Abstract
Background: This study examined the effectiveness of solar water disinfection (SODIS) in removing coliform bacteria from water sources in Anguilla after hurricanes.

Aims and Objectives: The objective of this study was to assess the efficacy of SODIS as a low-cost and accessible method for water disinfection in post-disaster scenarios, explicitly focusing on the reduction of coliform bacteria in water samples collected from various cisterns.

Materials and Methods: Water samples were collected from different cisterns and tested for the presence of Escherichia coli and total coliforms using filter and plate methods. The samples were divided into three groups: Exposed to 48 h of sunlight, kept in the dark as a control, or tested immediately after collection. The effectiveness of SODIS treatment was evaluated by comparing the coliform bacteria levels before and after exposure to sunlight.

Results: Results showed a significant reduction in coliform bacteria levels in the samples exposed to sunlight. Coliform colonies decreased from 724 in the initial samples to three colonies after SODIS treatment. Complete eradication was not achieved in all samples, but a notable decrease was observed in those with initial coliform bacteria.

Conclusion: These findings contribute valuable data supporting the efficacy of SODIS as a low-cost and accessible method for water disinfection in post-disaster scenarios. Further, research and improvements are necessary to optimize SODIS methods for cistern water treatment in challenging post-disaster contexts. Continuous exposure to bright and clear sunlight for 48 h may lead to a more substantial reduction in coliform bacteria. However, it is essential to acknowledge that post-hurricane situations rarely offer ideal weather conditions.

Key words: Solar Disinfection; Solar Water Disinfection; Cistern Water; Coliforms; Hurricane; Emergency; Disinfection; Potable-Water