Pollution represents a serious problem for the environment. The aim of this research was to assess the level of organic pollution of the Ouémé River and his physical quality. Nine physical and chemical parameters were measured in nine different stations between March and October 2016, during dry and rainy season. The methods used were those recommended by the French Association of Normalization (AFNOR). Data were subjected to descriptive statistical analysis and multivariate statistical technics, including principal component analysis (PCA) and variance analysis. The Leclercq Organic pollution index was used to assess the level of organic pollution. The values of the measured parameters suggest an organic pollution on all stations. The pollution degree varies according to the study area with contents that sometimes pass those recommended by the WHO standards. More advanced information about water quality for this study area were obtained. Therefore, this study will help stakeholders to better manage Ouémé River’s water.

Objective of this study was to understand farmer's management practices related to water quality and sanitary issue in order to assess the risks of these practices especially in the Upper Ouémé Delta. All the data related to this investigation were collected by field observations, interviews, surveys of farming households and focus groups. T he surveys were conducted with 387 farmers belongs to three districts of southern Benin (Bonou, Ouinhi, and Zagnanado). Results of study revealed that 97.48%, 57.78%, 76% of farmers respectively of the Bonou, Ouinhi, and Zagnanado districts grow food crops. Among these, 2.53%, 42.22% and 24% cultivate cash crops such as cotton and oil palm. According to survey results, soil conservation and tillage practices are widely practiced. Further, crops rotation and fallow are widely practiced in all studied districts and 84.84% of the surveyed farmers use chemical pesticides to maximize crop yields. Among these, only 2.32% farmers used aqueous extracts of Azaradichta indica leaves for protecting crops against pests. The sources of the environmental risk are the type of chemical product on pesticide used, its toxicity, the parallel circuits of provisioning of pesticides, and the lack of use of protection clothes for spraying these products. This practice allowed ground and water pollution and leads to public health matter. A promotion of good practices is essential for a durable exploitation of the natural resources of the Upper Delta of Ouémé area.

The current research was undertaken in the north of Benin Republic, to assess the pollution level of drinking water; with an emphasis on water sources (boreholes, wells, surface water, and fountain post) and water storage by households. To this end, five villages of the town of Manta were the target. The methodology was based on chemical and bacteriological analyses of water samples collected in October 2015, from ten water sources and four households. The results of chemical analyzes, revealed that two out of five (5) boreholes sampled, had higher than normal nitrate concentrations. Two (2) wells out of three (3) had high ammonium concentrations. As far as the bacteriological aspect is concerned, water from the boreholes and wells are contaminated with fecal germs (Escherichia coli and fecal streptococcus). There is also a large presence of mesophilic aerobic germs and coliform flora in all samples. On the other hand, lithological data from drill holes, in the study area, indicate a preponderance of various schist and alterites that are depleted of fluorides and phosphate compounds. The geological cross-section shows that the aquifer in the town seems to be very homogeneous and does not indicate any tectonic structure that could explain contamination due to horizontal flow. This contamination reflects the lack of hygiene and sanitation near water storage points, the uncontrolled use of pesticides and fertilizers. The use of water protection equipment and hygiene awareness will considerably reduce pollution at the household level.