Microbiological and physico-chemical quality of the ziga dam lake in Burkina Faso

The practice of activities on the shores of the Ziga Dam Lake involves the use of products that can affect the quality of its water, thus upsetting the ecological balance of the environment. In order to prevent this damage, it is necessary to regularly monitor the quality of the lake's water, because without this, no decision can be taken to protect it. The objective of this study is to evaluate the microbiological and physico-chemical quality of the dam lake. For this purpose, we evaluated in 16 water samples taken from the lake, the concentrations of coliforms, fecal streptococci, Escherichia coli, suspended solids, ammonium, nitrite, nitrate, and orthophosphorus. Electrical conductivity, pH and temperature were measured during the collection of the 16 samples. The results of the analyses show that the micro-organism load varied between 10,000 UFC/100 ml and 60,000 CFU/100 ml for coliforms, 1,500 CFU/100 ml and 20,000 CFU/100 ml for faecal streptococci and 100 CFU/100 ml and 1,300 CFU/100 ml for E. coli. The mean values of the physico-chemical parameters measured were 1.63±0.28 mg/l for ammonium, 14.13±4.62 mg/l for suspended solids, 95±29.12 μS/cm for electrical conductivity, 1.37±1.43 mg/l for nitrates, 0.06±0.01 mg/l for nitrites, 0.22±0.03 mg/l for ortho phosphates, 7.72±0.12 for pH and 21.74±0.93°C for temperature.It appears from this study that parameters such as conductivity, nitrates, nitrites, pH, phosphorus and temperature are favorable to maintain its quality. On the other hand, parameters such as ammonium and suspended solids show values that exceed the standards set by the state of Burkina Faso. Given the importance of this dam lake in the region, the use of the banks and even the water from the dam must be monitored more closely. Indeed, these punctual measurements carried out give an idea of the degradation of the water quality. In addition, the concentrations of the less acceptable microorganisms (coliforms, streptococci and E. coli) can quickly change and endanger the lives of consumers.