Greywater in the drains of a sewered community in Ghana

Abstract

With less than 5% sewerage coverage and abysmal greywater management, Ghana’s environment could be highly polluted, especially water resources. The few sewered communities may be guilty of pollution from greywater discharge into stormwater drains. In this study, Asafo, Ghana, was used as a case study to assess greywater characteristics in the major drains in a sewered community. The approach involved desk study reviews and laboratory analysis of greywater samples. The findings showed some inhabitants discharge greywater into neighbourhood drains instead of sewers. Most greywater sources from reviews and sampled drains failed the discharge limits for major contaminants including turbidity (39.4–2,880 NTU), BOD 5 (64–700 mg/L), COD (207–2,308 mg/L), TSS (70–4,720 mg/L), TDS (420–2,860 mg/L), nutrients – TKN, NH 3 -N, NO 3- -N, NO 2- -N (0–218.5 mg/L), total P and PO 43- (1.24–26.18 mg/L), elemental species – Na, K, Mg, etc (0–1.6 mg/L), and microbiological – total and faecal coliforms, and E. coli (2.95–10.4 log CFU/100 ml). High strength greywater accounted for odour emissions where flows stagnated. Greywater characteristics are highly variable but have potential for biological treatment as the BOD5:COD ratios ≥0.5. Ghanaian greywater, including flows from a sewered community, is untreated and polluted, and our environment is unsafe.