Nitrogen Pollution and Fecal Contamination of Well Water in Divo, Southwest Ivory Coast: Characterization and Health Implications
DONGO Koffi René *
Laboratory of Industrial Processes for the Synthesis of the Environment and New Energies (LAPISEN) of the Joint Research and Innovation Unit for Agronomic Sciences, Processes and Transformation (UMRI-SAPT) of the National Polytechnic Institute Félix HOUPHOUËT-BOIGNY (INP-HB), BP 1093 Yamoussoukro, Côte d'Ivoire.
KOUAME Kouakou Benoit
Laboratory of Environmental Sciences and Technology (LSTE), UFR Environment, Jean Lorougnon Guédé University, BP 150 Daloa, Ivory Coast.
KONAN Gbangbo Rémis
Laboratory of Geographical Sciences, Civil Engineering and Geosciences (LASCIG3) of the Joint Research and Innovation Unit for Engineering Sciences and Technology (UMRI-STI) of the National Polytechnic Institute Félix HOUPHOUËT-BOIGNY (INP-HB), BP 1093 Yamoussoukro, Côte d'Ivoire.
ZEDOU Abalé Molière
Laboratory of Industrial Processes for the Synthesis of the Environment and New Energies (LAPISEN) of the National Polytechnic Institute Félix HOUPHOUËT-BOIGNY (INP-HB), BP 1093 Yamoussoukro, Côte d'Ivoire.
*Author to whom correspondence should be addressed.
Abstract
Access to quality drinking water is a major public health issue, particularly in urban and peri-urban areas of developing countries. Its use for food or hygiene purposes requires excellent physicochemical and microbiological quality. Thus, to assess the quality of well water in the city of Divo in western Côte d'Ivoire, an evaluation of the physico-chemical and bacteriological quality was carried out and focused on 18 wells in this locality. The methodology adopted is based on a sampling campaign of several wells in the city of Divo, followed by laboratory analyses. The physicochemical parameters measured include temperature, pH, conductivity, nitrogen ions (NH₄⁺, NO₂⁻, NO₃⁻), chlorides and orthophosphates. The bacteriological analysis targeted mesophilic aerobic germs (MAGs), Escherichia coli, faecal streptococci, Salmonella and Shigella. A fecal contamination index (FCI) was calculated. The results reveal significant nitrogen pollution, marked by high levels of ammonium (55.1 ± 13.2 mg/L), nitrites (7.7 ± 5.1 mg/L) and nitrates (34.1 ± 22.6 mg/L). The average pH is acidic (5.3 ± 0.6), the mineralization low (average conductivity of 6.2 ± 4.4 μS/cm), and the high temperatures (31.2 ± 0.2 °C), reflecting the vulnerability of shallow aquifers. Microbiologically, 98% of the samples contained GAM, 26.31% E. coli, and all were positive for Salmonella and Shigella. The average TFR above 150 confirms a high level of faecal contamination. These results indicate that the majority of well water in Divo is unfit for consumption without treatment. Measures to protect wells, water treatment and community awareness are essential to safeguard public health.
Keywords: Well water, nitrogen pollution, faecal contamination, physico-chemical quality, contamination index