final report 030110 - ssru
TRANSCRIPT
Final Report
Research Title
The Development of Rainwater Harvesting System for
community
By
Dr. Nathaporn Areerachakul
This project was supported by Suan Sunandha Rajabhat University
2011
Abstract
Research Title : The Development of Rainwater Harvesting System for
community
Author : Dr. Nathaporn AreerachakulYear : 2011
.................................................................................................
The rainwater harvesting and utilization project was established in Bangsaiy Municipality,
Ayuthaya province. This report has concluded its evaluation of the potential of rainwater
harvesting as and alternate water resource, has formulates its recommendations regarding
minimum water quality standard, guidline and usage demands in communities, and methods
of treatment, storage, and gutter system for potable purpose ( based on fundamental data
collections). Additionally, the ways in which to incorporate rainwater harvesting with
existing public water systems and state of the role for further promote rainwater harvesting.
In this report, it presents a narrative discussion, associate map, rainwater harvesting sytem,
key stakeholder interview, and other illustrations relating to the potential benefits and
advantages that may be derived from rainwater harvesting in the area.
The final part of this report has presented the possible pilot project including design criteria
of rainwater harvesting and treatment system.
However, it should be note that the develop of training and understanding of materials on
rainwater harvesting and its treatment system are necessary to help communities to
understand the appropriate systems and realize the full potential of rainwater harvesting in
their communities.
Keywords: rainwater harvesting, stakeholder, pilot project
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Acknowledgements
This project was gratefully thanked to many of people, including representatives from anumber of agencies represented on the municipality, villager.
Many thanks to Suan Sunandha Rajabhat University for funding support in this project
Dr. Nathaporn Areerachakul
November 2011
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Table of Contents
ACKNOWLEDGEMENTS II
ABSTRACT II
TABLE OF CONTENTS IV
LIST OF TABLES VI
LIST OF FIGURES VII
LIST OF FIGURES VII
ACRONYMES AND GLOSSARIES VIII
ACRONYMES AND GLOSSARIES VIII
CHAPTER 1 - INTRODUCTION 1
1.1 Background 1
1.2 Research Objectives 3
1.3 Rationale of the Study 4
1.4 Scope and Limitations of the Study 4
1.5 Research Methodology 5
CHAPTER 2 - LITERATURE REVIEW 6
2.1 Overview of Water Supply and Management in Thailand 6
2.2 Current Situation and Issues of Rainwater Harvesting in Thailand 8
2.3 Community Rainwater Harvesting Systems 15
2.4 User Demands Assessment in Water Supply Provision in Small Communities 22
2.5 Considerations in Designing Rainwater Harvesting Systems for Small Communities 26
CHAPTER 3 – OVERVIEW OF RAINWATER UTILIZATION IN BANGSAIYMUNICIPALITY 29
3.1 General Profile 29
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3.2 Provision of Water Supply and Drinking Water Services 33
3.3 Rainwater and Its Utilization 35
CHAPTER 4 – ASSESMENT OF USERS DEMAND IN WATER SUPPLY ANDRAINWATER UTLIZATION 37
4.1 Users Background 37
4.2 Demands in Water Supply and Drinking Water 40
4.3 Demands in Rainwater Utilization 43
4.4 Roles and Perceptions of Stakeholders in Rainwater Utilization
4.5 Summary of User Demands
CHAPTER 5 – PRELIMINARY DEVELOPMENT OF RAINWATER HARVESTINGIN BANGSAYI MUNICIPALITY
5.1 Criteria for Designing Appropiate Pilot Project 48
5.2 Design of Pilot Project for Rainwater Harvesting Systems 50
CHAPTER 6 - CONCLUSIONS AND RECOMMENDATIONS 55
6.1 Conclusions 58
6.2 Recommendations 57
REFERENCES 58
APPENDICES 63
APPENDIX I - GENERAL SUPPORTING DATA 64
APPENDIX II – WATER SUPPLY AND DRINKING WATER SYSTEMS INBANGSAIY MUNICIPALITY 85
APPENDIX III – DESIGN OF RAWATER HARVESTING SYSTEMS 92
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List of TablesTable 1-1: Number of Sample Sizes in Three Sub-districts of Bangsaiy Municipality 4Table 1-2: Selected Users from Public Institutions 4Table 1-3: Key Informants Invited to Focus Group Discussion 5Table 2-1: Typical Hazards with Rainwater Tanks 11Table 2-2: Rainwater Characterization in Various Locations at Rajamangala University of
Technology Thanyaburi and at Ayutthaya Province 13Table 2-3: Comparison between Roof Catchment System and Ground Catchment System 19Table 3-1: Summarization of Land Use in Bangsaiy Municipality 31Table 3-2: Groundwater Information in Bangsaiy District 33Table 3-3: Number of Private Irrigation Basins in Bangsaiy Munipality 35Table 4-1: Levels of Income and Education of Respondents 38Table 4-2: Educational Level of the Residents Surveyed 38Table 4-3: Number of Users of Selected Public Insitutions 40Table 4-4: Frequency Distribution of Volume of Water Demands Per Month 41Table 4-5: Percentage Distribution of Perception in Water Tariff 42Table 4-6: Interest of Rainwater Utilization 45Table 4-7: Number of Respondents and Their Preference in Using Rainwater for Different
Functions 45Table 4-8: Demands in rainwater utilization of selected public institutions in Bangsaiy
Municipality 46Table 5-1: Components of a Pilot Project and its Cost Estimation Designed for Household
Users 52
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List of Figures
Figure 1-1: Mean Annual Rainfall in Thailand from 1971-2000 1Figure 1-2: Research Framwork 1Figure 1-3: Ayutthaya Province and Location of Study Area 3Figure 2-1: Low Cost Rainwater Harvesting in Developing Countries (Roof Catchment and
Storage) 16Figure 2-2: Roof Catchment and Storage 17Figure 2-3: Arrangements in a Ground Catchment and Storage 18Figure 2-4: Arrangements in a Rock Catchment System 19Figure 2-5: Storage Tank in Developed Countries 20Figure 2-6: Arrangement for Gutter Filter in Down Pipe Filter 21Figure 2-7: An Advanced Rainwater Harvesting, Treatment and Reuse System 21Figure 3-1: Bangsaiy Municipality 30Figure 3-2: Boundary of Bangsaiy Municipality 30Figure 3-3: Schematic Model of Medium Sized Groundwater Water Supply System 34Figure 4-1: Household Size and the Number of Families Per Household 38Figure 4-2: Frequency of Water Users from Different Water Sources 40Figure 4-3: Water Demands in Different Functions 41Figure 4-4: Frequency of Dissatisfaction with Quality Demands of Piped Water 42Figure 4-5: Frequency Distribution of Different Soruces of Drinking Water 43Figure 4-6: Percentage of Households With and Without Jar 44Figure 4-7: Percentage of Residents using Rainwater in Different Purposes 44Figure 4-8: Dissatisfaction With Quality Demands in Rainwater 45
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CHAPTER 1
INTRODUCTION
1.1 Background
Rainwater is one of significant water sources in Thailand due to its abundance. It has been
widely used in various sectors in society especially household and agriculture. Being
dominated by monsoon, rainwater can be harvested mainly in rainy season which generally
starts in June and lasts until October in most parts of the country with average rainfall per
annum at 1,500-1,600 mm (Phayomjamsri, 2008). Figure 1-1 presents mean annual rainfall
from 1971 to 2000 in Thailand by region. Rainwater utilization has been evidenced for more
than 2,000 years in the country (Prempridi, 1982). Runoff from rock and ground catchment
systems are mainly used for livestock consumption, nurseries and small scale irrigation while
rainwater harvested from rooftop at household is popular for domestic use including drinking
and cooking (Visvanathan, 2006).
Figure 1-1: Mean Annual Rainfall in Thailand from 1971-2000Source: www.tmd.go.th
Given the progress of country development, access to basic infrastructure has been
considerably increased particularly piped water supply systems serving domestic sectors. In
2002, 95% of Thailand's urban populace accessed to water supply but only 82% had the same
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access in rural areas (ADB, 2005). It should be noted that only a small proportion of rural
population has access to piped water, which means they must rely on rain water and
improved water storage. However in recent years, Thai Government had set a target to
provide piped water supply to all villages by the years 2008. As a result, based on a survey
conducted in 2005, approximate 85% of the villages were provided with village water supply
systems (UN-Water, 2006). Several surveys demonstrate that piped water in Bangkok meets
official quality standards but those living in rural areas have slightly lower quality drinking
water. This can explain why 50% of rural dwellers selected drinking bottled water whereas
only 17.5% of urban dwellers drank piped water based on a survey conducted by the National
Statistical Office in 2000. Being popular in inferiority to bottled water, the same survey
shows that both urban and rural residents still used rainwater for drinking at the proportion of
25.7 and 16.7 % respectively (NESDB, 2004). Although residents in many areas of Thailand
particularly those who live remotely are still using rainwater, they are doubtful in its quality
nowadays due to being contaminated from polluted environment. A combination of the
increase access to piped water supply, availability and coverage of bottled water in the
market and concerns in rainwater quality has made a decline in rainwater utilization.
Demands of rainwater harvesting in central part of the country are actually not as high as
other regions for example northeast which is relatively dry and alternative water supplies
such as rivers and groundwater are of poor quality. However given current water problems in
terms of quality and quantity, seeking alternative water sources like rainwater is becoming
essential. In addition water pricing tends to be a future concern of Thai residents as
government authorities in charge of water supply may increase water tariffs which are now
set at low rates and do not reasonably reflect actual costs. Therefore harvesting rainwater is
not only an alternative way of coping with water scarcity but also can help users particularly
in household sector to save expenses paid for water bills.
Among other provinces located in Chao Phraya River Basin in the central region, Ayutthaya
is one of top ranks, apart from Bangkok Metropolitan Region1, in water demands which are
predominately used in paddy and crop farmings as well as in industrial sector. Mainly water
supply in this province comes from two sources namely surface and ground water. Although
potential of harvesting rainwater is likely as the length of rainy season is last up to 6 months
1Bangkok Metropolitan Region consists of 6 provinces which are Nonthaburi, Pathumthanee, Nakornpathom,
Samutprakarn, Samutsakorn and Bangkok.
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which the average precipitation is accounted for 300 mm. with a potential to increase to the
maximum level of 900 mm., common practices of rainwater utilization are rarely found at
present. Similar to other provinces in Thailand, cement and earthern jars were used to be
containers for collecting and storing rainwater in Ayutthaya in the past but they were
abandoned when the local residents were able to access to piped water and bottled drinking
water. Considering circumstances of high growth in water demands, shortage in water supply,
increase of water tariffs, sufficient levels of rainfall and availability of the rainwater storage
devices, undertaking a pilot project in the province like Ayutthaya which can reflect the
situation in central part of Thailand in promoting rainwater harvesting may be an effective
way to demonstrate how to combine current technologies with existing resources and
materials under cost-effectiveness manner to resolve water crisis in the years to come.
In general, lack of stakeholder involvement and assessment of user needs at the beginning
often leads to failure of project implementation. For water supply projects, past experience
shows that communities will only maintain and pay for water supplies when they feel are an
improvement of existing systems and consider are worth spending their limited resource on
(IRC, 1991). Hence, this study gives priority to demand-base approach in investigating user
needs to ensure sustainability after the designed harvesting devices are installed. The
identified needs of users in the study area would then be incoperated in considering the
design of pilot project for rainwater harvesting.
1.2 Research Objectives
With the foregoing background, the main objective of this study is to design rainwater
harvesting systems which correspond to demands of users in small urban communities.
Bangsaiy Municipality in Ayuthaya province was selected as a case study. To achieve the
main objective, three sub-objectives are elaborated as follows:
(1) To evaluate potential of using rainwater as an alternative water source in small urban
communities;
(2) To assess user demands in rainwater utilization;
(3) To explore levels of service of rainwater utilization being suitable to small urban
communities; and
(4) To design a pilot project of rainwater harvesting and utilization systems which
correspond to the user demands.
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1.3 Rationale of the Study
In developing countries located in monsoon areas like Thailand where rainwater is currently
of no value for urban dwellers due to easily access to piped water supply at each household,
studies in rainwater harvesting for domestic use are of low interest. However it is needed to
undertake research to find out appropriate rainwater harvesting systems particularly for small
urban communities that are recently developed from a full rural structure to urban context. As
a matter of fact, in such transitional period, relying on only common water resources is risky.
This is due to some challenges including i) provisions of water supply to those communities
are not able to be reached to majority of the populations, ii) quality of the services is still poor,
iii) current water resources becomes degraded as a result of urban acitivities as well as
contamination of hazardous substances used in agriculture, and iv) water tariffs are at an
increasing pace. Given that most residents of such urban communities are familiar with
rainwater utilization for generations and devices to harvest and store rainwater are available,
therefore, integration of rainwater utilization into the existing water supply systems is
definitely beneficial to them.
Many studies on rainwater harvesting are focused on issues related to technology particularly
research conducted in developed countries. In addition, choosing technology for water supply
services in most cases is based on conditions and limitations of supply side rather than
considering user demands. It is widely recongnized that projects or studies about water
supply which apply principles of demand based approach are likely to be more acceptable
and effective. This study, thus, initially approaches water users to identify their demands
before steping further to take such considerations in desiging a pilot project of rainwater
harvesting which reasonably meets user needs and also fills gaps of exiting water supply
services.
1.4 Scope and Limitations of the StudyIn Thailand, a large proportion of rainwater is used for agricultural purposes. However the
focus of this study is limited to domestic use of rainwater in small urban communities. In line
with the size of the urban community studied, designing a pilot project of rainwater
harvesting systems would be at small scale under the context of simple structure of involved
institutions and stakeholders. With some specific economic settings, land use patterns, and
historical and cultural context that dominate perceptions of water users in the study area, the
level of service in this study may certainly be different from megacities or cities located in
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industrial zones. Thus applying findings of this study to large and complex municipalities
must be done with precautions.
Although there is a wide rage of users in the study area, scope of the study is limited to
household users and those who provide public services such as temples, schools, village
offices, and health stations. Users in business and industrial sectors were excluded because
their shares in water use are realtively small compared to household sector.
1.5 Research Methodology
1.5.1 Research Framework
Based on the main objective of this study set up, desigining a pilot project for rainwater
harvesting is based predominately on user demands. Since the current water supply services
would be related to user demands in alternative water sources like rainwater, identifying gaps
of the existing services must be considered thoroughly together with identifying the demands
in rainwater harvesting. In general water users, according to literature review, expect to have
services in which quality is high or at least meets standards, quantity is sufficient, costs are
reasonable, levels of service are convenient, and operation and maintenance of water supply
devices, if it must be undertaken by the users, have to be manageable. Hence all these aspects
would be investigated both for the current water supply services and rainwater harvesting
systems being piloted.
Apart from user demands in rainwater harvesting systems and current gaps in water supply
services, characteristics, potential and capacity of users, service providers and other
stakeholders in the study area must be determined. As stated earlier, main users this study
would focus on include households and public institutions such as temples, schools,
government offices, and health stations. All findings from user demandas and background of
users, service providers and key stakeholders would then be used to select appropriate pilot
project for rainwater harvesting systems based on considerations and criteria of the design.
Given that a rainwater harvesting system consists of three basic elements; a collection area, a
conveyance system, and storge facilities, the design must be made in all elements
accordingly. Figure 1-2 shows the research framework of this study.
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Figure 1-2: Research Framwork
Characteristics/ Potential /Capacity ofUsers (households and public institutions) / Service Providers/ Other stakeholders (NGOs, Government Authorities)
Current Gaps in Water Supply Services- Quality
- Quantity
- Costs
- Level of service
- Operation and maintenance
User Demands in Rainwater Harvesting- Quality
- Quantity
- Costs
- Level of service
- Operation and maintenance
Considerations and Criteria in ChoosingRainwater Harvesting Systems
Designing Pilot Project ofRainwater Harvesting for
Small Urban Communities
Available Systems- Catchment- Conyeance- Storage
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1.5.2 Approaches and Activities
To achieve the objectives, several approaches have beeen used. Critical dataset were
collected from various data sources with a range of data collection techniques as elaborated in
a matrix shown in Appendix I-A. The data collection-techniques used in this study include
survey with designed questionnaires, interview, review secondarty data, focus group
discussion and field observation. Secondary data was obtained mainly from local government
in the study area as it is a service provider of water supply. At first, collection of secondary
data and interview of key officials of relevant departments of the local government would be
conducted. After obtaining overview of water supply and rainwater utilization in the study
area, such data was subsequently used as a raw material in combination with literature review
to design a questionaire. While questionnaire survey was conducting, field observation was
undertaken along. Results from the survey and field onservation were preliminary
interpreated and summarized and then informed key stakeholders to receive their feedback
and comments when the focus group discussion was oraganized.
In some datasets for example an average volume of water used monthly can be obtained from
more than one source for the purpose of cross-checking. For example, quantitative water
demands per household can be calculated from a number of family members per household in
the study area. At the same time, the actual demand can be explored from the local
government which has its duty to charge customers based on volumes of water gauged by the
water meter. However, because the provision of water supply services of some villages is
made by their village committee, it would be plausible to trace back such data only in the
villages where water supply services are provided by the local government.
Selection of Study Area
The study area was selected based on the following criteria:
Small and recently established urban municipality located in Ayutthaya province; and
To some extent, having potential in rainwater utilization such as having sufficient
rainfall, using rainwater in the past, having been put in place rainwater collection and
storage devices.
Based on the criteria above, Bangsaiy municipality was selected as the study area. It is
located in Bangsaiy District where is situated in western part of Ayutthaya province with a
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distance from the province’s city center at 34 km. (Figure 1-3). Details of Bangsaiy
Municipality and the study area are elaborated in Chapter 3 and 4 respectively.
Figure 1-3: Ayutthaya Province and Location of Study AreaSource: www. thailandmaps.net and www.gofridaytravel.com
Sampling Design
Questionaire survey is one of the main tools used to identify gaps of current water supply
services and investigate user demands in rainwater utilization in household sector. Stratified
random sampling is the technique applied to design how to sampling households interviewed.
In Bangsaiy municipality, there are three sub-districts namely Taoloa, Kaewfah and Bangsaiy
The number of households of each sub-district is shown in Table 1-1. 100 households in the
study area were interviewed with the structured questionnaire. Out of 100 samples, the
number of households surveyed in each sub-district is then divided to correspond
proportionately to its number of households. The survey is designed to cover residents in
every village located in Bangsaiy municipality. In addition it attempted to collect information
from women as much as possible because they are more involved in house work which water
is used for such activity.
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Table 1-1: Number of Sample Sizes in Three Sub-districts of Bangsaiy Municipality
Sub-district Number of households Number of Samples
Taoloa 512 35
Kaewfah 545 35
Bangsaiy 495 30
Total 1,550* 100
Note: * There are 1,551 housholds in Bangsaiy Municipality in total. There is a household which is notclassified in any of the three sub-districts.
User Demands Assessment and Design of Pilot Rainwater HarvestingSystems
User demands in rainwater utilization of household sector are assessed predominately by the
questionnaire survey. The questionnaire is designed to cover four dimensions of the demands
based on literature review including quantity, quality, costs, and levels of service (Appendix
I-B). For the operation and maintenance of rainwater harvesting devices after installation, its
demand is assessed by interviewing and field observation. Apart from household users,
institutions located in the study area which provide public services to the society including
two temples, two schools and a health station were selected to represent other key water users
(Table 1-2). Interview and field observation are the technique applied to investigate their
demands. The same questions in the questionnaire survey are also used in interviewing those
key public institutions.
Table 1-2: Selected Users from Public Institutions
Institution Name RemarkTemple Bangsaiy Nai
Bangsaiy NokSchool Wat Bangsaiy Nai Primary school
Bangsaiy Wittaya Secondary schoolHealth station Taolao
Before concluding what user demands are in rainwater harvesting for this study area, focus
group discussion is held to reconfirm results from the questionnaire survey and field
observation. A leader of each village located in the municipality area, a representative from
key public institutions interviewed, officials from municipality and responsible government
agencies responsible for water and sanitation and other key stakeholders are invited to the
focus group discussion (Table 1-3).
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Table 1-3: Key Informants Invited to Focus Group Discussion
Sector Key Informant RemarkHoushold Village leader All leader from each villagePublic Institution Principal of the selected
schoolsBansayi Nai SchoolBangsaiy Wittaya School
Official of the selcted healthstation
Taolao health station
NGO Chief of Ayutthaya NaturalResources and EnvironmentVolunteers Network
Local government Official of Division ofEnvironment and PublicHealth, Bangsaiy MunicipalityOfficial of Division of WaterSupply, BangsaiyMuniciplaityMember of Municipal Council
Government authority Official of District Health
Based on user demands assessed in the earlier steps, a pilot rainwater harvesting system is
designed. Apart from technology being selected, other dimensions throughtout construction,
installation and operation phases have to be considered. These include location, capacity,
target users, cost and potential sources of financial assistance and critical success factors.
Mainly the design must cover three elements of the rainwater harvesting system which are
catchment, conveyance and storage. However design of treatment systems can propably be
added if findings from assessment of user demands show that potable water is needed and the
residents are not currently satisfy quality of rainwater.
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CHAPTER 2
LITERATURE REVIEW
2.1 Overview of Water Supply and Management in ThailandAccording to the water resources, Thailand consists of 25 major river basins, with an annual
rainfall between 1,200 and 2,700 mm. The volume of average annual run off is 200 billion
cu.m., but only 38 million cu.m., or 19 %, can be stored in reservoirs. The annual average
volume of rainwater is 800,000 cu.m., but only 40,000 cu.m. can actually be used. However,
the demand for water supply in Thailand is approximately 53 billion cu.m. annually. Almost
90 % is allocated for agriculture, 6 % for domestic consumption, and the rest for industrial
use. The combination of industrial growth, population growth and rising incomes has led to
an increased demand for water. It is estimated at 70 billion cu.m. annually in the next 10
years. Since water shortages may lead to a crisis, the effective management of water
resources and water supply is necessary to cope with water problems.2
The agencies involved
in water management in Thailand consist of the followings (Nitivattananon, 2005):
(1) Ministry of Natural Resources and Environment (MONRE) with main departments
namely Department of Water Resources (DWR) and Department of Groundwater (DGR),
Pollution Control Department (PCD) including Wastewater Management Authority (WMA).
(2) Ministry of Agriculture and Cooperatives (MOAC) including two main departments
which are Royal Irrigation Department (RID) and Land Development Department.
(3) Ministry of Interior (MOI) including Metropolitan Waterworks Authority (MWA),
Provincial Waterworks Authority (PWA), and a number of local government agencies
(LGAs) - such as municipalities.
(4) Ministry of Industry (MOInd) including Industrial Estate Authority of Thailand, and
Department of Industrial Works.
(5) Ministry of Energy (MOE) including Electricity Generating Authority of Thailand.
(6) Private sector including Eastern Water Resource Development Co. Ltd.
2http://www.boi.go.th/thai/how/water_supply.asp
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The investment program of the Provincial Waterworks Authority (PWA) has increased
supplies about 12 % a year. The PWA has the capacity to serve about 60 % of the 10 million
people living in the 220 cities and towns in 73 provinces under its jurisdiction with about 1.2
million cu.m. a day. The Metropolitan Waterworks Authority (MWA), responsible for
Bangkok and another 2 surrounding provinces, has a capacity of 3.2 million cu.m.supplied to
about 75 % of the metropolitan population. The results from surveys show that the access of
water supply has reached 98% of households in urban areas and 98.5% in rural areas
(Nitivattananon, 2005).
Despite these levels of access, many water quality problems remain, particularly
microbiological, and increasingly due to chemical contamination, affecting both ground and
surface water sources. The survey of a total of 68,501 villages for the whole country in 2003
by MOI, together with data of water supply construction from DWR and from Department of
Local Government Promotion in 2004 and 2005 respectively, found a total of 14,580 villages
without water supply system. The problems of water supply management in rural areas
include the following:
(1) There are several agencies involved with overlapping tasks, lack of coordination and
participation of LGAs, including selection of projects especially ground water supply.
(2) Problems related to inadequate (surface or ground) water sources especially in dry
period of Northeastern region.
(3) Poor quality of water supply due to Fecal Coliform bacteria including chemical and
physical aspects.
(4) Behavior of people in using traditional sources of water such as shallow wells with
mostly high contamination of Fecal Coliform bacteria.
To solve these shortcoming problems, the management policies are aimed to improve the
environmental standard, provide basic need in proverty area, and utilize low-cost and
appropriate technologies. According to the standard qualities of water used, Thai Industrial
Standards Institute (TISI) issued the standards for portable water and water supply as
illustrated in Appendix I-G. In addition, the 8th Development plan was regulated the demand
side management focused on the enhancing the efficiency of management system in order to
reduce water supply loss in the whole country to be within an average of 25 %. The supply
side management focused on the use of incentive measures and price measures including
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public relations for people to be aware of water deficit and behavior of water conservation
and reuse.
In rural areas, rainwater harvesting is one of the alternative technologies which can be used to
improve water supply and sanitation where conventional water supply systems such as
gravity and shallow wells are not feasible. The system simply collects the rain which falls
onto roofs, or via simple gutters into traditional jars, pots or storage tanks until required for
use. When required, the water is then pumped to the point of use, thus displacing what would
otherwise be a demand for main water supply. Rainwater harvesting technologies are simple
to install and operate. Local people can be easily trained to implement such technologies, and
construction materials are also readily available. It is convenient in the sense that it provides
water at the point of consumption, and family members have full control of their own
systems, which greatly reduces operation and maintenance problems. Running costs, also, are
almost negligible. Water collected from roof catchments usually is of acceptable quality for
domestic purposes. As it is collected using existing structures not specially constructed for
the purpose, rainwater harvesting has few negative environmental impacts compared to other
water supply project technologies. Although regional or other local factors can modify the
local climatic conditions, rainwater can be a continuous source of water supply for both the
rural and poor. Depending upon household capacity and needs, both the water collection and
storage capacity may be increased as needed within the available catchment area. Thus,
rainwater harvesting appears to be one of the most promising alternatives for supplying
freshwater in the face of increasing water scarcity and escalating demand in Thailand. The
pressures on rural water supplies, greater environmental impacts associated with new
projects, and increased opposition from NGOs to the development of new surface water
sources, as well as deteriorating water quality in existing reservoirs. It also provides the
ability of communities to meet the demand for freshwater from traditional sources, and
presents an opportunity for augmentation of water supplies using this technology.
2.2 Current Situation and Issues of Rainwater Harvesting inThailand
2.2.1 Rainwater Harvesting
Rainwater harvesting is a technology used for collecting and storing rainwater from rooftops,
the land surface or rock catchments using simple techniques such as jars and pots as well as
more complex techniques such as underground check dams. The popularity of rainwater
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harvesting and utilization is its decentralized nature located in proximity to the end user. It
avoids environmental problems associated with conventional centralized large-scale water
supply systems. Rainwater harvesting has been practiced in the Thailand from the past era. In
1979, the Royal Thai government formulated its policy of water resources development in
rural areas. The focus was on a decentralized scheme with co-ordination and planning
responsibilities given to the district and managed by local authorities with participation of the
user community. The three small scale technologies introduced were jars and tanks for
drinking water, shallow wells for domestic water and small weirs for agriculture. By 1987,
24% of the rural population was served by rainwater harvesting, 63% was served by weils,
rivers and springs while the remaining minority was served by piped water, tanker and
bottled water. The 1990 census reported the population served by rainwater harvesting had
increased to 35 % (WHO/UNICEF, 2004). The jar programme is very much in operation at
present.
There are two types of Thai rainwater harvesting systems which are the individual household
jars and more community oriented tanks. Both are surface structures with jars varying in its
capacity from 1.2 to 2.0 cu.m. and tanks from 7.5 cu.m. to 10 cu.m.. Both these structures are
widely seen in most rural areas in Northeast Thailand, though jars are more commonly used.
Jars and small capacity ferrocement tanks are in use in few urban households. According to a
1992 review by the National Economic and Social Development Board (NESDB), the
number of 2 cu.m. rain jars in use in Thailand increased from virtually none to 8 million in
1992. Commonly used systems are constructed of three principal components; namely, the
catchment area, the collection device, and the conveyance system (Srinivas, undated).
Catchment areas refer to the area where rainwater is collected such as rooftop catchment, land
surface catchment and rock catchment. The collection devices are the devices for collecting
rainwater, i.e. storage tanks or rainfall water containers and the conveyance systems mean the
systems required to transfer the rainwater collected on the rooftops to the storage tanks. This
is usually accomplished by making connections to one or more down-pipes connected to the
rooftop gutters. Rainwater harvesting is an accepted freshwater augmentation technology in
Thailand. While the bacteriological quality of rainwater collected from ground catchments is
poor, that from properly maintained rooftop catchment systems, equipped with storage tanks
having good covers and taps, is generally suitable for drinking, and frequently meets WHO
drinking water standards. Notwithstanding, such water generally is of higher quality than
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most traditional, and many of improved, water sources found in the developing world.
Contrary to popular beliefs, rather than becoming stale with extended storage, rainwater
quality often improves as bacteria and pathogens gradually die off (Wirojanagud, 1989).
Rooftop catchment, rainwater storage tanks can provide good quality water, clean enough for
drinking, as long as the rooftop is clean, impervious, and made from non-toxic materials (lead
paints and asbestos roofing materials should be avoided), and located away from over-
hanging trees since birds and animals in the trees may defecate on the roof. Eventhough there
are good strengths for this system used in rural areas, the disadvantages of rainwater
harvesting technologies are mainly due to the limited supply and uncertainty of rainfall. The
feasibility of rainwater harvesting in a particular locality is highly dependent upon the
amount and intensity of rainfall. Other variables, such as catchment area and type of
catchment surface, usually can be adjusted according to household needs. As rainfall is
usually unevenly distributed throughout the year, rainwater collection methods can serve as
only supplementary sources of household water.
An important factor affecting health of people in Thailand is the quality of drinking water
because villagers do not have access to piped water or centrally distributed potable water
supply. They rely on rainwater in the rainy season and ground water, from deep or shallow
wells, in the dry season. A major study on the rainwater quality in Thailand was conducted by
Wirojanagud (1989). The study examined bacteriological, pathogenic and heavy metal
contamination of rainwater samples collected from tanks, jars, roofs and gutter runoffs.
Despite to the results, it was concluded that, potentially, rainwater is the safest and most
economical source of drinking water since the contamination was slight. The analysis was
also found that the heavy metals included cadmium, chromium, lead, copper, iron,
magnesium passed WHO standards with the exception of magnesium and zinc, which are
considered to affect only the aesthetic quality of rainwater. Currently, water quality control in
roof water collection systems is limited to diverting first flushes and occasional cleaning of
jars. Boiling, despite its limitations, is the easiest and surest way to achieve disinfection. One
new method is to use photo-oxidation using uv radiation in strong sunlight to remove both the
coliform and streptococci. The technique involves placing transparent bottles of water in
direct strong sunlight for up to 5 hours. The implementation of the rainwater harvesting
program in Thailand is a good example of a country-wide rainwater jars implementation with
grassroots initiatives stimulated by NGOs, supported and encouraged by government both at
local, provincial and national levels.
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2.2.2 Rainwater Quality
The quality of rainwater flowing into rain tanks can not be mathematically estimated. Typical
collection and storage type of rainwater moreover results in the high potential for chemical,
physical and microbial contamination. Table 2-1 summarises the main water quality hazards
associated with rainwater tanks and their probable causes. Faecal coliforms or E. coli are
commonly identified in domestic tanks (Thurman, 1995; Victorian Department of Natural
Resources and Environment (1997). A surveying case in Victoria, Campylobacter was
identified in 6 of 47
Table 2-1: Typical Hazards with Rainwater TanksHazard Cause
Faecal contamination from
birds and small animals
Overhanging branches on roof, animal access to tank
Faecal contamination from
humans (above-ground tanks)
Human access to tank
Faecal contamination from
humans and livestock (below-
ground tanks)
Surface water ingress into tank
Mosquitoes Access to stored water
Lead contamination Lead-based paints on roofs, lead flashing on roofs,
increased corrosion of metals due to low pH from long
periods of contact between rainwater and leaves,
resuspension of accumulated sediment
Other contamination from
roof materials
Preservative-treated wood
Bitumen based materials
Chemical contaminants from
tanks, pipework etc.
Inappropriate material that does not comply with Aust.
Standards relating to food grade products or products for
use in contact with potable water
Dangerous plants Overhanging branches
Source: Australian Government (2004)
In a recent study, Han (2006) measured the water quality of roof water coming from
university student dormitory buildings at Seoul National University, South Korea. The main
findings are summarised as follows:
First flush showed a higher concentration of contaminants than later runoff;
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pH measurements reduced from 7.3 to 6.7 over a storm period of 50 minutes;
Turbidity decreased from 267 NTU to 30 NTU over a storm period of 50 minutes;
Over a long term of 1 year, pH varied between 6.5 and 9 and did not display seasonal
variations;
Over the same 1 year period, turbidity in the range of 207-10.6 NTU was recorded and
did not display seasonal variations;
The turbidity of stored water improved rapidly to about 2 NTU; and
The concentration of heavy metal measured over a 4 month period from April to August
2004 were in the following ranges, Al 0.22-0.02 mg/l, Cr 0.012-0.002 mg/l, Zn 1-
0.05mg/l, Cu 0.031-0.032 mg/l, Mn 0.13-0.02mg/l, As 0.033-0.02 mg/l, Cd 0.25-0 mg/l
and Pb 0.004-0 mg/l.
Pollutants in tank water can be generically identified as the containing colloidal solids, some
microbial pollutants, and micro-pollutants. As mentioned previously, the quality of rainwater
flowing into rain tanks cannot be mathematically estimated. While the quality of non-potable
purposes such as toilet flushing is acceptable, it does not meet drinking water standards and
guidelines. A reliable cost effective and relatively maintenance free in-line treatment will
allow the unrestricted use of rainwater, either as the main household water supply, or to
augment town supply.
In Thailand, Areerachakul (2009) tested quality of rainwater collected from tanks at two sites.
Both sites are located in central part of Thailand. The first site is the Rajamangala University
of Technology (RMUTT) situated in Pathumthani province. The rainwater tested was
collected from three concrete roofs in PVC tanks. The other site is located in Ayutthaya
province. The rainwater tested was collected from clay jars of five households. The results of
testing show that the quality of the water in Ayutthaya meets many of the parametric
standards specified in Austalian Drinking Water Guidelines (Table 2-2). The concentrations
of heavy metals were also at or below water quality standards. The quality of rainwater in
Ayutthaya has better than quality of rainwater than in RMUTT (in terms of DOC, total
coliform, fecal coliform, heavy metal, and mineral). This is because of the heavier pollution
in the more urban area of Thanyaburi where RMUTT is located compared to Ayutthaya,
which is less urbanized.
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Table 2-2: Rainwater Characterization in Various Locations at Rajamangala University ofTechnology Thanyaburi and at Ayutthaya Province
Parameter AWDG1
(2004)
Ayutthaya2 RMUTT3
pH 6.5 -8.5 6.4 6.7
CONDUCTIVITY (EC) (dS/m) < 0.8 0.082 0.78
TOTAL DISSOLVED SALTS (mg/L) 55.31 160
TOTAL SUSPENDED SOLIDS (mg/L) 400 428
TURBIDITY (NTU) <5 5.07 42
WATER HARDNESS (mg/L CaCO3 equivalent) <200 47 59
NITRATE (mg/L N) <50 14.1 18.6
CHLORIDE (MG/L) <400 1.45 1.35
SULPHATE (MG/L) <400 3.24 5.8
PHOSPHATE (MG/L) 0.86 1.5
CALCIUM (mg/L) 10.30 21.1
COPPER (mg/L) <2 0.03 0.19
IRON (mg/L) <0.3 0.54 0.875
MANGANESE (mg/L) <0.1 0.001 0.006
LEAD (mg/L) <0.01 0.017 0.174
ZINC (mg/L) <3 0.15 0.19
ARSENIC (mg/L) ND ND
CADMIUM (mg/L) ND ND
Total coliform (MPN/100 mL) <2.2 6.8 ≥1000
Fecal Coliform (MPN/ 100mL) <2.2 6.8 920
E. Coli (MPN/100mL) ND 2 20
DOC 2 .1 3 .3
ND = Non-detectable
1 Australain Water Drinking Guidelines
2Average of 10 samples at each of 3 locations at Ayutthaya
3Average of 10 samples at each of 5 locations at RMUTT
Source: Areerachakul (2009)
2.2.3 Policy and Programs on Rainwater Harvesting
Storing rainwater from rooftop run-off in jars is an appropriate and inexpensive means of
obtaining high quality drinking water in Thailand. With modern water problems, the
rainwater jar tradition offers a practical solution to groundwater salinity and water scarcity
common in Northeastern Thailand. Prior to the introduction of jars for rainwater harvesting,
many communities had no means of protecting drinking water from waste, mosquito
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infestation contamination and insect breeding. The resurgence of the rainwater jar tradition
began in 1979, when the Royal Thai government formulated policy for water resources
development. The focus was on the decentralized approaches to rural water development on
three low-cost technologies—rainwater jars and community water tanks for drinking water
supply, shallow wells for domestic water and water weirs for agriculture. Thailand's National
Jar Program, including the supply of communal tanks under the rural water supply program,
was launched in 1985 to promote the use of jars in rural households as a means of supplying
clean drinking water. This program was implemented in all regions of the country by
government with the active participation of individual households, village council and NGOs
(Sanitation Division, 1981). Two approaches have been used for the acquisition of jars. The
first approach involves technical assistance and training villagers on jar fabrication. This
approach is suitable for many villages, and encourages the villagers to work cooperatively.
The other benefits are that this environmentally appropriate technology is easy to learn, and
villagers can fabricate jars for sale at local markets. The second approach is applicable to
those villagers who do not have sufficient labour for making jars. It involves access to a
revolving loan fund to assist these villages in purchasing the jars. For both approaches,
ownership and self-maintenance of the jars are important. Villagers are also trained on how to
ensure a safe supply of water and how to extend the life of the jars. Working in partnership
with local NGO, Population and Community Development Association, the government
subsidized the cost of design and construction as well as training expenses and building
materials. Households play a key role in the project in terms of provisioning and maintenance.
They are responsible for securing their own rain jars either by making it themselves or by
purchase. Household representatives were taught simple and affordable designs by trained jar
makers. This encouraged villagers to work together and pool their resources whenever
necessary. In cases when villages do not have sufficient labor for making jars, they can
access a revolving fund to assist in purchasing the jars. The loan can be paid in equal
installments with no interest charged for three years. As a result, outright purchases of rain
jars increased.
Aside from addressing domestic water requirements at the community level, the initiative
incited substantial rural job creation and local mobilization. Today, the rainwater jars make
immediate and dramatic improvements in the quality of Thai rural life. Many households
actually prefer rainwater over groundwater for drinking because it is clearer and tastes fresh.
However, rainwater jars must be covered at all times to steer clear of grime and mosquito
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infestation. Rooftops must also be sturdy, clean, and made from non-toxic materials to ensure
rainwater quality. They must also be far from hanging tree branches to avoid bird and other
animal droppings. After the program was launched, many households shifted from thatched
roofs to zinc sheets to increase the volume of rain collected. Gutters and connecting pipes
were properly installed to maximize capture. The jars come in various capacities, from 100 to
3,000 litres and are equipped with lid, faucet, and drain. The most popular size is 2,000 litres
and holds sufficient rainwater for a six-person household during the dry season, lasting up to
six months. The results of the programme are good with 10 million rainwater jars constructed
in just over a 5 years period. Rainwater jars have been successful in the Northeast Thailand
because the technology is simple, inexpensive and understood by a majority of the rural
population. Among other factors are the acceptance of rainwater in this region, traditional use
of rainwater for drinking, common usage of traditional earthen vessels for rainwater
collection for domestic use, relatively cheap cost of the technology, access to water at each
house, and the unpalatability of ground water due to high salinity and hardness. The role of
the government in the supply and installation of rainwater jars is now over and this role has
been taken over by the private sector. However, the success of the Thai jar program has
reached international recognition, and other countries are pursuing similar technologies.
2.3 Community Rainwater Harvesting Systems
As stated previously, commonly used systems are constructed of three principal components;
namely, the catchment area, the collection device, and the conveyance system. The basic
principle of rainwater harvesting system in developing countries is illustrated in Figure 2-1
correspond in general to the basic systems that are defined in DIN (2002).
2.3.1 Catchment Systems
Every rainwater harvesting system consists of preferably waterproof catchment surfaces for
collecting the rainwater (e.g. roof or ground surfaces), delivery systems for transporting
rainwater from the catchment to appropriate storage tanks (e.g. gutters or surface drains) and
the storage tank itself. Gutters and downpipes are usually made out of plastic or metal
because these materials are most durable (DTU, 1997). In contrast to the state-of-the-art,
automatic system controls and freshwater backfeed are usually not implemented in
developing countries. Further differences exist in terms of applied materials, level of
technology as well as the utilisation of rainwater.
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Figure 2-1: Low Cost Rainwater Harvesting in Developing Countries (Roof Catchment andStorage)Source: DIN (2002)
Rainwater with reasonable qualities can be collected by using rooftop areas that can be stored
to provide individual households in rural areas with adequate water supplies. By directing the
rainfall on the roof areas to flow through the simple collection gutter arrangements, water that
would otherwise join surface run-off can be gainfully utilized. Roofs which are made of tiles,
slates, corrugated iron/tin or asbestos sheets are more appropiate. Thatched and lead sheet
roofs are not suitable because of the health hazards. A typical roof catchment and storage
arrangement is shown in Figure 2-2. The amount of rainwater that can be harvested will
depend on the area of the roof. The storage tank, however, has to be sufficient capacity to
take care of the longest dry season in a normal year. To deal with the exceptional dry years,
another 50% surplus storage must be added. The minimum basic drinking and domestic water
requirement of a family of six persons is 40 liters per day. Thus, for an average dry season of
3 months, the water storage required will be 3 × 30 × 40 × 1.5 = 5400 L.
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Figure 2-2: Roof Catchment and StorageSource: Gould (2003)
Rainwater harvesting using ground or land surface catchment areas is less complex approach
to the collecting of rainwater. This approach improves the runoff capacity of the land surface
through various techniques including collection of runoff with drain pipes and storage of
collected water. Compared with the rooftop catchment techniques, ground catchment
techniques provide more opportunity for collecting water by a larger surface area. By
retaining the flows (including flood flows) of small creeks and streams in small storage
reservoirs (on surface or underground) created by low cost (e.g., earthen) dams, this
technology can meet water demands during dry periods. There is a possibility of high rates of
water loss due to infiltration into the ground, and, because of the often marginal quality of the
water collected. This technique is mainly suitable for storing water for agricultural purposes.
Various techniques available for increasing the runoff within ground catchment areas
involve: i) clearing or altering vegetation cover, ii) increasing the land slope with artificial
ground cover, and iii) reducing soil permeability by the soil compaction and application of
chemicals. Arrangements in a ground catchment for rainwater harvesting are shown in Figure
2-3. Storage facilities for ground catchment rainwater harvesting system can be either above-
ground or below-ground. Both techniques should be however protected from contamination
by providing an adequate enclosure that prevents entry of pollutants. Dark storage conditions
using a tight cover technique is required to prevent algal growth and mosquito breeding.
There is a wide choice of construction materials of storage tanks. Small storage containers
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can be built up by clay, wood or water-proofed bamboo frameworks. While large storage
tanks can be constructed using stone or brick masonry works, ferro-cement or reinforced
cement concrete.
Figure 2-3: Arrangements in a Ground Catchment and StorageSource: Gould (2003)
Ground catchments for community water supply need appropriate management and
maintenance systems. It may be necessary to provide fencing or hedging to protect against
damage and contamination. Trees and shrubs can be planted around catchment to limit the
entry of wind blown materials and dust into the catchment area. The comparisons between
both catchment systems are illuatrated in Table 2-3.
Another catchment system is called rock catchment system. It is a rainwater catchment area
developed from a rock outcrop to catch and concentrate runoff intoa storage structure for later
use. Stone gutters are made to collect the runoff from the rock catchment area, and direct the
rainwater into a storage structure. The storage structure can be a tank or reservoir above a
dam. If the dam lies above settlements, water can be supply to stand posts through a gravity
fed pipe network. The rock catchment system is shown in Figure 2-4.
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Figure 2-4: Arrangements in a Rock Catchment SystemSource: UNEP (undated)
Table 2-3: Comparison between Roof Catchment System and Ground Catchment System
Comparison items Roof catchment system Ground catchment system
1. Propose To provide individual
households for consumption
Mainly to allocate for
agricultural purposes
2. Land required Small area for storage device Larger surface area
3.Water quality Less contaminants Poor
4.The amount of water
collected
Adequate for individual
households depend on the
roof area
More opportunity to collect
water due to the larger
surface area
5. Additional equipments Appropiable collection
devices and conveyances
Appropiable collection
devices and conveyances, in
addition, fencing or hedging
may be necassary
2.3.2 Collection Devices
Storage tanks: Storage tanks for collecting rainwater harvested using guttering may
be either above or below the ground. Precautions are required in the use of storage
tanks including provision of an adequate enclosure to minimise contamination from
human, animal or other environmental contaminants, and a tight cover to prevent algal
growth and the breeding of mosquitos. Various types of rainwater storage facilities
can be found in common practice, for examples cylindrical ferrocement tanks and
mortar jars. The storage capacity should be calculated to take into consideration the
length of any dry spells, the amount of rainfall, and the per capita water consumption
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rate. For example, a three person household should have a minimum capacity of 3
(Persons) x 90 (L) x 20 (days) = 5 400 L.
Rainfall water containers: As an alternative to storage tanks, battery tanks (i.e.,
interconnected tanks) made of pottery, ferrocement, or polyethylene may be suitable.
The polyethylene tanks are compact but have a large storage capacity (ca. 1 000 to 2
000 l), are easy to clean and have many openings which can be fitted with fittings for
connecting pipes. In Asia, jars made of earthen materials or ferrocement tanks are
commonly used. Some examples of rainwater storage devices in developed countries
and developing countries are shown in Figure 2-5.
Figure 2-5: Storage Tank in Developed CountriesSource:DIN (2002)
2.3.3 Conveyance Systems
Conveyance systems are required to transfer the rainwater collected on the rooftops to the
storage tanks. This is usually accomplished by making connections to one or more down-
pipes connected to the rooftop gutters. When selecting a conveyance system, consideration
should be given to the fact that, when it first starts to rain, dirt and debris from the rooftop
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and gutters will be washed into the down-pipe. Thus, the relatively clean water will only be
available some time later in the storm. There are several possible choices to selectively
collect clean water for the storage tanks. The most common is the down-pipe flap. With this
flap it is possible to direct the first flush of water flow through the down-pipe, while later
rainfall is diverted into a storage tank as shown in Figure 2-6.
Figure 2-6: Arrangement for Gutter Filter in Down Pipe FilterSource: DIN (2002)
An advanced rainwater harvesting, treatment and reuse system is shown in Figure 2-7. In this
method, rainwater is treated using microfiltration system and disinfected using UV rays
before passing it to the municipal water supply system.
Figure 2-7: An Advanced Rainwater Harvesting, Treatment and Reuse SystemSource: http://www.rwh.in/rainwatr/rain414.gif
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2.4 User Demands Assessment in Water Supply Provision inSmall Communities
2.4.1 User Demands Assessment in Water Supply Provision
Many of the past rural water supply projects were lacking in involving target communities to
plan, implement, operate, and maintain services in a way that benefits and satisfies key
sections. This has led to lacking a sense of ownership and unclear responsibilities for
maintenance. Consequently, after funding agencies or relief organizations completed the
contruction phase for a while, those facilities do not function properly and were quickly
abandoned because communities were unable to operate and maintain them.
To choose a range of suitable water supply technologies and management systems to meet
user needs, past experience shows that there are three fundamental considerations as follows
(IRC, 1991).
i) Level of service and technology provided must be appropriate. This can be
assessed through having community participation in decision making process.
ii) Users must be willing to contribute, in cash and kind, to make the services
operated and keep them maintained.
iii) The water agency must be cabable of providing continuous support.
After operating water supply services, user satisfaction heavily relies on how continuity of
access to safe and sufficient water can meet minimum requirements, meaning that quality and
quantity of water supply are of prime concerns for water users in general (IRC, 1991).
The evaluation of costs of various levels of service and community information and
involvement are key compoments in analysis of willingness to pay for and support a new or
improved water supply system. Willingness to pay and level of service are interrelated.
Making decision on service levels should be based on affordability and willingness to pay by
community members. Willingness to pay is most influenced by the actual and perceived
utility and benefits of an improved wter supply. There are two key factors likely to influence
willingness to pay which are i) the level and value of time saved and ii) the perceived
convenience, reliability and quality of the service. Where existing water sources are
conveniently located even though they may not provide safe water, providing a low level of
service with the laest costly solution may provide too little perceived benefits to the users to
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get them to be willing to pay for construction or maintenance of an improved water supply
system. However, convenience, reliability, and quality affored by a higher level of service,
and public education regarding the potential benefits, are likely to increase willingness to
support a new water supply system (Daniel, 1987).
In terms of quantity, water demand or water availability has become a major concern in many
countries due to their increasing population, industrial growth and infrastructure growth at a
fast rate. In order to ease such a problem, rainwater usage is an acknowledged choice to
promote significant potable water saving for consumption and/or outdoor usage (Hermann,
1999). The study by Enedir G and his team showed the results performed over 195 cities
located in southeastern Brazil that potable water demand in the residential sector ranged from
90 to 300 litres per capita per day and in average rainfall ranged from 500 to 3400 mm per
year. The potential saving was 41% ranging from 12% to 79 % in average. Also the same
study demonstrated the significant potential and indicated that rainwater could probably be
used for both potable and non potable pueposes (Enedir, 2007). Furthermore, Enedir G and
his team observed the roof catchment area, water tank size and water demand. Based on
findings of the study, it is recommened that rainwater tank capacity should be determined for
each location depending on potable water demand, roof area and daily rainfall.
2.4.2 Studies on Users Demand in Rainwater Harvesting in Thailand andDeveloping Countries in Asia
Many cities in developing countries obtain their water from great distance. But this practice
of increasing dependence on the upper streams of the water resource supply area is not
sustainable. Building dams in the upper watershed often means submerging houses, fields and
wooded areas. It can also cause significant socio‐economic and cultural impacts in the
affected communities. In addition, some existing dams have been gradually filling with silt. If
not properly maintained by removing these sediments, the quantity of water collected may be
significantly reduced. In establishing their water supply plans, cities have usually assumed
that the future demand for water will continue to increase. Typically, city waterworks
departments have made excessive estimates of the demand for water and have built
waterworks infrastructure based on the assumption of continued development of water
resources and strategies to enlarge the area of water supply. The cost of development is
usually recovered through water rates, and when there is plenty of water in the resource area,
conservation of the resource is not promoted. This tends to create a conflict when drought
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occurs, due to the lack of policies and programmes to encourage water conservation. It has
even been suggested that the lack of promotion of water conservation and rainwater
harvesting is due to the need to recover infrastructure development costs through sales of
piped water. The exaggerated projection of water demand leads to the over-development of
water resources, which in turn encourages denser population and more consumption of water
In 1979, the study by Rajendra (2001) presented that The Royal Thai Governmet declared the
policy of water resource development for rural areas. Three small scale technologies which
were jar and tank construction for drinking water, shallow wells for domestic water and small
weirs for agriculture had been introduced in this project. The household drinking water was
especially targeted by using jar and tank (Ariyabandu, 2001). Thailand's National Jar
Program, including the supply of communal tanks under the rural water supply program, was
launched in 1985 to promote the use of jars in rural households as a means of supplying clean
drinking water. The results of the programme are good with 10 million rainwater jars
constructed in just over a 5 years period.
In addition, the 8th Development plan was regulated the demand side management focused on
the enhancing the efficiency of management system in order to reduce water supply loss in
the whole country to be within an average of 25 %. Storing rainwater from rooftop run-off in
jars is an appropriate and inexpensive means of obtaining high quality drinking water in
Thailand. Its utilisation is now an option along with more 'traditional' water supply
technologies, particularly in rural areas.
In Singapore, which has limited land resources and a rising demand for water, is on the
lookout for alternative sources and innovative methods of harvesting water. Almost 86% of
Singapore’s population lives in high-rise buildings. Light roofing is placed on the roofs to act
as catchment. Collected roof water is kept in separate cisterns on the roofs for non-potable
uses. A recent study of an urban residential area of about 742 ha used a model to determine
the optimal storage volume of the rooftop cisterns, taking into consideration non-potable
waterdemand and actual rainfall at 15-minute intervals. This study demonstrated an effective
saving of 4% of the water used, the volume of which did not have to be pumped from the
ground floor. As a result of savings in terms of water, energy costs, and deferred capital, the
cost of collected roof water was calculated to be S$0.96 against the previous cost of S$1.17
per cubic meter. A marginally larger rainwater harvesting and utilisation system exists in the
Changi Airport. Rainfall from the runways and the surrounding green areas is diverted to two
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impounding reservoirs. One of the reservoirs is designed to balance the flows during the
coincident high runoffs and incoming tides, and the other reservoir is used to collect the
runoff. The water is used primarily for non-potable functions such fire-fighting drills and
toilet flushing. Such collected and treated water accounts for 28 to 33% of the total water
used, resulting in savings of approximately S$ 390,000 per annum
In Bangladesh, rainwater collection is seen as a viable alternative for providing safe drinking
water in arsenic affected areas. Since 1997, about 1000 rainwater harvesting systems have
been installed in the country, primarily in rural areas, by the NGO Forum for Drinking Water
Supply & Sanitation. This Forum is the national networking and service delivery agency for
NGOs, community-based organisations and the private sector concerned with the
implementation of water and sanitation programmes in unserved and underserved rural and
urban communities. Its primary objective is to improve access to safe, sustainable, affordable
water and sanitation services and facilities in Bangladesh. The rainwater harvesting tanks in
Bangladesh vary in capacity from 500 litres to 3,200 litres, costing from Tk. 3000-Tk.8000
(50 USD to 150 USD). The composition and structure of the tanks also vary, and include
ferro-cement tanks, brick tanks, RCC ring tanks, and sub-surface tanks. The rainwater that is
harvested is used for drinking and cooking and its acceptance as a safe, easy-to-use source of
water is increasing amongst local users. Water quality testing has shown that water can be
preserved for four to five months without bacterial contamination. The NGO Forum has also
undertaken some recent initiatives in urban areas to promote rainwater harvesting as an
alternative source of water for all household purposes.
In the Philippines, a rainwater harvesting programme was initiated in 1989 in Capiz Province
with the assistance of the Canadian International Development Research Centre (IDRC).
About 500 rainwater storage tanks were constructed made of wire-framed ferro-cement, with
capacities varying from 2 to 10 cu.m. The construction of the tanks involved building a frame
of steel reinforcing bars (rebar) and wire mesh on a sturdy reinforced concrete foundation.
The tanks were then plastered both inside and outside, thereby reducing their susceptibility to
corrosion relative to metal storage tanks. The rainwater harvesting programme in Capiz
Province was implemented as part of an income generation initiative. Under this arrangement,
loans were provided to fund the capital cost of the tanks and related agricultural operations.
Loans of 200 USD, repayable over a three-year period, covered not only the cost of the tank
but also one or more income generating activities such as the purchase and rearing of pigs,
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costing around 25 USD each. Mature pigs can sell for up to 90 USD each, providing an
income opportunity for generating that could provide sufficient income to repay the loan.
This type of innovative mechanism for financing rural water supplies can help avoid the
requirement for water resources development subsidies.
2.5 Considerations in Designing Rainwater Harvesting Systemsfor Small Communities
Effectiveness of the rainwater harvesting depends on appropriate design of the systems.
Being a storage or recharge structure, an improperly designed system will lead to operational
problems for example high costs in operation and maintenance (Inima, undated). It may even
lead to abandon the systems put in place. Generally, considerations in designing the rainwater
harvesting systems especially for the ground catchment system depend on:
Location of structures
The problem of location of community water retention structures is very important in
ensuring project success. An improper location of a structure can lead to problems
such as:-
a) Community conflicts arising out of site ownership wrangles.
b) Increased frequency of undesirable incidents such as accidental falls or animal
attacks when fetching water
c) Hydrological failure of the structure due to excessive water seepage, or damage
arising from excessive storm drainage.
Principles to be considered in locating the structures
- Travel distances to the water retention structures by both animals and human beings
- There is need to take advantage of the land slope. The retention structures should
placed on land slopes that will enable them gather enough water and fill during the
rain seasons.
- The rainfall harvested by the structures can be lost very quickly through seepage or
evaporation. To minimize seepage losses the geology of the site needs to be
considered.
- The water retention structures in the project areas should be built to reduce the need
for human handling of the runoff.
- A perimeter fence should be built around water retention structures to prevent
animals from falling into the water.
- The designs should be flexible and can be modified by reducing or increasing the
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dimensions depending on the finances available
- An appropriate technology should be selected depending on the available local
materials and manpower
Furthermore, the considerations of storage tank volume can be determined by the following
factors
Number of persons in the household: The greater the number of persons, the greater
the storage capacity required to achieve the same efficiency of fewer people under the
same roof area.
Per capita water requirement: This varies from household to household based on
habits and also from season to season. Consumption rate has an impact on the storage
systems design as well as the duration to which stored rainwater can last.
Average annual rainfall
Period of water scarcity: Apart from the total rainfall, the pattern of rainfall -whether
evenly distributed through the year or concentrated in certain periods will determine
the storage requirement. The more distributed the pattern, the lesser the size.
Type and size of the catchment: Type of roofing material determines the selection of
the runoff coefficient for designs. Size could be assessed by measuring the area
covered by the catchment i.e., the length and horizontal width. Larger the catchment,
larger the size of the required cistern (tank).
Design procedure:
Suppose the system has to be designed for meeting drinking water requirement of a five-
member family living in a building with a rooftop area of 100 s.q.m. The average annual
rainfall in the region is 600 mm (average annual rainfall in Delhi is 611 mm). Daily drinking
water requirement per person (drinking and cooking) is 10 litres.
1. Following details are available:
Area of the catchment (A) = 100 sq. m.
Average annual rainfall (R) = 611 mm (0.61 m)
Runoff coefficient (C) = 0.85 1. Calculate the maximum amount of rainfall that can be
harvested from the rooftop:
Annual water harvesting potential = 100 x 0.6 x 0.85= 51 cu. m. (51,000 litres)
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2. Determine the tank capacity: This is based on the dry period, i.e., the period between the
two consecutive rainy seasons.
For example, with a monsoon extending over four months, the dry season is of 245 days.
3. Calculate drinking water requirement for the family for the dry season
= 245 x 5 x 10= 12,250 litres
As a safety factor, the tank should be built 20 per cent larger than required, i.e., 14,700 litres.
This tank can meet the basic drinking water requirement of a 5-member family for the dry
period. A typical size of a rectangular tank constructed in the basement will be about 4.0 m x
4.0 m x 1.0 m.
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CHAPTER 3
Overview of Rainwater Utilization in Bangsaiy Municipality
3.1 General Profile
3.1.1 General Conditions
Bangsaiy Municipality was selected as the study area. It is one of 34 municipalities in
Ayutthaya province and located western from the center of provience. In the municipality
area, there are 19 villages situated in three sub-districts which are Bangsaiy, Taoloa and
Kaewfah. In Bangsaiy, Taolao, Kaewfah subdistricts, there are 4, 9 and 6 villages (Moo)
respectively. The area of the municipality is 5.5 km2 or 3437.5 Rai3. A map showing location
of Bangsaiy district and the boundary of municipality which is illustated by the dash lines are
shown in Figure 3-1 and Figure 3-2 respectively.
3Rai is a Thai unit of area. One unit of Rai is equal to 1,600 s.q.m.
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Figure 3-1: Bangsaiy MunicipalitySource: www.zoomhit.com
Figure 3-2: Boundary of Bangsaiy MunicipalitySource: Division of Secretary, Bangsaiy municipality
The study area is located on the flood plains which Klong (canal) Chaeo Jed-Bang Yee Hon
passes through the central municipality area and has been served as the main surface water.
There are approximately 1,550 households in municipality area with a population of 5,403,
out of which 2,646 residents are males and 2,757 are females4. In the past, all population
lived along the canal because the canal played the important role as the main transportation
route and water source for agiculture. Despite being an efficienct transportation route in the
past, some people have settled in the communities where roads and modern facilities have
been constructed nowadays. Thus, there are two main communities which are old canal
community and modern city community where roads are more convenient and widely used
for transportation.
4This information is based on a census survey in 2008.
Klong Chaeo Jed-Bang Yee Hon
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Agriculture and farmings are the major occupations in municipality. The main crop is rice
field, while fruits and vegetables are planted for domestic consumption in some areas. The
agriculture area in Bangsaiy municipality is 1,400 Rai or 40 % of all municipality area (3,500
Rai). The other occupations are wholesale, services, and household industries.
In accordance with development strategies in the past 3 years, fundamental facilities such as
roads, sanitary and traffic systems have been rapidly developed. There are four schools which
are responsible for elementary and secondary levels. The other public services consist of 1
post office, 2 banks, 1 cooperative market, 1 health station, 1 private clinic, and 2 drug stores.
The administrative units of municipality are divided into legislative section and management
section and the mayor is responsible in municipal government. The per capita annual gross
revenue is in average of 2,000 to 30,000 THB, while the total gross domestic product of the
municipality is about 116.2 million THB. The land use in Bangsaiy municipality can be
categorized as shown in Table 3-1
Table 3-1: Summarization of Land Use in Bangsaiy Municipality
Type of land use Area (Rai) %
Agricultural area 2,292 66.66
Farm 5 0.15
Household 635 18.47
Road 90 2.61
Temple 44 1.29
School 39 1.13
Surface water 100 2.91
Public area 200 5.82
Other 33 0.96
Total 3,438 100
Source: Strategic Plan 2010-2013, Bangsaiy Municipality
3.1.2 Climate and Rainfall
Ayutthaya Province has the same climate as other provinces in the central region of Thailand,
that is, under influence of the northeastern monsoon in winter and the southwestern monsoon
from the Gulf of Thailand. As a result, the rainy season is very long. The annual average
temperature is 26.7 to 28.9°C. The highest temperature is 31°C while the lowest one is 24°C.
The average rainfall of the province is approximately 1,342.7 mm. which the average rainfall
per month ranges from 5.1 to 269.2 mm. There are three main seasons as follows:
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Rainy Season: The season begins in May or the beginning of June and lasts until
October. The rain falls and and more frequently falls in August or September. Rainfall
in Ayutthaya province is influential due to the southwestern monsoon and depression
storms from South China Sea. In October, however, the rain falls less. The rainy
season usually lasts approximately for 5 months.
Winter: Winter begins in November and ends in January. From November, the season
is changed from rainy season to winter as the southern monsoon is weaken and
replaced by the northeastern monsoon. However, the temperature is not significantly
decreased. The winter usually lasts for 3 months.
Summer: This season begins in February and ends in April. From February, as the
northeastern monsoon is weaker, the climate is hot and hottest in April due to the
radiation of the sun and the high pressure covering from South China Sea and the
Pacific Ocean, which is the origin of the southeastern monsoon blowing to the Gulf of
Thailand. However, Ayutthaya province is not very hot as there are many rivers and
canals. The summer lasts usually for 4 months.
3.1.3 Water Resources
Noi River is one of several rivers which flows pass Ayutthaya province. It is separated from
the right side of Chao Phraya River in Muang District, Chainat province and is merged again
with Chao Phraya River in Ratchakhram Sub-district, Bang Sayi District. The river is totally
145 km long while flowing passes Ayutthaya Province for 30 km. Klong Chaeo Jed-Bang
Yee Hon is the main canal passing through the centre of Bangsaiy municipality. There are
other six canals also serving the municipality for the agriculture and consumption purposes
which are Lum Wang Chan, Nom Mor Keang, Kum, Nong Sone, Cor Tun and Don Puck
Kom. In the past, the flooding period took usually 4-5 months whereas the water level would
be highest in December, then it would be decreased. When the water was completely
downed, it was the time harvesting period was started. However, such abundance in the
flooding period has been lost after the construction of Chainat Dam or Chao Phraya Dam in
Chainat Province since 1957 with the purpose to develop the areas on the both banks of Chao
Phraya River and other minor rivers, thus there is no more the flooding period at present.
Groundwater is another water resource in this municipality and the main use is mostly for
consumption. According to the information of groundwater wells in Bangsaiy District
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recorded as shown in Table 3-2, it can be recognized that people consume groundwater as a
main source of water only.
Table 3-2: Groundwater Information in Bangsaiy District
Location Depth of well(m)
Normalwater level
(m)
Decreasingwater distance
(m)
Water flow(cu.m./hr)
Klong Kum 168.0 9.0 45.0 3.40Klong Tun 144.0 9.0 48.0 4.45Bangsai 168.0 9.0 38.0 3.40Sai 201.0 18.0 70.0 4.0Kor Tarn School 156.0 9.0 15.0 22.73Veteran agriculturistCommunity
184.5 15.3 8.26 18.01
Moo Sakae Village 192.0 25.0 50.0 10.0Bangsai Police Station 170.0 9.0 3.0 50.0
Source: http://map.dgr.go.th
3.2 Provision of Water Supply and Drinking Water Services
3.2.1 Water Supply
The water resources for domestic use in Bangsaiy Municipality area generally come from
groundwater. However, the communities along the canals use water from canal for gardening
and washing while groundwater is used for consumption. Generally, authorized organizations
such as Department of Groundwater Resources, local administrations or private enterprisers
search for groundwater wells and install groundwater pumping systems for the communities.
In Bangsaiy Municipality, there are 18 groundwater wells, of which 9 wells have been
managed and maintained by the Division of Water Supply of Bangsaiy Municipality while
the other 9 wells are under responsibility of village committees where the wells are located
in.
The groundwater wells managed by the city municipality are located in Bangsaiy and Taolao
sub-districts and serve for 600 households. Each is a medium-sized well which suits for
approximately 51-120 households. Out of the 9 wells, there is only one well located in Taoloa
sub-district which a treatment system has been installed. The water pumped up from the other
8 wells is distributed via piping systems without any treatment. The schematic model of
groundwater supply system of Bangsaiy Municiaplity is illustrated in Figure 3-3. The
Bangsaiy Municipality strategic plans of 2010-2012 are emphasized on the improvement of
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quality of life including the development of water supply systems. In the plan, it is stated that
there are 14 projects relevant to improvement of water supply services being executed as
follows:
4 projects of constructing new groundwater wells;
5 projects of water supply piping systems and groundwater wells maintenance; and
5 projects of installing water treatment systems for quality improvement.
At present, the municipality charges water tariff at the rate of 4 THB per cu.m. and the fee for
maintaining water meter at 5 THB per month. According data recorded by the municipality in
2009, the average amount of water supply used in first half of the year is 12,400 cu.m./ month
and the revenue collected from providing water supply services including water meter fees is
30,616 THB.
Figure 3-3: Schematic Model of Medium Sized Groundwater Water Supply SystemSource: Department of Water Resources (2003)
As mentioned previously, a half of the groundwater wells in the municipal area is
administered and managed by village committees where the wells are located. Each village
committee for water supply is established to collect fees, regulate policies and maintain the
systems. The water supply tariff charged for these communities is 4 THB per cu.m. In some
villages, the profits gained from collecting the fees are spent for remuneration of staff who
has the duty for collecting the fees and the improvement of water quality such as treatment
system installation. Not all the villages are successful in administration and could have
profits. Transparency of the adminstative system is a key success factor.
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3.2.2 Drinking Water
The piped water produced from groundwater is not well treated and qualified for drinking.
The water quality is often poor due to excessive contaminations of bacteria and chemicals
like cadmium, iron, lead, manganese, and excessive suspension. Apart from using the piped
water, rainwater is also used as a source of drinking water. However, quality of rainwater is
still doubtful for most people and a further treatment is a common practice. Being as such,
majority of inhabitants in municipality treat water before drinking. In general, the inhabitants
treat the piped water or rainwater by boiling or purifying it by a small-scale purifying device
at home. An alternative in access to drinking water is to buy bottled water in which its
commercilaized volumes are of 1 liter and 20 liters (1 gallon). Potable water in municipality
is produced by private vendors and community-own-enterprises. Retail prices from the
private vendors are generally 5 THB more expensive than the community-own enterprises per
gallon. This is due to the better quality of production, delivery service and the registration
with the authorized organizations such as Food and Drug Administration. Ground water is
used as a source for both suppliers. For public institutions like schools and temples, a water
purifier and buying bottle water are also common practices.
3.3 Rainwater and Its UtilizationRainwater has been a valuable water resource which can be easily gained on site. In Bangsaiy
municipality, rainwater utilization can be categorized into two main purposes including
agriculture and domestic consumption.
Agricultural purpose
To minimize land degradation and sustain crop productivity in communities, management
and efficient utilization of rainwater is important. The Office of Central Land Consolidation,
Department of Royal Irrigation, is responsible for the management of Klong Chaeo Jed-Bang
Yee Hon. An irrigation canal and maintenance program has been established in order to
control and manage the irrigation water from Klong Chao Jed-Bang Yee Hon. Several
irrigation basins have been built for water storage in dry season. In accordance with the
survey data from the Department of Agricultural Extension in 2006 as shown in Table 3-3, it
was found that some farmers also built their own irrigation basins for both agricultural and
domestic purposes.
Table 3-3: Number of Private Irrigation Basins in Bangsaiy Munipality
Sub-districts Number of basins Number of usablebasins
Available wateraccounted in
number of days
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Kaewfah 7 7 2,555Taolao 16 10 3,650Bangsai 15 8 2,920Source: Department of Agriculture Extension (2006)
Domestic use purpose
At present, the water resources provided for domestic use in Bangsaiy municipality area
mostly come from piped water systems pumped from the groundwater wells. However,
the rainwater harvesting systems have been put in place from the ancestors many
thousand years ago. Mortar jars and tanks have been the most popular storage devices
found in households and public places even though the purpose for utilization is not for
drinking water nowadays. The maximum size of jars found in the municipality has a
capacity of 2 cu.m. and two or more jars are used in a household. These rainwater storage
devices were received from government organizations about 10 years ago when Royal
Thai Government formulated its policy on water resources development in rural area to
store the potable water in dry season. Roof catchment systems have been brought to
collect rainwater by using rooftop areas in which rainwater can be collected into the jars
and tanks to provide individual households with adequate water supply. By directing the
rainfall on the roof areas to flow through the simple collection gutter arrangements, water
that would otherwise join surface run-off can be gainfully utilized. Prior to the harvesting
procedure, it is essential to clean the roof area by rainwater when it starts to rain. The jars
may also become breeding places for mosquitoes if the containers are not kept closed. By
this reason, the local residents ususally cover the jars and tanks by a lid, net, thin fabric or
even mesh. Such practice can also prevent dropping of physical contaminants to keep the
stored rainwater clean.
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CHAPTER 4
Assesment of Users Demand in Water Supply and
Rainwater Utlization
The characteristics of community such as number of population, age, gender, education,
livelihood and income are the important factors that influence behaviour of people in using
rainwater. Perception and behavior of local residents, satisfaction of existing water supply
services, affordability of water users, environmental conditions such as air pollution around
that area, current situation of rainwater utilization are also significant factors that determine
user demands. All data related to these factors is summarized and interpreted in this chapter.
Then the findings from assessing user demands would be used further for desiging an
appropriate pilot project in rainwater harvesting which could respond to these needs.
4.1 Users Background
Water users in Bangsaiy Municipality can be categorized into two main groups including
users from household sector and public institutions. Background of household users is first
descriped based on the questionnaire survey and then followed by other users particularly
public institutions based on conducting the interview and field observation.
Houshold users
100 households were included in this survey as stated in Section 1.5.2. 43% and 47% of all
the respondents are males and females respectively. Average household size ranges from 3 to
5 members. Figure 4-1 presents percentage of households at different number of families and
members per household.
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Figure 4-1: Household Size and the Number of Families Per Household
Levels of income are classified into three groups according to Gross National Income per
capital for developing countries (GNI), calculated by using the World Bank Atlas method,
which are low (< 975 USD), low to middle income (976 - 11,905 USD) and high income (>
11,906 USD). Based on the samples, majority of inhabitants in this municipality are
categozied into the low income group (Table 4-1) with an average income ranging from
3,500 – 20,000 THB per month per household (approximately 1,050 – 6,000 USD per year).
Table 4-1: Levels of Income and Education of Respondents
Level of income per month (THB) %
<3,500 - 20,000 71
20,001 - 35,000 14
35,001 - 65,000 8
65,001 - 85,000up 7
Education influences perception and decision making of people to use rainwater. Table 4-2
shows that 55% of respondents are less educated than primary school or graduated in primary
school. However, the gap of education level is relatively small. It can be concluded that most
respondents in this municipality at least are literate.
Table 4-2: Educational Level of the Residents SurveyedEducational level %
primary school or less 55
secondary school 24
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diploma 11
bachelor degree 10
Public institutions
In municipal area, as noted in Chapter 1, there are several water users rather than the
household sector but focus of this study is on public institutions. Background of selected
public institutions including two temples, two schools and one health station described here
covers only an average number of users in these institutions as shown in Table 4-3.
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Table 4-3: Number of Users of Selected Public Insitutions
Institution Name Number of usersTemple Bangsaiy Nai* 10
Bangsaiy Nok* 6School Wat Bangsaiy Nai 250
Bangsaiy Wittaya 800Health station Taolao 15Note: * The number presented includes only monks living in the temples. In a monk holy day and special eventsof Buddhism, local residents come to the temples to do some activities. The average number of users for suchactivity could rise up to one hundred per day.
4.2 Demands in Water Supply and Drinking Water
4.2.1 Household users
From the survey, all respondents are connected to the piped water. Given various sources of
water, a frequency of respondents using water from each source is depicted in Figure 4-2.
There are 29 households using rainwater and 20 households using water from the river or
canal.
Figure 4-2: Frequency of Water Users from Different Water SourcesSource: Field Survey (2009)
In terms of water function, it is found from the survey that the different source of water is
used for different fuction, for example a household may use piped water for housework and
showering while bottled water is bought from vendors for drinking and water from river is
taken for gardening. Figure 4-3 shows that water is mostly used for housework such as
cooking and cleaning as a highest proportion of respondents selected this function as the first
rank (42 respondents). Other than being used for housework, respondents use water for
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gardening function more than drinking as a larger numbers of respondents put gardening
function in the first rank more than drinking.
Figure 4-3: Water Demands in Different Functions
Demands in water include quality and quantity. In terms of quantitative demands, as shown in
Table 4-4, 34 % and 33% of the surveyed households use water at the range of 400-600 and
100-400 cu.m. respectively. More than 90% of the respondents use water lower than 800
cu.m. per month.
Table 4-4: Frequency Distribution of Volume of Water Demands Per Month
Volume of water usage per month (cu.m) %
40-100 4.3
101-400 33.0
401-600 34.0
601-800 22.3
8,001-1,000 4.3
1,001-1,200 2.1
Total 100.0
In terms of qualitative demands, those who use piped water are not fully satisfied in quality
of service. Water flowing is the first concern. Water quality and smell are also the top
concerns (Figure 4-4).
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Figure 4-4: Frequency of Dissatisfaction with Quality Demands of Piped Water
In terms of affordability to pay for water tariffs, 94 % of respondents are able to pay on a
monthly basis while 6% cannot sometimes afford the tariff and skip the payment from time to
time. 70 % of the respondents perceive that the water tariff is appropriate while 30 %
perceive that it is expensive (Table 4-5).
Table 4-5: Percentage Distribution of Perception in Water Tariff
Price Satisfaction %
Very Expensive 0
Expensive 30
Appropiate 70
Cheap 0
Total 100%
For drinking water, there are three main water sources which are rainwater and piped water
and bottled water. Bottled water is the most popular while no respondents use rainwater as a
water source for drinking (Figure 4-5). It should be noted that some respondents use water for
drinking more than one source. For example, some households buy drinking water from
vendors and they also boil rainwater for drinking. There are 65 surveyed households buying
bottled water from vendors, 50 surveyed households filtering or boiling piped water before
drinking and 16 surveyed households filtering or boiling rainwater before drinking.
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Figure 4-5: Frequency Distribution of Different Soruces of Drinking Water
4.2.2 Public institutions
The demands in water supply and drinking water of the selected public institutions are similar
to the household sector. All the institutions are connected to piped water. The two temples
and Bangsaiy Wittaya School have their owned groundwater wells located on-site while
Bangsaiy Nai School and Taoloa Health Station are connected to the piped water systems of
the municipality. None of them use rainwater although some of them such as Bangsaiy Nai
School have rainwater tanks and jars put in place. All the institutions use both piped water
treated with an on-site filtration device and bottle water except Bangsai Nok Temple which
relys solely on bottled water.
4.3 Demands in Rainwater Utilization
4.3.1 Household users
Although majority of households in Bangsaiy Municipality are connected to piped water,
some households still have jars and use them for collecting rainwater. Based on the survey,
78 % of the respondents have jars, of which 61 % do not use rainwater collected and 17 %
use it. 22 % of the respondents do not have jars and not do use rainwater as shown in Figure
4-6. It means that a large proportion of households have jars without using them. There are
three reasons of having jars. First, there is a belief that if ordaination takes place, a new jar
should be bought and placed in front of the house. Second, there was a policy from central
government ten years ago to provide jars for local people living in rural areas. This policy
aimed helping people to cope with water shortage in the dry season. Third, jars have been a
container for collecting rainwater for drinking.
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Figure 4-6: Percentage of Households With and Without Jar
Each household uses rainwater for different functions. Some households use rainwater more
than two functions such as drinking and housework. From the survey, Figure 4-7 shows that
37 and 35 % of the respondents who still use rainwater collected for drinking and gardening
respectively.
Figure 4-7: Percentage of Residents using Rainwater in Different Purposes
In terms of quanlitative demands of rainwater, the top two concerns are water quality and dirt
contamination. Although the problems of smell, turbidity, dirt and taste are not highly
significant, these concerns would be taken into consideration when a pilot project is designed.
(Figure 4-8). It shoud be noted that the respondents could select more than one concern in
rainwater quality.
%
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Figure 4-8: Dissatisfaction With Quality Demands in Rainwater
According to the observation and questionnaire survey, it is found that majority of the local
dwellers are interested in using rainwater if its quality meets the standard. 91 % of the
respondents are interested in using rainwater, while 6.5 % are not interested and 2.5 % are
interested if they encounter some problems with current water supply (Table 4-6).
Table 4-6: Interest of Rainwater UtilizationInterest of using rainwater %
Interest 91
No interest 6.5
Interest if current water supply has some problems 2.5
The largest proportion of respondents (65 households) prefers to use rainwater for drinking.
In addition to drinking, they prefer to use it for housework (45 households) and gardening (58
households) as shown in Table 4-7. If we consider portable and non-portable use, the local
respondents prefer to use rainwater as a non-potable source including gardening and
housework (103 households). It should be noted that the respondents could select more than
one preference of rainwater functions.
Number of respondents
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46
Table 4-7: Number of Respondents and Their Preference in Using Rainwater for DifferentFunctions
Function No.of HH
Housework 58
Drinking 65
Gardening 45
Other purposes 5
Total 173
4.3.2 Public institutions
Table 4-8 summarizes demands in rainwater utilization of the five public institutions selected
and interviewed in this study.
Table 4-8: Demands in rainwater utilization of selected public institutions in BangsaiyMunicipality
Demands in rainwaterutilization
Institutions
BangsaiyNok
Temple
BangsaiyNai
Temple
WatBangsaiy
Nai School
BangsaiyWittayaSchool
Taoloahealthstation
Current use of rainwater No No No No No
Rainwater collection andstorage devices
No No 4 tanks atcapacity of
33 cu.m.and gutter
systems
No No
Concerns in rainwaterquality
Bird droppingcontamination
Dirt Chemicalsubstances
Dirst andchemical
substances
Chemicalsubstances
Interest of rainwaterutilization
No Yes Yes No Yes
Prospected purposes ofusing rainwater
No Potable use Portableand non-potable
use
No Portableand non-potable
use
4.4 Roles and Perceptions of Stakeholders in Rainwater UtilizationBelow is a list of stakeholders who play key roles in water supply and saniation services in
Bangsaiy Minicipality. Their roles in being responsible for water suplly services and their
perceptions in rainwater utilization of each stakeholder are described in this section based on
the interview and focus group discussion undertaken.
Municipality – Policy of municipality on provision of water supply and drinking water
services are influential in the success of promoting and implementing a rainwater utilization
project. Currently, groundwater is only one source of water supply for domestic use. Quantity
is not an issue in the municipality area due to the abundance of groundwater resources.
Although quality of the piped water is not poor at the moment, but the municipality has
planned installing treatment systems to improve water quality for non-portable use. Given that
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47
the water tariff charged by the municipality is relatively low, increasing the tariff is likely and
it will probably be an issue in forthcoming due to the high price of electricity for pumping up
groundwater. At present, the municipality does not have policy in promoting using rainwater
as an alternative water source. However if a pilot project of rainwater harvesting is proved of
its potential and benefits, the municipality can provide financial support for replicating the
pilot.
Environment NGO – There is an active environment NGO in the municipality. It consists of
students and a group of teachers from the schools in Bangsaiy District. This NGO has a strong
linkage with similar NGOs in the other districts of Ayutthaya province. At present, water
saving or coping with water shortage is not a mission of this NGO and so for rainwater
harvesting. However this NGO has a potential in teaching and encouraging children in the
municipality area to make them aware of benefits gained and importance of rainwater
harvesting. Basically, the Chief of the NGOs perceives that rainwater harvesting would bring
benefits to the local residents as rainwater is a free water resource. It is worthwhile to repair
existing collection and storage devices to help reduce costs of water. Given that rainwater
quality is a concern, a suggestion from the NGO is that monitoring quality of collected
rainwater after installing a pilot project is needed in order to prove efficiency and advantages
of the pilot project and to educate water users.
Health stations and District Public Health Office – Public health agencies are responsible for
the quality of drinking water. These agencies can help testing quality of rainwater harvested
whether it meets standards.
Village committees – At present, water supply services in 9 villages of Bangsaiy Municipality
are run by their village committees. Some of which even has potential in manufacturing
bottled water. Generally, based on questionnaire survey and focus group discussion, rainwater
is preferable source of drinking water for Bangsaiy residents, if it is treated properly, and so
for village committees. Hence it is likely that a pilot project can be implemeted in such
villages where manufacturing bottled water is taking place. By implementing rainwater
harvesting system, a centain extent of substitution of groundwater with rainwater can help the
villages reduce some expenses particularly electricity costs spent for pumping the
groundwater up.
4.5 Summary of User Demands
Water conservation is not a high key issue in Bangsaiy Municiplaity because of low water
tariff and abundance of groundwater. This means that demands in quantity is fulfilled.
However quanlitative demands are still required particularly drinking water if ranwater is used
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as a source. Since dirt and dust contaminated from the first flush of rooftops while the rain is
initially fallen, a pilot project must be designed in a way that can prevent these contaminants.
From the survey, it is found that expenses for drinking water are relatively high. It can be
interpreated based on the survey findings that the local residents are not affordable to pay for
high capital investment like installing an on-site purifying water device. This can be seen from
the high percentage of local residents who currently buy bottle water. Obviously, there are two
levels of service for the bottled water. In general, private operators offer delivery services with
more expensive water costs. Contrary to the delivery service, the community-owned-
enterprises sell bottled water at lower rates but the buyers have to get the water by themselves.
Due to the affordability to pay, a pilot project which has a lower level of service but provides
drinking water at a low price is likely to be successful more than an on-site system with a high
level of service at a high price. Community-owned-exterprises seem to match to these
demands but they need to receive financial support from the government for initial investment
and reserved funds.
In the municipality, more than half of households have already devices for collecting and
storing rainwater, so a pilot project being designed to serve household level should not be
different from the existing systems so that people can handle it conveniently and successfully.
In addition, no extra large budget is required if a pilot project can build upon the systems
which have been abandoned. For a large pilot project with more complicated operation and
maintenance systems, it can be installed where the community-owned-enterprises are located
as these communites are capable of coping with an advanced operation and maintenance
systems.
Apart from designing a pilot project to meet the user demands, educating water users to
realize in benefits gained from a rainwater harvesting pilot project is very important. The
education should be conducted to make them ensure in quality of rainwater.
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CHAPTER 5
PRELIMINARY DEVELOPMENT OF RAINWATERHARVESTING IN BANGSAYI MUNICIPALITY
The development of rainwater harvesting in Ayutthaya could be adopted by assessing the
value of rainwater harvesting systems. In this area, with reliable municipal water supply for
use within commercial developments to supply or augment potable water used in toilet
flushing and landscape irrigation. Given the low tariff of water supply (4 to 5 THB per cu.m.),
almost end users are satisfied. However, there are some water quality issues which should be
concerned such as turbidity, water flow, and contamination of dust as aforementioned in
Chapter 4. To develop sizing approach for rainwater harvesting systems, the following water
balance should be considered (Heather, 2007);
Supply ≥ Demand
To develop the supply side of the equation, monthly rainfall and catchment area must be taken
into consideration. For the demand side, it could be developed based on a certain context of
study area such as socio-economic conditions and cost estimation. In the study area where
water supply tariffs are relatively low compared to the costs of drinking water (at the average
of 5 to 12 THB per litre), the highest potential to preliminarily develop rainwater harvesting in
terms of demand could be for drinking water compared to other purposes. Based on the
questionare survey and interviewing, more than 90% of water users are willing to use
rainwater for drinking because of its good taste and the culture of people in this area but the
quality of rainwater should be in acceptable level. However, at present, the local residents use
rainwater for non-potable purposes such as gardening. Therefore, a pilot project could be set
up and applied based on the results in potable and non potable uses. For drinking water
purpose, it is necessary to have a treatment system to meet the WHO standards. For non-
potable purposes which can be used for toilet flushing, gardening or cleaning, such treatment
processes are not much concerned. However it should meet the user demands. From findings
of users demand for the household sector, the quantitative demands are at an approximation of
30 to 50 cu.m. per month. For public institutions, quantitative demands of the selected schools
are highest compared to other institutions at 100 cu.m. per month.
5.1 Criteria for Designing Appropiate Pilot Project
The main design criteria of rainwater harvesting can be classified as followings.
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a) Materials
Roof materials should be avoided painting or using materials which contain lead. Lead based,
bitumen- based (tar) coating and paints are not recommend, as they may leach hazardous
substances.The lead level detected in the rainwater samples collected from Ayutthaya as
stated previously in Section 2.2.2 shows that the cement roofs widely used in the country do
not cause lead contamination in rainwater. Hence in the study area, the cement based without
coating is suitable for collecting rainwater.
A wide range of materials is made of rainwater tanks and jars such as plastic, ferrocement,
stainless steel, and polyethylene. All kind of tanks should be cleaned periodically.
Gutters and pipes can be divided into main two types which are metal and plastic. Material
recommended for pipe is polyethylene because metal may contain lead and hazardous
substances.
b) Taste and odor
The taste and odor of rainwater can be deteriorated by algae, dead animals, soil and decayed
vegetation accumulated in the gutter and tank. Therefore, the tank and gutter must be cleaned
and tank should be covered to protect mosquitoes and organic matters.
c) Disinfection methods
The disinfection can be made by chlorination, UV radiation, boiling, and filtration. The most
common use in the study area is boiling. UV radiation can be used but the UV lamp has to be
changed based on its life time. A water filter can be installed to enhance water quality. If
filtration is selected, maintenance needs to be adequate. Filtration processes such as
membrane, activated carbon, resin and reverse osmosis (RO) need to be maintained according
to instructions recommended by manufacturers to avoid problems.
First flush devices can be additionally installed to reduce contaminants and keep the roof
catchments clean.
e) Size of storage vessels
The size of storage vessels depend on:
Volume of water needed;
Volume and pattern of rainfall;
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Area of roof catchment; and
Security of supply required.
Volume of water needed: The volume of water needed may vary from one area to another.
Quantitative water demands depend on the number of people, average consumption per person,
the ranges of use, the use of water conservation and devices.
Volume and pattern of rainfall: Commonly the information source of rainfall is Department
of Meteorology. Additionally, it is important to consider yearly variation, seasonality of
rainfall and the occurrence and length of dry periods.
Area of roof catchment: Roof areas must be calculated to estimate volumes of rainwater
harvested. The flat or plane area should be determined. The slope and area of tiles or metal is
not the main issue.The average catchment area for small, medium and large houses are
aproximately 100 – 150, 150 – 200, and > 200 s.q.m respectively.
Security of supply required: In an area without main water supply, rainwater can be a
valuable source of drinking water. The study by Conway (1999) examined rainwater
harvesting in an arid location in Central Australia where the average rainfall is only 119 mm.
per year. A house with a roof catchment area of 266 s.q.m. is able to collect 61.25 kL of water
in a 27 kL tank and provide 168 L of water per day. In worst case of 40 years rainfall of 9.5
kL, rainwater could be collected to provide water supply of 26 L per day. The rainwater
collected would not be sufficient for all purposes but it could provide drinking water. This
could be particularly important in the areas where groundwater is too salinity and hard to treat
as drinking water. In the area with plenty of water supply like Ayutthaya, rainwater can be
used for non-potable and potable functions. The use of rainwater as an alternative source of
water for any purposes has the potential to reduce pressure on the limited surface and ground
water resources used to supply water to urban and rural communities.
One problem of designing size of rainwater tanks is space limitation. This problem in the
study area can be resolved by installing rainwater tanks at a community centre where a large
space is available.
5.2 Design of Pilot Project for Rainwater Harvesting Systems
Based on the survey of user demands, two scales of rainwater harvesting systems are
appropriate to the context of Bangsaiy Municiplaity. One pilot system should serve household
users and the other serves public institutions.
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Capacity: The maximum volume of rainwater can be calculated by using the below equation.
Run off (litres) = A x (rainfall – B) x roof area (s.q.m.)
where
A = 80-85% collection efficiency (Martin, 1980)
B= the lost associated with absorption and wetting of surfaces a value of 2 mm permonth (24
mm per year) ( Martin 1980)
The estimate tank size can be calculated by using following equation for each month;
Vt = Vt-1 + ( run off – Demand)
where
Vt = theoretical volume of water remaning in the tank at the end of the month
Vt-1 = Volume of water left in the tank from the previous month
The volume of run off could be calculated by using 80-85% collection efficiency of using
system in first flush.
5.2.1 Pilot 1
Technology: The simple treatment for developing countries is a practical treatment method
which is inexpensive. Improvement of rainwater quality can be simply made by installing a
first flush device which is cut off the first flush of rainwater event. It is easily to be installed,
simple operated and available in a number of different sizes to suit to different requirments.
For disinfection, filtration with membranes, radiation with UV and chlorination can be
applied. For drinking water, a filtration system with a low- pressure membrane of a pore size
of 0.1 mm. can be effectively removed protozoa, bacteria, algae and other microorganisms. A
membrane module can consist of a fine-meshed sieve with some 10,000 porous plastic fibers
that forms a web within a cylindrical housing. A pump propels contaminated water from
outside of the module through the membrane to the inside. Any particle exceeding 0.1 mm. -
which includes all bacteria – literally gets stuck. However, the treated water may still be
contaminated with some viruses. With a diameter less than 100 nm, viruses are small enough
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to slip through the pores. That is why a filtration device is therefore coupled with a
disinfection system. The study by Areerachakul (2009) demonstrated that the combination of
Granular Activated Carbon (GAC) – biofilter- and submerge membrane could be another
option to treat the rainwater to meet the drinking water standard.
Therefore, the pilot project of rainwater harvesting system for potable use should compose of
i) first slush device, ii) gutter, iii) pipes, iv) storage tanks and v) treatment systems. For the
pilot project materials of harvesting systems could be available in various materials based on
catchment size, rainfall daily, and cost of material.
Capacity: 5,000 gallons (150,000 litre)
Location: In this study, a possible site suitable for the pilot project is the household where
water treatment systems for drinking water are put in place and its location is at the center of
the community. This house which is a grocery currently provides drinking water for their
relatives and sells bottled water. Additionally, its catchment area is large enough to serve for
3-4 households.
Cost estimation and financial assistance: Costs of a pilot project of rainwater harvesting
system serving for a household without water treatment systems are estimated at less than
50,000 to 80,000 THB. Such system consists of below components.
Table 5-1: Components of a Pilot Project and its Cost Estimation Designed for HouseholdUsersComponents Cost (THB) Specification
Storage system
A plastic tank 20,000 - 30,000 Volume of 1,500 to 2,000
gallons per tank
A pump 7,000 to 10,000 1/2 horsepower shallow-
well at 20-30 psi
Screen covering the cistern < 3,000
Plastic pipes Costs are varied depending
on length and diameter
PVC for outdoor and CPVC
for indoor
Conveyance system
A roof-washer Varied based on roof area
but < 10,000
Water diaphragm pressure
storage tank
5,000 Volume of 20 gallons
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Treatment system
A series of filters 800 bahts each Pore sizes at 20 and 5
microns
Replaceable filter cartridges 3,000
An ultraviolet light 15,000 Sterilizing capacity at 10
gallons per minute
40 watts
Maintenance costs are approximately 5,000 THB per year which include costs of cleaning the
gutters, cisterns and screen. Replacement of UV lamps and filters need to be done
periodically. Cost of a fluorescent tube is about 3,500 THB.
Appendix III-A gives an example of detailed designing and cost estimation of a rainwater
harvesting system with a 5,000 gallon of ferrocement vessel.
For the system without treatment process because of existing treatment sytem, the cost could
less than 100, 000 bahts as shown in table 5.1.
Critical success factors: Public health authorities recommend periodic testing of water for
faecal coliform bacteria to make users confident in rainwater quality.
5.2.2 Pilot 2
Technology:The pilot 2 use similar technolgy with pilot 1. In this study, an estimate each tank size for is
1,500 gallons (30,000 litres). The total tank are 6 tanks, therefore the estimated total volume
are 180,000 litre (based on existing tank inschool). The details of calculating tank size are
shown in Appendix III-B.
Location: The possible effective site is at Wat Bangsai Nai School.
Costs and financial assistance: Six existing tanks will be selected to be renovated. If the
tanks cannot be renovated, estmated cost of purchasing a new tank is about 30,000 to 50,000
THB. The existing filtration system can still be used by connecting it to the renovated
rainwater harvesting system. However, the new treatment system may be installed to compare
maintainance costs between using groundwater and rainwater. The cost of renovation and
installing a new treatment system is about 150,000 to 200,000 THB. Only minor cost of
piping system, and maintainance could be a bit higher comparing with pilot 1. However, with
first flush device, and higher gravity pressure because of tank size, the cost to treat rain water
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and pump is not significantly different comparing with pilot 1. The total cost would be
400,000 THB.
.Critical success factors:
The periodic water quality test and maintenance are recommended. The variable of annual
rainfall may affect the capacity of rainwater harvesting system.
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CHAPTER 6
Conclusions and Recommendations
6.1 Conclusions
Potential of Using Rainwater
Similar to other regions in Thailand, rainwater is one of important sources for domestic water
supply for both non-potable and potable use in Bangsaiy Municipality for a long period. Being
located in Ayutthaya where the average annual rainfall of 1,347 mm. is not as high as other
regions such as southern part of Thailand, the rainfall in Bangsaiy Municipality, if harvested,
is sufficient for portable use particularly drinking and cooking throughout the year for the
whole year and other domestic purposes in the long rainy season. Although the quality of
rainwater has been much a concern of the local residents due to the increase of polluted
environment, in accordance with past studies and research, chemical parameters particularly
heavy metals meet the drinking water standards. High biological contaminants which mainly
come from flusing rooftops when rainwater is harvested at the beginning of the rainfall can be
removed with hygienic handling of rainwater, improving rainwater collection methods and
installing simple treatment systems. According to the questionnaire survey and field
observation, approximately, one third of households have rainwater conveyance and storage
facilities put in place, although some of such facilities are not in good conditions. Considering
supply side, with no doubt, there is a high potential in rainwater harvesting in small urban
areas like Bangsaiy Municipality.
Assessment of User demands in Rainwater Utilization
In addition to the supply side, assessment of user demands is applied in this study to reduce
risk of failure when a pilot project of rainwater harvesting is really implemented. Demands are
assessed in five dimensions including quantity, quality, willingness to pay, levels of service
and operation and maintenance of rainwater harvesting facilities. The key users including
household users and public institutions were assessed their demands in this study.
For household users, piped water supply from groundwater nearly covers all areas of Bangsayi
Municipality at present. As a consequence, quantitative demands in rainwater are declining. In
contrast, qualitative demands are still high both for rainwater and piped water. Physical and
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biological contaminants - such as bird droppings, dust, and pathogenic organisms - and
asthetic apperances are at the top concerns in water quality of the surveyed households. As
such, it is necessary for the local residents to seek alternative water sources which are safer or
to improve quality of available water sources, mainly piped and rainwater, for drinking.
According to the survey, purchasing bottled water and treating water by boiling or purifying it
with on-site purification devices are among dominated options of drinking water. Given the
local culture and confidence in using rainwater in the past, a high demand level of using
rainwater is found in this study. More than 90% of respondents are interested in using
rainwater if its quality meets the standard.
Nowadays piped water tariffs are considerably low ranging from 4 to 5 THB per cu.m.
Approximately, 70% of household surveyed are satisfied with the current rates. However, the
tariffs cannot be maintained at these rates for long because of the increase of fuel prices which
are main operating costs for pumping groundwater. Therefore using rainwater as an additional
water source can help reduce water expenditure. On the contrary, expenses in relation to
drinking water such as purchasing bottled water and installing purification equipment are
relatively high. Given the circumstances of the high payment for drinking water, it is reflected
in a finding from the survey that 63% respondents who currently purchase bottled water are
interested to shift to using rainwater as a source of drinking water if its quality is improved.
This proportion can be future target users of using rainwater for drinking if a pilot project is
implemented.
Levels of service of the current water supply are very high as almost every household can
access individually to the piping system. For supplying drinking water, there are two levels of
service. Those who could afford moderate to high prices of water costs could gain a higher
level of service such as home delivery services of bottled water run by private operators and
installing on-site purification equipment. Relative low prices of drinking water are also
available with a lower level of service. This appears in the case of drinking water services of
community-owned-enterprises in which prices of bottled water per gallon is in average 5 THB
cheaper than prices fixed by private enterprises but users must be proactive in access to the
drinking water by themselves. Therefore a pilot project of potable and non-potable rainwater
shoud be designed in such a way that deliveries of stored rainwater for domestic use is similar
to, or at least not lower than, the current levels of service.
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Rainwater coveyance systems and storage devices installed at households are operated and
maintained by their owners. Operation and maintenance activities are basically simple for
example periodic cleaning the conveyance systems and devices and repairing and changing
broken equipment. The current piping and treatment systems of water supply require
maintenance by technicians. Similarly, installed on-site purification systems for production of
drinking water require periodic maintenance by professionals such as changing filters or
membranes. Therefore on-site rainwater harvesting systems of a pilot project for non-potable
use which installation of filtration and disinfection are not necessarily added, it shoud be
designed to be easily operated and maintained by their owners. Otherwise, if advanced
rainwater harvesting systems are required in case of potable water, there is a demand in
enhancing capacity of local technicians. Alternatively, getting technicians of private operators
in water supply sevices in touch with the local users has to be initiated to help prevent
operation and maintenance problems foreseenable in long run.
For public institutions, based on interviewing, there are two key factors influencing demands
in rainwater utilization. The first one is the desire to conserve historical traditions related to
rainwater utilization. The second one is related to creating awareness and educating young
generations in water conservation. Apart from these, basically, the other demands are similar
to household users.
Design of a Pilot Project for Rainwater Harvesting Systems
Rainwater harvested can be used as potable and non potable use. However using rainwater for
drinking has more potential and directly responds to the demands of household users and
public institutions. For portable use, rainwater must be treated to remove the contaminants and
generally the main required treatment processes are filtration and disinfection. The existing tank
in schools could be use as integrate water resource during dry period. Furthermore, this
rainwater could be combined with drinking water treatment sytem in school and/or household
to mak drinking water as alternate resource. Additionally, Rainwater harvesting system in the
study area could be combined with the existing system as shown in Appedix IIb
However, to develop future potable water usage such as drinking water, some simple
treatment have to include such as first flush device. Therefor, in this study, the possible site
location could locate in school and in household which locate in communities because of the
high potential to supply rainwater for consumption.
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6.2 Recommendations
In other part of Thailand and developing countries, the design pilot project might be change
depending on annual rainfall and catchment area. Acceptionally, the main system of rainwater
harvesting woul be the same. For example, in North East of Thailand which has shorter period
of rainy season and less annually rain fall, the larger storage and larger catchment area may
define to use and adaptable.
As mention the results from questionares, the main critical factor to do drinking water from
rain water is the quality of rainwater. People in study area worry about water quality and also
some disease especially bird flu. It is recommended that the pilot project should not much big
size to test the drinking water and make sure that people accept the quality of drinking water
from rainwater.
For nonpotable purpose, there are 6 ferrocements in Wat Bang Sai Nai schools already made
but need to maintainace and fix the systems. These could be run as model for non potable use
which is safe cost more than doing the new one. For alternative drinking water, By pass use
with existing drinking water treatment sytem are available.
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Appendices
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Appendix I - General Supporting Data
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Appendix I-A: Research Objectives, Datesets, Data Sourcesand Data Collection Techniques
Research
Objective
Dataset Data Source Data Collection
Technique
To evaluate
potential of using
rainwater as an
alternative water
source in small
urban communities
Socio-economic
conditions: age
distribution, gender
proportion, educational
level, landuse, and
culture
- Local government
- Village leaders
- Review of
secondary data
- Interview
- Observation
Environmental
conditions: : water
resources and quality,
climate, rainfall levels,
water supply systems,
air pollution
-Local government
- Department of
Meteriology
-Department of Water
Resourses
- Pollution Control
Department
- Review of
secondary data
- Interview
- Focus group
discussion
Behaviour, attitude
and perception
- Village leaders
- Villagers
- Questionnaire
survey
-Interview
-Observation
-Focus group
discussion
Policies and plans of
local government in
relation to water
issues
- Local government -Review od
secondary data
- Interview
To assess current
gaps of water
supply services
- Quantity
- Quality
- Levels of service
- Affordability and
willingness to pay
- Villagers ande other
users such as temples,
schools and other public
agencies
- NGOs
- Questionaire
survey
- Interview
- Focus group
discussion
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- Operation and
maintenance
- Service providers
To assess user
demands in
rainwater
utilization;
- Quantity
- Quality
- Levels of service
- Affordability and
willingness to pay
- Operation and
maintenance
- Villagers ande other
users such as temples,
schools and other public
agencies
- NGOs
- Service providers
- Questionaire
survey
- Interview
- Focus group
discussion
To design a pilot
project of
rainwater
harvesting systems
which correspond
to the user
demands
- Average size of
roofs
- Estimated costs of
collection and
storing devices
- Estimated costs of
parts for a treatment
system
- Villagers and village
leader
- Internet (Market prices)
- Observation
- Interview
- Secondary
data
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Appendix I-B: Questionaire
แบบสอบถาม
ความตองการการใชน้ําและการใชน้ําฝน ในอําเภอบางซาย จังหวัดพระนครศรีอยุธยา
คําช้ีแจง:
แบบสอบถามนี้ ออกแบบเพ่ือการศึกษาวิจัยเกี่ยวกับ การใชน้ําและการอนุรักษน้ําฝนของประชาชนในที่อยูอาศัย
กรุณาทําเคร่ืองหมาย ในขอความที่ตรงกับความเปนจริงหรือความคิดเห็น ของผูตอบมากที่สุด
สวนที่ 1: ขอมูลสวนตัว
1.ชื่อหัวหนาครอบครัว/บุคคลที่สัมภาษณ
(ความสัมพันธกับหัวหนาครอบครัว)
ชาย ( ) หญิง ( )
2. ที่อยู
…………………………………………………………………………
………
………………………...…………………………………………………
……
…………………………………………………………………………
………
3. เบอรโทรศัพท
4. อาชีพ
สวนที่ 2: สภาพเศรษฐกิจและสังคม
5. จํานวนครอบครัวในที่พักอาศัยหรืออาคาร
6. จํานวนสมาชิกในที่พักอาศัยหรืออาคาร
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7. รายไดเฉลียตอเดือนของครอบครัว (รวมรายได
ของสมาชิกทุกคนในครอบครัว(
8. การศึกษา ( )ประถมศึกษา ( )มัธยมศึกษา/ปวช ( )ปวส/อนุปริญญา
( )ปริญญาตรีขึ้นไป
สวนที่ 2: สภาพและเงื่อนไขปจจุบัน
9. แหลงน้ําที่มีหรือใชในบาน) ทําเคร่ืองหมายทุก
แหลงที่เคยใช (
(i) น้ํา ประปา ( ) (ii) บอน้ําต้ืน ( )
(iii) น้ําบาดาล ( ) (iv) แมน้ํา ( )
(v) ค/ูคลอง ( ) (vi) น้ําฝน ( )
(vii) น้ําขวด ( )
(viii) แหลงอ่ืนๆ ( ) ระบุ ……………………………………
10. ทานใชน้ําในประโยชนใชสอยหรือกิจกรรม
ใดมากที่สุด )1-3เรียงจากมากสุดไปนอยสุด(
( ) ในครัวเรือน เชน หงุตม ,ซักผา ,ชําระลาง
( )ดื่ม
( )นอกครัวเรือน เชน ทําสวน ,รดน้ําตนไม
( )อุตสาหกรรมในครัวเรือน เชน ทําน้ําผลไม ,รานอาหาร )โปรดระบุ……......)
11. ครัวเรือนใชน้ําตอเดือนเทาไร )กรุณาขอถาย
เอกสารบิลคาใชน้ําเดือนลาสุด (
โดยเฉลี่ยตอเดือนปริมาณการใชน้ําตอครัวเรือน = ………………. ลิตร/ลบ.ม .
12. คุณจายคาน้ําทั้งหมดเทาไร บิลคาน้ําเฉลี่ยตอเดือน = ……………………บาท
)กรุณาขอถายเอกสารบิลคาใชน้ําเดือนลาสุด(
13. คุณคิดวาบิลคาน้ํา ถูก หรือ แพง แพงมาก แพง กลางๆ ถูก ถูกมาก ไมรู/ไมมี
ความเห็น
14. ยากหรือไมในการจายคาน้ําสําหรับครอบครัว
ของคุณ
ยาก ( ) ไมยาก ( )
16. คุณมีปญหาเกี่ยวกับน้ําในครัวเรือนหรือไม
(ทําเคร่ืองหมายทุกขอที่มีการกลาวถึง (
มี ( ) ระบุแหลงน้ําน้ําที่ใช:…………………..
(i) คุณภาพน้ําไมดี ( ) (ii) น้ําถูกตัด ( )
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(iii) น้ําไหลไมแรง ( ) (iv) มีกลิ่น ( )
(v) สีไมใส ( ) (vi) ไมสะอาด ( )
(vii) ใสคอรีนมากเกินไป ( ) (viii) รสชาดไมดี ( )
(ix) น้ํากระดางมาก ( ) (x) อ่ืนๆ โปรดระบุ ( )
……………………….
ไมมี ( ) ……………………………………………………….
17. ปจจุบันทานไดนําน้ําฝนมาใชหรือไม ใช ( ) ไมใช ( ) – ขามไปขอ 21
18. ทานนําน้ําฝนมาใชในประโยชนอะไรบาง(ทํา
เคร่ืองหมายทุกขอที่มีการกลาวถึง (
( ) ในครัวเรือน เชน หงุตม ,ซักผา ,ชําระลาง
( )ดื่ม
( )นอกครัวเรือน เชน ทําสวน ,รดน้ําตนไม
( )อุตสาหกรรมในครัวเรือน เชน ทําน้ําผลไม ,รานอาหาร )โปรดระบุ……......)
19. ถาทานใชน้ําฝนปญหาอะไรที่คุณเจอ
(ทําเคร่ืองหมายทุกขอที่มีการกลาวถึง (
(i) คุณภาพน้ําไมดี ( ) (ii) มีกลิ่น ( )
(iii) น้ําไหลไมแรง ( ) (iv) มฝุีนและสารอ่ืนเจือปน ( )
(v) สีไมใส ( ) (vi) ไมสะอาด (
)
(vii) รสชาติไมดี ( ) (viii) น้ํากระดางมาก ( )
(ix) อ่ืนๆ โปรดระบุ ( )
20. ทานพอใจกับคุณภาพน้ําฝนที่นํามาใชหรือไม พอใจมาก พอใจ กลางๆ ไมพอใจ ไมพอใจ
มาก
ไมรู/ไมมี
ความเห็น
21. ทานมีรางน้ําฝนและ/หรือตุมรับน้ําฝนในบาน
หรือไม
(i) มี ,แตไมไดใช เพราะ…………………………………………………..
(ii) มี ,ใชสําหรับ…………………………………………………………..
(iii) ไมมี
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22.ในครอบครัวของทานดื่มน้ําโดยตรงจากแหลง
น้ําอ่ืนๆหรือไม
มี, ใชน้ําขวด ( ) คาใชจายตอเดือนในการใชน้ําขวด ……………………บาท
มี, ( ) จากแหลง...........................................................................
ไมมี, กรองกอนใช ( )
คาใชจาย เพ่ือทําใหน้ําสะอาด เปนจํานวน …................…… บาท
ไมมี, ตมกอนใช ( )
ไมมี, กรองและตม กอนใช ( )
23. ทานมีวิธีกักเก็บน้ําใชอยางไร )ทํา
เคร่ืองหมายทุกแหลงที่เคยใช(
(i) ถังสเตนเลส ( )………ลิตร,…….ใบ
)ii) ถังพลาสติก ( )………ลิตร,……..ใบ
(iii) ตุมน้ํา ( )………..ใบ
(iv) บอน้ํา ( )
(v) อ่ืนๆ…………………………..
สวนที่ 3: การรับรูและคานิยมการใชน้ําฝน
24. ทานใหความสนใจเกี่ยวกับการกักเก็บและใช
น้ําฝนบางหรือไม
สนใจ ( ) เพราะ…………………………………
ไมสนใจ ( ) เพราะ…………………………………………………
บางคร้ังเมื่อมีปญหาน้ําหรือแลง ( )
25. ถาทานจะใชน้ําฝนปญหาอะไรที่ทานกังวล
(ทําเคร่ืองหมายทุกขอที่มีการกลาวถึง (
(i) คุณภาพน้ําไมดี ( ) (ii) มีกลิ่น ( )
(iii) น้ําไหลไมแรง ( ) (iv) มฝุีนและสารอ่ืนเจือปน ( )
(v) สีไมใส ( ) (vi) ไมสะอาด (
)
(vii) รสชาดไมดี ( ) (viii) น้ํากระดางมาก (
)
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(ix) อ่ืนๆ โปรดระบุ ( )
26. คุณคิดวาคุณจะนําน้ําฝนมาใชประโยชน
อะไรบาง (ทําเคร่ืองหมายทุกขอที่มีการกลาวถึง(
( ) ในครัวเรือน เชน หงุตม ,ซักผา ,ชําระลาง
( )ดื่ม
( )นอกครัวเรือน เชน ทําสวน ,รดน้ําตนไม
( )อุตสาหกรรมในครัวเรือน เชน ทําน้ําผลไม ,รานอาหาร )โปรดระบ…ุ…...)
27. คุณคิดวาตําแหนงถังเก็บน้ําฝนที่ใดที่
เหมาะสมกับพ้ืนที่ใชสอยในบานคุณ
( ) บนดิน ( )บนดาดฟา/หลังคา ( )ใตดิน ( )ไมมีความเห็น
……จบการทําแบบสอบถาม……
ขอขอบคุณในความรวมมือ
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Appendix I–C: Summary of Questionaire SurveyPart 1
1. Household Information
Number of families in a household
Number of families Frequency Percent1 71 72.52 17 17.43 7 7.14 3 35 - -
Missing 2 -Total 100 100.0
Number of members in a household
Number of members Frequency Percent1 2 22 8 83 20 204 25 255 23 236 15 157 3 38 3 39 1 1
Missing - -Total 100 100.0
Income in household/month
Income in HH/month No.HH Education No.HH
<3,500 - 20,000 71 Less -primary school 55
20,001 - 35,000 14 secondary school 24
35,001 - 65,000 8 diploma 11
65,001 - 85,000up 7 bachelor degree 10
Total 100 Total 100
2. Current situation of water utilization
Source of water utilization in household
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Source of water FrequencyTap water 99Pond 2Ground water 4River 16Canal 20Rainwater 29Bought water 95
*From 100 respondents
Rank of water usage demand in each function
Function most medium leastIn household usage 49 5 1Drinking 12 21 29Garden 32 23Small industry 4
Price of water usage per month in each household
Amount of water usage in eachhousehold (baht)
No.ofhousehold %
10-50 4 4.3%
51-100 31 33%
101-150 32 34%
151-200 20 21.3%
201-250 4 4.3%
251-300 0 0%
301-350 2 2.1%
351-400 1 1%
missing 6
Total 100 100.0%
Cost satisfaction of tap water
Cost satisfaction Frequency %Very expensive 0 0%Expensive 28 28.6%Appropriate 65 66.3%Cheap 0 0%Very cheap 0 0%No idea 5 5.1%missing 2Total 100 100.0%
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Affordability to pay of tap water according to schedule
Affordability to pay Frequency %Every month 94 94.9%Sometime 5 5.1%Rarely - -Missing 1Total 100 100.0%
Cleanliness water perception of people in currently situation of water supply
Problems FrequencyQuality of water 16Lack of service 4Discontinuity 51Smelling 18Turbid 3Dirty 15Chlorine 12Brackish 8Hard water -No problem 8No comment 6
The source and cleaned process of drinking water
Source and process of cleaned drinking water FrequencyFiltration from tap water 18Filtration/boiling from tab water 50rainwater -Filtration/boiling from rainwater 16Bought water 65
Cost for bought water per month
Cost for bought water Frequency %Less than 100.- baht 19 29.8%100 - 200.- baht 35 54.7%201 - 300.- baht 4 6.2%301 - 400.- baht 2 3.1%401 - 500.- baht - 0%501 - 600.- baht 2 3.1%601 - 700.- baht 2 3.1%More than 701.- baht - 0%Missing 1Total 65 100.0%
The container of drinking water
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The container of drinking water FrequencyKettle/ pot 3Plastic container 26Plastic bottle or glass bottle 17Other (Filtration, Glass, Jar) 5
The container of water usage in household
The container of water usage in household FrequencyStainless tank less than 50 L -Stainless tank 51 – 100 L -Stainless tank more than 101 L 1Plastic tank less than 50 L 4Plastic tank 51 – 100 L 16Plastic tank more than 101 L 24Jar 45Pond -Other ( cement pond, basin) 10Total 100
3. Current situation of rainwater utilization
Rainwater utilization in household
Rainwater utilization in household Frequency Percent
Yes 28 28.9%No 69 71.1%Missing 3 -
Total 100 100.0%
Function usage of rainwater
Function usage of rainwater Frequency Percent
In household usage 5 14.3%Drinking 13 37.1%Outdoor 12 34.3%Small industry 5 14.3%Missing - -
Total 35 100.0%
Cleanliness water perception of people in currently situation of rainwater
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Problems FrequencyQuality of water 30Smelling 4Discontinuity 2Dust and substance 18Turbid 3Dirty 29Taste 4Brackish 4
Quality satisfaction of rainwater
Quality satisfaction Frequency %Very satisfaction - 0%Satisfaction 4 14.3%Middle 10 35.7%Dissatisfaction 6 21.4%Very dissatisfaction 5 17.8%No idea 3 10.8%missing 7Total 35 100.0%
Number of household which have jars
Have jar No have jar Total
-Use rainwater 16 -
17%
-not use rainwater 60
61%
Total 76 21 97
78% 22% 100%
4. Perception and willingness of people to use rainwater
Willingness to use rainwater
Willingness to use rainwaterNumber of household %
Interested 82 91%Not interested 6 6.5%
Sometime when has problem 2 2.50%
Total 90 100%
Anxiety of people to use rainwater
Problems FrequencyQuality of water 70
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Smelling 24Discontinuity 3Dust and substance 72Turbid 27Dirty 57Taste 17Brackish 8
Functional demand of people to use rainwater
Functional demand of rainwater Frequency
In household usage 58Drinking 65Outdoor 45Small industry 5Missing -
Total 35
Opinion of people to install rainwater container
Position of install rainwater tank Frequency %On ground 65 72.2%On deck/roof 19 21.1%Underground - 0%No idea 6 6.7%Missing 10Total 100 100.0%
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Appendix I–D: Summary of Interviewing Key InformantsStake holder interview summary
The list included individuals who are actively involved in water issues and represent a crosssection of water regions across several major stakeholder groups including:
Municipalities Agriculture Environmental representation Regional Water Planning Federal and State Officials and User ( Health office,School)
Conclusions from the Stakeholder
1. Water conservation is not high significant issues among stakeholders because of low price
of water supply. However, the municipalities are not benefit from tab water and also lost more
than 90% due to electricity and maintainance.
People who are actively involved in water issues are most concerned about the water quality
including rainwater water quality because of the bird flue. Stake holder almost belive that if
rainwater can be used as drinking water. It will be the high potential because more than 90%
buy drinking water from vendor.
3. Virtually government stakeholder wants to see a statewide campaign to educate the public
about the need for rainwater utilization. In fact, education, simple treatment technology is
considered the top strategy for taking rainwater as drinking water or other purposes to the next
level in Bangsai.
4. Funding for utilization of rainwater is highly desirable, with strong support for a drinking
water pilot project and development of existing rainwater tank in school or temple in study
area.
5. Rainwater Utilization strategies included in the research are favored by most stakeholders.
Outside of these strategies, education and public awareness, and pricing or rate structures are
preferred by most stakeholders
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Appendix I–E: Summary of Focus Group DiscussionSummary of meeting/focus group and field visit notes
Place: ศาลาประชาคม หมู 1ตําบล แกวฟา อําเภอ บางซาย จังหวัด พระนครศรีอยธุยา
Date/time:
Team of researchers: ดร. ณัฐพร อารียราชกุล (นักวจิัยหลัก); น.ส. สรัญญา สุจริตพงศ (ผูชวยนักวิจยั); น.ส. ธนภัทร อานมณี
(ผูชวยนักวจิัย)
List of participants: 1. นาย สมศักดิ์ สันธินาค (ประธานเครือขายอาสาสมัครทรัพยากรธรรมชาติ และส่ิงแวดลอม)
2. นาง จินตนา พ่ึงฤทธี (ประธานกองทุนหมูบาน)
3. นาง สุมาลี ดวงดี (ผูใหญบานหมู 4 ตําบล บางซาย)
4. นาง บุญนะ จิตกังวล (ประธาน สหกรณการเกษตร บางซาย จาํกัด)
5. นาย อนุชา ผลเจริญ (สมาชิก หมู4 ตําบล แกวฟา)
6. นาย สมชาย บุญงาม (รับจาง)
7. นาย นอม (รับจาง)
8. นาย อนุชา กรุงสีฟา (ทํานา)
9. นาง ลัดดา สุเพียร (แมบาน)
10. นาย ธวัช วฒันคุณ (รองประธานชุมชนหมู1 ตําบล บางซาย)
11. คุณ กัลยา ยืนยวง
12. นาย สมนึก การุไช...
13. นาย ชยัณรงค เกียรติบัติ (ผูใหญบาน)
14. นาย ศริิ ผลเจริญ (ประธานนํ้าประปาหมูบาน)
15. นาย ทองหยด คาํศรี (กรรมการผูสูงอายุ)
16. นาย บุญเล็ก เกียรติยศ (สมาชิกสภาเทศบาลตําบลบางซาย)
17. นาย สําอาง เอียมสะอาด (สมาชิกสภาเทศบาล)
18. นาย ประวิทย เพชรแดง (แมบาน)
19. นาย ฉลอง การร่ืนศรี (ขาราชการบํานาญ, ประธานสภาวฒันธรรม)
20. นาย จาํนงค บํารุงเขต (ขาราชการบํานาญ, ประธานชมุชนหมู1 ตําบล บางซาย)
21. นางสาว สมาพร ธาราทรัพย (ผูใหญบาน)
22. นาย สยาม สัญูเดช (ประธาน ชมรมกาํนัน ผูใหญบาน อําเภอ บางซาย)
23. นาย วิรัช สุภีสุนทร (ผูใหญบาน)
24. นาย นิคม จิตกังวล (ผูชวยผูใหญบาน)
25. นาง ลัดดาวรรณ สาสนะ (ประธานชมุชนพอเพียง หมู3 ตําบล บางซาย)
Objectives of this meeting เพ่ือฟงความคิดเห็นของชุมชนและผูท่ีเกี่ยวของตอระบบตนแบบ
เพ่ือรับทราบแนวทางการจดัการระบบตนแบบหลังการกอสราง
เพ่ือนําผลท่ีไดจากการระดมสมองไปใชในการปรับปรุงการออกแบบระบบตนแบบ
เพ่ือเก็บขอมูลเพ่ิมเติมนอกเหนือจากท่ีทําการสํารวจจากครัวเรือนและการ
สัมภาษณหนวยงานท่ีเกีย่วของ
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Opinion and recommend ผูอํานวยการโรงเรียนวัดบางซายใน
สนใจโครงการน้ี โดยอยากใหแบงเปน 2ท่ีคือ นํ้ากรองไวใชในโรงเรียน และกรอง
ไวดื่ม
แนะนําใหนําไปติดตัง้ไว 1หรือ 2 ท่ีในโรงเรียน แลวคอยนําไปขยายผลในหมูบาน
ประธาน ชมรมกํานัน ผูใหญบาน อําเภอ บางซาย
ใหคํานึงถงึงบประมาณ วาจะเอามาจากไหน เชน เทศบาล หรือ สวนกลาง
ใหคํานึงถงึวาฝนไมไดตกตามฤดกูาล จะจดัการอยางไร
แนะนําใหเอาไปไวท่ีโรงเรียน เพราะขยายผลเปนแบบปากตอปาก โดยแนะนําท่ี
โรงเรียนวัดโคกตาพรหม เพราะนํ้าท่ีใชอยูเปนนํ้าบาดาล และเคม็
แนะนําติดตั้งท่ีบานกํานันดวย เพราะคนรูจักเยอะ
สมาชิกสภาเทศบาล
เทศบาลมงีบสนับสนุน
แนะนําใหไปตดิตั้งท่ี โรงเรียนบางซายวิทยา
สนใจใหไปติดตั้งท่ีบาน เพราะมคีนดูแล และมีเคร่ืองกรองขนาดใหญไวกรองนํ้า
บาดาลแลว
ประธานเครือขายอาสาสมคัรทรัพยากรธรรมชาติ และส่ิงแวดลอมเทศบาลมีงบ
สนับสนุน
เห็นดวยกับโครงการน้ี แตอยากใหรับรองเร่ืองคุณภาพนํ้ามากกวาน้ี
แนะนําใหทําในโรงเรียน, วัด หรือโรงงาน เพราะพ้ืนท่ีรับนํ้านาจะเพียงพอกวา
หลังคาบาน และงบประมาณในหมูบานนาจะไมเพียงพอ นอกจากน้ีขยายผลได
เร็วเพราะเด็กๆจะนําไปบอกผูปกครอง
แนะนําใหทํากระจายเปน 4 แหง จาก 16 อําเภอ (โครงการละ 4 อําเภอ) โดยอาจ
ทํา 2 ท่ีกอน: กลุมแรก บางซาย, เสนา, ลาดบัวหลวง, ผักไห; กลุม2 บางปะอิน,
หญาแพรก
เร่ืองราคาคานํ้า ตามกฎกระทรวงฯ ใหเก็บท่ียูนิตละ 11.-บาท แตตอนน้ีไม
สามารถเก็บได เพราะชาวบานไมยอม จงึเก็บยูนิตละ 4-5.- บาท
แนะนําวาหากทําในชุมชน ควรมทุีกชุมชน ชุมชนละ 50 ครัวเรือน
ผูใหญบานหมู 5 ตําบลแกวฟา
ในหมูบานจะมีระบบกรอง โดยใชแบบชาวบานคือ แสงแดด-ถาน-ขี้เถา-ทราย-
หิน-บอเก็บ และแจกจายใหชาวบานใช สวนในระบบดื่ม ท่ีมีระบบตางหากใน
บางซายมี 4 แหง: เตาเลา (ม.9), บางซาย (ม.7,ม.5), เทพมงคล (ม.3), แกวฟา
(ม.5)
ขาราชการบํานาญ, ประธานสภาวัฒนธรรม
แนะนําใหทําบาน คุณสําอาง เพราะเปนรานขายอาหาร และชมุชนหนาแนน
แนะนําวาถาเปนวดั ใหตดิตัง้ท่ีวดับางซายนอก
แนะนําวาจะไปตดิตั้งท่ีไหนก็ได แตท่ีสําคัญควรกระจาย ใหท่ัวถึง และมีคนท่ีมี
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ศักยภาพ มคีวามรูคอยดูแล
ประธานนํ้าประปาหมูบานหมู 4 ตําบลแกวฟา
เก็บคานํ้าหนวยละ 5.-บาท มีท้ังหมดประมาณ 60 ครัวเรือน แตใชจริงๆ
ประมาณ 70 ครัวเรือน
ราคาท่ีเก็บไดตอเดิอนประมาณ 6,000-7,000.- บาท เสียคาไฟประมาณ 4,000.-
บาท ใชบอเก็บ 15Q บอเจาะมาแลว 3 ป
ปญหาท่ีเกดิคือ ทอแตก, ไฟดับทําใหปมจายไมทํางาน นํ้าจึงหยดุไหล
ความเห็นสวนรวม
นํ้าดื่มจากนํ้าฝนผานการกรอง นาจะดกีวานํ้าประปาบาดาลผานการกรอง แต
กังวลเร่ืองขี้นก
สานมากไมเอานํ้าฝนมาใชในครัวเรือนเพราะมีนํ้าประปาอยูแลว และไมมีท่ีเก็บ
Survey โรงเรียน บางซายวิทยา, ประปาหมูบาน หมู6 ตําบลแกวฟา, บานคุณ ศิริ ผล
เจริญ ประธานประปาหมูบานหมู 6 ตําบลแกวฟา และวดับางซายนอก
โรงเรียน บางซายวิทยา มีนักเรียน 775 คน ระดับ ม.1-ม.6 มีถังเก็บนํ้าจาก
บาดาล 15Q และมีตัวกรองสําหรับนํ้าดื่มโดยเฉพาะ แตเดก็สวนมากซื้อนํ้าดืม่
เปนขวดดื่ม (5.-บาท/ขวด)
ในหมูบานมทีีก่รองน้ําดื่มหมูบาน (เร่ิมในป2551) ปจจุบันดูแลโดยกาํนัน
ใหบริการโดยมีตูหยอดเติมนํ้า 5.-/20 ลิตร แตปจจุบันใชไมไดแลว ขณะน้ียังไมมี
การจดัการท่ีแนนอน การตัดสินใจผาน คณะกรรมการประปา และ
คณะกรรมการกองทุนหมูบาน
ประปาหมูบาน ถงับาดาลเร่ิมใชตั้งแตป 2545 และไดงบตอยอดมาจาก
โครงการ SML จึงไดเปล่ียนทอเปน PVC และเปล่ียนตัวกรอง ถาไมผานตัวกรอง
จะมีสนิมในนํ้า ประมาณ 10 ปจึงเปล่ียนท่ีเจาะใหม คานํ้าเก็บยูนิตละ 5.-บาท
ท้ังหมดประมาณ 100 ครัวเรือน ไดรายรับประมาณ 8,000-9,000.- บาท รายจาย
ประมาณ 4,000.-บาท ดังน้ันจึงมีเงินเหลือ ปญหาท่ีเกดิคือ นํ้าไหลไมแรงพอ
โดยเฉพาะชวงเสาร-อาทิตย
ปญหาท่ีเปนตวัแปรทําใหขาดทุนมีดังน้ี (ขอมูลจากการสัมภาษณ คุณศิริ
ประธานประปาหมูบาน)
1. corruption
2. ชาวบานขาดสวนรวม หรือจิตสํานึกในการชวยกันดแูลรักษา เชน ทอแตก ทํา
ใหขาดทุน
3. ขาดคนดูแลท่ีมีความรู ประสบการณ
วัดบางซายนอก ปจจุบันใชนํ้าบาดาลขดุเอง สวนนํ้าดืม่ซื้อนํ้าท่ีเปนแกลลอน
และกรองนํ้าดื่มเอง แตมีปญหาเร่ืองนํ้าไมสะอาด ตองเปล่ียนไสกรองบอยๆ ใน
วัดมีพระท้ังหมด 6 รูป มีญาติโยมมา 40-50 คนในวันพระเล็ก และ 100 คนขึ้นไป
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ในวันพระใหญ การจดัการเร่ืองนํ้ามีกรรมการวัด และพระลูกวดัดแูล
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Appendix I-G: Water Quality Standards of Thailand
Items Maximum acceptable
concentration
Maximum allowable
concentration
1. Physical Characteristics
Colour, Pt-Co unit 5 15
Taste acceptable acceptable
Odour acceptable acceptable
Turbidity, NTU 5 20
pH range 6.5-8.5 Less than 9.2
2. Chemical Substances (mg/L)
Total dissolved solids 500 1500
Iron 0.5 1.0
Manganese 0.3 0.5
Copper 1.0 1.5
Zinc 5.0 1.5
Total Hardness (CaCO3) 300 500
Calcium 75 200
Manganese 50 150
Sulphate 200 250
Chloride 250 600
Fluoride 0.7 1.0
Nitrate as NO3 45 45
3. Toxic Substances
Mercury 0.0001 -
Lead 0.05 -
Arsenic acid 0.05 -
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Selenium 0.01 -
Chromium 0.05 -
Cadmium 0.01 -
4. Biological Characteristics
Standard Plate Count 500 -
coliform organisms (MPN)
per 100 cm3
Less than 2.2 -
E.Coll none -
Source: Thai Industrial Standards Institute, 1978
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Appendix II – Water Supply and Drinking Water Systems inBangsaiy Municipality
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Appendix II-A: Water Supply and Treatment Systems
(a) (b)
(a) Groundwater Collection Tank and
(b) Treatment System Managed By Bangsaiy Municiplaity
(c)
(d)
(c) Groundwater Collection Tank and
(d) Treatment System Managed By the Village Committee of Moo 5, Keawfah Sub-district
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(e) (f)
(e) Groundwater Collection Tank and
(f) Filtration Tank of Bangsaiy Wittaya School
(g) (h)
(g) Groundwater Collection Tank of Bangsaiy-Nai Temple
(h) Groundwater Collection Tank of Bangsaiy-Nok Temple
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Appendix II-B: Drinking Water Systems
(a)
(b)1 Litre of Bottled Water 20 Litres of Bottled Water
(c)(d)
Drinking water treatment system ofa private operator
Drinking water treatment system ofa community-owned-enterprise
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(e)
(f)
On-site Purification System ofBangsaiy-Nok Temple
Household Medium-SizedPurification System
(g)
(h)
On-site Purification System ofBangsaiy Wittaya School
On-site Purification System ofWat-Bangsaiy-Nai School
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Appendix II-C: Rainwater Harvesting Systems
Household Rainwater Collection System
Rainwater Jars
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Large Scale of Rooftop for Harvesting Rainwater at Wat-Bangsaiy-Nai School
Abandoned Rainwater Cement Tanks of Wat-Bangsayi-Nai School
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Appendix III – Design of Rainwater Harvesting Systems
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Appendix III-A : Example of Designing and Cost calculationof a Rainwater Harvesting System with FerrocementVesselsa) Detaled design
Heavy dutyferrocement
Tank volume 5000.00 gallons
Height 8.00 feet
Wall thickness (av) 2.25 inches
Roof thickness 1.75 inches
Floor thickness 8.00 inches
Roof rise/tank diameter 0.10 ratio
Floor beyond walls 6.00 inches
Density of material 100.00 lbs/ft3
Hoop spacing 12.00 inches
Major reinforcing diameter 0.50 inches
Note that volume under roof below is in ADDITION TO to capacityabove.
Diameter 10.31 feet
Diameter/ height 1.29 ratio
Volume 668.36 Cubic feet
Volume under roof 43.66 Cubic feet
Volume under roof 326.63 Gallons
Total volume 712.02Cubicfeet
Radius 5.16 Feet
Roof rise 1.03
Circumference 32.40 Feet
Roof area 83.54Squarefeet
Wall area 259.19Squarefeet
Total stucco area 342.73Squarefeet
Floor area 100.53Squarefeet
Total area 443.26
(cylinder) 426.28
Roof volume 12.18 Cubic feet
Wall volume 48.60 Cubic feet
Total stucco volume 60.78Cubicfeet
Total stucco volume 2.25Cubicyards
Floor volume 67.02Cubicfeet
Floor volume 2.48Cubicyards
Total volume 127.80 Cubic feet
Total volume 4.73Cubicyards
Material vol/water vol 5.57 ratio
Weight of material 12,780.09 lbs
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Weight of water 44,424.11 lbs
Total weight 57,204.20 lbs
Force on soil 3.95 psi
Force on soil 569.03 psf
Max hoop stress 95.67 psi
Rebar density 0.73% %
Max hoop stress rebar alone 13,158 psi
b) Cost calculation
MaterialUnitcost 5000 gal
3/8” rebar (20’ pieces) 12 30 360
1/2” rebar (20’ pieces) 200 0.00
Lath (27”x8’ pieces) 300 27 81006x6x10x10 Welded Wire Mesh (7’x200’
rolls) 5600 1 5600
1/2” Hardware cloth (4’x100’ rolls) 1600 1 1600
Tie wire (big looped bundles) 120 2 240
Cement (94 lb bags) 250 18 4500
Plaster sand (yd3) 1200 4 4800
Water (gal) 0.01 500 5
Thoroseal/Bonsal Sure Coat (50 lb bags) 400 7 2800
Color (lbs) 120 5 600
Hog rings (25 lb boxes)37 1600 0.00
Hog ring staples (boxes of 10,000) 400 1 400
Dobies 20 30 600
Poles 700 6 4200
Concrete (yd3) 4000 2 8000
Approx. cost (THB) 41805
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Appendix III-B: Tank Size with 90% Security of Supply
Tank Size (KL)
Volume
required
(litre/day)
Annual
rainfall
Roof area (s.q.m.)
100 150 200 300 400 500 600
60 150
300
400
500
600
20
14 6 4
6 3 3
4
3 2
100 150
200
400
500
600
900
34 27
33 19 17
10 8 6
11 6 5 4
8 5 4 3
6 4
200 250 26 21
300 29 20 17
350 26 17 13 12
400 19 14 11 10
500 20 12 10 8
600 25 15 10 8 7
900 26 13 10 7
1200 18 10 8 6
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Nathaporn Areerachakul (PhD)
Faculty of Industrial Technology
Rajhabhat Suansunandha University
Mobile: 6684 6947565
Email: [email protected]
Qualifications :
BSc 1990 King Mongkut Institute of Technology Ladkrabang, Bangkok, Thailand M.B.A. in Finance and Banking 1995 Sripathum University Bangkok, Thailand MEnvEng 2000 University of New South Walse, Sydney Australia PhD in Engineering 2008 University of Technology, Sydney
Current Position:
Head of Research and Evaluation Faculty of Science and Technology, Rajamangala University ofTechnology ThanyaburiSenior LecturerCommittee Of Graduate School Chulalongkorn University in Technopreneurship and InnovationManagement program (TIP)
Previous employments:2011 – Rajabhat Suansunandha University (start 1 April 2011)2002 – Lecturer at Rajamangala University of Technology Thanyaburi.Publications and Experience
Previous experience in construction management in high rise and low rise building and ExtensiveStrength on the Water and Wastewater treatment plant system;
- Advance Oxidation Processes (AOPs)- Filtration systems- Biomonitoring- Conventional water treatment processes etc.- Environmental management
Funded Projects from 2007-2011
- The Development of Filtration and Hybrid System for Household Rainwater Jar, ThailandResearch Fund, 2007 to 2008
- The Development of Rainwater pre-treatment systems Using in Laboratory, NRCT 2007- Visiting Scholar Royal Thai Government with Asian Institute of Technology 2007- The use of membrane filtration hybrid system for removing organic matter from surface water
2008 NRCT- Photocatalysis hybrid system Thailand research fund and office of higher education 2009,
2010- The development of rainwater harvesting system for community 2011 Suan Sunandha
Rajhabhat University- Titanium doped with metal for water treatment 2012 Nanotechnology
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