Environmental Impact of Coffee Processing Effluent on the Ecological Integrity of Rivers Found in Gomma Woreda of Jimma Zone, Ethiopia

The environmental impact generated from coffee processing effluent was assessed by comparing reference sites with downstream locations. The physico-chemical parameters of coffee effluent on average consists of very high amount of BOD (2200mg/l), NO₃ (26.4mg/l), low pH (4.3), and zero DO values. Thus, BOD values as high as 1900mg/l and 1700mg/l were found at the downstream sites of Bore and Fite rivers, respectively. The cluster analysis was effective in clustering the downstream sites of Fite and Bore rivers. Based on the principal component analysis, fresh water loving species of Heptagenidae and Hydropsycidae had higher weighted average for oxygen while pollution tolerant species of Chironomidae and Oligocheata had higher weighted average for BOD. The habitat score of the study sites was in the range of 29% (very poor) up to 84% (excellent). In general, the integrity of most of downstream sites was impacted by the coffee processing activity in the area.