Sustainability appraisal of arsenic mitigation policy innovations in West Bengal, India

Abstract

Treatment of arsenic-contaminated shallow groundwater upon extraction has become imperative to provide safe drinking water in remote villages in West Bengal, India. Arsenic removal plants (ARPs) stabilising arsenic-rich waste water ‘in situ’, despite saving valuable time and money, require high technical expertise for operation and maintenance, which is difficult to facilitate in rural communities lacking the necessary infrastructural support. Contrarily, arsenic removal units (ARUs) have been widely accepted by the society for their user-friendliness. However, most of them produce a high volume of hazardous sludge, safe commercial reuse of which can be done by ‘ex situ’ stabilisation with clay bricks. Based on the number of ARPs and ARUs needed to help households seeking remedy, a cost–benefit analysis of the remediation and waste-management aspects is performed by system dynamics modelling. For a major arsenic-affected district of the state, the simulation results suggest that in lieu of ARPs, installation of ARUs is deemed to be financially sustainable for at least 15 years from now, if the arsenic-laden bricks are sold at a price 20% higher than normal. Future projections of groundwater draft and stress in the region commensurately confirm the economic and environmental sustainability of the arsenic remediation.