A screening approach for assessing groundwater quality for consumption in small islands : case study of 45 inhabited islands in the Maldives

Abstract

The expense and logistical difficulties of groundwater assessment in geographically dispersed, small landmasses, prevent it from being widely applied in small island developing countries. We propose a survey-based approach for screening groundwater quality using crowd-sourced information. A household-level survey was conducted in 45 selected inhabited islands across 11 atolls of the Maldives. In each island, covering a sample size between 16 and 85 (median 50) households, use of groundwater, the perceived quality and household groundwater treatment methods applied, were surveyed. The respondents perceived groundwater as highly contaminated and non-potable, but due to the lack of alternative water resources, almost all respondents used it for non-potable purposes. Over 84% of the surveyed islands reported varying degrees of elevated salinity. The water quality indicators of odor, color, and debris were seen to be significantly correlated to each other, but salinity did not show such a correlation. Salinity increased with population density and decreased with the area of the island as well as the latitude. Household treatment of groundwater was rare. Due to the ease of deployment, rapidity of assessment, low cost, and good spatial coverage, crowd-sourced water quality screening can be a viable and important approach alongside detailed groundwater investigation studies.