An investigation of the environmental health risks from rural sanitation infrastructure: with a case study from Fiji

Abstract

Access to safely managed sanitation has emerged as a global challenge. Nearly half the global population lives in rural areas and generally relies on on-site sanitation systems. Sustainable Development Goal target 6.2 aims to achieve adequate and equitable sanitation by 2030. Currently, all regions are off-track in achieving the target due to the inequalities between the regions and rural and urban areas. Assessing sanitation back-end containment safety is a continuing challenge due to the unquantified variability of types of sanitation back-end infrastructure present in rural communities. This research aimed to investigate the environmental health risks from on-site sanitation back-ends in rural communities with a case study in Fiji (Western Pacific region). The Fijian case study involved 29 rural communities from five water catchments across the three main islands. The results from the sanitation observation data showed that 58% of the studied households used uncontained plastic or metal tanks as back-ends. However, 51 – 64% of the studied households inaccurately reported uncontained tank-type back-ends as septic systems. The over-reporting of septic systems highlighted the underlying challenges with data accuracy and the need to provide clear categorisation of sanitation back-ends. Lateral transport of the contaminants was limited to 10 m from the sampled back-ends, predominantly due to the silt and clay-type soils. This significant finding highlighted the protective nature of soil with lower permeability in restricting the lateral transport of faecal sludge contaminants. A novel distance and soil-type-based sanitation risk assessment framework was developed. The framework was then applied to a case study in Timor-Leste (South-East Asian region) to assess its applicability. This research significantly contributed to the understanding of back-end containment safety. These findings will contribute to advancing the progress towards achieving SDG target 6.2.