Willingness to pay for arsenic-safe drinking water

Tubewell reported to have arsenic contamination (Image: India Water Portal Flickr)
Tubewell reported to have arsenic contamination (Image: India Water Portal Flickr)
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Lack of access to safe drinking water is a daunting development challenge and a quarter of individuals globally do not have access to safe drinking water in their homes. Among several pollutants causing contamination of drinking water and hence creating public health hazards, elevated level of arsenic in groundwater is a major one that affects millions of people worldwide.

It remains a silent killer since neither is the presence of arsenic detected by human senses nor is the testing of the level of arsenic always included in the regular water quality tests.

Epidemiological studies have documented several symptoms that are manifested post-long-term exposure to arsenic. These include arsenical skin manifestation, deposition in arsenic in hair, nail, urine, etc. Long-term ingestion also leads to skin cancer, diabetes, pulmonary and cardiovascular diseases, resulting in loss of productivity, and higher rates of morbidity and mortality.

The current statistics of the World Health Organization suggests that at least 140 million people in 50 countries are consuming drinking water with a highly elevated level of arsenic, and the presence of this toxic chemical is regularly being detected in new locations.

A recent paper ‘Willingness to pay (WTP) for arsenic-safe drinking water: A case study to understand societal embedding of ECAR technology in rural West Bengal, India’ analyses users’ willingness to pay for safe drinking water in a resource-poor region in West Bengal, India, with dangerously high groundwater arsenic concentrations.

The study was carried out during the installation of an Electro Chemical Arsenic Remediation (ECAR) water treatment plant at the site. ECAR was invented and patented by Gadgil Lab at the University of California, Berkeley and Lawrence Berkeley National Lab, USA.

ECAR is an iron-based electro-coagulation technology with a demonstrated efficiency to reduce arsenic levels from >500 μg/l to <10 μg/l. Previous field trials of ECAR conducted in India and Bangladesh yielded consistent performance and the technology was suitable for a community-scale micro-utility business model.

The site for the 10,000 LPD-ECAR demonstration plant was set up at Dhapdhapi High School in Baruipur administrative block, 24 Parganas (South) of West Bengal, India. The project commenced in 2014 and aimed to implement and commercialize a 10,000 litres per day (LPD) prototype of ECAR. This was the first large-scale demonstration of ECAR in the field.

The Ganga-Brahmaputra-Meghna basin, comprising of parts of India and Bangladesh, is one of the areas worst hit by this problem with millions of people being exposed to the risk of arsenic contamination.

The district of North 24 Parganas was the first place where an elevated level of arsenic (more than 50 μg/L, the then permissible national limit) was detected in groundwater. The modelled probability of arsenic concentration in groundwater exceeding the permissible limit of 10 μg/L for this area in the future was also found to be very high.


A primary survey was carried out to understand societal embedding challenges of ECAR and WTP was estimated for ECAR-treated arsenic-safe drinking water, based on contingent valuation method (CVM). During the period of commissioning, a range of stakeholders was interviewed at regular intervals with structured questionnaires along with unstructured consultations and focused group discussions. Using a contingent valuation method, the study elicits WTP, based on a stratified random sample of 1003 households.


The study demonstrates the importance of exploring the ability and willingness of the consumers to purchase a service provided by new technology and investigates several local factors that shape the WTP of consumers.

Apart from arsenic contamination, the community in the study area faced many challenges related to collection and quality of drinking water, including malfunctioning of and over-burden on deep tube-wells, non-payment of rental charges and resultant lack of maintenance of piped water supply, lack of an accountable mechanism for quality check of available packaged drinking water, etc.

The study reveals that the perceived benefit of an arsenic remediation technology is likely to be underestimated given the lack of awareness about arsenic, and therefore, it is important that the social anxieties related to the technology must be minimized.

A feeling of participation, inclusiveness, and transparency created through regular communication are important interventions to reduce perceived risk. Those who lived in the proximity of the treatment plant witnessed the process of commissioning, participated more frequently in knowledge dissemination workshops, asked questions, expressed their anxieties, received responses from the research team, and finally emerged as powerful stakeholders with a sense of ownership.

These stakeholders subsequently stated higher WTPs for arsenic-safe drinking water. The school model, where the plant is installed within a school premise through collaborations, worked efficiently as the school became instrumental to maintain the connection between the research team and the community.

The primary survey carried out during the commissioning of the plant also helped in alleviating misgivings about the present operations and future functioning of the plant.

In the study area, only 21% of respondents were aware of the danger of high arsenic concentrations in groundwater, however, a large number of the respondents reported irregularity of drinking water supply and a lack of quality assurance.

About 64% of the respondents were willing to pay for ECAR-treated safe drinking water. Participants opting for home delivery were willing to pay more than those willing to collect water from the plant. The average WTP was high enough to recover the operational cost of the plant.

Households with higher income and educational attainment, more awareness about arsenic contamination, and living in proximity to the plant were willing to pay more than the others. Regular interaction with the community, maintaining transparency, and interacting closely with the local administration created a sense of local ownership for the technology that was found to be crucial for the societal embedding of the technology.

The results of the study re-emphasize the role of community involvement in the social embedding of a technology. Similar results are also found in studies conducted in countries such as Bangladesh and Mexico where community involvement was found to be one of the most important determinants of WTP as well as the willingness to accept the technological intervention for provisioning of safe drinking water.

All these suggest that investment in improving the drinking water system becomes a no-regret and economically sustainable decision when the benefit of such technology is admitted by the community. The ECAR demonstration plant was envisioned to have a sustainable business model to remain operational beyond the project lifetime.

Results from the WTP survey showed that the majority of the respondents in the catchment area were willing to pay for safe water; some were even willing to pay a higher amount for home delivery. It revealed an indicative price range that was crucial to confirm that the cost of production could be matched with the purchasing power of the community. Based on the WTP survey and operational costs, the price was fixed at Rs. 0.60/liter for collection from the location and Rs. 0.65/liter for home delivery.

The experience from the ECAR trial clearly shows that appropriate site selection, communication, engagement with the local community and understanding the demand pattern are important factors that can enhance societal embedding of a technology. These social innovation components are as important as engineering design innovations and are essential for societal embedding, especially in places with a memory of technology failures.

However, special effort is needed to create trust and sustainable demand for arsenic safe water through a price mechanism, repeated science communication, and transparent information-sharing on water safety aspects among consumers.

The full paper can be viewed here

Post By: Amita Bhaduri