Scope and Challenges of Sustainable Drinking Water Management in Assam

Abstract

Results of the Arsenic Screening and Surveillance Program in Assam revealed 29\% of a total 56,180 public sources analyzed to be above the WHO safety guideline of 10 mu g/L, exposing an unguarded population of 8,47,064 to the risk of arsenic contamination and resultant health hazard. Water security and water safety have thus emerged as a major concern in Assam. With surface water resource often contaminated with bacteriological, inorganic, and organic contaminants, groundwater continues to be the major source of drinking water especially in rural Assam. Arsenic contamination of groundwater sources and unreliability of surface water sources have led to an increased concern regarding safe drinking water supply in affected areas. Results of the Arsenic Screening and Surveillance Program demonstrated that the Titabor area lying along the southern bank of the Brahmaputra River in Assam is one of the arsenic hot spots in the region. This led to the formulation of the largest piped water supply scheme in the state to provide arsenic-free safe water to a design population of 1,90,000. Surface water from two tributaries of the Brahmaputra River, viz., Dhansiri and Dayong, is used to supply arsenic-free treated safe water. While adequate surface water availability in the vicinity of such high arsenic-contaminated aquifers has provided a viable alternative, this is infeasible in areas with discreet contaminated sources with scarce surface water sources nearby. Thus, an integrated approach based on groundwater and surface water can be a strategy; the choice often depends on surface water availability and sustainability of deeper safe aquifers subject to economic viability. Composite solutions like integration of rainwater harvesting structures, water recharging, delineation and safeguarding safe aquifers, reuse and recycling, water saving technologies, and smart systems are part of a composite option necessitated for addressing the gaps and inadequacies in ensuring safe drinking water in the region.