Spatial arrangement of well and latrine and their influence on water quality in clayey soil – a study in low-income peri-urban neighborhoods in Lichinga, Mozambique

Abstract

In this study, the influence of the spatial arrangement of shallow wells and pit latrines on water quality was evaluated in clayey soil during dry and rainy seasons, using 123 randomly selected wells. The distance between well and the nearest latrine was measured and the location of the well in the yard was characterized. The colony forming units (CFU/100 mL) of fecal coliforms were quantified, and pH, electrical conductivity (CE) and turbidity were measured. 100% of the wells were located less than 25 m from the latrine, 74.8% were located in the middle of the yard. In the dry season, 42.4% of the samples presented up to 12 CFU/100 mL, and in the rainy season, 84.4% presented up to 139 CFU/100 mL. 56.9% had pH values between 6.5 and 8.5, and 63.4% presented EC values between 50 and 571 μS/cm. In the dry season, 40.7% of the samples had values below 5 NTU, and 59.3% up to 50 NTU. In the rainy season, 86.6% had values between 6 and 300 NTU. Pearson's correlation between all variables was weak. The wells are susceptible to high fecal contamination, although the clayey soil seems to mitigate the expected high levels of microbial contamination. HIGHLIGHTS 100% of the wells are less than 25 meters from the nearest latrine.; In 57.6% of the dry season samples, bacterial CFU/100 mL were not detected.; In the rainy season, 84.4% of the samples were positive for bacterial CFU/100 mL.; The clay soil seems to mitigate the expected high levels of bacterial contamination.;

Keywords

• distance from the latrine
• fecal coliforms
• fecal contamination
• latrines
• shallow domestic wells
• well location