Calculating of treatment plant efficiency by using the Canadian council of ministers of the environment water quality index

This study included measures of the water quality index for wastewater in Aldujail district treatment plant before and after treatment using the Canadian Council of Ministers of the Environment water quality index (CCMEWQI) that depends on local conditions and issues. Eight properties versus eleven times before and after processing were used for calculating CCMEWQI. The plant efficiency was calculated by using the values obtained from the available data and the water quality index. The results showed a difference between the value of the water quality index before and after treatment, the value of CCMEWQI before treatment indicated that the water quality was poor, but it was marginal after treatment. The overall efficiency was 47.4% but it was different with respect to biochemical oxygen demand (BOD) and chemical oxygen demand (COD) during months of the year, as the maximum removal efficiency of (BOD) was 89% in November while the minimum removal efficiency value was 85% in June, but the maximum and minimum removal efficiency of (COD) was 86% and 79% in May and February respectively; the other characteristics did not show any significant changes in efficiency.