Published on: 24.2.2023
Information produced by Finnish Environment Institute
Looking for Solutions for Arsenic in Drinking Water in Nepal
Arsenic contamination of groundwater is an environmental health problem in several regions affecting many people, especially in developing countries. In Asian countries high arsenic levels pose health risk for an estimated 65 million people.
Funded by Finland’s Ministry for Foreign Affairs, the ‘Towards arsenic safe drinking water in Nepal (NeAs)′ project strives to reduce the consumption of arsenic-containing drinking water in Nepal. The project supports its Nepalese partner organisation, Department of Water Supply and Sanitation Management (DWSSM), in its efforts to help the local water sector operators in solving the arsenic problem and finding as arsenic safe water sources as possible. The project is implemented in cooperation with the Geological Survey of Finland (GTK) and the Finnish Environment Institute (Syke).
The Ministry for Foreign Affairs of Finland provides funding under the Institutional Cooperation Instrument (ICI) for projects that seek to strengthen the expertise of government bodies in developing countries. The implementation of the ICI projects is largely based on visits to the target country and having the partner organisation’s staff visit Finland for educational purposes.
The arsenic in groundwater in Nepal is mostly of a geological origin. During the last 25 000 years, arsenic-bearing rocks in the Himalayas have eroded, forming deposits in the Nepalese lowland regions (Terai) where they now cause high arsenic levels in groundwater. Long-term exposure to arsenic from drinking water and food can cause arsenicosis and various types of cancer. The most important action in affected communities is the prevention of further exposure to arsenic by the provision of a safe water supply.
Better tools for assessing well water quality
The pilot area of the NeAs project is in the Terai in Parasi (Western Nawalparasi, Province 5) which is one of the districts most affected by arsenic. In Parasi, nearly 12 % of the tube wells have the arsenic concentration over 50 ppb that exceeds the acceptable level for maximum concentrations of arsenic in safe drinking water as defined by WHO, 10 ppb. One goal of NeAs project is to create an operations model from project’s actions at the pilot area to be repeated in other areas in Terai.
The occurrence of arsenic is strongly linked to the hydrogeological characteristics. The geology in the NeAs pilot area is very diverse and small-scale. The significance of the geological conditions has not been fully understood in the past, which is why the observations made during well boring have not been systematically recorded and the wells have been constructed with a maximum volume of extracted water in mind. Less attention has been paid to the quality of the extracted water, especially its arsenic concentration. Therefore, one of the key objectives of the project is to develop water analytics, especially laboratory operations since they are essential for determining water quality.
Raising awareness on harmful effects of arsenic
To support decision making in arsenic mitigation, a conceptual model on arsenic migration in typical hydrogeological conditions at NeAs pilot area Parasi has been created based on studies prior to NeAs project. The model will be updated as more data is gained by field studies and groundwater sampling at the pilot area. The first NeAs sampling tour took place in June 2022.
A challenge in data sharing is the low degree of digitalisation in Nepal. Even though the stakeholders are willing to cooperate and share data, finding paper reports in archives takes time.
A plan for DWSSM’s arsenic related communication will be prepared for raising citizens and decision makers awareness on harmful health effects of the arsenic contaminated groundwater and on functional risk mitigation measures. The first new communication material about arsenic created in NeAs project is the report on arsenic removal methods based on a literature review. The report ‘Review of Arsenic Removal Methods in Water Supply and A Case Study of Predesign Cost Estimation in Nepal’ is available in the internet.
The next step in the project is the Nepalese partner organisation’s trip to Finland, which will take place in May 2023. The purpose of the trip is to study the Finnish practices in laboratory operations, water treatment and data management. During the trip, other Finnish operators will also be provided with an opportunity to present their technical solutions on arsenic removal technologies and field analytics of arsenic, for example.
Image: Taina Nysten