Validity of the application of open dug well sanitary survey methodology in the development of a water safety plan in the Maldives islands

Abstract

As practised in the remote Maldives islands, groundwater exploitation using open dug wells with on-site sanitation systems causes major microbial contamination of well water. Surveys show that 75% of the Maldives population currently rely on rainwater tanks for drinking water. Global climatic change causes prolonged drought periods and extensive rainfall events causing flooding. In addition to rainwater storage tanks, the very limited land area makes the utilisation of the natural underground reservoir an essential water source for the remote Maldives islands. Therefore, it becomes vital to protect the groundwater quality in these islands.Using methods published by World Health Organisation (WHO) for combined hazard identification and faecal contamination, a surveillance study of open dug wells was carried out in six selected islands of the Maldives. The aims were to assess the current risks and sustainability of the open dug wells in the study areas with respect to sanitation related health issues. The field study involved systematically collecting data about sanitary hazards in the neighbourhood of wells and well water quality, including thermo-tolerant faecal coliform counts. The results showed that the great majority (83%) of wells were, as expected, faecally contaminated. However, the expected benefit of using combined sanitary survey and faecal contamination level assessment to prioritize specific remedial actions to improve the microbial quality of well water was not realized in this study, in contrast to earlier published studies. The principal reasons for this methodological failure are: Irrespective of the impact of climate change on sea level and rainfall patterns, it is concluded that current on-site sanitation practices are unsustainable. A major programme of disciplined construction of septic tanks with careful attention to tile field design would be required to address the problem of faecal contamination of the aquifer. the geological setting of the Maldives is extremely vulnerable overall, particularly since there is effectively no soil layer

How we assess water safety: A critical review of sanitary inspection and water quality analysis

“…This mechanism requires that sanitary inspection be carried out on multiple sources. Many studies cite prioritization of water sources for rehabilitation or repair as a major benefit of sanitary inspection and it is the main objective of the SHI (Bacci and Chapman, 2011;S Barthiban and Lloyd, 2011;Lloyd and Suyati, 1989;Lloyd and Bartram, 1991). Monitoring for the purpose of intervention prioritization can significantly improve water supply service quality (Bartram, 1996).…”

Improving Risk Assessments by Sanitary Inspection for Small Drinking-Water Supplies—Qualitative Evidence

“…When a trend in failures within water supplies is noticed, the SI form provides a tool which allows the operative to work out the cause and how to address it [11,12,41,42]. This allows the identification and prioritization of supplies within a geographical area, which in turn may be used to allow water supply managers and surveillance agencies to prioritize remedial measures within their programs.…”

“…The approach supports the identification and management of observable conditions or circumstances that may favour certain hazardous events and introduce hazards which may become a risk to health [7]. Published studies show that SIs have a number of additional applications, such as a surveillance tool [11,12], for operational purposes [13,14], as a component of a WSP [15], in research [16][17][18][19][20][21][22][23][24][25][26], and in outbreak investigation [27,28].…”