IJERD – International Journal of Environmental and Rural Development (2012) 3-1

Research articleerd

Groundwater Resources Development by Riverbank
Filtration Technology in Thailand
KRIENGSAK SRISUK*Groundwater Research Center, Faculty of Technology, Khon Kaen University, Khon Kaen,Thailand
Email: kriengsk@kku.ac.th

LAA ARCHWICHAI, KEWAREE PHOLKERN AND PHAYOMSARAPHIROM
Groundwater Research Center, Faculty of Technology, Khon Kaen University, Khon Kaen,Thailand

SUMRIT CHUSANATUS AND SITISAK MUNYOU
Department of Groundwater Resources, Ministry of Natural Resources and Environment,
Bangkok, Thailand
Received 19 December 2011

Accepted 18 April 2012(*: Corresponding Author)

Abstract Riverbank Filtration (RBF) is the influx of river water to the aquifer induced bya hydraulic gradient and it is a low-cost and efficient alternative water treatment fordrinking-water applications. The objectives of the project are to study the feasibility ofRBF technology, design the pilot system,  evaluate the feasibility of the project on socioeconomic and environmental impact and transfer the knowledge of RBF technology to thestate enterprise organizations, local administrative authorities and other related parties.  
The  project  consists  of  3  phases,  fesibility  study  (11  months),  design  and  construction  (14  months)  and  operation  and  maintenance  (12  months).  Therefore,  the  specific  objective  of  this  paper  is  to  review  the  basic  concepts  of  the  first  phase  and  present  some  case  studies  such  as  Kompahangpet  area  for  detailed  study  prior  the  design  and  construction  phase. Thetarget areas are initially focused along the main river courses in Thailand such as Mekong,Ping and Chaophraya Rivers. The study procedure consists of detailed investigations:hydrology, hydrogeology, water demand, suitable socio-economic conditions, andappropriate environments. Mathematical groundwater modeling will be employed toevaluate the suitability of the selected sites. Then we will design pilot system for large
scale groundwater resources development to verify that the method could be successfullyemployed for water resources management and could be further expanded to other areas
and extended to other interested parties or organizations in the future.
Keywords riverbank filtration technology, groundwater and surface water conjunctive use,hydrology, hydrogeology, water resources management

INTRODUCTION
Riverbank Filtration (RBF) is the influx of river water to the aquifer induced by a hydraulicgradient. Collector wells located on the banks in a certain distance from the river (Figs. 1 and 2)
create a pressure head difference between the river and the aquifer, which induces the water fromthe river to flow downward through the porous media into the pumping wells. By applying thissystem of water supply extraction, two different water resources (surface and shallow groundwater)
are in conjunctive use. Riverbank Filtration (RBF) is a low-cost and efficient alternative water
treatment for drinking-water applications. There are two immediate benefits to the increased use ofRBF: minimizing need for adding chemicals like disinfectants and coagulants to surface water tocontrol pathogens, and decreasing costs to the community without increased risk to human health.
RBF has been successfully practiced for more than 100 years in European countries and is a currentⒸ ISERD

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method for water supply in many countries. For example, 50% of potable water supplies in theSlovak Republic, 45% in Hungary, 16% in Germany and 5% in the Netherlands are obtained fromthe riverbank filtration system (Grischek et al., 2002; Hiscock and Grischek, 2002; Tufenkji et al.,2002 and Lee and Lee, 2010). RBF has also been applied to acquire drinking water in many cities
in the United States.
In Thailand, the Department of Groundwater Resources (DGR) awarded financial support to a
consultant consortium to carry out the study on the feasibility of developing the RBF project along
the major rivers to mitigate water shortage problem and provide optional supplementary water
sources for domestic and industrial consumption. One of the main tasks in the RBF development
project is the first phase, which is costly and time consuming. It is expected that after the pilot RBF
system in Thailand is constructed and completed, the knowledge and know-how from the projectwill be used for the development of the master plan for the RBF system in the whole country. TheRBF project, if successful, will demonstrate the systematic and sustainable integrated managementof surface water-groundwater conjunctive use so as to increase efficiency in the mitigation andremediation of yearly water shortage problem in the future.

Fig. 1 Generalized schematic section of a riverbank
filtration site (After Ray, 2002)

Fig. 2 Cross section and plan view of ahorizontal collector well (After Hunt,2010)

METHODOLOGY
There are five main tasks conducted during the feasibility study phase (I) as shown in Fig. 3,
namely 1) Data collection, compilation and analysis, 2) Selection of the potential areas for RBF
construction (at least 8 sites), 3) Field investigations, 4) Public dissemination and participation,and 5) Formulation of the master plan of RBF for Thailand.

Public Information
Dissemination and PublicParticipation

Data Collection ,Compilation and Analyses

Selection of the Potential Areas for RBF(At least 8 areas)

Field Investigation- Groundwater Resources- Surface Water and Irrigation System- Land use- Water Uses and Water Demand- Water Balance- Mathematical Groundwater Modeling- Initial Environmental Evaluation- Socio-economic Base line Data
- Preliminary Design of the RBF System- Rank the suitability of each area for development RBF

Master plan for Large Scale Groundwater Resources Development Using
Modern Riverbank Filtration TechnologyFig. 3 Protocol of the feasibility study phase (I)Ⓒ ISERD

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DEVELOPMENT OF THE SITE SELECTION PROCEDURE
In this study, the development of the site selection criteria for the RBF was initiated by reviewingand compiling existing RBF case studies worldwide. The various site selection criteria from theavailable case studies were focused upon the key performance indicators for RBF system. Essential
data clusters and necessary specific parameters were identified and categorized. The selection
procedure is divided into 3 steps (Fig. 4), namely; Step 1: Potential River Basin Level, attempts toidentify the RBF potential areas in Thailand at the river basin (regional) scale; Step 2: Potential
Local Areas Level, attempts to identify the RBF potential local areas within the potential river
basins obtained from Step 1; Step 3: Potential Site Level, attempts to identify the RBF potentialsites and locations within the local areas obtained from Step 2. The potential sites and locations
obtained from Step 3 will be used for more detailed site investigations to determine the RBF key
performance parameters for the RBF system design and construction. After more detailed
examination of existing available data was carried out, a new adjustment and arrangement of datagroups and selection procedure was conducted. Considering the site selection procedures, steps andselection criteria in Fig.4, a series of thematic maps were compiled or prepared for each selection
steps. River basin map in Thailand (Fig. 5) and the distribution of areas 2-km away from mainriverbank were acquired to overview the availability of surface water. The thematic map fromQuaternary geologic map was overlaid on the groundwater quality map to obtain the RBF
hydrogeologic suitability map. The preliminary potential areas for the RBF system derived fromFig. 6 covering approximately 15,839 km2. The river hydrograph information shows that the river
flow of the main rivers varied from 4 - 12 months flow duration.
Step  1:  Potential  areas  at  river  basin  scale  level
Geoloy/Geomorphology

Hydrogeology-Unconsolidated aquifers, groundwater  -Quaternary Geology

quality  with  TDS  <  1,500  mg/l.

Hydrology- Main  river  system  in  25  river  basins

Step  2:  Potential  areas  at  local  scale  level
Hydrology- Rivers  with  river  f low  duration  not  less  than  9  months  period

Hydrogeology-  Aquifers  with K>  1   m./day    -  No  clay  layers  capping  the  river  bed
-  Aquifer  thickness  greater  than  10 m.

Water  Quality- Surface  water     quality  of  type  1  to  type  4  -  Not  affected  by  sea  water  or  saline  water

Step 3:  Potential areas at sites and locations scale level(for RBF feasibility study and design)   Hydrology- Maximum  river  flow  velocity-  River  f low  duration

Landuse  Hydrogeology-  Aquifer  permeability  -  Aquifer  thickness  Water  supply  production  (Provincial  Water  Supply)-  Water  supply  shortage  duration-  Present     watersupply  production

Water  Quality  -  groundwater  quality  (TDS), -  surface  water  quality  ( surface  water  typs)    Potential areas/sites for RBF feasibility study and preliminary design

Fig. 4 Overall procedures for RBF site selection
River water quality map was obtained from the Department of Pollution Control. The RBFaquifer thickness and aquifer permeability were reviewed and compiled from the existing RBF
system case studies and the range of practical aquifer thickness and aquifer permeability values
were identified and the suitable range was selected to fit the existing available data for Thailand. A
total number of 13,581 available groundwater wells were compiled from the National Groundwater
Database, DGR. A number of 4,881 groundwater wells with well logs were sorted and 414 wells
satisfied the criteria. The distribution of 414 groundwater wells were prepared as well asⒸ ISERD

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hydrologic data consisting of existing 190 river gauging stations, river cross sections and profiles,
river hydrographs, and river flow velocity were compiled and analyzed. Land use data and maps ofvarious scales were compiled from the existing database of the Department of Public Works andthe Department of Land Development. The expected main water users from the RBF system inThailand are the Provincial Waterworks Authority. Water demand for provincial water supply is,therefore, considered as one of the parameters for RBF system site selection. The water demand forprovincial water supply as of 2010 was compiled.
At the local and site suitability scale level, the considered site selection criteria include 5components, namely, hydrology, hydrogeology, water quality, land use, and provincial watersupply production capacity as categorized, scored and weighted in Table 1. Based on the scoring
and weighting of the selection criteria, there are twelve potential areas as indicated in Fig. 6.
Subsequently, the RBF system key performance parameters for preliminary RBF system will besystematically analyzed for designing and constructing for the first two sites in the phase II. The
site investigation data determined from this stage of data acquisition as shown in Figs. 7, 8 and 9
are representing one of the detailed case studies (Kamphaengphet area).
Table 1 Scoring and weighting of selection criteria
Selection  Criteria

Type
123Score

Unit

1

Weight3

5100

Hydrology
1.1 River  Flow  Velocity

m/sec

0.5-1

1-1.5

≥  1.510

1.2 River  Flow  Duration

Month910-111215

2.1 Aquifer  Thicknessm.

10 – 14.915 – 19.9

≥  20

20

2.2 Aquifer    permeability

m./day1 – 4.9

5 – 9.9≥  10

10

Hydrogeology

Water  Quality
3.1 Surface  Water  3.2 Groundwater    (TDS)

4

Landuse (RBF systemconstruction site)

5Water  Supply  Production  (Provincial  Water  Supply)
5.1 Raw  water  shortage

5.2 Present Water Supply Production

Water  Type

4

3

1- 2

5Mg/l

601 - 1,500

301 - 600

≤  30010Landuse Type Community/ Agricultureindustry

Open/public5Month<11- 3≥    3

5

mil.  cu.m.  /year<11-5≥  5

20

CASE STUDYKamphaengphet area (No. 6 in Fig. 6) was selected by a ranking procedure, where the detailed
study including hydrologic and hydrogeologic investigations was conducted. The Ping River is themajor river flowing across Kamphaengphet Province which is located in Central Thailand.
Hydrologic investigation consists of the study of river morphology, infiltration tests (field andlaboratory), stream profile measurements and water quality sampling as shown in Fig. 7. There are
32 observation wells (diameter of 2 inches) and 12 test wells (6 inches), pumping tests and quantityand quality monitoring of surface and groundwater was conducted over the area of 70 km2 during
the year 2011. A hydrogeologic map under a scale of 1:50,000 was constructed in order to evaluate
the yield of shallow groundwater and interaction between river water and shallow groundwater.
Subsequently, detailed physical and chemical parameters were analyzed and then a numerical flow
model was applied to determine the available yields of groundwater and the behavior of interactionof river water and groundwater. Moreover water demand from Provincial Waterworks Authority ofKamphaengphet Province and initial engineering design, public hearing and SWOT analysisⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2012) 3-1(Strength, Weakness, Opportunity and Threat) from the local communities will be evaluated for thefinal site selection prior the construction phase (Phase II).

Fig. 5 Locations of the potential
areas for RBF feasibility
study

Fig. 6 Twelve areas delineated for potential RBF
system detailed feasibility study and design
Case study: Kamphaengphet Area

SUMMARY AND CONCLUSIONSRBF has the potential to supply water to numerous cities around the world. Many cities arecurrently using surface water that is often of poor quality. Gradual conversion of surface water
intakes to bank filtration can help improve the water quality. The development of the site selection
criteria for the RBF system was initially commenced by identification of selection criteria forregional area scale site selection and then zoom-in into the local area scale level and finally to thesite and location scale level. The established key performance criteria for the RBF system site
selection include 5 groups of data sets, namely; hydrology, hydrogeology, water quality, land use in
the construction site, and water demand. Once the potential sites or locations for the RBF system
are finally selected, a detailed field investigations program was made for the RBF sitecharacterization. The obtained site parameters will be used for preliminary RBF system design andpilot construction.
By the way, RBF system is a new technology of conjunctive use of surface and groundwater
resources for Thailand. RBF also offers an innovative solution for water resources management ofthe project. It offers many advantages in terms of low cost, simplicity, robustness etc. A successfulproject depends upon strong technical understanding combined with support by government, waterauthorities and communities.

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Fig. 8 Hydrogeologic investigations: observation
well and test well drilling and monitoring

Fig. 7 Topography and hydrology ofKamphaengphet area

Fig. 9 Hydrogeologic cross sections of the potential RBF site (Kamphaengphet Area)Ⓒ ISERD

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ACKNOWLEDGEMENTS
Our appreciations and thanks are delivered to the Department of Groundwater Resources (DGR),
Ministry of Natural Resources and Environment, Thailand, for providing financial support to thefirst phase of the RBF project. Special thanks to the participating research staff from theGroundwater Research Center (GWRC), Khon Kaen University, for assistance in graphic
preparation and arrangement.
REFERENCES
Archwichai, L, Srisuk, K., Chusanatus, Pholkol, K., Munyou, S. and Saraphirom, P. 2011. Development ofthe site selection criteria for Riverbank Filtration Project, Thailand. Proceeding Conference on Geology,Geotechnology and Mineral Resources of Indochina (GEOINDO2011), 350-359, 1-3 Grischek, T.,
Schubert, J., Jasperse, J.L., Stowe, S.M. and Collins, M.R. 2007. What Is the Apppropriate Site for RBF,
ISMAR6 Proceedings, 466-474. Phoenix, USA.
Grischek, T., Schoenheinz, D. and Ray, C. 2002. Siting and design issues for riverbank filtration schemes, C.
Ray et al.(eds.), Riverbank Filtration, Kluwer Academic Publishers, The Netherlands, 291-302.
Grischek, T., Schoenheinz, D., Worch, E. and Hiscock, K.M. 2002. Bank filtration in Europe - An overviewof aquifer conditions and hydraulic controls. Dillon, P., ed., Management of Aquifer Recharge for
Sustainability, Balkema, Rotterdam, 485-488.
Hunt, H.C. 2010. Riverbank filtration to improve raw water quality. New England Water Works Association
Conference, Rockport, Maine, 59.
Lee, S.I. and Lee, S. 2010. Development of site suitability analysis system for river bank .
Ray, C., Grischek, J., Schubert, J., Wang and Speth, T. 2002. A perspective of riverbank filtration. Journal ofAmerican Water Works Association, 94(4), 149-160.
Sandhu, C., Grischek, T. and Kimothi, P.C. 2009. Annual report cooperation centre for riverbank filtration(CCRBF) Haridwar, India.
Department of Groundwater Resources (DGR) 2011. Progress 1. Report of Large Scale Groundwater
Resources Development Using Modern Riverbank Filtration Technology Phase 1: Feasibility Study on
Large Scale Groundwater Resources Development Using Riverbank Filtration (RBF) Technology.
Groundwater Research Center, Khon Kaen University, Thailand.

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