Utilisation of ecological sanitation technology and microbial risks associated with the use of its byproducts in Burera district, Rwanda

Abstract

Ecological sanitation (Ecosan) concepts are emerging worldwide to boost sanitation coverage and agricultural production. Ecosan aims to achieve a rational use of human excreta through urine diversion and treatment of faeces, although it is surrounded by excreta disgust and related health risks. Ecosan concepts have been implemented for more than a decade in Burera district, Rwanda. However, little is known about its utilisation among farmers. This study was therefore carried out to assess the utilisation of Ecosan concepts and microbial risks associated with the use of faecal by-products in Burera district, Rwanda. A mixed method study was conducted, comprising four specific objectives. Objective 1 was a mixed-method research with both quantitative and qualitative data. Up to 374 household users of Ecosan toilets of the urine dehydration dry toilet (UDDT) technology and 20 key informants participated in this study. About 60.6% of household users were unable to practice both urine diversion and the use of faecal by-products. Semi-annual faecal pit emptying (AOR 3.38, 95% CI (2.18-17.91), ash use (AOR 1.65, 95 % CI (0.93-4.64), and presence of concrete latrine slabs (AOR 7.31, 95% CI (2.94-17.95) contributed to better utilisation of Ecosan technology. Whereas, unaffordable cost, phobia of touch of excreta, and poor maintenance contributed to poor utilisation. Objective 2 was a quantitative study that targeted households and public Ecosan facilities. Data were collected by using an adopted sanitation facility readiness checklist. The limited Ecosan technology in service (37.3%) comprised UDDTs made of wood slabs in household. Most (71.4%) of Ecosan facilities provided basic access and 41.6% of them were not reliable, and smelt bad with flies’ presence. Objective 3 was quantitative and qualitative where, the data were collected following the Quantitative Microbial Risk Assessment (QMRA) framework under the probabilistic model of the Monte Carlo simulation. An estimated annual risk of infections comprised Schistosoma species (88%), Ascaris lumbricoides (90%), Entamoeba species (99%), and E. coli species (62%)in semi-solid faecal byproducts. These concentrations were above World Health Organization (WHO) standards of associated infective risks of 0-10% of helminths and protozoa in treated faecal products applied in the gardens. Objective 4 was qualitative and targeted three farmers’ cooperatives who were users of faecal byproducts. Six Focus Group Discussions (FGDs), comprising 48 participants were involved. A grounded theoretical lens was applied using thematic content approaches. Farmers perceived byproducts as useful, trusted, and willing to apply them in their gardens. However, microbial contamination and bad smells were found to slow down their use. The overall utilisation of Ecosan technology was poor. This resulted in improper faecal by-products treatment and immature use, with a high-risk of helminths and protozoa infections. The scale-up of Ecosan technology and sustainable use, therefore, needs to focus on addressing these barriers and adopting implementation best practices.