Use of Appropriate Technology for Water Quality Improvement in a Community Managed Water Supply Demonstration Project in Phnom Penh, Cambodia

Transcription

1 Paper Presented at the 3 rd WEPA International Forum, October 2008, Putrajaya, Malaysia Use of Appropriate Technology for Water Quality Improvement in a Community Managed Water Supply Demonstration Project in Phnom Penh, Cambodia Ranjith Perera Coordinator, Demonstration Projects South East Asia Urban Environmental Management Applications Project Asian Institute of Technology, Bangkok

2 Introduction Many local authorities in developing countries are unable to provide safe water This problem is acute in peri-urban areas which are not covered by municipal supply Peoples Alternatives - Buy from water vendors - Use water from rivers, canals etc. - Pump ground water - Use harvested rainwater

3 Rainwater Harvesting in Containers

4 Rainwater Harvesting in a Pond

5 Quality of Harvested Rainwater Harvested from roof Harvested from pond Contaminated by dust and particles Contaminated by fecal matter Turbidity

6 Water Supply Demonstration Project in Cambodia Three-pronged Demonstration 1. Application of appropriate and affordable technology and transfer of knowledge for water quality improvement 2. Mobilizing communities for finding solutions for their problems through a participatory process 3. Involving alumni of AIT as Change Agents

7 Beneficiary Community Tropeang Chork Community in Sangkat Prey Veng in Phnom Penh (106 HH, 527 people) Located 24km from the city center Under the jurisdiction of Phnom Penh Municipality, but no municipal infrastructure and service provision People engaged in casual work, small businesses, motorcycle taxi driving, rice cultivation etc. Average monthly income of people 200,000 Real ( 50 USD)

8 Sources of water before the project initiative Harvested rainwater in Jar Harvested rainwater in Pond Water vendor Groundwater from a tube well Brought by a cart from the pond Collected from the roof and water vendor

9 Baseline Situation Soil pit for road construction Converted to a rainwater harvesting pond Harvested rainwater in the pond is very muddy with high level of silt Contain E-coli

10 Project Initiatives 1. Appropriate water treatment method 2. Affordable method of construction 3. Participatory planning and management process 4. Cost sharing mechanism for construction - AIT-CIDA Partnership Project (12,450 USD for construction work and technical support - Community contribution (land for treatment system and labor) - Other sources (NGOs and CBOs 3,050 USD) 5. Cost sharing mechanism for operations, maintenance and water distribution

11 Water Treatment System Three Challenges How to treat harvested rainwater which is having high turbidity and contaminated with E-coli How to design and construct a treatment system within the available budget How to design a treatment system which is simple for the community to operate and maintain

12 Model Construction Construction cost reduction of 50% was possible by switching from RCC construction to Ferrocement construction No precedence was available in Cambodia for the use of ferro-cement technology for water treatment systems - Useful to educate the community about the system -Provided an opportunity to give hands-on training on ferrocement construction - Useful for building the confidence of the community - Provided an opportunity to get participation of both men and women in the project

13 System

14 C.F.S. Tank and Slow Sand Filter Treated Water Water Treatment System Ferro-cement Constructions

15 Output Results Water Demand 28.6 Cum/day Designed Capacity 30.0 Cum/day Actual Output at project completion 25.0 Cum/day Present Output 15.0 Cum/day Reasons: High turbidity of raw water Inadequate maintenance

16 Results of the First Water Quality Test Parameters Unit Standards Water Quality WHO MIME Raw Water Treated Water Iron mg/liter ph Turbidity NTU <5 < Total Hardness mg/liter <100 < Total Coli form CFU/100 ml ,000 0 E-coli CFU/100 ml 0 0 5,040 0 Salmonella CFU/100 ml ,000 0

17 Indications of Improvements Aspect of Improvement Condition before Project Condition after Project Ave. distance travel to fetch water 1.5 km 200m Average time spend to fetch water One hour Twenty minutes Frequency of fetching water Once in a day Two times in three days Transport mode used Push-cart/motorcycle Push-cart/motorcycle/walk Average price paid for water USD 2.17 per Cum USD 0.5 per Cum Perception on water Quality Poor, unsafe for drinking Good, safe for drinking

18 Observations Community s share of the cost is about 80% AIT-CIDA contribution (18%) trigged the outflow of this social capital Decrease efficiency of the system, due to; - high turbidity of raw water - poor functioning of the flocculation coil - poor functioning of the slow sand filter - poor maintenance, especially during the rainy season and rice cultivation season Decreasing confidence of the community Reluctance to contribute to the water distribution pipe network

19 Sustainability Measures Provide an additional C.F.S. Tank for increasing the efficiency Reinstall the slow sand filter and further training on installation and maintenance of the filter Consolidation of the banks of the pond to reduce siltation and thereby turbidity Trials on growing aquatic plants and ground cover

20 THANK YOU