Water Safety Conference 2010 Yonghwan Kim The potential for using rainwater to provide safe drinking water in rural areas: a case study of Cukhe Village, Vietnam

Contents Introduction 1 Introduction 2 Installation 3 Conclusion 4 Suggestion Water Safety Conference November 2-4 2010, Kuching, Malaysia

1. Introduction Water Safety Conference November 2-4 2010, Kuching, Malaysia

“Rain For All” Activity Object Demo project for Sustainable water management in Asia Site & Period Cukhe village in Vietnam, 16th Jan. 2010 ~ 26th Jan. 2010 Participants 14 students from Seoul National University & Hanoi University RWH installation with local people & Curtural exchange between Korea and Vietnam Water Safety Conference November 2-4 2010, Kuching, Malaysia

Pollution from domestic sewage Cukhe Village Poor village in rural area No centralized Water supply 3 water resources - Surface water, Ground water, Rainwater Surface water Pollution from domestic sewage Hanoi, Vietnam 12km Ground water Arsenic contaminated Nhue river Cukhe Village Water Safety Conference November 2-4 2010, Kuching, Malaysia

Potential of Rainwater Quality Temperature pH Turbidity EC As Cd Cu Fe (℃) (NTU) (mg/L) Average 19.4 7.195 2.36 99 0.010 0.032 Standard 6.5-8.5 2 0.05 1 0.3 Ni Pb Zn SO4 NO2 Br NO3 PO4 0.004 0.097 2.238 1.04 1.862 0.02 0.01 3 Except for turbidity, all the chemical substances tested satisfy the Vietnam water quality standards. → We can drink rainwater after boiling. Quantity Abundant annual rainfall : 1,633 mm (Global average : 880 mm) Water Safety Conference November 2-4 2010, Kuching, Malaysia

Sustainability of RWH Water Safety Conference Sustainable Environment Social Economy Sustainable Traditional water supply option Half of households already using RWH Low installing & maintaining cost Require low energy Low effect on environment No chemical added to rainwater Water Safety Conference November 2-4 2010, Kuching, Malaysia

Object RWH has potential for drinking water supply alternative To check problems in existing RWH To suggest technical improvement for water quality treatment To confirm quantitative feasibility of RWH system Promote RWH as a major drinking water supply Water Safety Conference November 2-4 2010, Kuching, Malaysia

2. Installation Water Safety Conference November 2-4 2010, Kuching, Malaysia

Existing Rainwater Tank Catchment Gutter Pipe Storage tank Water Safety Conference November 2-4 2010, Kuching, Malaysia

Existing Rainwater Tank Without filtering system → Containing many particles Unsealed Rainwater Tank → Exposed to dust, sunlight, and insect Water shortage during dry season Water Safety Conference November 2-4 2010, Kuching, Malaysia

Quality treatment Water Safety Conference Catchment Filter Polyethylene Portable Catchment (3m(w) × 3m(l)) Asbestos - Harmful material Filter Sedimentation tank 0.5mm sieve Removing large particles such as leaves Calm-inlet pipe → Preventing disturbance of settled part icle → Reducing kinetic energy Removing small particles Storage tank Plastic material designed for drinking purposes Isolating rainwater from external environment → Long term storage is possible Water Safety Conference November 2-4 2010, Kuching, Malaysia

Quality treatment Case 1. Roof catchment Case 2. Portable catchment Catchment area : 21 m 2 Tank capacity : 2 t Catchment area : 9 m 2 Tank capacity : 2 t Water Safety Conference November 2-4 2010, Kuching, Malaysia

Quantity management Water Safety Conference Sufficient capacity storage tank Concerning precipitation and demand : Capacity → 2t Collecting area Volume of tank Available demand Number of cycles. days (m2) (t) (l/day) (days) Case1 21 2 20 3.5 350 Case2 9 15 2.6 347 Separate use of drinking water and domestic water Ground water Rainwater Water for domestic use such as wash, shower, cleaning Water for drinking and cooking Water Safety Conference November 2-4 2010, Kuching, Malaysia

3. Conclusion Water Safety Conference November 2-4 2010, Kuching, Malaysia

Conclusion 1. Existing rainwater tank satisfy quality except for turbidity. There is quantity problem in dry season. 2. Installing RWH with proper catchment, filter and sedimentation tank improves water turbidity. Residents feel safe drinking rainwater after boiling. 3. Using rainwater only for drinking and cooking make it possible to supply rainwater throughout the year. 4. RWHs can play an important role in providing a sustainable water resource and resolving water problem over the world Water Safety Conference November 2-4 2010, Kuching, Malaysia

4. Suggestion Water Safety Conference November 2-4 2010, Kuching, Malaysia

One Company One Rainwater Tank Hailuu elementary school Finished fine shape RWH Hailuu elementary school 5,000 USD From company Made by local people Bottled water for each class (780 USD per year) Technical assistance Water Safety Conference November 2-4 2010, Kuching, Malaysia

Let’s make world that everyone feel happy First user is best user Let’s make world that everyone feel happy Water Safety Conference November 2-4 2010, Kuching, Malaysia

Thank you! Water Safety Conference November 2-4 2010, Kuching, Malaysia