Evaluating the effect of Sato pans on the performance of ventilated improved pit latrines.

Abstract

To evaluate the effect of Sato Pans on the performance of ventilated improved pit latrines (VIP); parameters such as fly presence, smell prevalence, outside ambient and inside superstructure conditions, and filling rates were assessed. Outside ambient and inside the superstructure conditions included wind speed, temperature while inside pit parameters evaluated included pH and Oxygen Reduction Potential (ORP). Thirty ventilated improved pit latrines comprising 15 with Sato Pans and 15 without them were considered in this study that was carried out in Bwaise II, Kampala Uganda. Fly presence was assessed by physical observation while smell was assessed using the Nasal Ranger Olfactometer. The VIP latrines installed with Sato Pans performed significantly better (p<0.05) than those without Sato Pans in regards to reduced smell prevalence and numbers of flies. For the VIP latrines installed with and without Sato Pans Pit; temperature, wind speed, pH and ORP were consistently, significantly different (p<0.01) for samples collected from both latrine types at the surface (0 m) and at depths of 0.5 m below the surface. The improved performance of VIP latrines installed with Sato Pans was better in terms of parameters of smell and fly presence was partly linked to the habitual cleaning required to manage them. Filling rate of latrines with and without Sato pans were insignificant different (P=0.078) at 95% significance. The installations of Sato Pans on VIP latrines enhance performance in terms of reduced smells and fly nuisances as well as reduced filling due to difficulty to dump non-faecal materials in their containments.