WATER SAFETY
PLAN
LINDEN
GUYANA
Prepared by the Caribbean Environmental Health Institute (CEHI)
in Conjunction with the Ministry of Health, Guyana and the Guyana Water
Incorporated (GWI) with support from the Project Partners The U.S. Centers for
Disease Control and Prevention (CDC), the National Oceanic and Atmospheric
Administration (NOAA), the U.S. Geological Survey (USGS), the Pan American
Health Organization in Guyana (PAHO-Guyana),
April 2009
1
ACKNOWLEDGEMENTS
The Caribbean Environmental Health Institute (CEHI) would like to thank the
Government of Guyana for its support for this project and for the assistance
provided through its Ministries of Health and Housing and Water and the Guyana
Environmental Protection Agency. We would also like to thank the United States
Centers for Disease Control and Prevention (CDC), the National Oceanic and
Atmospheric Administration (NOAA), the United States Geological Survey
(USGS).and the Pan American Health Organisation (PAHO) who supported this
project as part of the National Programme of Action/Water Safety Plan (NPA/WSP)
Partnership group.
CEHI would also like to acknowledge the guidance provided by the National
Steering Committee that was ably led by Dr Bheri Ramsaran Minister in the
Ministry of Health, Guyana.
The inputs of Mr Karan Singh and Ms Savitri Jetoo of GWI, Dr Ashok Sookdeo and
Ms Yohani Singh of the Ministry of Health, and Mr Samuel Wright, Consultant,
were invaluable in the development of the Plan.
CEHI would also like to acknowledge the inputs of all the participants in the various
workshops held during the development of the Plan. Finally, CEHI would like to
acknowledge the assistance provided by all of the key stakeholders and residents
of Linden, for whom it is hoped this Plan can be implemented in order to improve
the state of their environment and improve the quality of drinking water which they
receive.
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LIST OF ACRONYMS
CBH
CBWMP
CDC
CEHI
CMO
DFID
DWC
DWSS-GUY
EH
EHO
EHU
EPA
F&D
GNBS
GPA
GWI
HACCP
HH
IDB
IMC
IT
LEAP
M&CC
M&TC
MoE
MoH
MoLG&RD
MOU
NOAA
NPA
NRW
NTU
PA/PE
PAHO
POE
PSA
PSI
RDC
RHO
RWH
SOP
TCU
UNESCO
UNICEF
USGS
VIP
WASH
WHO
WSP
WTP
Central Board of Health
Caribbean Basin Water Management Programme
US Centers for Disease Control and Prevention
Caribbean Environmental Health Institute
Chief Medical Officer
Department for International Development
Drinking Water Container
Drinking Water Surveillance System in Guyana
Environmental Health
Environmental Health Officer
Environmental Health Unit
Environmental Protection Agency
Food and Drugs
Guyana National Bureau of Standards
Global Programme of Action
Guyana Water Incorporated
Hazard Analysis and Critical Control Points
Household
Inter-American Development Bank
Interim Management Council
Information Technology
Linden Economic Advancement Programme
Mayor and City Council
Mayor and Town Council
Ministry of Education
Ministry of Health
Ministry of Local Government and Regional Development
Memorandum of Understanding
National Oceanic and Atmospheric Administration
National Programme of Action
Non Revenue Water
Nephelometric Turbidity Units
Public Awareness/Public Education
Pan American Health Organisation
Point of Entry
Public Service Announcement
Pounds per square inch
Regional Democratic Council
Regional Health Officer
Rain Water Harvesting
Standard Operating Procedures
True Colour Unit
United Nations Educational, Scientific and Cultural Organisation
United Nations Children’s Fund
United States Geological Survey
Ventilated Improved Pit
Water Sanitation and Hygiene
World Health Organisation
Water Safety Plan
Water Treatment Plant
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TABLE OF CONTENTS
1.0 INTRODUCTION............................................................................................... 1
1.1 BACKGROUND ..............................................................................................................1
1.2 LINDEN .........................................................................................................................2
1.3 WHAT IS A WATER SAFETY PLAN?.................................................................................4
1.3.1 Main Objectives of a Water Safety Plan ............................................................................ 5
1.3.2 Benefits of a Water Safety Plan......................................................................................... 5
1.3.3 Inclusion of a Household Survey in the Water Safety Plan ............................................... 5
1.4 LINKAGE BETWEEN NATIONAL PROGRAMME OF ACTION (NPA) AND THE WATER SAFETY
PLAN (WSP) FOR LINDEN ...................................................................................................6
1.5 WATER SAFETY PLAN TEAM ..........................................................................................7
2.0 WATER SUPPLY SYSTEM DESCRIPTION FOR LINDEN .............................. 9
2.1 WATER SERVICE PROVIDER AND RELATED AGENCIES .....................................................9
2.2 HEALTH-BASED STANDARDS .........................................................................................9
2.3 WATERSHEDS.............................................................................................................10
2.4 WATER TREATMENT PLANTS .......................................................................................10
2.4.1 Amelia’s Ward Sub-system ......................................................................................... 13
2.4.2 LPC Treatment Sub-system........................................................................................ 15
2.4.3 McKenzie Sub-system................................................................................................. 18
2.4.4 West Watooka Sub-system......................................................................................... 20
2.4.5 Wisroc.......................................................................................................................... 23
2.5 DISTRIBUTION .............................................................................................................25
2.5.1 Eastern Bank - Linden Water System ......................................................................... 28
2.5.2 Western Bank – Linden Water System ....................................................................... 28
2.6 WATER QUALITY .........................................................................................................30
2.6.1 WATER QUALITY MONITORING .................................................................................30
2.6.2 DISTRIBUTED WATER QUALITY .................................................................................32
2.6.3 HOUSEHOLD WATER QUALITY ..................................................................................33
2.7 POINT-OF-USE PRACTICES ..........................................................................................34
2.7.1 Household Water Treatment ........................................................................................... 34
2.7.2 Household Water Storage ............................................................................................... 35
2.8 OFF - NETWORK WATER USE ......................................................................................35
3.0 HAZARD IDENTIFICATION AND RISK ASSESSMENT................................ 36
3.1 HAZARD IDENTIFICATION .............................................................................................36
3.2 PRIORITISATION OF HAZARDS......................................................................................37
4.0 CONTROL MEASURES ................................................................................. 38
5.0 CORRECTIVE ACTIONS................................................................................ 39
6.0 MONITORING OF CONTROL MEASURES ................................................... 56
7.0 VERIFICATION ............................................................................................... 63
8.0 MANAGEMENT PROCEDURES .................................................................... 67
8.1 STANDARD OPERATING PROCEDURES (SOPS) ............................................................67
8.2 CONTINGENCY PLANS .................................................................................................68
9.0 SUPPORTING PROGRAMMES ..................................................................... 69
9.1 OPERATOR TRAINING ..................................................................................................69
9.2 INTRA AND INTERAGENCY REPORTING SYSTEM FOR DRINKING WATER QUALITY DATA ..70
9.2 PUBLIC AWARENESS AND PUBLIC EDUCATION (PA/PE)................................................71
10.0 PERIODIC REVIEW OF THE WATER SAFETY PLAN ................................ 73
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11.0 REVISION OF THE WATER SAFETY PLAN ............................................... 74
12.0 SUMMARY OF KEY FINDINGS AND RECOMMENDATIONS .................... 75
12.1 Overarching/Inter-Agency................................................................................................. 75
12.2 Watersheds/Source .......................................................................................................... 75
12.3 Treatment ......................................................................................................................... 75
12.4 Distribution........................................................................................................................ 76
12.5 Consumers ....................................................................................................................... 76
List of Tables
Table 1.1: Steering Committee Members ................................................................ 7
Table 1.2: Other Partners ........................................................................................ 8
Table 2.1: Current Reference Water Quality Standards .......................................... 9
Table 2.2: Main Source of Drinking Water for Households for Linden Municipality
(PAHO, 2005)........................................................................................................ 10
Table 2.3: Linden Water System Summary ........................................................... 12
Table 2.4: Amelia's Ward Completion Data........................................................... 13
Table 2.5: Final Water (Source GWI Laboratory Results, for the year 2007) ........ 31
Table 2.6: Plant Readings ..................................................................................... 32
Table 2.7: Distributed Water.................................................................................. 33
Table 2.8: Summary of Water Quality at Consumers’ Premises from Household
Survey, December 2007........................................................................................ 33
Table 5.1: Hazards and Corrective Actions ........................................................... 41
Table 6.1: Monitoring Procedures ......................................................................... 58
Table 7.1: Verification Procedures (Water Quality) ............................................... 65
Table 7.2: Verification Procedures (Surveillance).................................................. 66
Table 8.1: Standard Operations Procedures ......................................................... 67
Table 8.2: Emergency Procedures ........................................................................ 68
Table 9.1: Reporting Mechanisms for Inter and Intra-agency Reporting ............... 70
Table 9.1: PA/PE Interventions ............................................................................. 72
Table 10.1: Audit Routine for GWI......................................................................... 73
List of Figures
Figure 1.1: Map of Guyana...................................................................................... 3
Figure 1.2: Map of Linden ....................................................................................... 4
Figure 2.1: Linden Water Treatment Plant Location Map ...................................... 11
Figure 2.2: Flow Diagram - Amelia's Ward Treatment Plant.................................. 14
Figure 2.3: Flow Diagram - LPC Treatment Plant.................................................. 17
Figure 2.4: Flow Diagram - McKenzie Treatment Plant......................................... 19
Figure 2.5: Flow Diagram - West Watooka Treatment Plant ................................. 22
Figure 2.6: Flow Diagram - Wisroc Treatment Plant.............................................. 24
Figure 2.7: Linden Distribution System Pipe Materials .......................................... 26
Figure 2.8: Linden Distribution System Pipe Diameters ........................................ 27
List of Appendices
Appendix I
Appendix II
Appendix III
Glossary
Proposal for the Improvement of Linden’s Water Supply Infrastructure
Household Water Use and Health Survey Report for Linden
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Appendix IV
Appendix V
Standard Operating Procedure – Jar Test Procedure
Draft Outline for Focus Group Meetings for the National Programme of
Action/Water Safety Plan (NPA/WSP)
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EXECUTIVE SUMMARY
The town of Linden in Region 10 of the Co-operative Republic of Guyana was chosen as
the pilot project in an initiative that would allow Linden to adopt a holistic approach to
addressing the key issues of watershed management and drinking water quality. This
report focuses on drinking water quality through the development of a Water Safety Plan
(WSP) as recommended under Chapter 4 of the World Health Organisation (WHO)
Guidelines for Drinking Water Quality 3rd Edition (2004). A WSP is a methodology
developed by the World Health Organisation (WHO) to help drinking water suppliers
improve and maintain water quality. It provides a comprehensive risk assessment and risk
management approach that includes all steps in the water supply chain; from catchment to
consumer. It provides an opportunity for a drinking-water supplier to assess, modify, and
build upon existing good management practices. A WSP aims to improve drinking-water
quality by optimizing:
•
•
•
control of source-water contamination;
the removal, reduction, or inactivation of contaminants during treatment processes;
the prevention of re-contamination during distribution, storage, and handling.
The town of Linden is located 107 km inland from Guyana’s Atlantic coast, on the east
and west banks of the Demerara River. Linden is the second largest town in Guyana and
occupies an area of approximately 140 sq km. This town, which developed around the
bauxite mining industry, with a population of approximately 40,000, is the main population
centre of Region 10.
Traditionally the major economic activities were centred on the bauxite industry which
developed after the discovery of this mineral in the 1920’s. By 1960 the industry prospered
and supported over 8,000 workers in the region. Declining world market prices and
increasing cost of production resulted in the contraction of the industry, resulting in the
declining living standards in the region. However, still a substantial number of the regions
population is employed by the bauxite industry.
Linden’s main water supply is derived from three primary sources – surface water intakes
from the Demerara River and the Dakoura Creek, and groundwater intakes from the
Coastal Aquifer (A- Sands). Guyana Water Incorporated (GWI) is the sole utility company
responsible for providing potable water for both domestic and industrial use. GWI operates
five water treatment plants (WTPs) in Linden and provides household connections for up
to 70% of Linden’s residents.
The issues relating to watershed concerns are detailed in another document, the National
Programme of Action (NPA). As a result the WSP developed for Linden focused on issues
relating to the five water treatment plants, the distribution system and household practices.
The WSP does not, however, traditionally provide for identifying hazards that could
compromise drinking water quality after it reaches the household, such as contamination
associated with water collection, storage and treatment practices within the home. As a
result, in December 2007, a Household Water Use and Health Survey was conducted in
order to understand what happens to the water from the time it reaches the home to the
point of consumption. The information from this Survey served to greatly enhance the
scope of the WSP and to provide greater insight into the challenges faced by the town of
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Linden with respect to drinking water quality and practices relating to water safety, hygiene
and sanitation at the household level.
The five water treatment plants are located in Amelia’s Ward, Linden Power Company
(LPC), McKenzie, West Watooka and Wisroc. The first three plants are located on the
east bank of the Demerara River whilst the latter two are located on the west bank of the
Demerara River. LPC, McKenzie and West Watooka include the most chemical processes
and source their water from the Demerara River. Amelia’s Ward uses ground water as the
source and Wisroc is the simplest plant in operation with source water from the Dakoura
Creek. The water quality standards used by GWI are the WHO Drinking Water Quality
Guidelines with a relaxed standard for iron (iron naturally occurs in the area as a result of
the soil type and is very expensive to remove totally; there are no proven health risks
associated with iron (WHO).
Guided by a Steering Committee, the WSP focused on determining the exact processes
for each plant and documenting in detail the processes through flow charts. The entire
operation was examined and water quality records for the raw water, water throughout the
process, treated water, distributed water and water at consumers’ premises were found,
analysed and documented in great detail. Based on these records together with a number
of site visits and stakeholder consultations in Linden, the Water Safety Co-ordinator was
able to determine the challenges of the treatment plants, distribution system, household
practices, data recording, feedback, consumer awareness and monitoring systems.
Through extensive stakeholder consultations, a number of recommendations were made
to the Steering Committee. These recommendations included technical solutions together
with procedural and monitoring activities that were required in order to ensure that the
drinking water quality would meet the guidelines as recommended by the WHO, standards
to which Guyana aspire to achieve.
Some of the key findings and recommendations of the WSP process included:
Overarching/Inter-Agency
Key Findings:
• Importance of including agencies other than the water utility in WSP planning
process
• Lack of formal and informal mechanisms for coordination between agencies
• Lack of formalized and executed intra and inter-agency reporting mechanisms
for routine sharing of water quality monitoring data
Recommendations:
• Continue oversight of WSP implementation by the Steering Committee
• Establish both intra- and inter- agency reporting mechanisms
• Formalize mechanisms for routine (monthly) reporting of water quality data and
surveillance data between GWI, MoH, and other relevant agencies
• Develop and formalize emergency surveillance data reporting mechanisms
• Establish a water surveillance database to be instituted collaboratively by
relevant agencies
Watersheds/Source
Key Findings:
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•
•
Poor quality of Demerara river water limits the ability of treatment plants to
meet water quality standards
Contamination of ground and surface waters through usage of pit latrines.
Recommendations:
• Explore option of sourcing only Dakoura Creek, and/or relocating effluent pipes
• Increase enforcement of existing sanitation guidelines and expand guidelines to
incorporate VIP latrines
• Pursue funding options for improved sanitation
Treatment
Key Findings:
• Treatment plants not operating optimally – need for operator training
• Lack of consistent water quality testing and documentation at critical control
points in the water treatment process
• Lack of a system for routine review, analysis and feedback to operators of
existing water quality monitoring records
• Need to establish in-plant standards that are consistent for all treatment
facilities
Recommendations:
• Optimise treatment processes through plant operator training programmes Develop operator training manuals, with the view to mandatory certification for
operators
• Set appropriate health-based water quality standards (with incremental targets
for compliance), especially for turbidity
• Develop specific Standard Operating Procedures
Distribution System
Key findings:
• Capital Investment needed to repair leaks
• High non-revenue water from leaks and non-payment
• Lack of routine monitoring, review and feedback at points along distribution
network
Recommendations:
• Repair leaks and replace pipes where necessary, reduce network vulnerability
• Develop non-revenue water programme, including leak detection and demand
suppression
• Establish schedule for routine monitoring in the distribution system
• Establish routine for reporting results of monitoring by MoH to GWI
• Develop and implement targeted public relations programme, customer service
training for GWI personnel,
Consumers
Key Findings:
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•
•
•
Improper storage that may lead to re-contamination of water
Lack of knowledge about effective home treatment methods
Inconsistent water supply
Recommendations:
• Establish formal outreach programmes with consumers
• Develop PA/PE materials that would target proper storage and treatment of
water in the home
• Encourage the use of appropriate sanitation facilities such as Ventilated
Improved Pit Latrines (VIPs)
• Encourage safe, alternative water supply such as rain water harvesting (RWH)
The project was financially supported by the US Centers for Disease Control and
Prevention (CDC) and the National Oceanic and Atmospheric Administration (NOAA).
Project partners also include the US Geological Survey (USGS), the Caribbean
Environmental Health Institute (CEHI), and the Pan American Health Organisation (PAHO)
Guyana office. These principal agencies have supported the work of national-level
agencies including the Guyana Environmental Protection Agency (EPA), the Ministry of
Health (MoH), Guyana Water Incorporated (GWI); the country’s main water provider, and
representatives of relevant industry, and local government in the execution of this project.
A Steering Committee, chaired by the Minister in the Ministry of Health and comprising
representatives from the Ministries of Health, Housing and Water, and Local Government,
Linden Interim Management Council (IMC), GWI, EPA, US CDC (local office) and PAHO
was set up to provide strategic direction and project oversight.
iv
1.0 INTRODUCTION
1.1 Background
Recognising the importance of water to sustainable development and improved public health and
sanitation in the region, the Government of Guyana along with national, regional and international
partners, established a team to oversee the development of a pilot project in the community of Linden
Guyana, which would adopt a holistic approach to addressing the key issues of watershed management
and drinking water quality. The approach would incorporate good watershed management practices
aimed at ensuring the integrity of source waters with a strategy that optimised drinking water supply
systems.
The adopted approach has given rise to the merger of two initiatives – the development of a National
Programme of Action (NPA) under the global framework of the Global Plan of Action (GPA) and the
Cartagena Convention on Land Based Sources of Marine Pollution (LBS Protocol) and a Water Safety
Plan (WSP) as recommended under Chapter 4 of the World Health Organization (WHO) Guidelines for
Drinking Water Quality 3rd Edition (2004).
The project was financially supported by the US Centers for Disease Control and Prevention (CDC) and
the National Oceanic and Atmospheric Administration (NOAA). Project partners also include the US
Geological Survey (USGS), the Caribbean Environmental Health Institute (CEHI), and the Pan American
Health Organisation (PAHO) Guyana office. These principal agencies have supported the work of
national-level agencies including the Guyana Environmental Protection Agency (EPA), the Ministry of
Health (MoH), Guyana Water Incorporated (GWI); the country’s main water provider, and representatives
of relevant industries and local government in the execution of this project. A Steering Committee,
chaired by the Minister in the Ministry of Health and comprising representatives from the Ministries of
Health, Housing and Water, and Local Government, Linden Interim Management Council (IMC), GWI,
EPA, US CDC (local office) and PAHO was set up to provide strategic direction and project oversight.
The project team held the first inception mission in November 2006. This mission was aimed at
promoting the NPA and WSP concepts and at gaining much needed political buy-in amongst key policy
stakeholders including GWI, the Ministries of Housing and Water, Health, and Local Government. The
mission also allowed the project team to gain a better understanding of some of the critical issues related
to water resources management as well as the state of the country’s water supply.
The community of Linden was considered well suited for piloting this integrated NPA/WSP approach. Not
only did it have active and committed community groups and strong local government structures, but it
was also unique in that the community was situated within the well-defined watershed of the Demerara
and relied primarily on surface water as its source of supply. An integrated NPA/WSP pilot project in
Linden therefore presented an opportunity to directly link natural resource management issues related to
industrial, forestry and agricultural best practices, land use planning, and waste disposal, to issues
affecting water quality and its associated health impacts. This recommendation of the project team was
subsequently endorsed at the first meeting of the Steering Committee held in January 2007.
The project was officially launched in Linden in May 2007, during which an NPA/WSP stakeholder
training session was conducted to sensitize community and agency stakeholders as to the process of
developing an NPA and a WSP, and the benefits to be derived from these outputs. The meeting also
sought to chart the way forward for project implementation and to obtain the commitment of the various
interest groups involved.
1
The project execution model involved the use of a consultant in the development of the plan. The initial
parts of the document were written primarily by the Guyana Water Inc. in conjunction with the local coordinator. CEHI assumed the role of the local co-ordinator for the NPA and eventually replaced the local
co-ordinator for the WSP.
1.2 Linden
The town of Linden is located 107 km inland from Guyana’s Atlantic coast, on the east and west banks of
the Demerara River (see Figure 1.1 Map of Guyana). Linden is the second largest town in Guyana and
occupies an area of approximately 140 sq km. This town, which developed around the bauxite mining
industry, with a population of approximately 40,000, is the main population center of Region 10. Upper
Demerara/ Upper Berbice. Coomacka, Ituni, Kwakwani, and Rockstone are among other population
centers accessible from Linden. A detailed map of Linden is shown in Figure 1.2. In addition to its
bauxite reserves, the Linden/Region 10 area is endowed with other resources such as gold, kaolin,
laterite, and timber (information courtesy of the Linden Economic Advancement Programme (LEAP)).
Traditionally the major economic activities were centred on the bauxite industry which developed after the
discovery of this mineral in the 1920’s. By 1960 the industry prospered and supported over 8,000 workers
in the region. Declining world market prices and increasing cost of production resulted in the contraction
of the industry, resulting in the declining living standards in the region. However, still a substantial
number of the regions population is employed by the bauxite industry.
Linden’s main water supply is derived from three primary sources – surface water intakes from the
Demerara River and the Dakoura Creek, and groundwater intakes from the Coastal Aquifer (ASands).GWI is the sole utility company responsible for providing potable water for both domestic and
industrial use. It is estimated that GWI provides household connections for up to 70% of Linden’s
residents (GWI Hi Affinity Database). Issues related to ageing infrastructure, illegal connections,
unaccounted for water, and an inconsistent power supply, have all served to compromise GWI’s
operations and consequently the quality, quantity and reliability of its supply to consumers.
As with most areas outside of the capital, Georgetown, GWI is not responsible for wastewater
management. This responsibility falls under the local town councils. Septic tanks are a common means
of domestic sewage disposal, whilst many households also use pit latrines. Given the permeable nature
of the soil conditions within the vicinity of Linden, there are concerns that ground water intakes could be
at risk from untreated discharges.
The responsibility for solid waste disposal resides with the local authorities. There are no landfill facilities
for solid waste disposal. It is estimated that approximately 6,700 kg/day is collected and transported to
one of two open dump sites where open burning takes place (IDB, 2000). Indiscriminate dumping of
household waste into the Demerara and its tributaries also continues to be a source of concern for
authorities.
Emissions from bauxite mining operations also pose a concern with regards to the air quality. Concerns
in relation to dust emissions extend to concerns regarding water quality in instances where household
rainwater harvesting systems are used to augment the water supply.
Given the nature and complexity of the environmental issues facing the community of Linden, there is the
recognition that a holistic approach needs to be adopted to address the issues that pose a threat to water
quality. It is against this backdrop that the WSP for Linden was developed.
2
Linden
Figure 1.1: Map of Guyana
(Source: State of the Environment Report for the Demerara Watershed 2006)
3
Figure 1.2: Map of Linden
(Source Guyana Water Inc)
1.3 What is a Water Safety Plan?
A WSP is a methodology developed by the World Health Organisation (WHO) to help drinking water
suppliers improve and maintain water quality. It provides a comprehensive risk assessment and risk
management approach that includes all steps in the water supply chain, from catchment to consumer. It
provides an opportunity for a drinking-water supplier to assess, modify, and build upon existing good
management practices.
As a preventive, multiple barrier approach to ensuring safe drinking-water, the WSP adopts a
methodology based upon the Hazard Analysis and Critical Control Points HACCP system used by the
food manufacturing industry for ensuring compliance with industry quality standards. The WSP therefore
focuses attention on the identification and prioritisation of hazards at key points within the water supply
system; the design of control measures to mitigate these risks; and the establishment of management
plans and procedures for taking necessary corrective actions and conducting ongoing operational
4
monitoring. Management plans by extension may also include supporting programmes and verification
procedures that ensure the effectiveness of measures outlined in the WSP.
The WHO Guidelines for Drinking Water Quality outline three main components of a WSP. These
include:
1) The conduct of a system review and assessment involving the examination and documentation of
the entire water supply system, with a view to determining whether the system can provide water
that meets pre-determined health based standards. The assessment also serves the purpose of
identifying key points where there is the potential for harmful contaminants to be introduced into
the supply system, including an assessment of the likelihood and severity of such occurrences.
The formulation of the corrective actions to mitigate those risks also forms an integral part of this
component.
2) The enhancement of overall risk management through the development of operational control
measures. These measures would include monitoring procedures for each key or critical control
measure identified to ensure the effectiveness of each control measure.
3) The development of management and communication plans which document the WSP
components, including the system assessment, operational monitoring and verification protocols.
The management plan also serves the purpose of describing actions to be taken during routine
operations, as well as during times of incident. As noted above, management plans may also
include the need for ongoing support programmes. These may include operator training
programmes, research and development, evaluation procedures and community awareness and
outreach programmes.
1.3.1 Main Objectives of a Water Safety Plan
A WSP aims to improve drinking-water quality by optimizing:
•
•
•
control of source-water contamination;
the removal, reduction, or inactivation of contaminants during treatment processes; and
the prevention of re-contamination during distribution, storage, and handling.
1.3.2 Benefits of a Water Safety Plan
•
•
•
•
•
It is a powerful tool to help the water provider optimize system operations and apply improved
management practices.
It contributes to an improved understanding of the water supply system and an increased
awareness of threats to water quality.
It facilitates communication and collaboration among stakeholder groups.
It can assist in heightening community awareness of practices that negatively impact the quality of
source waters.
It can assist in leveraging financial support for capital improvement needs by building donor
confidence.
1.3.3 Inclusion of a Household Survey in the Water Safety Plan
As noted above, the Water Safety Plan (WSP) aims to identify hazards to drinking water quality that can
be introduced at multiple points from “catchment to consumer.” It does not, however, traditionally provide
for identifying hazards that could compromise drinking water quality after it reaches the household, such
5
as contamination associated with water collection, storage, treatment and user practices within the home.
As a result, in December 2007, a Household Water Use and Health Survey was conducted in order to
understand what happens to the water from the time it reaches the home to the point of consumption.
The survey, consisting of a household questionnaire and testing of household water samples, looked at
issues such as consistency of water delivery, quality of delivered and stored water, community
perceptions, and consumer practices concerning water use that impact customer satisfaction and the
safety of drinking water within the home.
Specific aims of the household survey were:
1. to determine the quality of household water at the point of collection and at the point of
consumption; to determine the quality of water reaching consumers and to identify whether
deterioration of water quality occurs as a result of storage and handling practices;
2. to describe water use and treatment practices at the household level, user satisfaction, and
perceptions of water quality by consumers;
3. to estimate the prevalence of diarrhoeal illness in the population, evaluate its possible association
with water-related variables, and describe health-seeking behaviours;
4. to determine the quality and consistency of water service provision, identify issues of special
concern, and evaluate the impact that interruptions in service or pressure or other service-related
issues may have on the safety of water consumed.
Information derived from this survey is further elaborated on in Section 2.6.3.
1.4 Linkage between National Programme of Action (NPA) and the Water
Safety Plan (WSP) for Linden
The approach chosen for this process was unique in that it is the first to merge the WSP initiative
together with an NPA. The NPA addresses the threats posed by land-based activities on the coastal and
marine ecosystems, whilst the WSP looks at assessing water supply systems with a view to developing
management and operational plans that serve to address potential risks of contamination of the water
supply at critical points within the water supply system.
The National Programme of Action is a conceptual guide developed in response to the commitment of
several countries to addressing the concerns regarding the state of the coastal and marine eco-systems
under the framework of the Global Programme of Action (GPA) for the Protection of the Marine
Environment from Land-based Activities. The NPA takes national priorities, geographic and geologic
characteristics, local political, institutional and regulatory frameworks and other domestic factors into
account in formulating strategies for minimising the destructive impacts of pollution on the marine
environment.
Although drinking water quality is not expressly stated and directly addressed in an NPA, issues related
to watershed management and source water protection are of relevance to the WSP process, given the
fact that an understanding of the nature and extent of pollutants entering the water system is critical to
determining the extent of treatment required and the possible health risks associated with consuming
poorly treated or untreated water.
In this NPA/WSP joint demonstration project, the two processes were developed in parallel. By allowing
the watershed issues that are traditionally included in a WSP to be addressed by the NPA, a more indepth assessment of the watershed and source waters, as well as more large-scale environmental issues
such as those affecting the aquifers and corresponding oceanic features was possible. This combined
approach allowed for an assessment greater in scope than would have been achieved through either the
6
WSP or the NPA alone. The Plans are presented jointly, and where the WSP would normally address
issues in the watershed, reference is made to the corresponding sections of the NPA. Great synergies
were realised given the commonality of issues relating to and impacting on the quality of raw water. The
steering committee identified for the WSP was the same for the NPA so that both processes were jointly
discussed at the steering committee meetings. The recommendations of both initiatives are highly
interlinked and would allow the authorities in Linden to make the necessary interventions to improve the
quality of water available to the residents of Linden.
1.5 Water Safety Plan Team
The successful implementation of a WSP is dependant on the commitment of policy makers, regulators,
service providers and community interest groups as a whole. As such, a Steering Committee was set up
to provide guidance to the project and to ensure involvement and buy-in to the process at the political
level. Given the need for a multi-agency, multi-sectoral approach, the Steering Committee comprised
policy makers and technical experts from the health, water and environmental sectors, along with local
government representatives from Linden. The members of the Steering Committee are mentioned in
Table 1.1. The other Partners and persons involved in the development of the Water Safety Plan are
mentioned in Table 1.2.
Table 1.1: Steering Committee Members
NAME
OFFICE
RESPONSIBILITIES
Dr Bheri Ramsarran
Minister within the Ministry of
Health
Office of the President
Chairman
Mr Navin Chandarpal
Ms Savitri Jetoo
Dr Ashok Sookdeo
Dr Teofilo Montiero
Ms Yohani Singh
Mr Orrin Gordon
Mr Hance Thompson
replaced by Ms Tashana
Redmond
Mr Khalid Alladin replaced
by Ms Geeta Singh
Mr Julius Farber
Ms Debra MontouthHollingsworth
Ms Nicollette Henry
Mr Renwick English
Guyana Water Incorporated
(GWI)
Director, Environmental
Health, Ministry of Health
PAHO/WHO Guyana Office
Ministry of Health
Chairman, Interim
Management Council, Linden
Environmental Protection
Agency
Environmental Protection
Agency
Ministry of Local Government
and Regional Development;
Regional Chairman -Region 3
Permanent Secretary,
Ministry of Housing and
Water
US Centers for Disease
Control - Guyana
Environmental Protection
Agency
Ms Audreyanna Thomas
7
Steering Committee
Member
Steering Committee
Member
Local Co-ordinator
Project Partner
Steering Committee
Member/Secretary
Steering Committee
Member
Steering Committee
Member
Steering Committee
Member
Steering Committee
Member
Steering Committee
Member
Steering Committee
Member
Steering Committee
Member
Steering Committee Member
Table 1.2: Other Partners
NAME
AGENCY
RESPONSIBILITIES
Ms Camille Roopnarine
Caribbean Environmental Health
Institute
Caribbean Environmental Health
Institute
US Centers for Disease Control
US Centers for Disease Control
US Centers for Disease Control
Water Safety Plan Coordinator
National Programme of
Action Co-ordinator
Technical Advisor
Technical Advisor
Technical Advisor
Dr Christopher Cox
Ms Angella Rinehold
Ms Lana Corrales
Dr Rick Gelting
8
2.0 WATER SUPPLY SYSTEM DESCRIPTION FOR LINDEN
2.1 Water service provider and related agencies
Potable water is supplied to the population of Guyana by the Guyana Water Inc (GWI). GWI provides
water to over 145,000 homes, offices and schools across Guyana. It also provides water to Amerindian
communities in the Hinterland. The company supplies over 300,000,000 litres of water per day.
Guyana Water Incorporated (GWI) was established, resulting from the merger of the Guyana Water
Authority (Guywa) and the Georgetown Sewage and Water Commissioners (GS&WC), on May 30, 2002.
This was done through the Water and Sewerage Act of 2002. GWI operates five water treatment plants
in Linden. These plants will be described in detail later in this section. The overall management of all
GWI operations is done at the head office in Georgetown. This also includes Capital Investment Projects
and billing. In Linden, there is a Divisional Manager who oversees meter readings and other divisional
management issues.
The Ministry of Health has a mandate for developing the regulatory framework for the definition of
drinking water quality standards and for the monitoring of the quality of water that is used by consumers.
Through the Regional Health Office in Linden, Environmental Health Officers routinely sample and test
the water quality. Since the severe floods of 2005, PAHO/WHO has been working with the
Environmental Health Unit (EHU) and other agencies to develop a Drinking Water Surveillance System in
Guyana (DWSS-GUY). This surveillance of drinking-water quality will allow the EHU to continuously
assess and review the safety and acceptability of drinking-water supplies”.
The Environmental Protection Agency (EPA) has a mandate to promote, facilitate and coordinate
effective environmental management and protection: and the sustainable use of Guyana’s natural
resources.
2.2 Health-based Standards
The Government of Guyana does not have any technical standards for water quality referenced in any
regulations or laws. However, the WHO Guidelines for Drinking-Water Quality 3rd Edition have been
used as a guide by GWI for their treatment plants, with a relaxed standard for iron (see Table 2.1). These
standards have also been adopted by the MoH for its monitoring and surveillance programmes. It is
recognised that the aquifers in Guyana are characterised by high iron content and the reduction of these
levels requires expensive treatment. For this reason, and also taking into account the fact that iron is not
detrimental to health, the decision was made to relax the standard for iron. Further details on these
parameters are explained in Appendix I – Glossary.
Table 2.1: Current Reference Water Quality Standards
Parameter Monitored
GWI Standards
pH (at treatment plant, 6.5 – 8.5
finished water)
Turbidity (at treatment <5 NTU
plant)
Aluminium (point of use)
Iron (point of use)
0.2 mg/l
0.3 mg/l
Notes
No WHO health-based guideline value
Above 5, the water appearance is not
appealing to consumers. *1 NTU is the
desirable value that should be achieved
No WHO health-based guideline value;
GWI uses a relaxed value 0.5 mg/l
9
Parameter Monitored
Chlorine (residual) (Point
of Use)
Faecal coliform/E Coli
Total coliform
GWI Standards
0.2 mg/l
Notes
Disinfectant of distribution system
0
0
WHO recommends 0 coliforms as an
indicator of adequate disinfection
2.3 Watersheds
Please refer to Chapter four of the NPA document (put the formal name) for a detailed description of the
watershed and sources of water for Linden.
2.4 Water Treatment Plants
The Linden water system comprises five treatment plants, one pressure booster stations, four
discontinued elevated storage tanks, miles of transmission and distribution pipelines (PVC, HDPE, cast
iron), and three different sources of water; the Demerara River, Dakoura Creek and the Coastal Aquifer
(A-Sands). There are some existing raw water lines that previously provided water for industrial use and
for fire fighting (hydrants).
The Linden water system serves about 70% of the total population. The system’s total operational
capacity is the sum of the capacity of its five (5) treatment plants. According to a Bureau of Statistics
Population and Housing Census – 2002, 3,895 households were serviced by piped water to their
dwelling. Table 2.2 details the various sources of drinking water for the Linden municipality.
Table 2.2: Main Source of Drinking Water for Households for Linden Municipality (PAHO, 2005)
Piped
into
dwelli
ng
Piped
into
Yard
Public
Stand
pipe
Tubewell,
Borehole
with
pump
Prote
cted
Dug
well
Protec
ted
spring
Bottled
Water
Rain
water
collect
ion
Unprot
ected
dug
well
Unprotected
Spring
Pond,
River,
Stream
3,895
1,147
499
10
22
333
291
332
24
469
264
Each plant has an associated transmission and distribution system, which forms a separate sub-system
of the Linden water system. Adjacent distribution systems are connected and are often manually
adjusted to support the immediate demands of neighbouring communities. While Linden’s treatment
capacity can meet the current demands, the actual delivery of water to the community is limited by nonrevenue water (NRW), pumping, supply, and lack of optimisation of the individual plants. The treatment
plants are:
1.
2.
3.
4.
5.
Amelia’s Ward
LPC
McKenzie
West Watooka
Wisroc
The locations of the water treatment plants are shown in Figure 2.1, Linden Water Treatment Plant
Location Map. Table 2.3 Linden Water System Summary provides an outline of the various treatment
capacities of the Linden water system.
10
Figure 2.1: Linden Water Treatment Plant Location Map
(Source: GWI)
11
Table 2.3: Linden Water System Summary
Treatment
Plant
Location
Source
Amelia’s
Ward
South
Amelia’s
Ward
3,636
m³
LPC
Ground
1985
water - A
Sands
Aquifer
Demerara
1961
River
Alumina
Plant,
Spreightland
Watooka,
at Demerara
McKenzie/Wismar River
Bridge
5,000
m³
3,960 m³
1956
5,000
m³
3,960 m³
McKenzie
Year
Treatment
Components
Commissioned Capacity
Design Operation
West
Watooka
West Watooka
Demerara
River
1968
7,272
m³
Wisroc
Wisroc
on Dakoura
Creek
Dakoura
Creek
1976
5,909
m³
3,456 m³
5,500 m³
5,909 m³
12
Aeration,
chlorination
Hours of
Service Areas
Operation
filtration, 24 hours
Central, North, South & East Amelia’s
Ward, Cinderella City, Squatters Area
5:00 am – Spreightland, Retrieve, Rainbow City,
10:30 pm
Industrial Area. Old, New & Lower Kara
Kara, North Cocatara
5:00 am – Old, New & Lower Kara Kara, Rainbow
10:30 pm
City, Retrieve, Industrial Area, North
McKenzie,
Noitgedacht,
Cocatara,
Redwood
Crescent,
Constabulary
Compound,
Watooka,
Fairs
Rust,
Surapana, Richmond Hill
Coagulation,
flocculation, 5:00 am – West Watooka, Wismar Silver town, Silver
sedimentation,
filtration, 10:30 pm
City, Christianburg, Half Mile
chlorination
Pre-Filtration, chlorination
24 hours
Wisroc, Block 22, Blueberry Hill, Canvas
City, Section of One Mile
Coagulation,
flocculation,
sedimentation,
filtration,
chlorination
Coagulation,
flocculation,
sedimentation,
filtration
(pressure), chlorination
2.4.1 Amelia’s Ward Sub-system
The Amelia’s Ward Treatment Plant is located on Well Road, about 300 metres south of the
Linden Highway, in Amelia’s Ward.
Description
The treatment system comprises the following components:
• two sub-surface wells (only one in service)
• low-lift pumps (150 m3/min)
• 10” transmission line (wells to plant)
• cascade aerator
• monoscour filters (2)
• clear well
• high-lift distribution pumps (2)
• backwash Pumps
The flow diagram for the Amelia’s Ward treatment system is shown in Figure 2.2, Flow
Diagram - Amelia’s Ward Treatment Plant.
Extraction/Intake
Water for the Amelia’s Ward Treatment Plant is extracted by two wells about 600 metres
southwest of the treatment plant. The wells tap the A-Sands Series at a depth of 54 and 60
metres, respectively. The well completion data is summarised in Table 2.4. One well is
secured by a protective security fence.
Table 2.4: Amelia's Ward Completion Data
Well
Well # 1
Well # 2
Completion Type
&
Depth (m)
Depth
of
Casing
54.86
Fibreglass
60.96
Fibreglass
Pumps
Subtech
Goulds
Extraction
rate
M3/hr
80
Notes
Out
service
of
180
Cascade Aerator/Precipitator
The raw water is pumped from the well # 2 (via a 10” line) to the cascade aerator which sits
on top of the contact tank, allowing water to enter the tank from above. Well #1 requires
cleaning, air lifting and another pump. The cascade aerator is a natural draft, free trickle
pool-type aerator and uses stainless steel material and aluminium louvers.
The trays are packed with coal. Aeration of the well water facilitates extraction of high
concentrations of noxious gases (e.g. hydrogen sulphide, methane, carbon dioxide) from the
water and the transfer of oxygen from air to the water. This oxidises the iron and manganese
to allow their precipitation.
Filtration
Water is routed to two monoscour filters through a two-way splitting box and into a 25 cm ∅
pipeline. The filter operation is manual. There is a backwash interval of once per shift.
13
P-156
P-168
Blower
2-way Splitter
Filter
Filter
Chlorine
P-195P-164
To Chemical Feeds
Aerator Tank
Clear Well
P-167
P-198
P-198
P-194
P-165
Backwash Pump
P-280
P-155
Extraction From Water Wells
E-45
Figure 2.2: Flow Diagram - Amelia's Ward Treatment Plant
14
High Lift Pumps
Central, North,
South & East A/
Ward,
Cinderella City,
Squatters Area.
2.4.2 LPC Treatment Sub-system
The treatment plant at the Linden Power Company (LPC) is located at the abandoned
alumina plant. The water treatment plant consists of two essentially identical systems. The
no 1 system has a further system of de-ionisation but this is out of operation. The plants
originally treated water for use in the power plants for the alumina processing and provided
drinking water for Retrieve community, within the vicinity of the alumina plant. Subsequent to
the closure of the alumina plant (1985), Linmine operated the power plant and the water
system and continued supplying water to the community. The LPC began operation as a
separate power generator in 2001 and continued supplying water to the community under a
contract with GWI. The LPC subsequently terminated operations in 2005 and GWI then
assumed operation of the plant as part of the Linden Water Supply System.
Description
LPC comprises of two treatment process chains. The design capacity of plant I and plant II
are 2839m3/day and 2614m3 /day respectively. There are no flow meters in the system,
therefore the actual operating capacity is unknown. The plants are operated in parallel until
clear well storage, at which point they are operated in series as treated water from the clear
well from Plant I feeds (is pumped to) the clear well at Plant II. Discharge from the LPC
system is from the clear well in Plant II.
The treatment system comprises the following components:
•
high Lift Pumps (2)
•
clarifiers (2)
•
booster Pump
•
backwash Pumps
•
anthracite Filters (2)
•
transfer Pump (2)
•
clearwells (2)
The flow diagram for the LPC treatment system is shown in Figure 2.3: Flow Diagram - LPC
Treatment Plant.
Extraction/Intake
The Demerara River is the source of water for the LPC plants. There are two high-lift pumps
at the intake. Intake flows are screened to remove debris and river borne materials. The
system is designed for one pump to service the treatment plant and the other the needs of
the power plant. Currently, only one pump is in operation. A booster pump pressures the
flow before it enters the clarifiers. Manual control valves manage the flow to the clarifier.
Clarifier – Coagulation, Flocculation and Sedimentation
The water is collected at a sample port and tested for pH prior to entry to the clarifier.
Chemical pumps (manual controls) deliver lime (CaCO3) and alum (Al2(SO4)3) to control pH
as an aid to flocculation. The rate of addition of alum and lime is tied to the specific gravity of
water in the filter. Specific gravity is routinely monitored for this purpose. Gravity flow
delivers water to the filters and is manually controlled. The clarifier is de-sludged routinely to
maintain efficiency. The process is managed at a control panel within the treatment plant.
Filtration
The filter media consists of 1.82 feet of anthracite beds. The filters are designed to remove
residual turbidity, pathogens or organic chemicals. Flow through the media takes about 35
15
minutes. The filter system is backwashed (manually) once per day. The system is
periodically air lanced to enhance the filter process.
Disinfection/Clear Well Storage
The treated water flows into underground clear well storage tanks where chlorine (gaseous)
is added as a disinfectant. Residual chlorine concentration is continually monitored at a
sample port on the discharge line.
It should be noted that the state of the LPC plant is under serious consideration by GWI and
plans are in place to decommission this plant. These and other plans by GWI are included in
Appendix II.
16
Figure 2.3: Flow Diagram - LPC Treatment Plant
17
2.4.3 McKenzie Sub-system
The McKenzie Treatment Plant is located in Watooka, on the eastern bank of the
Demerara River just south of the McKenzie Wismar Bridge. The plant and associated
systems were constructed in 1956 and originally served the communities of the eastern
bank and the needs of the bauxite plant. A raw water distribution network supported
the power plants and other bauxite processing activities. This network also provided
water for the fire hydrants. Parts of the network still exist even though most fire
hydrants are in disrepair.
Description
The plant consists of
• high-lift intake pumps,
• mixing chamber,
• settling tanks,
• filter tanks,
• storage basins,
• discharge pumps.
The flow diagram for the McKenzie treatment system is shown in Figure 2.4: Flow
Diagram - McKenzie Treatment Plant.
Extraction/Intake
Water for this plant is extracted from the Demerara River; the intake area is at the
McKenzie Bridge where a 10-inch line delivers the water to the treatment plant. Intake
flows are screened to remove debris and river borne materials. The high-lift pumps
were originally sized to also supply water to the Bauxite Plant. The excess flow is now
discharged to the river pending resolution of the matter.
Clarifier – Coagulation, Flocculation and Sedimentation
3
Raw water flows through at a rate of approximately 170 m /hr and is discharged into a
mixing chamber (mixing depend on the turbulence of water entering the chamber),
where alum (Al2(SO4)3) and lime (CaCO3) is added via manually adjusted chemical
pump. The chemically charged water travel through a flume to enter eight (8) settling
tanks where the retention time is approximately 2.0 hrs.
Specific gravity is routinely monitored for this purpose. Gravity flow delivers water to
the filters and is manually controlled. The clarifier is de-sludged routinely to maintain
efficiency. The process is managed at a control panel within the treatment plant.
Disinfection
The clarified water from the settling basin then enters two (2) storage basins where
disinfectant is added from cylinder-mounted chlorinators. Residual chlorine
concentration is continually monitored at a sample port on the discharge line.
Filtration
Four (4) high lift (filter) pumps deliver chlorinated water from the storage basins through
twelve (12) pressure filters (only 6 currently operable) to the distribution system.
18
Chlorine
Chem
Pump
Chem
Pump
Figure 2.4: Flow Diagram - McKenzie Treatment Plant
19
2.4.4 West Watooka Sub-system
The West Watooka treatment plant is located in a fenced compound about 300 metres
west of the intake area at the Demerara River, the source for the water at this plant. The
internals, clarifier and the recirculators were recently (2006) rehabilitated/replaced.
Description
The West Watooka plant comprises the following components:
•
intake area/low-lift pumps (2)
•
clarifier
•
two (2) monoscour filters
•
backwash pumps
•
clear well storage basins
•
discharge pumps (high lift) (3 pumps)
•
intake and discharge line flow meters
The flow diagram for the West Watooka treatment system is shown in Figure 2.5: Flow
Diagram - West Watooka Treatment Plant.
Extraction/Intake
The Demerara River is the source of water for the West Watooka plant. The raw water is
pumped by two low-lift pumps (5000m3/day) and conveyed to the treatment Plant via a 41
cm pipe. Intake flows are screened to remove debris and river-borne materials.
Clarifier – Coagulation, Flocculation and Sedimentation
The raw water is sampled for turbidity, pH and specific gravity twice per eight (8) hour
shift. Lime (CaCO3) and alum (Al2(SO4)3) are added to the line (based on turbidity & pH)
just before the entrance to the recirculator. The chemical pumps (manual controls)
deliver lime and alum to control pH as an aid to flocculation. Precipitate, or floc, settles
to the bottom of the clarifier where the scraper guides it along the conical floor to the
sump. The current absence of a sludge pump reduces the efficiency of the de-sludging.
The clear water rises to the top and enters the launders that surround the clarifier and is
conveyed to the filters through gravity flow. This helps to reduce the exit velocity to a
minimum, which aids in obtaining water of low turbidity for subsequent filtration. A 41 cm
pipe conveys the flow into a splitter-box, which divides the flow equally into the three
filters.
Filtration
The filter media are designed to remove residual turbidity, pathogens or organic
chemicals. The filters originally used a single medium of sand, 25-30 cm up to 60-70 cm,
with effective grain size from 0.5-0.6 mm up to 0.8-0.9 mm. Regular maintenance is
required to maintain the order and efficiency of the filter.
The sand in the filters is supported by a gravel bed. An underdrain system below the
gravel bed serves as conduit for flow out of the filter and backwashing. The filters are
20
backwashed once per 8-hour shift. There is also an air line that was designed to aid in
the backwash of the filter. Flow through the media takes about 35 minutes.
Disinfection/Clear Well Storage
Filter effluent flows (by gravity) into underground clear well storage tanks, where chlorine
is added as a disinfectant. Residual chlorine concentration is continually monitored at a
sample port on the discharge line.
21
Figure 2.5: Flow Diagram - West Watooka Treatment Plant
22
2.4.5 Wisroc
The Wisroc treatment plant is located in a fenced compound on the northern bank of
Dakoura Creek.
Description
The Wisroc plant comprises the following components:
•
intake area/low-lift pumps (150 gpm)
•
pre-filtration tank
•
two (2) monoscour filters
•
backwash pumps
•
clear well Storage tanks
•
discharge pumps ( high lift)
The flow diagram for the Wisroc treatment system is shown in Figure 2.6: Flow Diagram –
West Watooka Treatment Plant.
Extraction/Intake
Dakoura Creek is the source for the Wisroc treatment plant. Intake flows at the creek are
screened to remove debris and creek-borne materials. The raw water is pumped by two
low-lift pumps and conveyed to the pre-filtration tank via a 41 cm ∅ pipe.
Pre-Filtration Tank
While this basin was designed for the addition of alum and lime for coagulation and
flocculation, these chemicals are not used at this plant because of the excellent water
quality.
Filtration
Water is then routed through a 25 cm ∅ mild steel pipe to a splitter box, which divides the
flow equally into the two 4.5 m ∅ monoscour filters. The filter media are designed to
remove residual turbidity, pathogens or organic chemicals. The plant is designed for the
use of backwash and pressurised air to enhance the filtration process. The filters are
backwashed once per eight (8) hour shift.
Disinfection/Clear Well Storage
Gravity flow carries the water from the filters to the clear well (12m x 12m; capacity 375m3)
for storage and chlorine disinfection.
23
Figure 2.6: Flow Diagram - Wisroc Treatment Plant
24
2.5 Distribution
This section provides a summary description of the distribution network of the Linden water
system. Some of the risks to the delivery of safe drinking water are related directly to the state
of the distribution network. The age and maintenance of a network are contributing factors in
the state of such a network. Inadequate and inconsistent supplies of water are also factors
which give rise to low pressure conditions and network tampering by customers/residents to
meet their needs when the supply is poor. This tampering potentially increases the risk of
contamination of the network through the creation of leaks and backflows into main distribution
lines. Customers are of the view that water should be free and, as such, often install illegal
connections.
The Linden water distribution network extends and covers ninety-five (95) percent of the
community. The total operational capacity of the Linden water system is 22,785 m3/day. The
total system capacity is an aggregate of the five subsystems, each associated with a treatment
plant.
Residents, businesses and other entities have supplemented the water delivered by GWI by
purchase and use of bottled water.
The network includes transmission and distribution lines, booster pump/stations, flow meters and
other components. It should be noted that there are three (3) discontinued over-head tanks.
The plants and associated distribution systems of the Linden Water System were constructed at
different periods in the development of Linden. This is also reflected in the different pipe
materials – such as polyvinyl chloride (PVC) and cast iron (CI). Cast Iron pipes occur within the
McKenzie sub-system. These pipes are the oldest, and are therefore generally used for the
purpose of transmitting raw water for industrial (bauxite plant) purposes and for fire hydrants.
Fire hydrants are currently located only in Cocatara, north McKenzie and Wisroc. Hydrants exist
in A/Ward, Niotgedacht, Watooka, Fairs Rust, and Richmond Hill.
There has been a constant upgrading and rehabilitation of the distribution system since 2001,
the most recent being the replacement of the older CI pipes in Cocatara and Central McKenzie.
The replacement of the lines was necessary to remove corroded CI pipes and improve water
pressure. GWI has proposed a final rehabilitation phase to address limitations in the distribution
system. Figure 2.7 shows the materials of the distribution system. Figure 2.8 shows the
different diameters of the pipes.
Some of the adjacent systems are interconnected but are not routinely operated as combined
units. Local system limitations and/or defects prevent the operation of a combined system.
Additionally, leakages, estimated at about thirty-five (35%), limit any optimization of adjacent
systems.
25
Figure 2.7: Linden Distribution System Pipe Materials
26
Figure 2.8: Linden Distribution System Pipe Diameters
27
2.5.1 Eastern Bank - Linden Water System
There are three (3) treatment plants and associated distribution networks on the eastern bank of
the Demerara River. These are the McKenzie, Amelia’s Ward and LPC Sub-systems. The
Amelia’s Ward system is the newest. There are no major operational problems associated with
this system. However, the limited hours of service, service disruptions, and pump failures have
caused customers to depend on household storage tanks.
The McKenzie sub-system is connected to the Amelia’s Ward Sub-system via a 200 mm Ø PVC
pipe at the Kara Kara Bridge. Neither system has enough pressure or capacity to supply the
other. An abandoned pump house and booster station in Kara Kara potentially could allow the
water from McKenzie to service the Amelia’s Ward system. However this pump house and
booster station were abandoned when the Amelia’s Ward treatment plant was commissioned in
1982 so extensive repairs may be required.
There are some notable concerns in the LPC distribution network; about twenty five (25%) of the
production is unaccounted for. The LPC and McKenzie networks are connected through
Industrial Area and Retrieve and facilitated by the new 150 mm Ø line from the bauxite plant.
Amelia’s Ward
The Amelia’s Ward sub-system serves the Central, North, South & East Amelia’s Ward,
Cinderella City, and some squatter areas. There are no system storage tanks or booster pumps
within the system.
The distribution system consists of 100, 150 and 200 mm Ø PVC pipes. The system is linked to
the McKenzie distribution system via the 100 mm Ø line (gate valve closed) at the bridge at Kara
Kara Creek. Previously a booster pump allowed the McKenzie system to serve Amelia’s Ward
but this has been abandoned since 1982.
LPC
The LPC plant serves the Retrieve, Rainbow City, Kara Kara, North Kara Kara, and North
Cocatara areas of Linden.
McKenzie
The McKenzie plant currently serves Old, New & Lower Kara Kara, Rainbow City, Retrieve,
Industrial Area, North McKenzie, Noitgedacht, Cocatara, Constabulary Compound, Watooka,
Fairs Rust, Surapana, and Richmond Hill. A booster pump pressurises the dedicated line for
delivery to Richmond Hill.
There are two discontinued overhead storage tanks in Rainbow City and Richmond Hill.
2.5.2 Western Bank – Linden Water System
Two treatment plants, West Watooka and Wisroc, and one converted booster station in Wismar,
service the customers on the western bank. The distribution network on the Western Bank of
the Linden water system is more complex, with a wider spatial distribution, more variation in
elevations, and generally greater challenges to system optimization.
The western network is interconnected, each plant /system is “plumbed” to service the network
of the other. Some areas, however, can only get water through manual adjustment of select
gate valves. These include Half Mile and Half-Mile Extension and parts of Canvas City. There
is currently not enough capacity and system pressure to service all the areas concurrently. The
28
booster station at Wisroc could address this limitation but the increased energy cost is a
consideration. The removal of the 3000 m3/day capacity of the Wismar treatment plant also
contributed to the current lack of capacity.
West Watooka
Three high-lift pumps pump the water from the storage tanks through a 51cm distribution line.
The West Watooka plant serves Wismar Flat, West Watooka, Silver Town, Silver City, 1st, 2nd &
3rd Alley, Christianburg, D’Anjou Park, and Victory Valley. The former treatment plant at Wismar
is now used as a booster station to enhance delivery to the service areas.
Wisroc
Three high-lift pumps pump the water from the storage tanks through a 51cm distribution line.
The Wisroc plant serves Wisroc, Block 22, Blue Berry Hill, Canvas City, and Sections of One
Mile.
29
2.6 Water Quality
This section discusses the water quality from the five water treatment plants and through
distribution and point of use. The data was derived from a number of sources. These sources
included:
•
Bi-weekly water treatment plant and distribution system water quality testing results, GWI
laboratory in Georgetown, 2007 records, (electronic format)
•
Water treatment plant operator “daily” water quality testing results, on-site testing at water
treatment plants, all records on file, (hard copy reports)
•
Mayor and Town Council “monthly” water quality surveillance results, Food & Drug
Department laboratory in Georgetown, 2006-2008 records, (hard copy reports)
•
Regional Democratic Council “monthly” water quality surveillance results, Food & Drug
Department laboratory in Georgetown, 2006-2008 records, (hard copy reports)
•
One-time independent water treatment plant and distribution system water quality testing
results, Eureka Medical laboratory in Georgetown – March 2008, (sampling conducted by
CDC)
•
Results of residual chlorine and microbiological testing at households connected to the GWI
distribution network during a household survey conducted in December 2007
•
One-time water treatment plant water quality testing results provided by plant operators
during the household survey – December 2007
2.6.1 Water Quality Monitoring
The water quality parameters of interest, based on the WHO guidelines, and the monitoring
regimes of GWI and the MoH are the following: (Explanations of these parameters are detailed
in Appendix I – Glossary)
pH
Turbidity
Colour
Iron
E coli
Aluminium
Residual Chlorine
Faecal Coliform
Total Coliform
Currently, water quality testing is carried out by plant operators of GWI, approximately every two
hours per shift at each treatment plant. Finished water is tested for pH, turbidity, chlorine
residual, and sometimes iron. Plant testing results are recorded on log sheets, sent to the main
Linden office at West Watooka periodically, then sent to Georgetown. However, after examining
records over the course of one year it was apparent that this regime is not being followed.
For the distribution system, sampling is carried out biweekly in the distribution system. Samples
are sent to Georgetown and measured for total coliforms, faecal coliforms, pH, turbidity, iron,
colour and aluminium. Samples are collected from certain locations within the plants (postaerator, post filter, finished water, etc.) and at approximately 12-14 locations throughout the
distribution system. However, due to problems with transportation and a lack of testing reagents
in Georgetown, sampling and testing does not occur according to schedule.
30
Analysis of the water quality for final water from the five water treatment plants shows a lack of
consistency of the results. This is an indicator that the systems need to be optimised. A
summary of that analysis is included in Table 2.5.
Table 2.5: Final Water (Source GWI Laboratory Results, for the year 2007)
Wisroc
West
McKenzie
LPC
Amelia’s
Watooka
Ward
pH
Consistently lower
Consistently
Consistently
Consistently
Consistently
than 6.5.
lower than
lower than
lower than
lower than
6.5.
6.5.
6.5.
6.5.
Low pH has no known direct health impact. However, low pH can increase corrosivity. This can
cause premature damage to metal piping and have associated aesthetic problems such as a
metallic or sour taste and staining of laundry, sinks and drains.
Inconsistent
Inconsistent
Inconsistent
Generally
Turbidity
Within the current
results,
results,
results,
within the
acceptable limit (5
turbidity
turbidity
turbidity
NTU). This could be current
routinely
routinely
routinely
acceptable
because the raw
higher than
higher than
limit (5 NTU). higher than
water turbidity is
limit.
limit.
limit.
Treatment
quite low.
Turbidity
seems to be
generally
effective in
increased
reducing
through
turbidity given
treatment due
the high
to oxidation of
levels in the
iron.
raw water.
There is no health-based guideline value for turbidity. High levels of turbidity can give rise to
significant chlorine demand, indicate treatment process control problems and adversely impact
disinfection efficacy.
Good iron
Poor iron
Good iron
Inconsistent
Iron
Iron is within the
treatment
treatment.
treatment
results.
acceptable limits.
process,
Routinely
There was
However, iron levels process,
consistently
violated the
consistently
about 80%
in the raw water do
within limits.
limit.
within limits.
compliance
not seem to be
but results
affected by the
were highly
treatment process.
variable
which
suggests
improper
process
control.
There is no health-based guideline value for iron. High levels of iron can cause bad tasting drinking
water and can stain laundry. This in turn can give rise to poor public perceptions about the quality of
water received and the ability of the water utility to provide water of an acceptable standard.
No
Consistent
Consistent
Aluminium Inconsistent results. Consistent
information
violation of
violation of
Al does not seem to violation of
available.
standard. In
standard. In
standard. In
be affected by the
most cases
most cases
most cases
treatment process.
31
Wisroc
West
McKenzie
LPC
Amelia’s
Watooka
Ward
the Al in the
the Al in the
the Al in the
final water
final water
final water
was higher
was higher
was higher
than raw
than raw
than raw
which
which
which
suggests
suggests
suggests
insufficient
insufficient
insufficient
alum removal alum removal alum removal
during the
during the
during the
process.
process.
process.
There is currently no health-based guideline value for aluminium due to limitations of available
health data.
Inconsistent
Inconsistent
Inconsistent
No
Colour
Routine violation of
the permissible limit. readings with readings with readings with information
routine
routine
routine
available.
Colour does not
violations.
violations.
seem to be affected violations.
by the treatment
process.
Approximately Approximately Approximately Approximately
Total
Approximately 50%
90% of the
25% of the
50% of the
Coliforms of the samples were 40% of the
samples were samples were samples were samples were
positive for total
positive for
positive for
positive for
positive for
coliforms. This
total
total
total
total
indicates
coliforms.
coliforms.
coliforms.
coliforms.
inadequate
disinfection.Samples This indicates This indicates This indicates This indicates
inadequate
inadequate
inadequate
inadequate
consistently did not
disinfection.
disinfection.
disinfection.
disinfection.
have faecal
coliforms.
According to the WHO, inadequate disinfection can increase microbial risks of diseases.
2.6.2 Distributed Water Quality
(Source: CDC results from March 2008 – one time sampling)
Table 2.6 describes several parameters for the treatment plants and the established monitoring
points along the distribution system as identified by GWI.
Table 2.6: Plant Readings
Wisroc
Residual
Chlorine
Other
Parameters
West
Watooka
McKenzie
LPC
Amelia’s
Ward
Minimal
No detection
No detection
Minimal
Detection
detection
detection
As seen in previous sections, the pH readings were low at all plants. There were
detections for total coliforms at the Amelia’s Ward Plant. Turbidity was acceptable
for all plants except Amelia’s Ward. Aluminium was higher than acceptable for all
plants where tested. Iron and colour were acceptable for all plants.
32
Table 2.7: Distributed Water
Residual
Chlorine
Wisroc
West
Watooka
McKenzie
LPC
Amelia’s
Ward
Distribution
System
No detection
No detection
No detection
Minimal
detection
Minimal
detection
Residual chlorine was detected at only two locations along the distribution system. This is of
great concern as the WHO recommends residual chlorine to be 0.2 - 1.0 mg/L for consumers at
point of use. The issue of disinfection needs to be addressed as a matter of priority.
2.6.3 Household Water Quality
Based on a Household Survey that was undertaken by the CDC in December 2007 information
was obtained on water quality, treatment and storage for consumers. For the full Household
Water Use and Health Survey Report for Linden, Guyana, refer to Appendix III. A summary of
the water quality at the Consumers’ premises in included in Table 2.8.
Most water delivered to the taps of consumers connected to the Linden GWI distribution system
contained no residual free chlorine. The target residual free chlorine levels for water leaving the
treatment plants set at each of the treatment plants is quite low. The target of 0.5 mg/L for water
leaving the Amelia’s Ward and Wisroc plants was determined based on the notion that water
from those sources are of comparatively highest quality, and therefore would consume the least
amount of chlorine in the distribution system. The operators aim for a minimal effective level (to
achieve a free chlorine residual of 0.2 mg/L at the most distal point of the distribution system)
and to avoid the water having a taste of chlorine, which is considered undesirable by
consumers. This minimum level, however, is not being achieved, as evidenced by the lack of
free chlorine residual found in tap samples.
Other water quality data reported by plant operators on survey days indicate that there are
additional parameters of concern. According to the WHO Guidelines for Drinking Water Quality,
median turbidity should be below 0.1 NTU in order to ensure effective disinfection, and that
turbidity of 5 NTU has an acceptable appearance to consumers. Turbidity levels above 0.3 NTU
are often associated with higher levels of disease-causing microorganisms such as viruses,
parasites and some bacteria (USEPA Primary Drinking Water Standards). Turbidity values in
finished water measured on survey days were as high as 15 NTU.
In addition, pH values measured on survey days from waters leaving the three treatment plants
sourced by the Demerara River were low.
Table 2.8: Summary of Water Quality at Consumers’ Premises from Household Survey,
December 2007
Amelia’s Linden Power
Ward
Company (LPC)
Mean free Cl2 leaving
plant on survey
days† (mg/L)
Mean pH leaving
0.56
0.79
33
McKenzie
1.21
West
Watooka
1.20
Wisroc
0.51
plant on survey
days†
Mean turbidity
leaving plant on
survey days† (NTU)
Free Cl2 at tap ≥0.2
mg/L (% of
households)
Free Cl2 in tanks ≥0.2
mg/L (% of
households)
Free Cl2 in DWC ≥0.2
mg/L (% of
households)
HH tap – total
coliforms+ (% of
households)
HH tank – total
coliforms+ (% of
households)
HH DWC – total
coliforms+ (% of
households)
HH tap –
E. coli+ (% of
households)
HH tank –
E. coli + (% of
households)
HH DWC –
E. coli + (% of
households)
Amelia’s Linden Power
Ward
Company (LPC)
6.3
5.4
McKenzie
4.9
West
Watooka
5.0
Wisroc
6.4
-
3.7
(range: 0, 7)
8.3
(range: 5,
12)
9.4
(range: 5, 15)
3.1
(range:
0, 5)
14%
7%*
8%
1%
10%
10%
4%
6%
5%
6%*
8.5%
8.5%*
1.8%
7.1%**
16.3%**
67%
55%
89%
54%
64%
75%
75%
100%
100%
67%
80%
88%
80%
100%
93%
0
18%
56%
8%
27%
50%
25%
50%
100%
0
40%
50%
10%
42%
71%
*includes one sample with >3.5 mg/L free Cl2 residual
** includes two samples with >3.5 mg/L free Cl2 residual
†Reported daily by plant operators on 7 survey days
2.7 Point-of-use Practices
Information on the quality of water received by consumers and their behaviour, such as at-home
treatment and storage, was obtained by the Household Survey that was undertaken by the CDC
in December 2007. The following sub-sections describe the key findings in more detail. For the
full Household Water Use and Health Survey Report for Linden, Guyana, refer to Appendix III.
2.7.1 Household Water Treatment
More than half of respondents reported that they treated their water in the home before drinking
it. However, in most cases where the household reported treating their drinking water, the water
sampled from the drinking water container did not contain any free chlorine residual. In six of
34
the samples of water that had been treated with bleach, residual free chlorine levels surpassed
the upper limit of the test method, indicating a lack of knowledge about appropriate home
chlorination or possible accidental introduction of bleach into drinking water containers. No
households that reported using a filter had filtered water available for testing at the time of the
survey.
The proportion of E. coli-positive samples was lower in samples that had been reportedly boiled
than in untreated samples (27% vs. 62%). While boiling is generally not recommended in a
chlorinated system due to its removal of chlorine, in this case where most tap water samples did
not have measureable free chlorine residual, boiling appeared to be an effective method for
reducing contamination.
Other than boiling and adding bleach, many respondents stated that they treated their drinking
water by allowing it to settle in a container, believing that settling constituted treatment for more
than just aesthetic concerns. This reflects a lack of knowledge about effective home treatment
methods and underscores the need for community education as long as home treatment
continues to be necessary.
2.7.2 Household Water Storage
Most GWI customers experienced periods of interrupted service and low pressure on most days.
Inconsistent service often necessitates secondary storage of water in the household, either in
tanks and large drums and/or in smaller drinking water containers. Secondary storage increases
the opportunity for the introduction of contaminants and increases hydraulic residence time (and
hence chlorine dissipation) prior to consumption.
The proportion of residual free chlorine-compliant samples was lower in stored versus tap
samples. Both total coliform and E. coli counts were higher in samples taken from tanks and
drinking water containers than from those taken directly from the tap, likely reflecting
contamination through increased handling or from storage in unclean vessels, combined with the
loss of chlorine through dissipation. While numbers were insufficient for statistical significance,
there was a trend towards decreasing free chlorine residual and increasing microbiological
contamination from taps to tanks to drinking water containers. The paired samples from taps
and tanks of the same households showed lower residual free chlorine levels in tanks than taps
unless bleach was added to the tank. Paired tap and drinking water container samples also
showed a loss of free chlorine residual in drinking water containers as compared to tap samples.
2.8 Off - network Water Use
A number of communities, including squatter communities and some as yet unincorporated new
housing developments are not currently on the distribution network. Residents of these areas
get their water supplies from springs, creeks and rain water collection. These areas include the
Amelia’s Ward new housing scheme, 3rd Phase/Phase 1B Wismar, Blueberry Hill squatter area,
Old England, and the West Watooka squatter area. In addition, there are unconnected
households interspersed within generally connected areas.
Some residents who are connected to the water distribution network also supplement their piped
supplies with water from the springs, creeks and rain when the system is non-operational or
pressure is low.
35
3.0 HAZARD IDENTIFICATION AND RISK ASSESSMENT
The identification and assessment of the impacts of hazards and hazardous events on the water
supply system is a critical component in the development of the WSP. According to the WHO
Guidelines for Drinking Water Quality, 3rd edition, hazards are defined as: physical, biological or
chemical agents that can cause harm to public health. Risk assessment involves the
identification of the threats to human health posed by each hazard, in relation to both the
likelihood and severity of the occurrence.
3.1 Hazard Identification
A preliminary hazard identification exercise for the Linden water supply system was conducted in
October 2007 as part of an NPA/WSP workshop held in Georgetown. The workshop sought to
obtain inputs from a variety of agencies and Linden stakeholders. Subsequent site visits were
made to corroborate preliminary information gleaned from that workshop. Further hazards were
identified through a thorough review and analysis of water quality testing and monitoring records
of GWI and Ministry of Health and through analysis of household survey results. Through these
activities, the WSP team developed a list of hazards which were categorised according to the
various stages of the supply chain – those occurring in the watershed, during treatment and
distribution, and in the household”. The information gathered was validated through further site
visits, independent laboratory sampling and analyses, stakeholder workshops and household
surveys.
These hazards were further deliberated on in a three (3) day Workshop held in Linden in
September 2008 with the aim of ranking these hazards/risks in order of priority. The hazards that
related to the watershed were discussed in a parallel NPA workgroup during the September
2008 workshop. The NPA grouping assessed these hazards as part of the NPA process and
these will be reported as part of the NPA document.
During the workshop, the WSP group was divided into two sub-groupings. One group, which
comprised of GWI employees, was charged with discussions specific to water safety as it related
to GWI operations. The other sub-grouping comprised of participants from monitoring agencies
such as the Ministry of Health, Regional Democratic Council for Region 10, Environmental
Health, Food and Drugs Department, PAHO etc. These groups were divided in this way so that
the various persons with different areas of expertise would be able to focus on the hazards that
most related to their area.
The two groups discussed hazards, the control measures and the limitations to control
measures. Where hazards were not found to be effectively controlled, corrective actions were
developed. These corrective actions were then prioritised, responsible parties were assigned
and targeted timelines were developed.
Where applicable, empirical data were used to justify the hazards. Often, several findings were
related to the same hazard. For example, the finding of levels that exceeded the recommended
standards for turbidity, iron, aluminium, colour, total coliforms and faecal coliforms all indicated
that treatment plants were not operated optimally. The other main hazards identified were:
RELATING TO TREATMENT:
• Insufficient chlorination practices
36
•
•
•
•
•
•
•
•
•
•
•
•
•
Lack of timely ordering and/delays in delivery of chemicals for water treatment and
laboratory testing
Equipment failures
Operators do not consistently record finished water quality
Poor quality of source water from the Demerara River
West Watooka intake is located near Bosai Mining company’s discharge pipe
Backwash and water from clarifier at West Watooka WTP are returned to river near
intake
Low pH of surface water
Lack of reliable and consistent sampling methods between agencies
Inconsistent and expensive power supply
High turbidity standard used (not a health-based standard)
No system in place for reporting WQ surveillance results from MoH to GWI
No system in place for reporting WQ surveillance results from regional bodies to central
MoH
Inadequate reporting system between GWI and the regulatory agencies
RELATING TO DISTRIBUTION:
• Leaks in the distribution network
• Lack of routine monitoring of chlorine residual in the distribution system
• Lack of consistent surveillance monitoring in the distribution system
RELATING TO THE HOUSEHOLD:
• Inadequate cost recovery
• Unsafe household treatment and storage practices
• Contamination of surface and ground waters through use of unsafe pit latrines
The hazards identified through the hazard analysis, and the associated findings are listed in
Table 5.1: Hazards and Corrective Actions. Watershed level hazards that were identified are
listed and discussed in the NPA Report.
3.2 Prioritisation of Hazards
Given the broad scope of the WSP, it is common to identify a large number of hazards and a
similarly large number of associated control measures. It is therefore necessary to rank these
hazards in order of priority, to ensure that needed resources are channelled in the most efficient
and effective manner.
WHO guidelines recommend the use of a semi-quantitative approach using a prioritisation
matrix. The objective of the matrix is to focus attention on the most significant hazards using a
ranking system that scores hazards based on the factors of likelihood and severity. .However,
given the largely subjective and time consuming nature of this exercise, a decision was taken by
the WSP partnership group to adopt a more qualitative risk management approach, which relied
on expert judgement and experience to reach consensus among team members in determining
priority areas of focus. The group also decided to delay priority ranking of risks until after control
measures had been considered. As a result, prioritisation would be discussed in Section 5.0,
Corrective Actions.
37
4.0 CONTROL MEASURES
The process of risk assessment involves the review of control measures at critical points within
the water supply system. Control measures are defined by the WHO guidelines as being actions,
activities and processes applied to prevent or minimise the occurrence of hazards in a water
supply system thereby ensuring that the quality of water supplied meets health based standards.
In considering the existence and effectiveness of control measures for the Linden water supply
system, the WSP team undertook:
• a review of the regulatory framework governing water resources management
• a review of the agencies with monitoring and surveillance responsibilities
• a physical review of GWI’s treatment and distributions systems
• a review GWI’s operating procedures, protocols, and documentation
• a review of laboratory capabilities
Examples of control measures identified included:
• relating to treatment: existing treatment processes, use of lime to raise pH, supervisory
oversight, maintenance of log sheets at WTPs, existing memorandums of understanding
between agencies for reporting water quality monitoring results
• relating to distribution: protocols for monthly sampling for chlorine and microbial
contamination, replacement of ageing pipeline
• relating to household-level factors: metering to increase cost-recovery, public outreach
campaigns through health centres, schools and general public service announcements to
address unsafe household treatment and storage practices
General findings included the fact that most of the control measures identified were never
documented or evaluated on the basis of efficiency. As a result, existing control measures
continued to be used regardless of whether they were effective or not. Limitations to the
effectiveness of the existing control measures were also noted.
For example, based on the results of water quality testing and the reports from the operators, it
was clear that the processes were not optimised as the water quality results were highly
variable. Given GWI’s financial status due to poor revenue collection, the plants face difficulties
with respect to the replacement of essential parts and procurement of needed consumables and
are therefore sometimes not able to ensure that the processes operate as required.
The monitoring agencies also have control measures in place, but many times these are not
structured or adhered to. Many of these control measures relate to communication protocols
between these agencies and the water utility. They also did not have a structured monitoring
regime in place for the water received by consumers and were consequently not testing all the
key parameters. These agencies are also hampered by lack of resources and the fact that their
main laboratory had been in the process of moving. As a result, they were not able to access
any laboratory facilities in order to ensure that water quality testing was done. These monitoring
agencies do engage in public education campaigns periodically, a lot of times they are
supported by PAHO. However, a lack of resources hampers the continuity of these
programmes.
All the control measures are stated in Table 5.1: Hazards and Corrective Actions. The
effectiveness of these existing control measures are also discussed in this table.
38
5.0 CORRECTIVE ACTIONS
After the control measures were discussed and evaluated, corrective actions were identified for
each hazard. After these had been identified, the corrective actions were prioritised. A ranking
of High (H), Moderate (M) or Low (L) priority were assigned to each corrective action. These
rankings were derived based on group discussions and consensus. The groups took a variety of
factors into consideration during their deliberations. These included the severity of the hazard
(based on the threats to health associated with poor water quality), the likelihood that the
hazardous event would occur, the feasibility of implementation of the action(s), and the
availability of financial and personnel resources to implement the action(s).
Some of the corrective actions include:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Optimise plant operations to ensure that proper water quality is obtained and that
variability is minimised
Operator training
Increase monitoring of all relevant water quality parameters by both GWI as well as the
monitoring agencies
Make infrastructural improvements
Establish sharing of information both within and external to GWI
Provide public education
Conduct monthly meetings in Linden with the utility and community members
Ensure that chlorine residual is monitored in the distribution network
Ensure that there is adequate inventory of all chemicals needed for the treatment plants
Increase pH of the water by the addition of lime or sodium hydroxide
Consider sourcing of water from the Dakoura Creek
Implement leak detection programme
Identify vulnerable households to pursue funding for improved sanitation
Replace filter media
Establish process for sharing water quality data with operators
Develop and implement line flushing programme
Develop and enforce planned maintenance programme
Improve supervision at plants
Develop national standards on Water Quality
Promote Rain Water Harvesting
Establish Water Surveillance Database
Develop and implement Standard Operating Procedures for all plants
Promote independent quality assurance testing for all water testing laboratories
The actions also called for the development of operational monitoring plans that include
timeframes, responsible parties for implementation and oversight personnel. Critical corrective
actions (those with a High Priority ranking) were identified. Barriers to implementation of these
corrective actions were also discussed. It was recognised that these barriers needed to be
overcome in order to ensure the success of any intervention. Ensuring that there is buy-in by all
the major stakeholders is one critical factor of success. It is important that this is done through
consultations (this has been on-going throughout the duration of the development of the WSP)
as well as effective Public Education and Awareness strategies (addressed in more detail in
Section 9.3).
39
The group discussions focused on the implementation of the Water Safety Plan and how
important the corrective actions were. It was recognised that even though there were
responsibilities assigned to every activity, there would be the need for periodic reviews by the
Steering Committee as well as future auditing of the plan to ensure the effectiveness of these
corrective measures. These issues are further elaborated on in Section 10.0.
Remediation measures were identified as being short, medium or long term with respect to
implementation and impact. There was the recognition by stakeholders that most of the
corrective measures identified were short term (i.e. within a 12 month period) and non-capital
intensive in nature. It was, however, recognised that even the seemingly simpler corrective
actions still required the commitment of the responsible agencies and the allocation of required
resources. In addition to assigning responsible parties to each corrective action, time frames for
initiation of each corrective action were determined, and these will provide a basis for
accountability to the Steering Committee for addressing the prioritised hazards.
Table 5.1: Hazards and Corrective Actions details the corrective actions identified. The priority
rankings are also listed next to each corrective action in this table. The responsible parties and
some suggested time frames are also noted.
40
Table 5.1: Hazards and Corrective Actions
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
Corrective Actions
Barriers to
Implementation
Priority
Responsible
Parties
Target
Timeline
Raw water values for
iron at the West
Watooka WTP higher
than raw water values at
McKenzie and LPC
despite the common
source (Demerara
River).
Findings listed beside
hazards above
(associated with lack of
optimised treatment) are
also due in part to the
poor quality of the
Demerara
Location of intake; EPA
regulations
Proximity of intake to
source of contamination
(Bosai operations); lack of
enforcement of EPA
regulations (?)
1) Explore option of
sourcing Dakoura
Creek; 2) encourage
EPA enforcement of
environmental
regulations
Funding; need for
feasibility
assessment (for
sourcing Dakoura)
H
GWI, EPA
1) Engage
EPA
immediately;
target
enforcement
by March 09
Alum/lime
(coagulation); settling;
filtration
Physical limitations of
existing infrastructure to
treat poor quality water
1) Explore option of
sourcing only Dakoura
Creek (and Amelia's
Ward)
Funding and need
for feasibility
assessment (for
sourcing Dakoura)
M-H
GWI
1) Feasibility
assessment
to be
completed by
Dec 09
Most samples taken at
all 5 WTPs were below
(well below in the case
of surface water WTPs)
GWI's pH standard of
6.5-8.5.
Lime
No lime is added
1) Chemical addition
for pH adjustment
(adding lime or sodium
hydroxide); 2) explore
sourcing Dakoura
Creek
Chemical cost;
cost of installing
new tanks
M
GWI
1) Dec 09; 2)
feasibility
assessment
to be
completed by
Dec 09
SOURCE WATER
West Watooka
intake is located
near Bosai
discharge pipe,
threatening
water quality
Poor quality of
Demerara
increases cost of
treatment and
limits the ability
of treatment
plants to meet
water quality
standards
(including
maintenance of
chlorine residual
due to high
turbidity)
Low pH of all
surface water
may cause
indirect health
effects (due to
corrosivity and
metal leaching)
41
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
Corrective Actions
Barriers to
Implementation
Priority
Responsible
Parties
Target
Timeline
Contamination of
ground and
surface waters
through usage of
pit latrines.
Pit latrines were
associated with higher
incidence of diarrheal
illness.
Old guidelines exist,
plans in place to
update guidelines for
VIP construction.
Guidelines for construction
of pit latrines are not
consistently followed.
MoH to identify
vulnerable households
and aggressively
pursue funds (from
funding agencies) for
improving sanitation for
these households.
Increase education and
enforcement of existing
sanitation guidelines
and expand guidelines
to incorporate
Ventilated Improved Pit
(VIP) latrines.
None
M
MoH
Dec 09
None
M
MoH/RDC,
M&TC
Jan 10
1) Optimise treatment
processes (operator
training; “train the
trainer” programme;
provide 24/7 service);
2) replace filter media
Lack of operator
capacity (no
minimum
qualification
requirements)
creates a
challenge for
designing an
effective
programme;
funding (for filter
media
replacement)
Impoverished communities
cannot afford to construct
latrines according to
guidelines.
TREATMENT
Treatment plants
are not operated
optimally
POE turbidity was
routinely higher than the
standard of 5 NTU at
McKenzie and LPC
WTPs and values were
highly variable.
POE iron concentrations
at McKenzie WTP
violated the standard of
0.5 mg/L in some of
samples, and values
were highly variable.
Alum/lime
(coagulation); settling;
filtration; at McKenzie,
regulate flow rate (raw
water intake)
Treatment processes not
optimised; need to replace
filter media
Coagulation, settling,
filtration
Treatment processes not
optimised; need to replace
filter media
The standard for
aluminium of 0.2 mg/L
was violated in POE
samples taken from
plants using aluminium
sulphate for coagulation
Jar testing for
optimisation (to
determine the
appropriate alum dose/
pH combination);
hydrometer;
Treatment processes not
optimised; need to replace
filter media
42
H
GWI
1) Jun 09;
2) Dec 09
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
(West Watooka,
McKenzie and LPC
WTPs).
sedimentation basin;
filters
Colour in POE samples
at all 3 conventional
plants (West Watooka,
McKenzie and LPC
WTPs) was highly
variable and routinely
and significantly
exceeded the standard
of 15 TCU. Colour
values were commonly
2-3 times the limit at
each plant.
Finished water at all 5
WTPs was commonly
contaminated with total
and faecal coliforms.
Alum/lime
(coagulation); settling;
filtration
Treatment processes not
optimised; need to replace
filter media
Treatment plant
processes (including
disinfection)
Treatment processes not
optimised; need to replace
filter media
Turbidity at Amelia's
Ward WTP was
consistently and
significantly increased
through the WTP,
resulting in frequent
POE turbidity levels
greater than the
standard of 5 NTU
despite raw water
turbidity values generally
below 2 NTU.
Aeration; filtration
Treatment processes not
optimised; need to replace
filter media
43
Corrective Actions
Barriers to
Implementation
Priority
Responsible
Parties
Target
Timeline
Hazard
Insufficient
chlorination
practices result
in insufficient
residual to
protect against
microbial
contamination
Findings
Existing Control
Measures
Limitations/Effectiveness
POE iron concentrations
at Amelia's Ward WTP
were consistently and
significantly above the
standard of 0.5 mg/L.
Aeration; filtration
Treatment processes not
optimised; need to replace
filter media
Treatment processes at
Wisroc WTP generally
did not reduce (and on
multiple occasions
contributed to) turbidity,
iron, aluminium and
colour. Consequently,
aluminium and colour
were frequently and
significantly in violation
of the recommended
standards.
Non routine distribution
sampling indicate low
presence of chlorine
residual
Treatment processes
Treatment processes not
optimised; need to replace
filter media. (Note:
addressed below is the
issue of operators
bypassing holding tank
and filters, which is
necessary because
network demand exceeds
plant capacity due to leaks
in the system and
consumer waste.)
Treatment processes not
optimised; need to replace
filter media (funding);
limited monitoring
(accountability/oversight;
resource constraints;
limited sharing of
information); work
remaining to repair leaks
Treatment plant
processes (including
disinfection)monitoring;
pipeline programme;
leak protection
programme (including
replacement of ageing
infrastructure
44
Corrective Actions
Barriers to
Implementation
Priority
Responsible
Parties
1) Optimise treatment
processes (operator
training; “train the
trainer” programme;
provide 24/7 service);
2) replace filter media;
3) establish a process
for sharing water
quality findings with
Lack of operator
capacity (no
minimum
qualification
requirements)
creates a
challenge for
designing an
effective
H
GWI
Target
Timeline
1) Dec 08; 2)
Dec 09; 3)-5)
Dec 08
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
Corrective Actions
Barriers to
Implementation
Water samples from
routine distribution
system water quality
monitoring (2007) were
commonly contaminated
with total and faecal
coliforms.
Treatment plant
processes (including
disinfection);
monitoring; pipeline
programme; leak
protection programme
(including replacement
of ageing
infrastructure)
Treatment plant
processes (including
disinfection);
monitoring; pipeline
programme; leak
protection programme
(including replacement
of aging infrastructure)
Treatment processes not
optimised; need to replace
filter media (funding);
limited monitoring
(accountability/oversight;
resource constraints;
limited sharing of
information); need to repair
leaks
Treatment processes not
optimised; need to replace
filter media (funding);
limited monitoring
(accountability/oversight;
resource constraints;
limited sharing of
information); work
remaining to repair leaks
operators; 4) increase
operator accountability;
5) developing and
implementing a line
flushing programme
programme;
funding (for filter
media
replacement);
valve accessibility
issues; limited
human resources;
inaccurate (or lack
of) network
drawings
Of 47 tap water samples
(no on-site storage)
taken from all 5
distribution systems for
microbiological testing
during the HH survey,
64% of samples were
positive for total
coliforms and 23% were
positive for E. coli.
Approximately 70% of
water quality samples
taken from the
distribution system
between January 2006
and March 2008 for
surveillance monitoring
by either RDC or M&TC
were positive for either
total or faecal coliforms
(or both).
Treatment plant
processes (including
disinfection);
monitoring; pipeline
programme; leak
protection programme
(including replacement
of aging infrastructure)
45
Priority
Responsible
Parties
Target
Timeline
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
Corrective Actions
Barriers to
Implementation
Priority
Responsible
Parties
Target
Timeline
Lack of timely
ordering and/or
delays in delivery
of chemicals for
water treatment
and laboratory
testing can
impact
operations and
monitoring.
Inventory; order and
follow up;
Inventory and ordering
practices in Linden are
effective; shipping delays;
delayed procurement
1) Ensure a 3-month
supply is on hand;
explore local
production of alum (no
target timeline); 2)
stringent contract
specifications with
supplier; 3) develop
and enforce a more
efficient procurement
programme in
Georgetown
Feasibility study
needed for local
production of alum
(sulphuric acid);
capital investment
needed for
production
facilities
H
GWI
1) Effective
immediately;
2) Dec 08; 3)
Dec 08
Equipment
failures affect
GWI's ability to
treat and deliver
water.
Spare part storage;
procurement system;
response maintenance
programme
Insufficient parts in
storage; dependency on
parts from overseas
(vulnerability to shipping
delays); limited local
capacity to machine parts;
procurement delays; no
preventive maintenance
programmes; lack of
availability of key
equipment to perform
maintenance
1) Develop and enforce
a planned maintenance
programme; 2) hire
maintenance personnel
(1) with oversight in
Linden; 3) link annual
materials plan to
budget process; 4)
empower division to
outsource repair jobs
(grant necessary
authority/autonomy); 5)
procure needed
equipment (pump
hoist)
Human resource
limitations for
preventive
maintenance;
limited local
personnel with
maintenance
skills; securing
buy-in within
finance group;
funding (to
procure needed
equipment);
management
resistance
Operators do not
consistently
record finished
water quality at
any of the 5
WTPs.
Supervisory oversight;
log sheets
Limited
supervisory 1) Increase operator
oversight/accountability
accountability through
increased supervisory
oversight
46
Human resources;
transportation
limitation
H
H
GWI
GWI
1) Mar 09; 2)
Mar 09; 3)
Sep 09; 4)
Dec 08; 5)
Dec 09
1) Effective
immediately
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
At West
Watooka,
backwash and
water from
clarifier (dislodge
water) is
returned to river
near intake (~40
ft away)
High turbidity
standard means
that disinfection
processes are
not optimised
and may pose
health risks.
Raw water values for
iron at the West
Watooka WTP higher
than raw water values at
McKenzie and LPC
despite the common
source (Demerara
River).
Location of intake
Proximity of intake to 1) Source Dakoura
source of contamination Creek; 2) relocate the
(plant discharge)
effluent pipe
GWI's turbidity standard
of 5 NTU is higher than
WHO and USEPA
standards/recommendati
ons. The data indicate
that all plants (except
Amelia's Ward) are
capable of achieving
POE turbidity
considerably below 5
NTU.
Turbidity limit of 5 is
used, in accordance
with WHO stated value
for aesthetic
acceptability by
consumers.
Not
a
health-based
standard. Lower turbidity
levels can be achieved by
GWI.
Inconsistent
supply of power
and high cost of
power affects
ability to provide
daily water
service
Inconsistent/unreliable
power supply affects
GWI's ability to
consistently treat and
deliver water.
Overhead treated
water storage
Existing pumps are
inefficient because of
insufficient maintenance;
network variables
(preventing optimal and
consistent operation of
pump); chemical
degradation of pump
47
Corrective Actions
MoH in collaboration
with GNBS and other
stakeholders review
third version of WHO
guidelines and set
national standards
(including turbidity)
based upon healthbased standards or
recommendations. May
propose step-wise
targets to reach
desired turbidity values
as system
improvements are
made.
1) Promote rainwater
harvesting (reduce
demand); 2) create a
preventive equipment
maintenance
programme (with
equipment history
cards); 3) non-revenue
Barriers to
Implementation
Priority
Responsible
Parties
Target
Timeline
Funding; need for
feasibility
assessment (for
sourcing Dakoura)
M-H
GWI
1) Feasibility
assessment
to be
completed by
Dec 09; 2)
relocate
effluent pipe
by Jun 09
Achieving
standard may not
be immediately
feasible; hence
this may need to
be done in a
stepwise
approach.
H
MoH
May-09
Funding (for
bringing overhead
tank on line or
exploring
alternative power
supplies);
competing
priorities for
M
GWI
1) Jun 09; 2)
3/09 (see
above); 3)
ngoing, to be
completed by
Dec 12; 4)
Dec 10; 5)
Dec 09; 6)
Hazard
DISTRIBUTION
The existing
water quality
monitoring plan
does not include
routine
monitoring of
chlorine residual
in the distribution
system
Leaks in
distribution
network make
system
vulnerable to
contamination.
Also cause
operators at
Findings
Existing Control
Measures
Limitations/Effectiveness
Corrective Actions
Barriers to
Implementation
High cost of power
affects GWI's ability to
provide 24/7 service to
customers, causing low
pressure conditions in
the distribution network
and requiring consumers
to store water at home.
Pump efficiency;
overhead storage to
allow gravity
distribution (Wisroc)
impellers; overhead
storage tank (at Wisroc)
not used (because of need
for pipeline to tank, as
existing pipeline is
undersized); hydraulic
analysis is needed
water programme (to
reduce leaks network
variability); 4) install
pipeline to deliver pipe
from Wisroc to tank; 5)
perform hydraulic
analysis; 6) explore
alternative power
options
funding; human
resource
limitations (for
preventive
maintenance);
feasibility analysis
for
alternative/backup
power supplies
48
Responsible
Parties
Target
Timeline
Dec 12
Human resources;
transportation
limitation; funding
(for
testing
reagents)
H
GWI
1) Jun 09
Implement
leak Soil type creates
to
detection and demand challenges
suppression
(non- identifying leaks;
revenue
water resource
availability (due in
programme)
part to prevalence
of leak problem
country-wide)
H
GWI
Ongoing, to
be completed
by Dec 12
Microbiological water Chlorine residual is not 1) Include chlorine
quality monitoring (in routinely tested
residual testing as part
distribution system)
of routine distribution
system monitoring
availability
of
Non-revenue
water Timely
(material,
programme (including resources
replacement of aging personnel)
pipeline material)
Priority
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
Wisroc to bypass
holding tank and
filters to
maximise flow
through plant
(deliberately
exchanging
quality for
quantity).
Treatment processes at
Wisroc WTP generally
did not reduce (and on
multiple occasions
contributed to) turbidity,
iron, aluminium and
colour. Consequently,
aluminium and colour
were frequently and
significantly in violation
of the standards. (Note:
problem also listed
above because it may
be due to either, or both,
unintentional and
intentional deviations
from optimised
operations)
Approximately half of the
households with GWI
connections interviewed
during the HH survey
reported that they did
not pay for water service
or paid less that the
billed amount. Some
consumers were
unwilling to pay for poor
quality service
Treatment processes
Operators bypassing
holding tank and filters,
which is necessary
because network demand
exceeds plant capacity
(due to leaks in the system
and consumer waste)
Billing; disconnection
campaign; public
outreach; customer
complaints line;
treatment processes
(to improve quality of
water and willingness
to pay)
Unwillingness to pay; poor
quality/service; incorrect
billing; poor response to
customer complaints
(customer services)
Inadequate cost
recovery affects
GWI's ability to
provide safe
water
49
Corrective Actions
Barriers to
Implementation
1) optimise treatment
processes; 2) customer
service training
(training of GWI
personnel and
consumers to ensure
understanding of
complaints procedure);
3) provide a toll-free
hotline; 4) develop and
implement targeted
(Linden-specific) PR
Insufficient
capacity among
customer service
trainers;
insufficient
commitment/profe
ssionalism to GWI
(among GWI
personnel);
inadequate
internal employee
care (affecting
Priority
Responsible
Parties
H
GWI
Target
Timeline
1) Jun 09; 2)
ongoing
process to
begin Dec
08; 3) - 5)
Dec 08
Hazard
MONITORING
There is no
system in place
by which GWI
water quality
monitoring
results reach the
surveillance
authority (MoH,
RDC, M&TC).
Findings
Existing Control
Measures
Limitations/Effectiveness
Corrective Actions
Barriers to
Implementation
Insufficient cost recovery
affects GWI's ability to
operate, maintain and
make capital
investments in the
system.
Metering; billing;
disconnection
campaign; public
outreach; customer
complaints line;
treatment processes
(to improve quality of
water and willingness
to pay)
Socio-political challenges
with disconnection (or full
cost recovery); customer
service training needs;
need to identify effective
medium to reach
customers; treatment
processes not optimised
(see limitations above);
cost of contacting GWI in
Georgetown
strategies and
programmes; 5)
identify effective
medium for reaching
consumers
Perceptions of GWI by
community affect
relations with GWI and
willingness to pay.
Public outreach (TV
programme, press
releases); monthly
meetings major
stakeholders
Limited effectiveness of
communication medium
morale and
limiting GWI
personnel
investment and
commitment to
company); belief
among consumers
that water should
be free;
enforcement of
disconnection
(limited human
resources) and
corruption among
contractors
None
There is a MoU between
the MoH and GWI for
sharing data however this
MoU is only applicable in
emergency situations.
Revise and formalise
the MoU to establish
routine and emergency
inter- and intra-agency
surveillance monitoring
and reporting
mechanisms.
Mechanisms for routine
data sharing will
include: (1) A GWI
intra-agency
mechanism for
cohesively collecting
and reporting
surveillance
information between
Commitment and
trust
Funding (for
purchase of
database
software); human
resources to
perform data
entry; human
resource
limitations within
MoH
50
Priority
H
Responsible
Parties
GWI (1,2)
Target
Timeline
Oct-09
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
Corrective Actions
Barriers to
Implementation
Priority
Responsible
Parties
Target
Timeline
M
MoH/CBH (3)
Oct-09
H
GWI,
MoH/CBH
Oct-09
H
M&TC, MoH,
RDC (4)
regional and national
level; (2) National level
GWI then reports
surveillance data to
Central Board of Health
on a monthly basis;
There is no
system in place
by which MoH
surveillance
results regularly
reach GWI.
Under the present
system, GWI learns of
unsatisfactory
surveillance findings
through a public health
advisory.
M&TC and RHO share
water testing
surveillance (chemical
and microB) data with
GWI on a monthly
basis.
No structural reporting
mechanism in place to
share data among these
three agencies (RDC/
MoH, M&TC and GWI).
RDC reports only go to the
RHO. GWI does not share
their testing data with
these agencies.
51
(3) CBH (MoH) shares
that information with
the RHO);
Mechanisms for
emergency
surveillance data
reporting is: GWI will
immediately inform the
Chief Medical Officer of
emergency events.
CMO will then inform
the relevant personnel
(MOH Env Health Unit,
M&TC). (Need to
define "emergency"
from health
perspective.)
Revise MoU as above
to include routine
surveillance reporting
between EHO and
MoH/RDC on a
monthly basis. (4) EHO
will report monthly
regional surveillance
data to the RHO. RHO
then reports monthly to
Institutionalising
this reporting
mechanism.
May-09
Hazard
Findings
Existing Control
Measures
No structural reporting
mechanism in place to
share data among these
RDC/ MoH and M&TC
There is not a
formalised
system in place
by which
surveillance data
collected by
regional bodies
is reported to
central MoH.
Lack of
consistent
Limitations/Effectiveness
Surveillance monitoring
of the distribution
Monthly monitoring and
sampling protocol
All relevant parameters are
not being monitored.
52
Corrective Actions
MoH and to regional
GWI. (Regional GWI
will be responsible for
reporting to central
GWI).
Emergency
surveillance reporting:
Inspectorate (Food and
Drug Lab)/EHO will
make calls to MoH,
RHO and M&TC. RHO
will share that info with
GWI.
Establish
a
Water
Surveillance database
to
be
instituted
collaboratively
by
relevant agencies.
Standard
Operating
Procedures need to be
developed
and
implemented. Should
include: 1) Sampling
methodologies,
frequency,
locations,
recording; 2) Testing
methodologies
&
quality assurance &
documentation;
3)
Recording & Reporting
schedule: routine &
emergency
Adopt routine schedule
as prescribed by WHO
Barriers to
Implementation
Priority
Responsible
Parties
Human resource
and expertise
constraint.
H
MoH Inspectorate/
EHOs
May-09
Securing funding
and expertise
M
MoH, M&TC,
PAHO
Oct-09
M
GWI,
MoH/RDC,
M&TC
May-09
H
MoH/RDC,
M&TC
May-09
None
Target
Timeline
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
Corrective Actions
surveillance
monitoring in the
distribution
system
system is not
consistently performed
by RDC or M&TC.
exists for RDC, M&TC.
Monitoring is not done as
planned.
Lack of reliable
sampling
methods and
consistency
between
agencies.
Microbiological sampling
methods are not
consistent between GWI
and RDC/M&TC, which
has raised concerns
about result validity.
water
surveillance
guidelines (population
and monitoring points).
Consider
alternative Financial
microbiology
and constraints
chemical field testing
kits for Environmental
Health Officers.
Independent
quality None
assurance (proficiency)
testing should be done
for GWI and F&D labs
to ensure consistency
of testing.
There is no
system in place
for reporting
surveillance
results to GWI.
Under the
present system,
GWI learns of
unsatisfactory
surveillance
findings through
a public health
advisory.
Limited
public
awareness and
education
regarding
household water
practices leads
The HH survey showed
that there is a lack of
knowledge
about
appropriate
home
treatment practices.
Barriers to
Implementation
WHO methodology is
being used by both
GWI, M&TC and MoH.
Different sampling
techniques might produce
different test results
MOU between GWI
and MoH
System by which
information shared is not
being followed (or does not
require that information is
shared)
1) Enforce MOU (or None
revise it to include
information sharing for
routine
operations,
including frequency of
sharing) and setting up
a
channel
of
communication/collabo
ration between GWI
and MoH
Routine public health
messages
delivered
through health centres
and schools as well as
posters
and
flyers
produced by MoH.
Perhaps messages are not
reaching target audience
or are in an ineffective
format.
Short
term:
make
existing
information
materials more readily
available to schools
and to households.
MoH print brochures
53
Financial
constraints
bureaucratic
procedures.
Priority
Responsible
Parties
M
MoH –
Standards &
Technical
Unit, Food &
Drug
MoH –
Standards &
Technical
Unit
H
M
H
and
GWI, MoH
Target
Timeline
Jul-09
Jan-09 &
annually
thereafter
1)Jun 09
MoH, RDC, May 09
M&TC
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
to
unsafe
treatment
and
storage practices
that
are
associated with
health risks.
Storage in household
tanks and household
drinking water
containers leads to loss
of chlorine and
increased opportunities
for contamination.
Basic public awareness
through general PSAs.
PSAs do not address
maintenance of storage
tanks.
Improper rain water
harvesting at household
level.
None
PSAs do not address rain
water harvesting issues.
54
Corrective Actions
and sends to RHO,
RHO passes on to
EHOs and M&TC who
then disseminate to
households
and
schools as part of
routine visits.
Long term: Develop
creative
and
stimulating PSAs for
populace through a
communication
mechanism
that
conducts
social
marketing
assessments. Include
impact evaluation.
Develop
and
disseminate
(as
mentioned
above)
information materials to
specifically
address
proper
maintenance
and use of storage
tanks and household
drinking
water
containers.
Develop
and
disseminate
(as
mentioned
above)
information materials to
specifically
address
proper
rain
water
harvesting and storage.
Barriers to
Implementation
Priority
Responsible
Parties
Target
Timeline
Financial
constraints and
bureaucratic
procedures.
M
MoH (with
assistance
from PAHO,
CDC,
UNICEF,
UNESCO)
Feb-10
Financial
constraints and
bureaucratic
procedures.
H
MoH
Aug-09
Financial
constraints and
bureaucratic
procedures.
H
MoH, EPA,
CEHI, GWI,
PAHO
Aug-09
Hazard
Findings
Existing Control
Measures
Limitations/Effectiveness
Corrective Actions
Barriers to
Implementation
HH survey found that
consumers turned to
unsafe alternate
supplies for drinking.
Public education is
done through house to
house visits by EHOs
and health workers.
Public education is only
being done through limited
means and only tackles
general
water
safety
issues.
Expand
public
education mechanism
to include community
leaders, edutainment
initiatives,
etc
to
disseminate
information designed to
dispel
incorrect
perceptions
about
alternative
water
supplies.
Financial
constraints and
bureaucratic
procedures.
55
Priority
H
Responsible
Parties
MoH
Target
Timeline
Aug-09
6.0 MONITORING OF CONTROL MEASURES
Once corrective actions have been defined and implemented, these need to be monitored to
ensure that they function effectively.
Effective monitoring relies on establishing:
• What will be monitored
• How it will be monitored
• The timing or frequency of monitoring
• Appropriate locations for monitoring
• Who will do the monitoring
• Who will analyse the samples
• Who will interpret the results
• Who receives the results for action
Based on the work of the Water Safety Plan some of the major monitoring procedures were
developed or reinforced. These are detailed in Table 6.1. Some examples of these are:
•
•
•
•
•
•
Key parameters such as turbidity, pH and iron should be monitored as part of the source
water protection programme
Turbidity should be monitored as part of the coagulation, flocculation, sedimentation and
filtration processes at West Watooka, LPC and McKenzie WTPs
Turbidity of final water will be measured after filtration to monitor the efficacy of filtration
at the West Watooka, LPC, McKenzie and Amelia’s Ward WTPs
Operator training to ensure they become familiar with the WTP operations
Standard Operating Procedures need to be developed (details are in Section 8.0)
Public Awareness and Public Education (PA/PE) programmes that have been developed
need to be monitored. This includes monitoring the frequency of distribution and
ensuring that the messages are being received.
It is important that operators understand the importance of performing on-going monitoring as
part of their routine work. They also need to record the monitoring results consistently and take
the necessary corrective actions when a process is out of control. In order for this to happen,
they need to be properly trained in all aspects of operations and monitoring. Equally important is
the role of the supervisors in the monitoring process. They have to be vigilant regarding water
quality through the monitoring of records and as well as through seeking ways to improve the
process. Contingency plans should be understood by all employees.
It is also important that there is a co-ordination of efforts between various agencies that perform
water quality testing. Recommendations have been made (Table 9.1) that address the timely
communication of monitoring results amongst GWI, MoH and all other local and regional
agencies.
In order to ensure that this takes place, complete Standard Operating procedures should be
developed (see Section 8.0 for more details).
The issue of water quality standards had been discussed since the inception of the Water Safety
Plan. Although Guyana has “adopted” the WHO guideline values, the country has never
developed national standards. It is recommended that national standards should be developed
for Guyana. This would be done through a technical sub-committee of the Guyana National
56
Bureau of Standards (GNBS).
This sub-committee would examine all the mitigating
circumstances, any existing documentation and studies and allow baseline studies to be
developed. This approach would allow the sub-committee to recommend standards that are
achievable, while at the same time providing a step-wise approach to allow for improvements.
57
Table 6.1: Monitoring Procedures
Critical Control
Measure
Parameter
to be
monitored
Acceptable Range
Where?
When is it
done
(frequency)?
By Whom?
Who ensures
that work is
done?
Corrective Action for
non-compliance
Comments
Source water
protection
programmes
(collectively)
Turbidity
Guided by NPA
Raw water
intake
08:00 AM daily
Plant
operators
pH
Guided by NPA
Raw water
intake
08:00 AM daily
Plant
operators
Contact appropriate
person(s) overseeing
source water protection
programmes
Iron
Guided by NPA
Raw water
intake
08:00 AM daily
Plant
operators
While higher frequency
would be ideal, it is
important to be realistic
about cost of reagents
and gradually increasing
operator
workload/responsibility
Coagulation,
flocculation,
sedimentation
(West Watooka,
LPC, McKenzie)
Turbidity
(after these
processes)
Sedimentat 08:00 AM daily
ion basin
effluent
Plant
operators
Perform jar test/daily for
optimal alum dose/pH
combination; check
operation of chemical
pumps; adjust flow
(down to increase
sedimentation time)
No jar testing equipment
at McKenzie or LPC
Filtration (all plants
but Wisroc)
Turbidity
Consult with hired
expert to determine
reasonable
expected range;
GWI empirical
study (after
optimisation
training) to
determine
appropriate range
in Linden
This standard will
be determined for
each plant
Plant
supervisors or
managers
Plant
supervisors or
managers
Plant
supervisors or
managers
Plant
supervisors or
managers
Final water
Plant
operators
Plant
supervisors or
managers
Backwash filters;
otherwise explore need
for filter replacement;
manual cleaning of filter
media; chemical
stripping of media
(caustic or acid)
08:00 AM daily
58
Critical Control
Measure
Parameter
to be
monitored
Acceptable Range
Where?
When is it
done
(frequency)?
By Whom?
Who ensures
that work is
done?
Corrective Action for
non-compliance
Filtration (Wisroc)
Pressure
(gauge)
1 to 5 psi
Gauge on
filter tank
08:00 AM daily
Plant
operators
Plant
supervisors or
managers
Disinfection
Chlorine
residual
Final water
08:00 AM daily
Plant
operators
Plant
supervisors or
managers
Distribution line
flushing
programme
Number of
times
flushed per
quarter
Pressure
(pressure
gauge)
Range needs to be
optimised as per
plant. This value
should ensure that
at least 0.2mg/l is
recorded at the
most distant point
At least one time
Backwash filters; if not
resolved by
backwashing, explore
need for filter
replacement (sieve
analysis); manual
cleaning of filter media;
chemical stripping of
media (caustic or acid)
Adjusting chlorine dose;
check turbidity
NA
NA
Distribution
maintenanc
e crew
Plant
supervisors or
managers
Pressure in the
distribution system
Distribution
lines
leaving the
WTPs and
Randomly
selected
points
throughout
the
distribution
systems
59
Disciplinary action
Comments
Critical Control
Measure
Parameter
to be
monitored
Acceptable Range
Where?
When is it
done
(frequency)?
By Whom?
Who ensures
that work is
done?
Corrective Action for
non-compliance
Operator training
Number of
operator
training
sessions
per year
Distribution
of PA/PE
materials
At least 4 (a
minimum of 2
formal training
sessions)
2
classroom;
2 plant
sessions
Quarterly
GWI
training
department
Scientific
Services
Manager; HR
Enforce training
Home
visits,
Schools,
public
events,
market etc
Beginning June
09
Annually –
home visits
Quarterly –
business visits
MoH
EHU, RHO
Different information
materials will need to be
developed to target the
different subject areas
such as RWH, Ventilated
Pit Latrines etc
December 09
MoH and
technical
partners
(GINA,
PAHO,
CDC)
GWI, MoH
(Central
and Local),
M&TC
GWI (Head
Office),
Steering
Committee
Whilst most SOPs will be
applicable across all five
plants, some will have to
be tailored to meet each
plant’s needs. This
process should be done
collaboratively with the
operators and
Public health and
hygiene education
Target subject
areas include:
Improved
Household
Practices,
Rainwater
harvesting, safe
alternative drinking
supplies, proper pit
latrine design and
construction
Public Service
Announcements
Standard
Operating
Procedures (SOPs)
needs to be
developed and
implemented.
Should include: 1)
Sampling
Frequency
of airing of
PSAs
Standard
Operating
Procedures
(SOPs)
For all five
treatment
plants
December 09
60
Comments
Critical Control
Measure
methodologies,
frequency,
locations,
recording;
2)Testing
methodologies &
quality assurance
& documentation;
3)Recording &
Reporting
schedule: routine &
emergency
Water Surveillance
database instituted
collaboratively by
relevant agencies
Establish National
Water Quality
Standards
Interagency
reporting system
from GWI to other
agencies (a.
Routine and b.
Emergency)
Parameter
to be
monitored
Acceptable Range
Where?
When is it
done
(frequency)?
By Whom?
Who ensures
that work is
done?
Corrective Action for
non-compliance
Comments
supervisors to ensure a
sense of ownership.
This approach will
greatly increase the
success of their use.
Water
Surveillanc
e Database
MOU
revised
(include
both
routine and
emergency
)
Monthly
Reports
received
For all
relevant
agencies,
housed at
the MoH
March 09
EHU,
Information
Technology
Department
MoH, Steering
Committee
For all water quality
parameters
Process begins
June 09
GNBS
Steering
Committee
For all water quality
results
Monthly for
routine
reporting
beginning June
09
Emergency –
as necessary
GWI,
a. MoH, GWI,
MoLG&RD,
EPA, PAHO,
CBH
b. GWI reports
to CMO who
will then inform
the relevant
personnel
(MOH Env
Health Unit,
M&TC).
61
Critical Control
Measure
Parameter
to be
monitored
GWI intra-agency
reporting
mechanism
between regions
and central head
office
Use of alternative
field test kits
Intra
agency
reporting
protocol
Receipt of
appropriate
field test
kits
Acceptable Range
Microbiological
tests for water
quality
Where?
For
distributed
water
When is it
done
(frequency)?
By Whom?
Who ensures
that work is
done?
On a weekly
basis
GWI
(Regional)
GWI (Head
Office)
EHU to
research field
test kits by
March 09
EHU,
PAHO
62
Corrective Action for
non-compliance
Comments
7.0 VERIFICATION
Verification provides the evidence that the overall system design and operations are capable of
consistently delivering water of a specified quality that meets identified health-based targets.
Verification includes compliance monitoring; internal and external auditing of operational activities
and determination of consumer satisfaction ( WHO Water Safety Plan Manual).
For water quality in Linden, it is imperative to verify that operational procedures are being
followed. This can be done through systematic assessment of the following parameters and
activities:
• E. coli and total coliforms not being present in the final water
• E. coli and total coliforms not being present at different points along the distribution systems
of each WTP
• Turbidity level at different points along the distribution systems of each WTP
• Chlorine residual at different points along the distribution systems of each WTP
• Formal internal and external review of operational monitoring records from each WTP
• Formal reporting of water quality testing results from laboratory to utility plant operators
Verification of the system operation can be done through compliance monitoring by the utility of
the parameters described above. Samples of finished water quality would be taken by the
operators and/or the supervisors and tested on site (for residual chlorine) or sent to the
Georgetown laboratory for analysis. Independently, samples would be tested routinely from
points along the distribution system, including the most distal points, by the Environmental
Health Officers and tested at the Laboratory of the Food and Drugs Division. It is very important
that the results are analysed, summarised and sent back to the plant and to the operators so
they can have adequate feedback on the quality of water they are responsible for treating. This
is not currently occurring and as a result this system was recommended as a corrective action.
This would not only allow for a sense of ownership and pride to be engendered but will also
assist the plant with operational plans and decisions. The current scenario demonstrates severe
lapses in testing, recording and reporting. Establishing these procedures would see a marked
improvement in the verification process and more importantly in the quality of treated water. It
would serve to highlight problems in a timelier manner. Having proper records would also
facilitate regulatory oversight.
Inter and Intra regional reporting systems have also been recommended for
development/improvement. The results of the reports shared would inform all concerned parties
about the quality of the water and any other incidents that should be highlighted. This would
allow the necessary agencies to make timely interventions to improve the water quality or
service delivery to the consumers. This system would also inform about other areas such as
leaks, tampering with the distribution system and alternative water supply sources.
The Ministry of Health has a Surveillance Unit, which is generally responsible for collecting,
validating, collating, analysing data and information dissemination to inform decision makers for
appropriate action (policy, budget allocation, prevention programmes, programme monitoring,
etc). They are mainly concerned with the ongoing monitoring of distributions and trends in
incidence and mortality of diseases and risk factors and this is achieved through systematic
collection, validation, analysis and interpretation of morbidity, mortality and risk factor data.
63
They work closely with the Environmental Health Unit on issues of water quality as poor water
quality is one of the contributing factors to illnesses.
The monitoring agencies such as the Ministry of Health Surveillance Unit, Environmental Health
Unit, Mayor and Town Council, Regional Health Officer etc. would be responsible for checking
the applicability of the national standards for water quality through review. They also have a
responsibility for water quality verification by testing for E Coli, Total Coliforms and Residual
Chlorine. They will also gauge consumer satisfaction by conducting household evaluation
surveys. Tables 7.1 and 7.2 detail these recommendations.
64
Table 7.1: Verification Procedures (Water Quality)
Parameter to be
monitored
Acceptable
Range
When is it
done
(frequency)?
Sampled
by
Tested by
Who ensures that
monitoring is done?
To whom
(internally) are
results shared?
To whom (externally) are results
shared? And how often?
Scientific Services Manager
Head of division
Central Board of Health (CBH); monthly
Scientific Services Manager
Head of division
CBH; monthly
Scientific Services Manager
Head of division
CBH; monthly
Scientific Services Manager
Head of division
CBH; monthly
Scientific Services Manager
Head of division
CBH; monthly
Scientific Services Manager
Head of division
CBH; monthly
Final Water/Distribution (where in distribution?) (West Watooka, McKenzie, LPC, Wisroc)
pH
6.5 - 8.5
Biweekly
Operators
GWI Georgetown
laboratory
GWI Georgetown
laboratory
GWI Georgetown
laboratory
GWI Georgetown
laboratory
GWI Georgetown
laboratory
Operators
Turbidity
Biweekly
Operators
Iron
<5 NTU (under
review)
<0.5 mg/L
Biweekly
Operators
Aluminium
<0.2 mg/L
Biweekly
Operators
Colour
15 TCU
Biweekly
Operators
Chlorine Residual
>0.2 mg/L
Biweekly
Operators
Total/Faecal
None
Biweekly
Coliforms
Final Water/Distribution (Amelia's Ward)
Operators
GWI Georgetown
laboratory
Scientific Services Manager
Head of division
CBH; monthly
pH
6.5 - 8.5
Biweekly
Operators
Georgetown lab
Scientific Services Manager
Head of division
CBH (Central Board of Health); monthly
Turbidity
Biweekly
Operators
Georgetown lab
Scientific Services Manager
Head of division
CBH (Central Board of Health); monthly
Iron
<5 NTU (this
target currently
under review)
<0.5 mg/L
Biweekly
Operators
Georgetown lab
Scientific Services Manager
Head of division
CBH (Central Board of Health); monthly
Chlorine Residual
>0.2 mg/L
Biweekly
Operators
Operators
Scientific Services Manager
Head of division
CBH (Central Board of Health); monthly
Total/Faecal
Coliforms
None
Biweekly
Operators
Georgetown lab
Scientific Services Manager
Head of division
CBH (Central Board of Health); monthly
Currently sampling for verification by GWI is done at nineteen locations along the distribution system. These points were chosen through a variety of criteria including ease of
access to a point source and representativeness of the system. Distal points on the system were also chosen. The monitoring agencies through the EHOs choose taps at the
consumers’ premises from which to sample the water quality. For thorough analysis, GWI should ensure that their points are maintained and the results should be analysed biweekly to ensure consistency.
65
Table 7.2: Verification Procedures (Surveillance)
What is being Monitored
Applicability of the National
Standards
Testing Laboratories
Proficiency (GWI, F&D)
Local Certification
When is this done?
By whom?
Who
receives the
results?
Five year review
GNBS and technical
team
MoH, EPA,
GWI
June, 2009
GNBS
GWI, F&D,
MoH
Water Quality (Distribution and Consumer)
E. Coli
monthly
Environmental Health
Officers (EHOs)
RHO, MoH
Total Coliforms
Chlorine Content (Residual
Chlorine)
monthly
EHOs
RHO, MoH
weekly
EHOs
RHO, MoH
Operator
results
treatment plants
from
Results of bi-weekly water
quality testing by GWI
personnel
Inter-agency
monitoring
and surveillance system
(include
emergency
surveillance system)
Household
Practices
(through
Sanitary
Inspections which includes
inspections
of
storage
facilities
and
use
of
alternative water supplies)
Behaviour - through impact
evaluation (Storage, RWH
System, Household
Treatment System)
Adoption of water
surveillance guidelines
Compiled by GWI
Supervisors
Water quality tested by
GWI laboratory and
results compiled by GWI
Scientific Services
Manager
Bi-weekly
Bi-weekly
Operators
GWI
Supervisors
Every three months
Surveillance, EH
National Food
Safety
Committee
Annually for
households
Quarterly/Businesses
EHOs
RHO, EHU
June, 2010 EH
March 2009
66
MoH, PAHO, M&TC
MoH
MoH, M&TC
8.0 MANAGEMENT PROCEDURES
8.1 Standard Operating Procedures (SOPs)
During the discussion of corrective actions, Standard Operating Procedures were highlighted as
being essential to the efficient and optimal operation of the water treatment plants. Whilst there
are procedures in place, these are not always documented nor enforced and as a result, the
system is prone to lapses in procedure. Additionally, ensuring the consistent communication of
water quality information is very critical to the on-going operations of the plants and this can only
be achieved if routine testing and recording takes place. Based on the findings of the Water
Safety Plan, several management procedures need to be developed for the plants as well as the
surveillance teams.
The Standard Operating Procedures are detailed in Table 8.1. This table summarises the types
of operating procedures that should be developed by GWI. These SOPs would detail all the
necessary activities that should be undertaken as well as responsibilities. An example of an
SOP is included in Appendix IV – Jar Test Procedure. Some of these procedures are simple
and rarely require review. Others can be obtained directly from manufacturer’s specifications
and manuals.
The procedures that should be developed would include the following categories:
•
•
•
Start-up Procedures - How to start up? What kinds of check procedures are needed?
What is the sequence of start-up?
Normal Operating Procedures - What are normal operating procedures? What are the
check points for normal operation? What are the minimum and maximum values of the
checkpoints? What is the normal range of chemical dosages?
Alternate Operating Procedures - How does the plant operate when the normal
conditions change, the raw water quality changes, or a process or piece of equipment is
out of service? An alternate operation procedure is usually a planned change to
accommodate major maintenance, increased demand, or use of an alternate source.
Table 8.1: Standard Operations Procedures
CATEGORY
DETAILS
Start Up Procedures
Normal Operating Procedures
These will provide a description
of the normal operation of each
process. Each description
assumes that the process is
operating properly as designed
and that all influent/effluent
parameters meet the required
standards.
Equipment Inspection – Physical, Mechanical, Electrical
1. A general description of the process including schematics
and related diagrams .
2. A description of the influent water quality including any
anticipated variations should be provided for each
unit/process. The description should include average,
maximum, and minimum conditions. Reference should be
made for any sampling/testing procedures which are
involved
3. A description of all variables which may have an effect
upon the unit/process operation. The maximum and
minimum conditions should be indicated.
a. A description of process variables would include loadings
67
CATEGORY
DETAILS
and feed rates applicable to the unit/process.
b. A description of equipment variables would include speed
settings, pump settings, etc. for the unit/process under
consideration. Individual components must be considered in
this description.
4. A description of valve positions related to normal
operation (i.e., normally closed, normally open) of the
process under operation.
5. A general description of the normal dosages of chemicals
used in the process under consideration. The procedure
should reference standard procedures for performance of
tests (i.e., jar testing) to determine precise dosages . Also
describe the calibration and adjustment of test equipment to
ensure accuracy
8.2 Contingency Plans
It is important that contingency plans are also developed to address any unforeseen event or
emergency. GWI should anticipate what these conditions would be and establish the
procedures for these conditions. It is important that operational staff know about these
procedures and know how to access them when necessary. These procedures would be
accessible in all offices. Posters summarising the most important emergency procedures would
be posted on all accessible common areas and would be reviewed as part of any employee
orientation process.
Table 8.2 details some of the most important emergency procedures that should be adopted for
Linden.
Table 8.2: Emergency Procedures
CATEGORY
Emergency Procedures
A list of potential emergency situations
such as power, well and water storage
failure, equipment failure, loss of supply,
toxic contamination, drought, loss of
aeration, chemical or disinfection systems
should be prepared and procedures
developed. Some examples include:
1. Distribution System Problems;
2. Equipment Failure;
3. Disinfection Failure;
4. Power Outages;
5. Loss of Supply;
6. Contamination of Supply;
7. Strikes;
8. Vandalism and Sabotage
DETAILS
1. A description of alternate power and power
sources detailing the access to and operation of the
source.
2. A description of the process with schematics and
diagrams should indicate warning, interlock
systems, and standby equipment.
3. A description of procedures for process bypass or
shut down and the effects should be accompanied
by schematics and diagrams.
4. An emergency notification list identifying who
should be contacted by priority should include
names, addresses, normal and alternate phone
numbers, the reason for the notification and the type
of information required
68
9.0 SUPPORTING PROGRAMMES
9.1 Operator Training
The WSP development process highlighted notable deficiencies within GWI’s water treatment
plant operations, which underscored the need for urgently addressing the issue of operator
training and re-training. As a result of the WSP process, the following training-of-trainers
programme is suggested. It ideally should cover a five day period and target a variety of
stakeholders recognising the need for a collective effort in tackling issues related to improving
water quality. It is proposed that a Water Treatment Plant expert be drafted for this training
exercise and that the training should be customised for Linden. To date one has been sourced
by GWI and is in the process of developing such materials. It is the medium-term plan on GWI
to ensure that all their operators are certified to an international certification body. The Scientific
Services Manager is currently examining working with the regional certification body Caribbean
Basin Water Management Programme (CBWMP).
Topics covered in the training programme include:
DAY 1-2
o
Trainer to get acquainted with 5 WTPs; customise presentations for Linden
DAY 3
Participants: plant supervisors, Linden’s system managers, HQ operations department, HQ
management (Scientific Services Manager)
o
o
o
o
o
o
o
Understanding source water quality; typical contaminants
Physical/chemical treatment processes
System optimisation
Activities for interaction/engagement/reinforcement
Operational monitoring plan development (monitoring within the plant; critical control points,
operational limits, monitoring locations and frequency, corrective action plans)
Template for operational monitoring plan
Group exercise to develop an operational monitoring plan
DAY 4
Participants: plant supervisors, Linden’s system managers, HQ operations department, HQ
management (Scientific Services Manager), HR & IR personnel, PAHO representative, Linden’s
M&TC & RDC EHOs, RHO, Director of Environmental Health, Health Surveillance Officer
o
o
o
o
o
Basic water quality/treatment principles (introductory for surveillance personnel; review for
Day 3 participants)
GWI final water monitoring procedures (plant and distribution system; parameters,
frequency, locations, methods)
MoH final water surveillance procedures (distribution system; parameters, frequency,
locations, methods; work from PAHO’s Water Surveillance Plan for Region 6)
Recording, reporting and evaluating data (within and between GWI and MoH)
Template for surveillance plans (operator and Environmental Health Oficers)
69
o
Breakout sessions to develop 1) operator monitoring plan and 2) surveillance plan; plenary
presentations for mutual awareness/buy-in
DAY 5
Participants: plant supervisors, Linden’s system managers, HQ operations department, HQ
management (Scientific Services Manager)
o
o
o
Operator incentives (performance-based promotions, encouraging investment/ownership)
Operator Health and Safety
Guidance on developing an operator training plan (including appropriate refresher intervals,
etc.)
9.2 Intra and Interagency Reporting System for Drinking Water Quality
Data
Mechanisms for formal reporting of water quality testing results were found to be lacking. The
WSP team developed a series of reporting guidelines to ensure the communication of water
quality data between agencies, thus increasing the capacity to detect problems within the
system and address them in the most timely manner possible. The following recommendations
are made with respect to agency reporting mechanisms:
Table 9.1: Reporting Mechanisms for Inter and Intra-agency Reporting
Reporting
Agencies
MoH (intraagency regional level):RDC
EHOs to RHO
MoH & Municipality
(interagency - regional
level):
M&TC EHOs to RHO
MoH & GWI
(interagency –
regional level):
RHO to GWI
MoH (intraagency –
regional to national
level):
RHO to Env. Health
Unit
GWI (intraagency –
regional to national
Routine Reporting Mechanism
and information reported
Emergency Reporting
Mechanism
EHOs submit to the RHO a compiled
monthly report on all water testing
(chemical and microbiological) done in
the region.
EHOs submit to the RHO a compiled
written monthly report on all water
testing (chemical and microbiological)
done in Linden.
Inspectorate Unit, Food &
Drug Labs immediately
informs the EHO(s) via
telephone of the lab results.
The EHO(s) immediately
informs the RHO of the
laboratory findings. The RHO
then informs the Director of
Environmental Health Unit
who will then inform GWI
Head Office (Scientific
Services Department).
RHO then immediately informs
the GWI Officer in Charge for
Region 10 of the laboratory
findings.
RHO then immediately informs
the Director of the Env. Health
Unit of the laboratory findings.
RHO submits a monthly report of
water quality monitoring to the GWI
Officer in Charge of Region 10.
RHO submits a copy of the monthly
report water quality monitoring to the
GWI Officer, to the Director of the
Environmental Health Unit.
Region 10 Officer in Charge submits a
weekly plant monitoring report, to the
70
GWI Officer in Charge for
Region 10 immediately
Reporting
Agencies
Routine Reporting Mechanism
and information reported
Emergency Reporting
Mechanism
level):
Region 10 Officer in
Charge to GWI Head
Quarters (HQ)
GWI (intraagency –
national to regional
level):
GWI Head Quarters
(HQ) to Region 10
Officer in Charge
GWI & MoH
(interagency –
national to national
level):
GWI HQ to MoH
Laboratory, GWI, HQ
informs the Scientific Services
Manager, GWI HQ
GWI HQ submits monthly laboratory
report, to the Region 10 Officer in
Charge
GWI HQ immediately informs
the GWI Officer in Charge for
Region 10 of the laboratory
findings.
GWI submits to the Food and Drug
Analyst Department, MoH a monthly
written report on all water testing
(chemical and microbiological) done in
and for Region 10.
MoH (intraagency –
national to national
and regional level):
CBH to Env. Health
Unit and RHO
MoH (intra and
interagency – regional
level):
RHO to RDC EHOs
and M&TC EHOs
The Food and Drug Unit then every
month distributes copies of the
monthly report from GWI to the Env.
Health Unit and RHO.
GWI HQ immediately informs
the Head, Food and Drug
Department, MoH via
telephone of the emergency
situation. This should be
followed by a written
emergency report.
Head, Food and Drug will then
immediately inform the
Director, Env. Health Unit and
the RHO of the situation.
RHO will distribute on a monthly basis
copies of the GWI report received
from Food and Drug Unit with the
EHOs (those from the RDC as well as
those from M&TC) in her region.
9.2 Public Awareness and Public Education (PA/PE)
Education and public awareness are important to the successful implementation of this WSP.
Education would increase knowledge about water safety and hence this should lead to improved
water quality and reductions in reported water borne illnesses. Awareness materials are tools
that will be used to deliver the messages to both the public as well as the operators in the water
treatment plants.
Based on discussions with the Project partners and the Steering Committee, some public
education interventions and public awareness tools were detailed. The interventions would take
place in late 2008 and early 2009. The public awareness materials would be used by GWI and
the monitoring agencies as part of their ongoing programmes. These are detailed in Table 9.1.
These interventions are planned collectively by the Steering Committee and implemented by a
consultant.
71
Table 9.1: PA/PE Interventions
PA/PE Intervention
Focus Group
Workshops
Video
Detail
This would involve targeted group meetings for three focus groups –
Public, Private Sector and Civil Society. Each workshop will be of two
days duration and will focus on each person’s/organisation’s roles and
responsibilities with respect to water. The sessions will be designed to
be highly interactive. Details of the plan for these workshops are
included in Appendix V.
Creation of a 20-minute informational video is planned that will
highlight the following main themes:
Part 1: Profiling the watershed and aquifer zones with a focus on
practices that negatively impact on the watershed and compromise
source water quality. Activities including mining, deforestation, poor
agricultural practices, indiscriminate solid waste discharge, and
contamination by sewage would be highlighted.
Part 2: Highlighting the operations of a water treatment plant including
steps in water abstraction and treatment. Viewers will learn how
irresponsible behaviour affects the process and makes the treatment
more complex and costly.
Part 3: Highlighting the challenges with respect to distribution systems
including. The dangers associated with illegal connections, leakages in
household systems, aged piping infrastructure and low water pressure.
Posters
Power Point
Presentation
Manual
Part 4: Will review how householders can augment and improve the
quality of their household supply through the proper use of household
rainwater harvesting systems. This section will also focus attention on
household water treatment techniques including chlorination.
The posters are intended to draw attention to the ways in which
activities in the watershed and consumer behaviour affect water
quality. These posters will be designed for use not only in Guyana but
will be generic enough for use in other countries in the Caribbean.
The NPA/WSP posters will be developed by the Steering Committee
and the Plant Operator Posters by GWI and reviewed by the Steering
Committee.
This narrated presentation will be used to highlight the development of
the Linden pilot project integrating both the NPA and WSP
approaches. It will include elements of catchment protection as well
as important elements of water treatment. These can be used as
general promotion of the process and can also be used to present to
policy developers who need to be educated as to the benefits.
Summary versions (handbook format) of the NPA and WSP
documents would be produced for wider circulation and usage.
72
10.0 PERIODIC REVIEW OF THE WATER SAFETY PLAN
The Water Safety Plan has been guided by the project Steering Committee. Once the Water
Safety Plan has been officially handed over to GWI and the monitoring agencies, the periodic
review of the Water Safety Plan can be done through the Steering Committee that would
continue to meet bi-monthly. The Water Safety Plan outlines recommendations that are timebound.
Guyana Water Inc. should adopt procedures to audit the implementation and operation of the
Water Safety Plan into their routine audit schedules. As a result, they have developed an audit
routine. There will be several levels of audit as in the Table 10.1 below:
Table 10.1: Audit Routine for GWI
Responsible Party
Supervisors
Activity to be audited
Intervals
Operators
Log
sheets; Daily
Operators’ log book; Visual
inspection of plant; Checking of
results with instruments
Divisional Engineer
Same as above
Spot checks as evidenced
by
signature
in
the
operators’ logbook and on
log sheets
Divisional Manager
Same as above
Periodic
Scientific
Services Same as above
At least quarterly
Manager
and
Operations Director
Maintenance Manager
All of the above
At least once per month
It is recommended that the GWI also work with the Ministry of Health to develop a schedule for
external audits. These audits can be semi-annual at most and would focus on key areas such
as the standard operating procedures (including operational monitoring and compliance
monitoring plans), operator training programmes, and action plans to address high-priority
hazards. In addition to improving adherence to established plans and procedures, these audits
are expected to improve communication both within GWI and between GWI and the MoH.
73
11.0 REVISION OF THE WATER SAFETY PLAN
By its very nature, a WSP is not intended to be a static operational document. As factors
impacting on a water supply system change and demands for water increase, the WSP will need
to be revisited to ensure that it continues to identify and respond to emerging risks and hazards.
The Water Safety Plan will also need to be revised as major improvements and capital
improvement works are implemented in Linden, taking into account that these changes will give
rise to new operating procedures, personnel and the need for retraining. Other factors including
changes in watershed usage and practices, brought about by mining, industrial, agricultural and
urban expansion, will serve to create additional source hazards that would need to be taken into
account.
It would also be necessary to review the WSP following any emergency incident or unforeseen
event. With respect to the occurrence of an unplanned event, a post-incident review should be
conducted by GWI to identify areas for WSP improvement, whether it is with respect to the
introduction of a new hazard; a revised risk requiring further risk assessment; the need for a revision
of an operating procedure; the need for further training or for enhanced communications. The
outcomes of the post incident review would largely inform the revisions required. Where possible, a
variety of stakeholders should be involved in this post-incident review.
GWI should inform the Steering Committee when these incidents occur so this can be discussed in
view of the need for making any changes necessary to the WSP.
Bosai plant and other business enterprises should be involved in the process given that they are
major stakeholders. They can be invited to be part of the team that examines the revision of the
Water Safety Plan.
The overall responsibility for the WSP review though should be with the Steering Committee. If
the Steering Committee is discontinued, this can then be done through the National Water
Council.
Other changes that would require a review and revision of the WSP include:
•
•
•
•
•
Change of roles and responsibilities of key staff
Personnel change
Identification of new hazards or elimination of existing hazards
Change in water treatment plant eg addition of a disinfection unit
Change in system operation or maintenance process or procedure
If there are no major incidents or changes that warrant a review, then an annual review should
be scheduled. This should be done to coincide with a scheduled audit so that the interest is
maintained and some of the same personnel can be used.
74
12.0 SUMMARY OF KEY FINDINGS AND RECOMMENDATIONS
12.1 Overarching/Inter-Agency
Key Findings:
• Importance of including agencies other than the water utility in WSP planning process
• Lack of formal and informal mechanisms for coordination between agencies
• Lack of funds for system infrastructure improvements and for chemicals
• Lack of formalized and executed intra and inter-agency reporting mechanisms for
routine sharing of water quality monitoring data
• Lack of reporting mechanism and contingency plans for emergencies
Recommendations:
• Continue oversight of WSP implementation by the Steering Committee
• Establish both intra- and inter- agency reporting mechanisms
• Establish both internal and external audit schedules
• Pursue funding options for system improvements from funding agencies
• Revise and formalize GWI intra-agency mechanism for cohesively collecting and
reporting surveillance information between regional and national levels
• Formalise mechanisms for routine (monthly) reporting of water quality data and
surveillance data between GWI, MoH, and other relevant agencies
• Develop and formalize emergency surveillance data reporting mechanisms
• Establish a water surveillance database to be instituted collaboratively by relevant
agencies
12.2 Watersheds/Source
*Refer to accompanying NPA document for most recommendations related to the watershed
and source waters
Key Findings:
• Poor quality of Demerara river water limits the ability of treatment plants to meet
water quality standards
• Contamination of ground and surface waters through usage of pit latrines.
• Lack of funds for expanding coverage of improved sanitation (VIP latrines)
Recommendations:
• Explore option of sourcing only Dakoura Creek, and/or relocating effluent pipes
• Increase enforcement of existing sanitation guidelines and expand guidelines to
incorporate VIP latrines
• Pursue funding options for improved sanitation
12.3 Treatment
Key Findings:
• Treatment plants not operating optimally – need for operator training
75
•
•
•
•
•
Lack of consistent water quality testing and documentation at critical control points in
the water treatment process
Lack of a system for routine review, analysis and feedback to operators of existing
water quality monitoring records
Need to establish in-plant standards that are consistent for all treatment facilities
Current turbidity standard not appropriate for optimal disinfection, plants found
capable of achieving lower turbidity
Need for formalisation of testing mechanisms (eg, use of Georgetown GWI
Laboratory, alternate laboratories, use of facilities in Linden etc)
Recommendations:
• Optimise treatment processes through plant operator training programmes - Develop
operator training manuals, with the view to mandatory certification for operators
• Increase accountability of plant operators through routine monitoring schedules and
increased supervisory oversight
• Establish GWI schedule for review of water quality monitoring records
• Set appropriate health-based water quality standards (with incremental targets for
compliance), especially for turbidity
• Develop specific Standard Operating Procedures
12.4 Distribution
Key findings:
• Capital Investment needed to repair leaks
• High non-revenue water from leaks and non-payment
• Lack of routine monitoring, review and feedback at points along distribution network
Recommendations:
• Repair leaks and replace pipes where necessary, reduce network vulnerability
• Develop non-revenue water programme, including leak detection and demand
suppression
• Establish schedule for routine monitoring in the distribution system
• Establish routine for reporting results of monitoring by MoH to GWI
• Develop and implement targeted public relations programme, customer service
training for GWI personnel,
12.5 Consumers
Key Findings:
• Improper storage that may lead to re-contamination of water
• Lack of knowledge about effective home treatment methods
• Inconsistent water supply
• Distrust between consumers and the utility
• High frequency of non-payment for water, leading to low cost recovery
Recommendations:
• Establish formal outreach programmes with consumers
76
•
•
•
•
•
Develop PA/PE materials that would target proper storage and treatment of water in
the home
Encourage the use of appropriate sanitation facilities such as Ventilated Improved Pit
Latrines (VIPs)
Encourage safe, alternative water supply such as rain water harvesting (RWH)
Improvement of cost recovery by GWI, use of meters, and improved billing.
Public outreach to improve human relations between GWI and consumer base
77
APPENDIX I
Glossary
(Terms as defined by the WHO and the CDC)
TERM
DEFINITION
Aluminium
Aluminium is the most abundant metallic element and constitutes
about 8% of the Earth's crust. It occurs naturally in the environment
as silicates, oxides, and hydroxides, combined with other elements,
such as sodium and fluoride, and as complexes with organic matter.
Chemical coagulants, usually salts of aluminium are dosed to the raw
water under controlled conditions to form a solid flocculent metal
hydroxide. Owing to limitations in the animal data as a model for
humans and the uncertainty surrounding the human data, a healthbased guideline value cannot be derived; however, practicable levels
based on optimization of the coagulation process in drinking-water
plants using aluminium-based coagulants are derived: 0.1 mg/litre or
less in large water treatment facilities, and 0.2 mg/litre or less in small
facilities
Coagulation/Flocculation This causes suspended and dissolved particles to clump together
under the influence of chemical aids for easy removal
Colour
Drinking-water should ideally have no visible colour. Colour in
drinking-water is usually due to the presence of coloured organic
matter (primarily humic and fulvic acids) associated with the humus
fraction of soil. Colour is also strongly influenced by the presence of
iron and other metals, either as natural impurities or as corrosion
products. It may also result from the contamination of the water
source with industrial effluents and may be the first indication of a
hazardous situation. Levels of colour below 15 TCU are usually
acceptable to consumers, but acceptability may vary. No healthbased guideline value is proposed for colour in drinking-water.
Control Measure
Any action and activity that can be used to prevent or eliminate a
water safety hazard or reduce it to an acceptable level.
Corrective Action
Any action to be taken when the results of monitoring at the control
point indicate a loss of control
Disinfection
This destroys or inactivates harmful, disease-causing
microorganisms
Faecal Coliforms/E Coli Faecal coliform bacteria are a specific kind of total coliform. The
faeces (or stool) and digestive systems of humans and warm-blooded
animals contain millions of faecal coliforms. E. coli is part of the
faecal coliform group and may be tested for by itself. Faecal coliforms
and E. coli are usually harmless. However, a positive test may mean
that faeces and harmful germs have found their way into your water
system. These harmful germs can cause diarrhea, dysentery, and
hepatitis.
Filtration
This removes suspended or colloidal particles from water as it is
passes through the filter media;
Hazard Analysis
The process of collecting and evaluating information on hazards and
conditions leading to their presence to decide which are significant for
water safety and therefore should be addressed in the WSP.
78
TERM
DEFINITION
Hazard
A biological, chemical or physical agent in, or condition of, water with
the potential to cause an adverse health effect. Another word for
hazard includes “contaminant”.
Iron is a very common element in the earth’s crust. Water naturally
contains iron. Iron is an essential nutrient needed for good health.
Water that is high in iron often contains iron bacteria that make a redbrown slime that can clog water systems. Iron bacteria do not cause
any diseases in humans. Iron bacteria are responsible for corrosion
of piping and plumbing. Iron in water of more than 0.1 to 0.2 mg/L
can cause the water to taste bitter or astringent and can stain
porcelain and laundry.
The act of conducting a planned sequence of observations or
measurements of control parameters to assess whether a control
point is under control.
The pH level tells you how acidic or basic water is. The pH level of
the water can change how water looks and tastes. If the pH of water
is too low or too high, it could damage your pipes and cause heavy
metals like lead to leak out of the pipes into the water.
Iron
Monitor
pH
Residual Chlorine
Sedimentation
Surveillance
Total Coliforms
Turbidity
The presence of chlorine residual in drinking water indicates that: 1) a
sufficient amount of chlorine was added initially to the water to
inactivate the bacteria and some viruses that cause diarrheal
disease; and, 2) the water is protected from recontamination during
storage. The presence of free residual chlorine in drinking water is
correlated with the absence of disease-causing organisms, and thus
is a measure of the potability of water.
Removes suspended or dissolved matter (turbidity) from water
Surveillance of drinking-water quality can be defined as the
continuous and vigilant public health assessment and review of the
safety and acceptability of drinking water supplies
Coliform bacteria are microbes found in the digestive systems of
warm-blooded animals, in soil, on plants, and in surface water. Many
of these microbes typically do not cause illnesses however, because
microbes that do cause disease are hard to test for in the water, "total
coliforms" are tested instead. If the total coliform count is high, then it
is very possible that harmful germs like viruses, bacteria, and
parasites might also be found in the water.
Turbidity in drinking-water is caused by particulate matter that may be
present from source water as a consequence of inadequate filtration
or from resuspension of sediment in the distribution system. It may
also be due to the presence of inorganic particulate matter in some
groundwaters. The appearance of water with a turbidity of less than
5 NTU is usually acceptable to consumers, although this may vary
with local circumstances. Particulates can protect microorganisms
from the effects of disinfection and can stimulate bacterial growth. In
all cases where water is disinfected, the turbidity must be low so that
disinfection can be effective. Turbidity is also an important
operational parameter in process control and can indicate problems
with treatment processes, particularly coagulation/sedimentation and
filtration. No health-based guideline value for turbidity has been
79
TERM
Validation
Verification
DEFINITION
proposed; ideally, however,
median turbidity should be below 0.1 NTU for effective disinfection,
and changes in turbidity are an important process control parameter.
Obtaining evidence that the elements of the WSP are effective
The application of methods, procedures, tests and other evaluations,
in addition to monitoring to determine
compliance with the WSP.
80
APPENDIX II: PROPOSAL FOR THE IMPROVEMENT OF
LINDEN’S WATER SUPPLY INFRASTRUCTURE
GUYANA WATER INCORPORATED
PROPOSAL FOR THE IMPROVEMENT OF LINDEN’S WATER SUPPLY
INFRASTRUCTURE
Background
The proposed action is focused on improving the state of water supply in the town of
Linden. The overall objective is to provide the residents of Linden with sustainable
access to potable water. Given the poor state of supply, conditions within the system are
not conducive to revenue generation and as such, the financial sustainability of the
system is uncertain. As a result of the poor state of the infrastructure within the system,
five water treatment plants are operated, but yet still an inadequate service is delivered
to the residents of the town.
It is proposed that the overall objective be achieved through the strategic
decommissioning of two treatment plants and development of treatment and production
capacity of the remaining three plants within the system. Additional infrastructure to
support this consolidation of treatment plants is also proposed under the action including
storage both in the form of elevated and ground reservoirs, transmission and distribution
mains, service connections installation/ rehabilitation, establishment of district metered
areas and domestic metering. New raw water sources with better quality than existing
sources will also be developed to further reduce treatment requirements and improve
operational efficiency.
These objectives are hoped to be achieved in a phased manner based on the availability
of funding. The immediate focus, however, is to reduce Non Revenue Water (NRW)
through service connection upgrades and metering in areas of where levels of service
are generally good and to ensure that the infrastructural support for the
decommissioning of McKenzie and LPC treatment plants is put in place.
81
It must be noted when GWI took over in 2003, GWI inherited six (6) treatment plants and
a dilapidated network. The Non-Revenue Water then was estimated at 70%. In an effort
to improve the water supply system, GWI has expended almost two hundred and fortyfour million (244M) from 2003 to 2007 in capital works.
Year
Capital Investment
($GM)
2004
186.7
2005
14
2006
13.1
2007
30
TOTAL
243.8
It must be noted also that prior to 2003 (during the El-Niño Period) a new well was
constructed at the Amelia’s Ward Treatment Plant to boost water supply.
Last but not least, the annual operational for the Linden Water Supply System is
estimated at one hundred and seventy million dollars ($G170M)
Existing Infrastructure
The existing water supply infrastructure of GWI includes transmission distribution
networks, treatment plants, boreholes and storage tanks (ground and elevated).
Projects Planned for 2008
The projects planned for 2008 basically target the reduction of NRW and the installation
of a transmission line to interlink Amelia’s Ward and McKenzie Water Treatment Plants.
The reduction of NRW is hoped to be achieved through the upgrading of distribution
networks which includes replacing of old cast iron networks with new PVC, the
upgrading of service connections and metering. The interlinking of the treatment plants
will provided the infrastructural support for the decommissioning of McKenzie and LPC
Water Treatment Plants.
The projects planned for 2008 are represented in the table below:
82
PROJECT FOR 2008
COST
$GM)
BRIEF DESCRIPTION
Expansion of Distribution Network
Installation of distribution
Installation of 1,300m of 100mm PVC distribution lines and 100 service
Lines, South Amelia’s Ward connections complete with water meters and meter boxes
Distribution Network Upgrade
Replacement of old cast iron network with new PVC. The project entails
Upgrading of North
the installation of 3,000m 100mm PVC pipe lines 200 service connections
Amelia’s Ward Distribution
complete with water meters and water meter boxes and the construction
Network
of 1 Public Stand Pipe Unit .
Upgrading of Silvertown
Distribution Network
Replacement of old cast iron network with new PVC. The project entails
the installation of 3,000m 100mm & 180m 150mm PVC pipelines and 250
service connections complete with water meters
Upgrading of Kara Kara
Distribution Network
Replacement of old cast iron network with new PVC. The project entails
the installation of 2,900m 100mm & 600m 150m pipelines and 200 service
connections complete with water meters and meter boxes
Leak Repairs and service
connection Upgrade,
Retrieve, Linden
Effect repairs to the water supply network (transmission and distribution
lines) in the project area and the installation /upgrading of 500 service
connections complete with water meters and meter boxes
Repair of leaks to North
Amelia’s Ward Water
Supply Network.
Upgrading of approximately six hundred (600) service connections
complete with the installation of water meters and meter boxes
Transmission Line Installation/Upgrade
Transmission Line Interlink
(Amelia’s Ward/ McKenzie)
Installation of 4km of 200mm Transmission Line (PVC and Ductile Iron)
Transmission Line Upgrade
( McKenzie/Richmond Hill)
Installation of 3km of 200mm Transmission Line (PVC and Ductile Iron)
10
13.7
23
16.4
12
12
36.5
25
IMPACT
BENEFIC
ARIES
Expansion of our revenue
collection base
500
persons
Improve Levels of service.
Expansion of our revenue
collection base. Reduction of
NRW
Improve Levels of service.
Expansion of our revenue
collection base. Reduction of
NRW
Improve Levels of service.
Expansion of our revenue
collection base. Reduction of
NRW
Improve Levels of service.
Expansion of our revenue
collection base. Reduction of
NRW
1,000
persons
1,200
persons
1,000
persons
2,500
persons
Improve Levels of service.
Expansion of revenue collection
base. Reduction of NRW
3,000
persons
Improve operational efficiency.
5,000
persons
Improve operational efficiency.
2,000
persons
Improve operational efficiency
4,000
persons
Procurement of Pump
Procurement of pumps
4
Procurement of 2 submersible pumps
152.6
TOTAL
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Projects Planned for 2009
The projects planned for 2009 are basically an extension of those from 2008 with the
aim of reducing NRW and improving overall operational efficiency. Additionally,
interventions will be made towards improving existing networks transmission capacity in
networks that are deficient in this regard. The reduction of NRW is hoped to be achieved
through leak repairs, servicing connections upgrade and metering projects. Improving of
transmission capacity will be realized through the installation of secondary transmission
lines (rings) in areas where it has been established that poor levels of services are as
result of poor network designs.
These interventions for 2009 comprise of the following:
9 Construction of six ground storage tanks each with a capacity of 2000m3. One
tank at each treatment plant, one at the booster station and another two within
the distribution network.
9 Rehabilitation of two elevated storage tanks, each with a capacity of 300m3.
9 Construction of two elevated storage tanks with a capacity of 300m3.
9 20km of transmission mains and 40km of distribution mains
9 15 district metered areas
9 Development of a new raw water source
9 Rehabilitation of three treatment plants
9 Raw water pump array
9 Cascade aerators
9 Rapid sand filters
9 Sedimentation tanks
9 Chlorinators
9 Booster pumps
9 Development of a booster pumping station.
9 The above physical outputs from the action are intended to provide synergy in the
sustainable delivery of potable water to the residents. Actual deliverables are the
licence targets of GWI relevant to service levels and quality of supply. The net
effect would be the overall reduction in operational costs while increasing levels
of service and revenue generation. The specific targets are as follows:
9 Minimum service pressure of 5m while delivering adequate flows
9 24 hour supply
9 Water quality in conformity to the WHO guidelines
9 Non-revenue water of 25%
84
APPENDIX III: HOUSEHOLD WATER USE AND HEALTH
SURVEY REPORT
HOUSEHOLD WATER USE AND HEALTH SURVEY FOR THE WATER SAFETY PLAN
LINDEN, GUYANA
DECEMBER 2007
BACKGROUND
The Water Safety Plan (WSP) aims to identify hazards to drinking water quality that can be
introduced at multiple points from “catchment to consumer.” It does not, however, traditionally
provide for identifying hazards that could compromise drinking water quality after it reaches the
household, such as contamination associated with water collection, storage and treatment
practices within the home. This Household Water Use and Health Survey was therefore
conducted as part of the Water Safety Plan for Linden, Guyana in order to understand the fate of
water from the time it reaches the home to the point of consumption.
The survey, consisting of a household questionnaire and testing of household water samples,
looked at issues such as consistency of water delivery, quality of delivered and stored water,
community perceptions, and consumer practices concerning water use that impact customer
satisfaction and the safety of drinking water within the home. This survey is intended to provide
information about customer experience and concerns for the WSP team to consider as they go
through the process of system and management evaluation and implementation of changes
resulting from the Water Safety Plan.
Five water treatment plants serve the residents of Linden, and each treatment plant serves its
own distribution area. Despite some connections between distribution areas, the system is
operated (through valve adjustments) such that each area is effectively an independent
distribution system. This survey, therefore, is an evaluation of five separate water treatment
plant service areas, under the management of Guyana Water Incorporated (GWI), the national
water utility of Guyana.
CDC provided technical assistance for survey planning and implementation in collaboration with
Guyana Water Incorporated and the Linden Health Department.
OBJECTIVES
Specific aims of the household survey were:
5. to determine the quality of household water at the point of collection and at the point of
consumption to determine the quality of water reaching consumers and if deterioration of
water quality occurs due to storage and handling practices;
6. to describe water use and treatment practices at the household level, user satisfaction,
and perceptions of water quality by consumers;
7. to estimate the prevalence of diarrheal illness in the population, evaluate its possible
association with water-related variables, and describe health-seeking behaviors;
85
8. to determine the quality and consistency of water service provision, identify issues of
special concern, and evaluate the impact that interruptions in service or pressure or other
service-related issues may have on the safety of water consumed.
METHODS
Sample selection
The survey was conducted in communities served by the five water treatment facilities operated
by Guyana Water Incorporated (GWI) in Linden, Guyana: Amelia’s Ward, Linden Power
Company (LPC), McKenzie, West Watooka, and Wisroc. Additional households from newly
developed areas and informal (squatter) settlements that were not connected to GWI’s
distribution network were also sought for inclusion to allow for comparisons between households
on and off of the piped water delivery system. (Table 1, Figure 1)
Because the survey was descriptive and not based on a single outcome variable, the total
sample size was determined based upon achieving a 95% confidence interval, ± 5% around the
most conservative estimate of several outcome measures of potential interest, including selfreported two-week diarrhea recall, the presence of residual free chlorine in tap water, and
household treatment of water. It was determined that a sample size of approximately 500 would
provide the desired level of confidence. The sample size of households not connected to the
GWI piped water system was not large enough to permit statistical analysis with households on
the distribution network; such comparisons are only to identify potential trends between these
different areas.
Maps indicating the service areas for each community were provided by GWI and the Guyana
Bureau of Statistics. Population estimates were based on the 2001 census, current GWI service
connection records, and estimates of community informants in newer settlements or where there
was no GWI service.
Selection of houses within the community was based on stratified systematic sampling. The
number of households visited in each community was allocated proportional to the size of the
community. The total number of households was divided by the sample size to produce a
sampling interval. The surveyors were assigned a random number between one and the
sampling interval and counted off this number from one corner of the community to determine
the house for the first interview. The surveyor then systematically walked through the community
selecting every nth household for inclusion in the survey. If no adult was home at a selected
household, the surveyor would return later that same day. If no adult was available upon return,
or if the house was abandoned or unoccupied, the next closest house was selected.
Ten local interviewers were employed to conduct the survey. A three-day training was provided
to review the questionnaire, household selection, interview techniques and water sample
collection and testing. The questionnaire and survey methods were pilot tested in the field. A
designated field coordinator managed the daily activities of field personnel. Community
sensitization, using local television announcements to inform people of the survey, was done in
order to increase participation and for the sake of interviewer safety.
Household Visits
At each selected household, a questionnaire was administered and water samples were tested
for free chlorine. For a subset of the selected households, water samples were also collected for
microbiological testing.
86
The household questionnaire aimed to gather information about demographics, sources of
water, consistency of service throughout the day and year, possession of a household storage
tank, storage and treatment practices within the home, handwashing practices, sanitation,
incidence of diarrhea and other illnesses, and health-seeking behaviors. Several questions were
aimed toward understanding perceptions of community members concerning water quality and
safety and other community and health concerns.
Water Testing
Water samples from each household were tested on site for free residual chlorine using the DPD
method and portable colorimeters (© 1996, Hach Company, Ames, Iowa, model CN-66).
Samples were collected from each household water source present or available at the time of
the survey, including household, yard or shared taps, storage tanks, and drinking water storage
containers.
Additional samples were collected from a randomly selected subset of households for
microbiological analysis. Surveyors were instructed to collect water samples from a random
numbered house directly from the household tap, from the household storage tank, and from the
household drinking water container, depending upon which sources were available at the time of
the survey. Samples were collected in sterile 100-ml plastic bottles and were transported in cool
boxes to a central location and processed within 6-8 hours of collection using the Del Agua
Portable Water Testing Kit (Oxfam-Del Agua, 2004). This is a field test kit that tests for total
coliforms and E. coli using the membrane filtration method, where membranes are incubated on
selective media and colonies are counted after 24 hours. Bottled water controls (blanks) were
also run each day to test the efficacy of the sterilization technique between groups of samples.
On each day of the survey, water treatment plant operators at each of the five plants were asked
to report the free residual chlorine, pH, and turbidity values of water leaving the plant.
Data Management
Questionnaires were reviewed and checked for clarity and cultural appropriateness through
question-by-question review with interviewers before and after pilot testing. Completed
questionnaires were reviewed with interviewers on a daily basis for accuracy and completeness.
All questionnaire and water sampling data were entered into an Epi InfoTM database (CDC,
version 3.3.2) and spot-checked for errors. Data were cleaned and analyzed using SAS (©
2002, SAS Institute, Cary NC, version 9.1).
RESULTS
Characteristics of households related to water, sanitation and health are found in Table 2.
Demographics
A total of 535 households from Linden were included in the survey. In most cases, the
respondents were women (80%), unless only the male head of household was available at the
time of interview. All respondents were at least 18 years of age, and 80% were over 30 years of
age.
The average family size was 4.4 persons (range: 1, 18), and the total number of children under
age five was 249, or 11% of the sample population. Seventy-three percent of homes were
owned, 15% were rented, and 16% were occupied rent-free (either squatters or care-takers).
The informal and unincorporated settlements included the Amelia’s Ward new housing scheme,
the Blueberry Hill squatter area, Watooka Hill, Siberian and Old England.
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Thirty-nine percent of respondents had completed only a primary school education, and 46%
had completed secondary school. Fifteen percent had completed either vocational/technical
school (9%) or college/university (6%). Post-secondary education was higher for men than
women (25% for males, vs.13% for females).
Water sources and service
Seventy-nine percent of respondents (419) received water from GWI directly to a tap inside their
home, and another 14% (74) used water from a tap in their yard or a shared standpipe as their
primary source. Twenty-three percent (125) of respondents regularly collected water from a
river, creek or spring; 20% (108) regularly purchased bottled water; 13% (70) purchased water
from a refilling station (where tap water is sold by a private company after it is reportedly retreated); and 41% (222) regularly collected rain water in addition to other sources of water.
Residents of the West Watooka and Wisroc water treatment plant (WTP) service areas were
most likely to supplement their tap water with river or spring water (49% and 18%, respectively).
Members of the Linden Power Company (LPC) and McKenzie WTP service areas were most
likely to purchase bottled water (37% and 34%, respectively) or to purchase water from a refilling
station (26% and 38%, respectively). Rain water collection was common in all communities
(Amelia’s Ward: 35%, LPC: 46%, McKenzie: 31%, West Watooka: 40%, and Wisroc: 38%).
Of those households that had a household tap, 86% experienced interruptions in service
resulting in less than 24-hour per day service. Four and a half percent of households reported
that their service was regularly out for two to three days at a time. Fifty-six percent had
experienced periods of several days without water service in the previous year. Most households
(87%) reported that they had problems with low water pressure on most days. The average time
for not having water was eight hours per day (range: 0, 22) (Table 3).
Amelia’s Ward and LPC WTP service areas experienced the greatest interruptions in water
service; 97% and 92% of respondents, respectively, reported daily periods without water.
Respondents from the LPC area also reported the highest incidence of low pressure and times
of the year when there is no service for several days at a time (Table 3).
During interruptions of service or periods of low pressure, people most commonly used water
stored in drums or buckets (40%), river or spring water (37%), rain water (33%), water from their
household storage tank (29%), or purchased bottled water (16%). Others responded that they
got water from a neighbor’s house (8%) or did nothing and waited for water service to return
(5%).
The 51 households that were not connected to the GWI distribution network most often got
water from the river or spring (40%), collected rain water (42%) or used a public standpipe
(14%). Of those households with no GWI connection, 15 (29%) were from Amelia’s Ward (with
13 of those from a new housing scheme that has not yet been incorporated into GWI’s network).
Other squatter or as yet unincorporated areas without water connections were: 3rd Phase/Phase
1B Wismar, the Blueberry Hill squatter area, Old England, and the West Watooka squatter area.
Additional households within GWI’s WTP service areas, but that were not connected to the
distribution network were found in Watooka Hill, Spikeland, Victory Valley, Siberian, Micah
Square, Nottinghamshire and Block 22.
Water storage
One hundred fifty-eight households (30%) had a water storage tank. Most (59%) were groundlevel tanks, and 41% were elevated. Fifty-two percent of the tanks were plumbed such that water
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flowed from the distribution system through the tank to the household tap. Forty-four percent of
the tanks were not connected to the household tap and were either free-standing or connected
to the distribution system only; thus water had a longer storage time. Four percent had a valve
system that allowed water from the distribution system to flow either directly to the tap or through
the tank to the tap.
Seventy-four percent of respondents reported that their tank had been cleaned in the previous
year. Sixteen percent said it had been cleaned one to five years ago and 10% said that their
tank had not been cleaned for at least five years. Thirty-one percent (49) of storage tank owners
reported that they added chlorine to their tank. Only 9% of tank owners had added chlorine in
the previous two weeks.
Ninety-eight percent of households kept drinking water in a container for serving in the home.
Most (79%) used closed containers, such as bottles or covered pitchers, for storing drinking
water, and 43% used open containers (exclusively or in addition to covered containers), such as
uncovered buckets or bowls.
Household water treatment
Eighty-seven percent of households used tap water for drinking; 35% reported drinking it directly
(without treatment) and 52% said they treated it before drinking. Those who treated their
drinking water at home (from tap or other sources) did so by adding chlorine or bleach (70%),
boiling (49%), or using a filter, such as coal, sand or cloth (2%). Twenty-two respondents (8%)
stated that their water was treated by settling, referring to the time the water remained in a tank,
drum, or other container. A free chlorine residual was found in only 18% of drinking water
container samples from households that reported treating their drinking water with bleach.
Water costs
Thirty-eight percent (153) of respondents who received GWI water did not pay for their water
service. The annual cost for residential water service for those who did pay was 8,000 Guyana
dollars (GY $), approximately $43 USD. Twelve percent (47) paid less than GY $7,000 annually,
39% (157) paid GY $7,000 – GY $9,000 (~$38 – $49 USD), and 12% (50) stated that they paid
more than GY $9,000 per year. In most of the latter cases, payments for amounts in arrears from
previous years were included. More than 5% of respondents reported having bills in arrears.
Most respondents (67%) did not pay for additional (non-GWI) water. The mean monthly amount
paid by those who did purchase additional water was GY $2800 (~$15 USD). Nine percent of
GWI customers reported spending more than GY $2,800 per month on bottled water or water
from a refilling station or truck. Money spent by GWI customers on additional water was highest
in the areas served by the McKenzie WTP (28% of residents) and lowest in West Watooka and
Wisroc WTP areas (4% of residents). Twenty-one percent of respondents who were not
connected to GWI’s system spent more than GY $2,800 per month on water from other sources.
Consumer perceptions and satisfaction
Nearly half (43%) of respondents considered water shortages in their community to be a big
problem, while 28% considered them to be somewhat of a problem, and 29% stated that they
were not a problem.
When asked if they believed the water from the tap was safe to drink (without secondary
treatment), 69% of respondents said that it was not; 17% said that it was safe to drink; and 13%
said it was safe to drink it sometimes. When asked why they believed it was not safe, most
people (93%) cited the appearance of the water - that it was dirty, cloudy, had particles in it, or
had a strange color. Other reasons mentioned were that it made them feel ill (6%), contained
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bugs or bacteria (6%), had a bad smell or taste (5%), was contaminated with chemicals or
pesticides (1%), or had too much chlorine (1%).
Sanitation
About 72% of households (384) used a flush toilet that was connected to a septic tank. Twentyeight percent used a pit latrine. The average number of users of the pit latrines was 5 (range: 1,
24). In the Amelia’s Ward, LPC and McKenzie WTP service areas, the proportion of households
with a flush toilet was 92%, 91% and 96%, respectively. In the West Watooka and Wisroc
service areas, 66% and 58% of households had a flush toilet, respectively, and pit latrines were
more concentrated in those areas. Households that were not connected to a GWI water
distribution system had the lowest proportion of flush toilets and most of those (67%) had pit
latrines. There is no sewer system in Linden.
Most households (61%) burned their solid waste. Thirty-four percent had it collected by a private
or public rubbish collection service; 14% buried it; 12% dumped it indiscriminately on the road, a
lot, or in the creek; and 6% carried their rubbish to a dumpsite.
Fifty-six percent of respondents said they used soap always or almost always when they washed
their hands and 43% said they sometimes used soap. There was no correlation in this survey
between reported frequency of handwashing and diarrhea incidence.
Diarrhea and Other Illnesses
Diarrhea was defined as having 3 or more loose or watery stools in a 24-hour period. A total of
87 cases of diarrhea was reported for the two weeks prior to the survey (representing 4% of the
estimated total population, based on an average survey household size of 4.4), including 33
(representing approximately 13%) of children under age five and 54 (representing approximately
3%) of older children and adults.
In most cases (75%), children under age five were taken to a health facility when they had
diarrhea. Five (16%) were given a home remedy, and two (6%) waited for it to go away on its
own without intervention. Older children and adults were less likely to seek medical care for
diarrhea; 20 (37%) went to a health facility, 14 (26%) used a home remedy, 13 (24%) purchased
medicine at a pharmacy without first visiting a health facility, and 6 (11%) waited for it to go away
on its own without intervention.
When analyzed using a logistic regression model, reported diarrhea in the 2 weeks prior to the
survey was not found to have a significant statistical association with any potential risk factors.
The 2-week cumulative incidence of diarrhea among children under 5 appeared to be higher
with increasing household size and among members of households with pit latrines. Incidence
was higher among people with free chlorine residual ≥0.2 mg/L in household drinking water
containers. There were no apparent differences in reported diarrhea incidence among children
based on having a household tank, having a tap (connection to GWI distribution system), or free
chlorine residual levels at the household tap or tank (Table 4).
When asked about other illnesses among children under age five in the previous two weeks, 28
(12%) were reported to have had the flu or common cold, and six (2.5%) had had a skin
infection. The cumulative incidence of other illnesses among older children and adults was low;
the most common illnesses reported included the flu or common cold (26 [1%]), skin infections
(26 [1%]), chronic diseases (9, [0.4%]), and vomiting/stomach ailments (7 [0.3%]).
Community Concerns
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When respondents were asked to rate a range of issues in their community, those most often
identified as being a “big problem” were mosquitoes (80.5%), HIV/AIDS (79%), rubbish (64%)
and water quality (61%). Other problems identified were crime (39.1%), chronic diseases (other
than HIV) (47%), respiratory infections (25%), diarrhea (24%), and skin infections (21%).
Combining responses for “big problem” and “somewhat of a problem,” mosquitoes, HIV/AIDS,
water quality, and rubbish were the most frequently-mentioned concerns (Table 2).
Free chlorine residual testing of tap and stored water
Free chlorine residual from tap water (direct from the distribution system with no storage time in
tank) was tested from 313 households (58%). Two hundred and thirty-six (75%) were negative
for chlorine, and a total of 293 (94%) had a free chlorine residual concentration below 0.2 mg/L.
Nineteen (6%) had a free chlorine residual concentration between 0.2 and 0.5 mg/L, and one
(0.3%) had a free chlorine residual concentration greater than 0.5 mg/L (max = 0.7 mg/L). The
mean concentration of free chlorine residual-positive tap water samples was 0.29 mg/L (Table
5).
The greatest percentage of tap samples with free chlorine residual levels above 0.2 mg/L was
found in Amelia’s Ward (14%) and the lowest percentage of free chlorine residual-compliant
samples was found in West Watooka (1%). The mean concentration of free chlorine residual
positive samples (≥0.2 and ≤3.5) was highest in LPC (0.4 mg/L) and lowest in West Watooka
(0.2 mg/L). Table 5 shows the results of onsite free residual chlorine testing from tap, tank and
drinking water container samples.
Water from drinking water containers such as pitchers, bottles, or jugs was sampled from 386
households. Three hundred and five (79%) were negative for chlorine, and a total of 355 (92%)
had free chlorine residual levels below 0.2 mg/L. Thirty-six (9%) had free chlorine residual levels
greater than 1.0 mg/L, including six that surpassed the upper limit of the test method (>3.5
mg/L). The mean concentration of free chlorine residual-positive drinking water container
samples (≥0.2 and <3.5) was 1.1 mg/L.
According to respondents, 175 drinking water container samples were untreated tap water. Of
these, 145 (83%) had a free chlorine residual level of zero (96% <0.2 mg/L). Of drinking water
container samples that had been boiled, 43 (91%) had no free chlorine residual (98% <0.2
mg/L), and 37 (50%) of samples reportedly treated with chlorine or bleach were free chlorine
residual-negative (66% <0.2 mg/L).
Water from a storage tank was tested from 135 households. One hundred (74%) were negative
for chlorine, and a total of 124 (92%) had a free chlorine residual concentration below 0.2 mg/L.
Eight (6%) had a free chlorine residual concentration between 0.2 and 0.5 mg/L. Only three
samples (2%) had free chlorine residual concentrations greater than 1.0, and two of those
surpassed the upper limit of the test method used (>3.5 mg/L). The mean concentration of free
chlorine residual-positive tank samples (≥0.2 and <3.5) was 0.43 mg/L.
When comparing residual free chlorine levels from 43 tap and tank sample pairs available from
the same household, five (12%) showed chlorine in the tap sample but not in the tank sample.
Seven (16%) chlorine-positive samples showed no difference between tap and tank, and four
(9%) had higher chlorine levels in the tank samples than the tap, with three of those from
households that reported adding bleach to their tank.
When residual free chlorine levels were compared from 129 tap and drinking water container
sample pairs from the same households, where the drinking water was untreated tap water,
eight pairs (6.2%) showed lower free chlorine residual in drinking water containers versus tap
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samples. In 23 free chlorine residual-positive pairs, there was no difference between drinking
water container and tap samples, and in 2 cases (1.6%) there was more free chlorine residual in
the drinking water container than the tap sample.
Residual free chlorine levels, pH and turbidity of water leaving the treatment plants were
provided by the plant operators on each of the seven survey days. The mean of reported
residual free chlorine levels of water leaving the Amelia’s Ward treatment plant was 0.6 mg/L
(range: 0.5-0.7, target: 0.5), the mean pH was 6.3, and turbidity was not taken (this is a ground
water source). The mean residual free chlorine from LPC was 0.8 mg/L (range 0.5-1.0, target:
1.0), mean pH was 5.4 and mean turbidity was 3.7 NTU. The mean residual free chlorine from
McKenzie was 1.2 mg/L (range: 0.4-2.0, target: 1.0), mean pH was 4.9, and mean turbidity was
8.3 NTU. The mean residual free chlorine from West Watooka was 1.2 mg/L (range: 0.8-1.7,
target: 1.5), mean pH was 5.0 and mean turbidity was 9.4 NTU. The mean residual free chlorine
from Wisroc was 0.5 mg/L (range: 0.5-0.6, target: 0.5), mean pH was 6.4 and turbidity was 3.1
NTU (Table 5).
Microbiological testing of tap and stored water
One hundred and forty-seven water samples were collected for microbiological testing. Fortyseven were taken directly from household taps. Of those tap samples, 30 (64%) were positive
for total coliforms and 11 (23%) were also positive for E. coli. Table 6 shows the results of
testing for total coliforms and E. coli from taps, tanks, and drinking water container samples.
Twenty-two samples were taken from household storage tanks. Nineteen of the tank samples
(86%) were positive for total coliforms and eight samples (36%) were also positive for E. coli.
Seventy-three samples were taken from household drinking water containers (pitchers, jugs etc.
stored in the refrigerator or counter). Of those samples, 66 (90%) were positive for total coliforms
and 31 (42%) were also positive for E. coli.
When 17 paired samples from taps and drinking water containers of the same households were
compared, where drinking water samples were untreated tap water, E. coli was found in 10
(59%) of drinking water container samples where the tap sample was E. coli-negative. There
were insufficient paired samples to compare tank and tap water results.
Of eight drinking water samples that contained water drawn from community springs, all were
positive for total coliforms and six (75%) were positive for E. coli. Two samples were taken
directly from community springs and both were positive for total coliforms (too numerous to
count). One of these samples taken directly from springs (One Mile/Wismar) was also positive
for E. coli, and the other (Old England) was not.
One sample was taken from each of the following sources: water obtained from a refilling
station, from a nearby dairy farm, from a bucket of water originally taken from a neighbor’s tap,
from a creek, and purchased bottled water. All of these samples were positive for total coliforms
and the last three were also positive for E. coli, including the bottled water sample.
DISCUSSION
The water delivery service provided by GWI to the town of Linden consists of five water
treatment plants and three water sources. The West Watooka, McKenzie, and Linden Power
Company (LPC) water treatment plants draw water from the Demerara River. The Wisroc
treatment plant draws from Dakoura Creek, and the Amelia’s Ward treatment plant draws from
two wells. In most cases, the distribution service areas for each treatment plant are independent,
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such that there is a single source of water for each household. The exception is in some areas
of Wisroc and West Watooka, where shortages in one system can be supplemented by the
other, such that some households may receive water from either source depending upon each
plant’s capacity to deliver sufficient quantity (depending on demand and source water
availability) and quality (depending on turbidity). Thus, the Linden GWI water delivery service
can be viewed as five distinct systems. People living in areas not served by GWI generally use
water drawn directly from the Demerara River or its tributaries.
Water quality
Most water delivered to the taps of people connected to the Linden GWI distribution system
contained no residual free chlorine. The target residual free chlorine levels for water leaving the
treatment plants set at each of the treatment plants is quite low. The target of 0.5 mg/L for water
leaving the Amelia’s Ward and Wisroc plants was determined based on the idea that water from
those sources is the cleanest, and therefore would consume the least amount of chlorine in the
distribution system. The operators aim for a minimal effective level (to achieve a free chlorine
residual of 0.2 mg/L at the most distal point of the distribution system) and to avoid the water
having a taste of chlorine, which is considered undesirable by consumers. This minimum level,
however, is not being achieved, as evidenced by the lack of free chlorine residual found in tap
samples.
Other water quality data reported by plant operators on survey days indicate that there are
additional parameters of concern. According to the WHO Guidelines for Drinking Water Quality,
median turbidity should be below 0.1 NTU in order to ensure effective disinfection, and that
turbidity of 5 NTU has an acceptable appearance to consumers. Turbidity levels above 0.3 NTU
are often associated with higher levels of disease-causing microorganisms such as viruses,
parasites and some bacteria (USEPA Primary Drinking Water Standards). Turbidity values in
finished water measured on survey days were as high as 15 NTU (see Table 5).
In addition, pH values measured on survey days from waters leaving the three treatment plants
sourced by the Demerara River were as low as 4.8 (see Table 5). This may be attributable to
naturally occurring bauxite and mining activity. Low pH can cause corrosion of distribution pipes,
adversely affecting the taste and appearance of water and can reduce the effectiveness of
coagulants used for flocculation.
Total coliforms and E. coli were measured from multiple sources (taps, household tanks and
household drinking water containers) from a random sub-sample of households. The presence
of total coliforms indicates inadequate disinfection and/or the presence of biofilms or leaks in the
distribution system. E. coli is evidence of recent fecal contamination. The proportion of total
coliform-positive and E. coli-positive samples found from water taken directly from taps in all five
WTP service areas was high (71% and 27%, respectively), indicating that inadequate primary
disinfection at the treatment plant and/or breaches in the integrity of the distribution system
combined with insufficient free chlorine residual contribute to reducing water quality. Results
from GWI’s 2007 routine monitoring show that the finished water from all five WTPs was
frequently positive for total and/or fecal coliforms, further indicating inadequate disinfection at the
treatment plant (see Linden Water Quality Data Analysis Report in WSP).
Inconsistent service also leads to greater reliance on alternate water sources that are generally
unsafe for drinking. While nearly all respondents had access to an in-house, yard or shared tap,
most stated that they used alternative water sources, such as the river, spring, rainwater
catchment, refilling station or bottled water to supplement their tap water supply, indicating that
the tap service alone was not considered a reliable source. The results of the small number of
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samples from alternative water sources that were tested suggest that further testing is needed to
evaluate the safety of these sources, including bottled water.
Water treatment
More than half of respondents reported that they treated their water in the home before drinking
it. In most cases where the household reported treating their drinking water, however, the water
sampled from the drinking water container did not contain any free chlorine residual, possibly
reflecting a discrepancy between reporting and practice, inconsistency in treatment practices, or
a lack of understanding of what constitutes treatment. In six of the samples of water that had
been treated with bleach, residual free chlorine levels surpassed the upper limit of the test
method, indicating a lack of knowledge about appropriate home chlorination or possible
accidental introduction of bleach into drinking water containers. No households that reported
using a filter had filtered water available for testing at the time of the survey.
The proportion of E. coli-positive samples was lower in samples that had been reportedly boiled
than in untreated samples (27% vs. 62%). While boiling is generally not recommended in a
chlorinated system due to its removal of chlorine, in this case where most tap water samples did
not have measureable free chlorine residual, boiling appeared to be an effective method for
reducing contamination.
Other than boiling and adding bleach, many respondents stated that they treated their drinking
water by allowing it to settle in a container, believing that settling constituted treatment for more
than just aesthetic concerns. This reflects a lack of knowledge about effective home treatment
methods and a need for community education as long as home treatment will continue to be
necessary.
Water storage
Most GWI customers experienced periods of interrupted service and low pressure on most days.
Inconsistent service often necessitates secondary storage of water in the household, either in
tanks and large drums and/or in smaller drinking water containers. Secondary storage increases
the opportunity for the introduction of contaminants and increases hydraulic residence time (and
hence chlorine dissipation) prior to consumption.
The proportion of residual free chlorine-compliant samples was lower in stored versus tap
samples. Both total coliform and E. coli counts were higher in samples taken from tanks and
drinking water containers than from those taken directly from the tap, likely reflecting
contamination through increased handling or from storage in unclean vessels, combined with the
loss of chlorine through dissipation. While numbers were insufficient for statistical significance,
there was a trend towards decreasing free chlorine residual and increasing microbiological
contamination from taps to tanks to drinking water containers. The paired samples from taps and
tanks of the same households showed lower residual free chlorine levels in tanks than taps
unless bleach was added to the tank. Paired tap and drinking water container samples also
showed a loss of free chlorine residual in drinking water containers as compared to tap samples.
Our previous studies have shown a similar trend of decreasing chlorination and increasing
contamination with increased storage time, from tap to tank to drinking water container.
Water costs
GWI water service is not metered in Linden; rather there is a standard annual residential rate of
GY $8,000 (~USD $40) per year, with higher rates for businesses and subsidies for pensioners.
With a national average annual per capita income of ~USD $1,130 (World Bank, 2006), this can
represent a substantial economic burden for some residents. Customers are sent bills annually
and are expected to pay them at the Linden GWI office, but GWI reports problems with non-
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payment. About half of households surveyed with GWI connections did not pay for their water
service or paid less than the annual cost, though they continued receiving water service. This
represents economic loss for GWI and a problem with GWI collections. About five percent of
households owed large bills from unpaid bills in previous years which they were unable to pay.
Some residents stated that they were resentful about over-paying for water when their service
was inconsistent, and many spent additional money to purchase bottled or refilling station water
for drinking.
Perceptions of water quality
In some cases, the use of alternative sources may not be due solely to a lack of tap service, but
rather reflects a preference for other sources. There is a perception among the general
population that the water source for the Wisroc water treatment plant, Dakoura Creek, contains
high quality water. This perception probably comes from the visual clarity of the water and its low
turbidity. The high number of users of river/creek/spring water observed among residents of the
Wisroc and West Watooka service areas (which have some overlap in water distribution) likely
reflects this perception.
This perception is shared by the water utility (GWI) plant operators. The target residual free
chlorine leaving the Wisroc treatment plant is set at 0.5 mg/L. The reasoning for this is that
because the source waters have low turbidity, it is considered clean; chlorine is therefore kept to
a minimum so that the water will not taste of chlorine.
The results of the microbiological testing, however, do not support this perception. The
proportion of total coliform positive tap samples from Wisroc (64%) was greater than from both
West Watooka (54%) and LPC (55%). Similarly, the proportion of E. coli positive tap samples
from Wisroc (27%) was greater than from West Watooka (8%), LPC (18%) and Amelia’s Ward
(0). Furthermore, the household survey results do not reflect the perceived concern over
excessive chlorination, as only 6 (1%) respondents reported that they believed the water was
unsafe due to too much chlorine.
Additional water quality data records from GWI’s 2007 biweekly WTP and distribution system
water testing (see Linden Water Quality Data Analysis Report in WSP) found that the presence
of total coliforms and fecal coliforms in water leaving the Wisroc plant was greater than in
samples taken from the distribution system, demonstrating that contamination is present in the
finished water at the treatment plant and cannot be attributed solely to the distribution system.
Further, the 2007 biweekly sampling results indicate that the percentage of total coliform
detections in the finished water at Wisroc WTP equaled that at McKenzie WTP and exceeded
those at West Watooka and LPC WTPs. Similarly, the percentage of fecal coliform detections in
the finished water at Wisroc WTP exceeded those at all 4 of the other WTPs. These findings
bring into question the perception that Wisroc water quality is superior to the other surface-water
treatment plants.
Water collected directly from springs is also widely believed to be safe and was reported as a
preferred drinking water source by some residents. While the number of samples tested was
small, total coliforms and E. coli were found in samples collected directly from springs and from
spring water stored in drinking water containers.
Diarrhea and other illnesses
While no significant statistical associations were found for childhood diarrhea, some trends did
appear. The higher incidence of diarrheal illness with increasing household size and among
people with pit latrines is consistent with known trends for these risk factors, as both large
household size and pit latrines provide increased opportunities for transmission of fecal-oral
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pathogens. The prevalence of pit latrines was highest among households that were not
connected to the GWI water distribution network (newly developed areas or squatter areas), so
pit latrine users were more likely to access water directly from the river or creek, increasing the
risk of infection through consumption of contaminated water. The West Watooka and Wisroc
WTP service areas had a higher number of pit latrine users than other WTP service areas and
the highest reported incidences of diarrhea; West Watooka also had the highest number of
households obtaining drinking water from a creek or spring. Additionally, it is possible that these
same source waters could be contaminated through leeching from nearby pit latrines, and that
handwashing practices were poor due to the lack of piped water, potentially further contributing
to the higher incidence of diarrhea observed among residents of those areas.
Unexpectedly, we found that diarrhea incidence was higher among people from households
where drinking water container samples contained residual free chlorine levels greater than 0.2
mg/L. Two of those five cases, however, came from households where the chlorine level in the
drinking water container was greater than 3.5 mg/L. Because of the very small number of cases,
it is possible that the results are skewed by illnesses from causes unrelated to water
consumption.
While respiratory illnesses and skin infections were mentioned as concerns by 65% and 59% of
respondents, respectively, reported incidence of these illnesses was low (0 and 4%,
respectively). Concern over these illnesses arises from dust, emissions and waste produced by
bauxite mining, which is the economic base of Linden. Exposure, either through water or air, to
dust and smoke caused by bauxite mining was frequently mentioned by respondents as an
additional concern.
Other community concerns
When asked about their biggest community concerns, the most common responses were:
mosquitoes, HIV/AIDS, water quality, and rubbish. The first two probably reflect extensive media
campaigns and public service announcements in response to the increasing rates of malaria and
HIV in Guyana – amongst the highest in the Americas.
Solid waste disposal is an obvious problem in Linden. With no officially designated site for
rubbish disposal, informal dumping sites can be found along the streets, in and near the river,
around the market area, and in the woods and undeveloped areas around Linden. This poses a
health risk in terms of vector control and injury, and threatens water quality. The frequent
burning of rubbish produces an additional risk factor for respiratory illness. Gutters blocked by
rubbish can create breeding grounds for malarial mosquitoes, which are a growing problem in
Guyana.
LIMITATIONS
This assessment faced several limitations. The sample size was calculated based on the ability
to evaluate certain variables, such as diarrheal illness for the entire population size of Linden. It
was not sufficiently large to make such associations for each of the water treatment plant service
areas independently. This limited our ability to describe associations between diarrheal illness
and potential risk factors given the different conditions of each water system.
The number of samples that could be tested for total coliforms and E. coli was limited by the
capacity of the available testing equipment. The number of microbial testing results, therefore, is
small and does not allow for statistical analysis of association with potential risk factors. Only
trends could be reported. In addition, this assessment did not include laboratory analysis for
chemical contaminants that may be present in the water supply.
96
Information on illness for all household members was requested from a single respondent, likely
contributing to under-reporting of illness incidence. Using two-week recall for diarrhea and other
illnesses is also subject to under-reporting due to recall bias. Incidence rates for diarrheal illness
in Linden could not be ascertained from health department and clinic data, so comparisons with
the results of this household survey could not be made.
Considerable variations in water quality can occur due to seasonal climatic changes that affect
the quality of source waters. Operational variations at the treatment plants can also affect water
quality. For example, the Amelia’s Ward treatment plant was not functioning for several days of
the survey due to a damaged well pump. On those days, households collected untreated well
water provided by the treatment plant, or used other alternative sources This survey was
conducted on seven consecutive days in December, and therefore may not accurately reflect
typical year-round water quality, water home storage and treatment practices, or the overall
health situation of respondents.
CONCLUSIONS AND RECOMMENDATIONS
1. The results of this assessment indicate insufficient chlorination at all GWI water service
areas in Linden. Target residual free chlorine levels leaving the treatment plants should
be increased to ensure a free chlorine residual at the most distal points in the distribution
system of at least 0.2 mg/L. The determination of appropriate target values should be
based upon the results of routine free chlorine residual testing in the distribution system
rather than assumptions about source water purity. A schedule of routine monitoring of
free chlorine residual in the distribution system, as well as evaluation of possible
breaches and/or biofilm contamination, should be established to both determine and
maintain adequate chlorination levels. This may require training of plant operators on
setting appropriate levels for disinfectants and also a system for regular communication
of water quality monitoring results to plant operators.
Other operational considerations beyond just chlorination levels should be included in
this analysis. For example, determination should be made through the WSP of
operational and/or structural improvements needed to achieve turbidity levels that will
allow for maximum effectiveness of disinfection. Adjusting pH and alkalinity of incoming
water may allow for more effective treatment, which would improve finished water quality
and potentially reduce the quantity and cost of chemicals for treatment.
Testing of raw and finished water for other potential contaminants identified in the Water
Safety Plan should be considered, including chemicals and other microbiological
parameters such as Giardia and Cryptosporidium.
2. Education both to the public and to plant operators should be provided about the risks
associated with drinking water directly or untreated from the Dakoura Creek and
community springs. Although these waters may be less turbid and therefore appear
“cleaner” to some residents than water from the Demerara River, the final water should
be treated to the same level of quality as other source waters and should not be
consumed directly.
3. Until adequate and consistent chlorination can be achieved at the treatment plants and
until consistent service precludes the need for household storage, home treatment of
drinking water can be an effective method of improving the safety of drinking water.
However, public education on home treatment methods needs to be disseminated as
97
current knowledge is low. Microbiological testing showed greater contamination in water
from household drinking water containers than from water taken directly from the tap.
Storage of drinking water in secondary containers leads to lower free chlorine residual
levels and creates opportunities for contamination through increased handling. Providing
consistent service of high quality water would eliminate the need for household storage
that creates these additional risks. Health education about proper use and storage of
water within the household could also help to reduce risks from these practices.
Messages should emphasize:
• appropriate dosing with bleach to ensure effective, but not excessive dosage;
• boiling, accompanied by careful handling and storage techniques to reduce the
reintroduction of pathogens after boiling;
• settling alone does not constitute an effective treatment method, thus another
method should also be used.
4. Water quality is considered a large problem by Linden residents, so improvements in
water quality and delivery would likely be met with positive public response. As GWI
progresses with the Water Safety Plan, informing the community of improvements to their
water service and educating the public about safe handling, storage and treatment within
the home could help improve public relations. Local cable television is a widely used
medium for delivering public service announcements in Linden and could be used to
inform people about actual or anticipated changes to water quality, or interim measures
that should be taken such as household water treatment.
5. Diarrhea incidence was most strongly associated with pit latrine use (although still not
statistically significant). Improved sanitation would both help to decrease potential
contamination of source waters and isolate pathogens from consumers. Therefore,
sanitation should be considered an important component of the Water Safety Plan.
6. Improved payment collection and customer satisfaction will need to be addressed if GWI
is to recover costs from consumers, as the current payment system is not effectively
recovering funds owed. GWI has a plan to install household water meters starting in
2008. Installing a metered system should improve their ability to track payment for water
use and increase satisfaction among paying customers since people will be billed only for
the water they use. GWI will need to continue to provide special payment provisions for
those customers who cannot pay due to poverty.
98
Table 1: Communities surveyed and estimated population size
Communities
GWI WTP service
area
Amelia’s Ward
Amelia's Ward Central, Amelia's Ward
South,
Brazina
Housing
Scheme,
Cinderella City, Self Help Area
Linden
Power Kara Kara Scheme, Old Kara Kara,
Company (LPC)
Rainbow
City,
Redwood
Crescent,
Retrieve, Spikeland
McKenzie
Constabulary Compound, Docama Circle,
Fair's Rust, Industrial Area, North
McKenzie, Noitgedacht, Nottinghamshire,
Richmond Hill
Surapana, Watooka
West Watooka
1st, 2nd, 3rd Alleys (Wismar Nuclear), Buck
Hill, most of Canvas City, Christianburg
(sections B and C), Half Mile, Silver City,
Silver Town, Watooka Hill, West Watooka,
Wismar Housing Scheme, parts of One
Mile and Victory Valley
Wisroc
Block 22, Blueberry Hill, D'Anjou Park, Ho
a Shoo, Micah Square, Wisroc, some of
Canvas City, part of Victory Valley, most of
One Mile/Extension
None
3rd Phase/ Phase 1B, Amelia’s Ward New
Housing Scheme, Blueberry Hill squatter
area, Old England, West Watooka squatter
area, Siberian
Linden Total
Estimated
# of HHs
population of surveyed
survey area
4,250
74
4,235
79
4,320
77
8,400
142
8,175
138
135
25
29,515
535
99
Table 2: survey population characteristics by water treatment plant service area
# of HHs Have an in- Have a water Have a flush Believe their
surveyed house
tap storage tank toilet
tap water is
and
GWI
safe to drink
connection
WTP service area
# of children
<5
w/
diarrhea in
previous 2
weeks
Paid
≥GY$2800/
yr on nonGWI water
71
66 (93.0%)
38 (55.1%)
65 (91.6%)
26 (36.6%)
0
7 (9.9%)*
Linden
Power
78
Company (LPC)
67 (85.9%)
24 (31.6%)
71 (91.0%)
6 (7.8%)
2 (7.4%)
8 (10.3%)*
McKenzie
71
61 (85.9%)
19 (27.1%)
68 (95.8%)
5 (7.0%)
0
20 (28.2%)*
West Watooka
134
120 (89.6%)
24 (18.1%)
88 (65.7%)
17 (12.7%)
14 (24.6%)
5 (3.7%)*
Wisroc
130
105 (80.8%)
34 (26.2%)
76 (58.5%)
31 (23.9%)
12 (16.4%)
5 (3.9%)*
No
water
treatment
plant 51
connection
na
19 (38.0%)
16 (32.0%)
na
4 (10.3%)
11 (21.6%)†
Linden Total
419 (78.6%)
158 (30%)
384 (71.8%)
86 (17.4%)
32 (12.9%)
56 (10.5%)
Amelia’s Ward
535
*
includes people with GWI connection only
includes
entire
†
survey
Three
highest
community
concerns
Mosquitoes
HIV/AIDS
Water
quality
HIV/AIDS
Mosquitoes
Water
quality
Mosquitoes
Water
quality
Rubbish
Mosquitoes
HIV/AIDS
Rubbish
Mosquitoes
HIV/AIDS
Rubbish
Mosquitoes
HIV/AIDS
Water
quality
Mosquitoe
s
HIV/AIDS
Water
quality
population
100
Table 3: Consistency of water service by water treatment plant service area
Have
24- Average # Experience
Experience
Consider
hr/day water of hours/ periods
of several
water
service
day
low pressure days/yr
shortages a
without
without
big problem
WTP
service
area
service
service
Amelia’s Ward
2 (2.8%)
13.5
62 (87.3%)
40 (58.8%)
40 (57.1%)
Linden
Power
6 (7.7%)
Company (LPC)
8.0
62 (95.4%)
42 (66.7%)
41 (53.3%)
McKenzie
13 (18.3%)
7.3
63 (90.0%)
26 (37.7%)
26 (36.6%)
West Watooka
21 (15.9%)
5.8
103 (78.6%)
66 (50.4%)
43 (32.8%)
Wisroc
23 (17.8%)
7.3
115 (89.8%)
84 (66.1%)
46 (36.5%)
Linden Total
65 (13.5%)
7.8
405 (87.1%)
258 (56.3%)
223 (42.6%)
101
Table 4: Potential risk factors for diarrhea and diarrhea prevalence in previous 2
weeks among children under five years of age
Variable
Frequency
with Odds
Confidence Limit
diarrhea (%)
Ratio*
(p-value)*
Hrs/day without water
(range 0-22)
1.01
0.93-1.09 (0.87)
# in HH
≥7 persons
17 (20.2)
3.09
1.02-9.35 (0.06)
5-6 persons
9 (11.0)
1.50
0.43-5.30 (0.77)
1-4 persons
6 (7.6)
ref
Have tank
No
27 (14.5)
1.80
0.45-10.21 (0.40)
Yes
5(8.6)
ref
Tap service
0.35-5.13 (0.66)
Yes
28 (13.3)
1.35
No
4 (10.3)
ref
Type of toilet:
Pit latrine
17 (18.3)
2.41
0.90-6.44 (0.08)
Flush (septic tank)
13 (8.5)
ref
Handwashing with soap
(respondent)
17 (13.1)
Always/almost always
†
†
15(13.0)
Sometimes
0
Never/almost never
Free Cl2 residual at tap
≥0.2 mg/L
2 (12.5)
1.12
0.12-10.215 (0.92)
<0.2 mg/L
22 (13.8)
ref
Free Cl2 residual in tank
<0.2 mg/L
3 (60.0)
†
†
≥0.2 mg/L
0 (0.0)
Free Cl2 residual in
drinking
0.35
20 (11.8)
water containers
0.09-1.33 (0.12)
5 (27.8)
<0.2 mg/L
ref
≥0.2 mg/L
*Logistic regression model adjusted for effect of clustering by WTP service area and
household
†
Unable to calculate due to zero values
ref = referent group for calculating odds ratio
102
WTP
service
area
Amelia’s
Ward
Linden
Power
Company
(LPC)
McKenzie
West
Watooka
Wisroc
None
Total
Linden
Table 5: Water quality data in different household samples and at treatment plants
Free Cl2 Free Cl2 Mean of Free Cl2 Free Cl2 Mean
Free Cl2 Free Cl2
at
tap at
tap free Cl2- in tank in tanks free Cl2- in DWC in DWC
<0.2
≥0.2
positive <0.2
≥0.2
positive <0.2
≥0.2
mg/L
mg/L
tap
mg/L
mg/L
samples mg/L
mg/L
samples
in tank
(mg/L)§
(mg/L)§
Mean
free Cl2positive
DWC
samples
(mg/L)§
Mean free
Cl2 leaving
plant
on
survey
days†
(mg/L)
Mean pH
leaving
plant on
survey
days†
Mean
turbidity
leaving
plant
on
survey
days† (NTU)
19
(86%)
3
(14%)
0.28
35
(90%)
4
(10%)
0.64
54
(91.5%)
5
(8.5%)
0.69
0.56
6.3
-
55
(93%)
4*
(7%)
0.40§
22
(96%)
1
(4%)
0.30
43
(91.5%)
4*
(8.5%)
1.60§
0.79
5.4
3.7
(range: 0, 7)
47
(92%)
4
(8%)
0.27
17
(94%)
1
(6%)
0.30
55
(98.2%)
1
(1.8%)
0.50
1.21
4.9
8.3
(range: 5, 12)
100
(99%)
1
(1%)
0.20
19
(95%)
1
(5%)
0.30
92
(92.9%)
7**
(7.1%)
1.68§
1.20
5.0
9.4
(range: 5, 15)
72
(90%)
8
(10%)
0.26
29
(94 %)
2*
(6%)
0.30§
87
(83.7%)
17**
(16.3%)
1.01§
0.51
6.4
3.1
(range: 0, 5)
na
na
na
3
(75%)
1
(25%)
0.20
19
(90.5%)
2*
(9.5%)
0.20§
na
na
na
293
(94%)
20
(6%)
0.29
125
(93%)
10
(7%)
0.43
350
(90.7%)
36
(9.3%)
1.27
0.85
5.6
6.1
*includes one sample with >3.5 mg/L free Cl2 residual
** includes two samples with >3.5 mg/L free Cl2 residual
§
Excluding samples that surpassed the upper limit of the test method (>3.5 mg/L)
†Reported daily by plant operators on 7 survey days
103
Table 6: Microbiological test results (total coliforms and E. coli) for direct-from-tap,
and tank samples
HH tank – total HH tank –
Source of water HH tap – total HH tap –
coliforms+
E.
coli+
coliforms+
E. coli +
sample
Amelia’s Ward
2 (67%)
0
3 (75%)
2 (50%)
LPC
McKenzie
West Watooka
Wisroc
None
Total Linden
drinking-water container (DWC)
HH DWC – total HH DWC –
coliforms+
E. coli +
8 (80%)
4 (40%)
6 (55%)
2 (18%)
3 (75%)
1 (25%)
7 (88%)
4 (50%)
8 (89%)
5 (56%)
4 (100%)
2 (50%)
8 (80%)
1 (10%)
7 (54%)
1 (8%)
2 (100%)
2 (100%)
19 (100%)
8 (42%)
7 (64%)
3 (27%)
2 (67%)
0
13 (93%)
10 (71%)
na
na
5 (100%)
1 (20%)
11 (92%)
4 (33%)
30 (64%)
11 (23%)
19 (86%)
8 (36%)
66 (90%))
31 (42%)
104
Figure 1: Linden Household Survey Water Treatment Plant (WTP) Service Area Distribution Map
Linden Power Co.
WTP service area
Blueberry
Hill
One Mile
Extension
Wisroc WTP
service area
Wisroc
Danjo Park
Cinderella
City
Ho a Shoo
Wismar
3rd Phase/Phase 1B
Block 22
WTP
Silver
City
Victory
Valley
One
Mile
WTP
Christanburg
Half
Mile
Silver
Town
Canvas City
Spikeland
Industrial
Constabulary
Area
Compound
Bauxite
Plant
Old England
Dakoura Creek
WTP
West Watooka
WTP service area
Watooka
Hill
Amelia’s Ward
WTP service area
Retrieve
WTP
Rainbow
City
Kara
Kara
Central Amelia’s Ward
New
Housing
Scheme
Brazina
WTP
South Amelia’s Ward
Tailings
pond
N. McKenzie
Richmond Hill
McKenzie WTP
service area
Noitgedacht
Fair’s Rust
Surapana
Demerara River
105
APPENDIX IV: Standard Operating Procedure
Jar Test Procedures
Prior to starting a jar test, a sample of the water to be tested should be analyzed for turbidity,
temperature, pH, alkalinity, hardness, and colour. The results should be recorded on a jar test
results form. The amounts of chemicals to be added to each of the six beakers should be
calculated and prepared for immediate addition to the beakers at the proper time.
9
9
9
9
9
9
9
9
9
9
9
Collect at least a two-gallon (eight litres) sample of water to be tested.
Immediately measure six 1000 ml quantities and place into six 1000 ml beakers.
Place all six beakers on the stirring apparatus.
With a measuring pipette, add increasing dosages of the coagulant solution to the
beakers as rapidly as possible. For example, add enough solution to be equivalent to a
10 mg/L dose in beaker #1 and add enough solution to be equivalent to a 12 mg/L in
beaker #2.
Add uniform amounts of the pH chemical solution to each beaker. These amounts should
be calculated so the finished water is approximately 7.0 to 7.5 pH. On a subsequent jar
test, the feed rates for both the coagulant and pH can be variable to determine the
correct dosage of each.
Add standard solutions and feed rates for any other chemicals normally used. If a
coagulant aid is used, the alum feed rate may be uniform for all six jars and the
coagulant aid could be the variable.
Quickly lower the stirring paddles into the beakers and activate the paddles immediately
for one minute at 80 rpm. The specified rate and time are typical of the action and
detention time found in many treatment plants, but calculations have to be made to meet
actual conditions present in your treatment process.
Reduce the mixer speed to 20 rpm for 20 minutes to simulate the flocculation basin
conditions. Again, time and rate adjustments should be made according to the treatment
plant conditions.
Record the time required for visible floc to form and describe the floc characteristics (pinhead sized floc, flake sized floc) during mixing.
j . Stop the stirrers. Allow the floc to settle for 30 minutes or for a period similar to your
plant conditions. Observe and note how quickly the floc settled, the floc appearance, and
the turbidity of settled water above the floc. You can remove a sample of the clear water
with a pipette for testing.
Using the sample of clear water from each beaker, measure the turbidity, pH, and
alkalinity of the water. Evaluate the results of the jar test. Several factors should be
considered such as rate of floc formation, type of floc particles, clarity of water between
floc particles, size of floc, amount of floc formed, floc settling rate, and clarity of water
above settled floc. The following comments will assist in evaluating the results.
Visible floc formation should begin shortly after the rapid mix portion of the jar test. During the
flocculation mixing, a number of small particles will gradually clump together to form larger
particles. Floc particles which are separate and fairly dense in appearance are usually better
than floc particles that have a light, fluffy appearance. Large floc is impressive but it is neither
necessary nor always desirable. Large, light floc does not settle as well as smaller, denser floc,
and it is more subject to shearing (breaking up).
The water between the floc particles should be clear and not hazy or milky in appearance. The
best chemical dosage is one which produces a finished water that meets the SDWA standards
106
at the lowest cost. The floc should settle quickly after the mixing has stopped. Floc that remains
suspended longer than 15 to 20 minutes would be carried over onto the filter media. The jar
tests can be repeated using other combinations of chemicals to produce the best results for
turbidity, pH, and alkalinity. The pH should preferably be between 7.0 and 7.5 and the alkalinity
should be greater than 40 mg/L and at least half of the coagulant dose rate.
Jar tests are an effective tool for predicting the results of the treatment process and evaluating
various combinations of chemical feed and different chemicals. These test results are used to
adjust or verify the feed rates in your treatment plant.
A jar test should be run at the beginning of each shift and more frequently when the raw water
turbidity is high or changing. There is no substitute for experience in evaluating jar test data.
Frequent tests will provide a basis for comparing results of the quality of finished water under
different conditions and aid in fine tuning of the chemical feed dose rates. Always verify the
effectiveness of a change in treatment based on a jar test result. To verify the jar test results with
treatment plant performance, after the changes have been in effect for sufficient time to show
results at the rapid mix chamber, collect a sample just down stream from the rapid mix chamber.
Mix the sample on the jar test equipment under the same conditions as the original sample (not
including the rapid mix simulation). This sample should show similar results to the original test
sample and a comparison of these results could be the basis for further fine tuning of the
chemical dosage.
107
APPENDIX V : DRAFT FOCUS GROUP MEETINGS PLAN
Draft Outline for Focus Group Meetings for the National Programme of Action/Water
Safety Plan (NPA/WSP)
1. Aim
The aim of these sessions is to provide members of communities in Linden with information on
the Water Safety Plan and the National Programme of Action (NPA/WSP) and to create an
environment/forum to enable a greater awareness among members of the public, private and
civil society sectors in areas of water resources management, water purification, water
conservation, household practices and sanitation and also to foster partnership building across
sectors in areas relating to the National Programme of Action/Water Safety Plan (NPA/WSP).
2. Objectives
•
To provide members of three communities in Linden with information on - water
resources management, water purification, water conservation, household practices and
sanitation relating to the National Programme of Action/Water Safety Plan (NPA/WSP).
•
To create opportunities for representatives of the public, private and civil society sectors
in Linden to engage in discussions and receive information on aspects of water and
sanitation as is relevant to the National Programme of Action/Water Safety Plan
(NPA/WSP).
•
To create opportunities for building strategic partnerships between the public, private and
civil society sectors in Linden in the area of water and sanitation as is relevant to the
National Programme of Action and the Water Safety Plan (NPA/WSP).
3. Target Audience
These Focus Group sessions will be divided into two sections:
1. Community Meetings
2. Two-Day Workshop for public, private and civil society sectors in Linden
4. Community Meetings
The communities selected for the Community Meetings are, Wismar, Amelia’s Ward and Mc
Kenzie.
a) Format for Community Meetings
108
The Format for the Community Meetings is as follows:
i)
One Meeting will be held in each community.
ii) Each Meeting is expected to have in attendance at least 30 persons from
the community.
iii) Delivery of Sessions
Discussions - The sessions will be very interactive (Please note that a Powerpoint
presentation will not be used for these meetings since I do believe that at meetings
such as these a more interactive approach is most effective).
b) Topics for Discussions
i)
Water Resources Management
ii) Water Purification
iii) Water Conservation
iv) Household Practices
v) Proper Sanitation and its Relations to Water (Impact of improper sanitation practicespositive and negative)
vi) Water Distribution in Linden
Please note that existing materials from the various agencies involved in the development of the
WSP/NPA will be used for discussions on the abovementioned topics.
C) Venue for Community Meetings:
i)
Linden Foundation School for the Amelia’s Ward Community meeting.
ii) Wismar Multilateral School for the Wismar Community meeting.
iii) New Silver City Secondary School for the Mc Kenzie Community meeting.
d) Dates and Time for Community Meetings:
i) 16 April 2009 at 17:00 hours – Wismar
ii) 17 April 2009 at 17:00 hours – Amelia’s Ward
iii) 18 or 19 April at 16:00 – Mc Kenzie
5. Workshop for Public, Private and Civil Society Sectors
This Workshop will bring together representatives from the public, private and civil society
sectors to assist them in developing a greater understanding of the Water Safety Plan and the
National Programme of Action and to build on current techniques of working together for the
successful implementation of the NPA/WSP).
109
The details for this Workshop are as follows:
Target Audience a) Public Sector
This group will include Government Agencies, Semi – Autonomous and other agencies - the
public service in Linden and large water users (surface water and ground water users - whether
for Agriculture or other use, uses chemicals, disposes of chemical waste, disposes of large
quantities of domestic waste).
i)
Hospital Representatives
ii)
Mining Representatives
iii)
Regional Democratic Council (RDC) Representatives
iv)
Mayor and Town Council Representatives
v)
Guyana Water Inc. (As the main water producer)
vi)
Ministry of Education (Regional Education Department)
vii)
Schools (Administration)
viii)
Members of the WSP/NPA partnership group (optional)
Etc.
b) Private Sector
The group will include businesses in Linden which are providing water services or are large
water users (whether it be surface water of ground water, whether for Agriculture or other use,
uses chemicals, disposes of chemical waste, disposes of domestic waste.
Restaurants
Hotels
Mining Organisations
Hair Dressing Salons
Drinking Water Producers (in Linden)
c) Civil Society
This group will include civil society organizations (CSOs) in Linden. It will include all CSO’s with
an interest in water, sanitation and hygiene.
Non Governmental Organisations (NGO’s)
110
Civil Society Organisations (CBO’s)
Faith Based Organisations (FBO’s)
Schools
Women’s Organisations
Youth Groups
Environmental Organisations
Media
d) Number of Participants 40
e) Venue LEAP – Conference Room
f) Date and Time:
Dates 20 -21 April 2009
Time 09:00 – 16:00 hours
g) Format for Sessions
i)PowerPoint Presentations on the following:
•
The Water Safety Plan (WSP) and it Relevance to Water Safety and Health and
Development Linden by Dr. Ashok Sookdeo – (Presenter confirmed)
•
The National Programme of Action (NPA) and its implementation in Linden Mr. Hance
Thompson (Presenter to be confirmed).
•
Building, Managing and Sustaining Partnerships for the Successful Implementation of the
Water Safety Plan/National Programme of Action (WSP/NPA) in Guyana
ii) Discussions
iii) Group Discussions
iv) Role Plays
v) Plenary
e) Focus Group Meeting 2 – 20 – 21 April 2009
This group will comprise of members from the Public, Private and civil society Sectors in Linden
and members of the NPA/WSP Partnership Team (optional).
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