A water quality analysis of rainwater collected from different roof catchments in rural, urban and industrial areas was conducted to determine its suitability for domestic purposes. Examination of the collected rainwater samples indicated that the bacterial quality was poor, and the physical and chemical qualities varied between each area and between each site. Rainwater from industrial area roof catchments had lead concentrations averaging two-fold higher than the WHO drinking water guidelines and also had high levels of turbidity, suspended solids and zinc. Water collected from rural area roof catchments had a higher concentration of nitrates and a slightly higher pH. Although lead was detected in urban area roof catchments, concentrations were not as high as the concentrations in the industrial area. The different roof types had an influence on the rainwater quality with zinc concentrations higher in galvanised iron roof catchments, while pH, conductivity and turbidity levels were higher in concrete tile roof catchments. The pollution of rainwater collected from roof catchments was mainly due to the diffused pollution from atmospheric deposition, and the number of dry days preceding a rainfall event affected the collected rainwater quality.
- Rainwater quality
- rainwater harvesting
- roof catchments
- bacterial quality
- © International Association on Water Quality 1993