Research & Development
 
R&D
Research & Development Section
           
Research & Development Section of the NWSDB is under the Development Section headed by Additional General Manager (Policy & Planning).
           
Address Research & Development Section           Tel: +94 11 2625196    
  Telawala Road           Fax: +94 11 2607238    
  Ratmalana           E-mail agmrnd@waterboard.lk    
Vision  
Mission

Exploit local expertise and material as far as possible to succeed with application oriented research activities. 

 
Identify and implement economic means of providing potable water to people of Sri Lanka while minimizing environmental pollution.
           
Short description of the activities carried out during the year 2008
           
1. Water pollution studies and mitigation efforts
           
Tri halo methane (THM) study
Joint project on Trihalo methane determination in the Greater Colombo distribution system as formulated along with testing facilities available with the ITI. 
           
Pollution study at Bomurualla, Nuwara Eliya
Joint research study with University of Sri Jayawardenepura on contamination of Bomurualla reservoir of Nuwara Eliya was initiated this year as demanded by the Planning and Design section of the NWSDB. It is observed  that pesticides, hospital wastes and leachate are threatening the safety of Bomurualla water where water intake of Ambagasdowa water supply scheme is located downstream.
           
Upgrading ambient water quality standard
Study of Kelani river pollution due to industrial pollution and updating  the current SLS 722, 1985 “Tolerance limits for inland surface waters used as raw water for public water supply” considering current European standards. This is important as it has been identified that pollutants such as polyaromatic hydrocarbons, textile dyes, surfactants and pesticide are recently identified as  main polluting compounds in the Kelani river water which may cause chronic illness among the water users. A joint study is being implemented with CEA, Open University and the University of Kelaniya with the assistance of JICA senior volunteer Mr. Yoshiki Goto.
           
2. Developing a sand sieving machine
At present there is a problem of getting graded sand for slow sand and rapid sand filters. The R& D section studied this problem and identified that the problem is due to lack of  knowledge among suppliers on sand preparation. We have identified two methods of filter sand preparation, namely blending and sieved sand and direct sieving from a stock pile. We are progressing towards making a simple sand sieving machine to popularize the filter sand preparation process.
           
3. Joint study with NRW Section on pipe joint leakages
A joint study has been initiated on leakage of old CI pipes and at PVC pipes of different manufacturers including unbranded pipe fittings sold in the market.
           
4. Pebble matrix filter project, Kataragama
This project is funded by the Word Bank under the “Development Market Place” competition which was awarded to Sri Lanka. The concept is to reduce the turbidity of raw water by about 90% without using chemicals using sand embedded pebble filter. This is recommended ideal pretreatment for slow sand filter.
           
5. Study on rain water quality
Rainwater harvesting system was established for the Building complex at Thelawala in this year with 4 cubic meter storage. Rain water is physico- chemically up to drinking water standard except for the high coliform levels.
           
6. Sociological research on piped water supply in Sri Lanka
This research study was completed by the University of Colombo during this year. Objectives of this study were identification of population growth rates in relation to migration trends, consumer satisfaction, consumer needs and attitudes. This study was highly appreciated by the senior staff as the content was rich in feed back from general public on NWSDB activities. 
           
7. Improvement of Water Treatment Process of Puttalam Water Supply Scheme
The existing Puttalam Water supply Scheme was commissioned in Year 1993.The design capacity of the scheme is 7000 m3/day. The raw water is extracted from deep bore holes as well as from Mee  Oya.

Several problems are identified in the treatment process especially in the no valve filters. Filter sand in one filter unit has been hardened due to incorrect acidity level of the raw water. The original green sand filter media was replaced by the local sand and that also got hardened. The alkalinity, hardness, Manganese and iron content are high in the raw water. According to the laboratory experiments, it has been identified that softening of water will address the problems prevailing in the treatment process.   The study plan was to identification of treatment process by laboratory experiments and to run a pilot plant at the site. The study is funded by ADB and the output will be utilized for the ADB improvement proposal for Puttalam Water Supply Project.
           
8. Experiment on Gravel bed flocculation
Gravel flocculation concept has been researched in 1980s in the Asian region and has been not implemented in Sri Lanka. This concept is very useful with respect to low energy consumption and low maintenance needs due to its simplicity. NWSDB has done a similar study in 1984 but has not been implemented. It has been proposed to do a practical implementation of gravel bed flocculation using the filter columns donated by JICA. The columns are being reinstalled at Ambatale the testing facility is being refurbished and it will be used for trial runs of gravel bed flocculation of river water.
           
9. Use of Polyaluminium Chloride (PACl) as a flocculent in water treatment.
As there was a sudden price increase of alum the there was a need to identify alternative coagulant. Laboratory experiments by R&D section before this price increase made it conclude that PACl was economical to be used for high turbid and high color waters. This was tested and implemented for Kondawattuwan water supply scheme. Subsequently it was found that it was about 30 to 50 % cheaper to use PACl for Ambatale, Kalatuwawa and Labugama compared to alum according to the prices of these two coagulants prevailed in the year 2008. 
           
Progress of the work at the end of the 2008
           
1. Water pollution studies and mitigation efforts.
           
Tri halo methane (THM) study
The project will be implemented in 2009 upon negotiations with the ITI.
           
Pollution study at Bomurualla
Initial samplings were done and the project will continue in 2009.
           
Upgrading ambient water quality standard
The Open University has offered HPLC facility for testing. Study being done to identify what parameters to be tested and whether testing facilities are available at different organizations. The work will continue into the year2009.
           
2. Developing a sand sieving machine
Purchases are completed and fixing the machine will continue in the year 2009.
           
3. Joint study with NRW Section on pipe joint leakages
The study will continue into the year 2009.
           
4. Pebble matrix filter project, Kataragama
Two filter units of 4.5m x 4.5 m were constructed during this year (Figure 1 below). This operation revealed that about 50 -60% of the turbidity could be removed by the these filter units. The present results are not up to the expected outcome of 90% removal.  As the head loss development too was not up to the expected levels, further experiments will be done during 2009 using available 1m x 1m model filter unit made under NERD assistance.

Future studies will focus on using available rock material instead of pebble for matrix filtration. 
           
Figure 1 - Pebble matrix filters at Kataragama
           
       
           
5. Study on rain water quality
Rainwater shall be treated to remove coliform if required to use for drinking purposes. Disinfection and domestic slow sand filtration are available options which are being investigated. The study will continue in the year 2009.
           
6. Sociological research on piped water supply in Sri Lanka
It was reported that population growth rates vary from 1-2% in general and exceptionally high   5-6% in Embilipitiya, Monaragala and Udawalawe. The report contained many problems faced by consumers. Corrective action will be taken by relevant regional offices of NWSDB and this study will be repeated in about four years time form now to reassess any changes.  
           
7. Improvement of Water Treatment Process of Puttalam Water Supply Scheme
The process determination laboratory tests have been completed and the model is being constructed (Figure 2).  The work will continue in the year 2009.
           

Figure 2 - Model construction out of ferrocement

           
       
           
8. Experiment on Gravel bed flocculation
The shifting of the filter columns from Kalatuwawa to Ambatale has been  done and part of the installation has been completed.  Trial runs of gravel bed flocculation will continue in the year 2009.
           
9. Use of Polyaluminium Chloride (PACl) as a flocculant in water treatment.
Jar testing will continue along with price variation data of alum and polyaluminium chloride to determine which flocculant is most suitable for each type of raw water throughout the country with respect to economy and final water quality.  This study will continue in 2009.
           
           
::: Updated on 2010.05.13 :::
           
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