The emergence of prefabricated VIP toilet seats with covers: The implication for odour control and potential improvement

Abstract

ABSTRACT The ventilated improved pit (VIP) latrine is a cheaper and convenient alternative to water-borne sanitation for many households in developing countries. To mimic the water closet toilet, some users have introduced prefabricated ceramic seats with covers, which are known to disrupt the odour control mechanism of the latrine. The objective of this study was to quantitatively establish the extent to which the use of seats with covers affects the ventilation rate in the VIP latrine and to explore whether an innovative seat with a partially-screened cover could significantly minimise the effect of seat covering. The ventilation rates in experimental latrines with various modifications of superstructure and user interface designs were monitored with an air flow meter. The study revealed that seat covering could lead to >87% reduction in the ventilation rate and allow the generation of <50% of the minimum ventilation rate required to achieve odour-free conditions in an otherwise standard VIP latrine. The study also established that lining part of the seat cover with an insect screen could increase the ventilation rate by more than three times and could attain the minimum ventilation rate when combined with the conventionally recommended superstructure design.