "JICA" (1997-1999) for
329 boreholes, "DANIDA I" (1999-2003) for 477 boreholes, "RWSP III" (2002-2005) for
200 boreholes, and "DANIDA II" (2004-2008) for 32 boreholes. There was also a period
of rehabilitation of boreholes from 1997-2000. (Theo Mensa, Eastern Region Water and
Sanitation Team engineer, personal communication)
Since 1994, as part of the National Community Water and Sanitation Program,
there has been new construction of 524 small-town pipe systems, 15,654 boreholes and
1,430 hand-dug wells (9). This brings the national coverage for potable water supply in
both rural communities and small towns in the country up to 51.7%, 5% higher than two
years previously (9). The CWSA plans to increase this coverage from 74% to 85% by
2015. The CWSA is currently developing a plan for regular monitoring of the quality in
small town pipe systems and random monitoring of quality in point sources. While the
plan includes regular monitoring of the pipe systems, the current policy is that each
85
District Assembly is responsible for testing two randomly selected boreholes each year
(Charlotte Engmann, National CWSA engineer, personal communication).
Also, since 1994, sanitation in Ghana’s rural areas has been addressed through the
construction of 2,184 institutional "KVIP" latrines and 42,588 household latrines (8).
Percentage of the rural population having access to sanitation facilities in 2008 stands at
38% access to shared facilities, 7% access to improved (KVIP) latrines at household
level, and 21% access to unimproved facilities (household latrines), with the remaining
34% having only open defecation options (40).
86
APPENDIX B
Water Facilities Monitoring Sheet for WatSans
87
88
89
APPENDIX C
Survey of Point-Source Water Supply
90
91
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42. 40 C.F.R. § 141 (2011)