Characterization and Quantification of Fecal Sludge in a Developing Urban Center: The Case Study of Bafoussam, West Region of Cameroon

Abstract

This study aimed to quantify and characterize fecal sludge (FS) from on-site sanitation systems and make it available to public services. This study employed two methods: one based on the demand for mechanical emptying, and the other based on a count of the number of trucks deposited on the site. The sludge samples were then taken from the pits, followed by physicochemical, bacteriological and parasitic analyses. The results showed that all 660 households surveyed had a commode, with 73% traditional latrines, 21% modern toilets with a septic tank, 4% flush toilets, 1% VIP latrines and 1% pipe latrines. The annual volume of FS discharged at the treatment plant is estimated at 2,880 m3/year using the truck count and 40,310 m3/year based on mechanical emptying demand. In addition, the FS characteristics showed great variability, with average values of pH (6.6), Salinity (2.7 ‰), Conductivity (4.7 mS/cm), Total Dissolved Solids (TDS: 0.555 g/L), Ammonium ion (1.914 g/L), Biochemical Oxygen Demand (BOD5: 2.858 g/L), Total volatile solids (TVS: 78.1%) and Dry Matter (DM: 12.4%). The analyses also revealed high bacterial and parasitic load with fecal coliforms concentration of 8.5 x 106 ± 0.6 x 106 CFU/100mL, fecal streptococci concentration of 3 x 106 ± 1.7 x 106 CFU/100 mL and 6767 ± 1782 helminth eggs. The findings from this study will provide the scientific basis for improving the feasibility of establishing a FS treatment plant in Bafoussam.