Greywater Quantities and Qualities in Low-Income Kumasi, Ghana: Implications for Sustainable Water Management.

Household greywater, comprising wastewater from laundry, kitchen, and bathroom activities, poses significant environmental and public health challenges in peri-urban communities with limited sanitation infrastructure. This study quantified and characterized greywater from 10 households in Kotei, a peri-urban community in Kumasi, Ghana, over a 10-week period in 2023. Using a cross-sectional design, daily greywater volumes were measured via a bucket-based approach, and physicochemical, microbial, and chemical properties were analyzed for laundry, kitchen, and bathroom streams. Results showed a mean daily greywater generation of 110.0 ± 64.2 litres per household, with bathing contributing 58% (63.4 ± 28.9 litres/day), laundry 23% (25.6 ± 20.1 litres/day), and kitchen 19% (20.8 ± 16.0 litres/day). Laundry greywater exhibited the highest organic loads (BOD5: 5431.67 ± 3440.42 mg/L; COD: 12469.00 ± 7325.75 mg/L), electrical conductivity (3825.00 ± 2635.61 µS/cm), and total dissolved solids (1600.89 ± 417.37 mg/L), while kitchen greywater had the highest microbial contamination (total coliforms: 136.17 ± 66.94 cfu/ml; E. coli: 34.83 ± 24.70 cfu/ml). Phosphate levels exceeded EPA guidelines across all sources, and trace metals (e.g., Pb, Fe) and triclosan were detected, indicating potential environmental risks. Multivariate Analysis of Variance (MANOVA) confirmed significant differences in greywater characteristics across sources (p < 0.001). These findings highlight the need for source-specific greywater treatment strategies to mitigate environmental pollution and enable safe reuse in water-scarce regions. The study aligns with SDG 6 (Target 6.3) and WHO reuse guidelines, informing global WASH policies. The study underscores the importance of tailored wastewater management policies in peri-urban LMICs to promote sustainable water use and protect public health.