Assessment of Heavy Metals in the Waters of the Senegal River Delta

Ahmed Dame MBOUP^1, , Alassane THIAM² and Abib NDIAYE³

¹Ecole Doctorale Développement Durable et Société, Université Iba Der THIAM, Thiès, Senegal

²UFR Sciences de l’Ingénieur, Université Iba Der THIAM, Thiès, Senegal

³Office des Lacs et Cours d’Eau, Saint-Louis, Senegal

Cite this paper:
Ahmed Dame MBOUP, Alassane THIAM and Abib NDIAYE. Assessment of Heavy Metals in the Waters of the Senegal River Delta. American Journal of Water Resources. 2025; 13(5):177-183. doi: 10.12691/ajwr-13-5-2

Abstract

The objective of this study is to evaluate heavy metals and their origins in raw water from the Senegal River Delta, the main source of water for local populations. These metals cause waterborne diseases, particularly bilharzia in humans and liver fluke in animals, despite the fact that the OMVS has begun installing water purification and treatment units to protect the health of users. To carry out this study, two campaigns of in-situ measurements of physical parameters such as temperature (°C), pH, and electrical conductivity (µS/cm), followed by sampling, were conducted on December 22, 2023 (just after the rainy season) at Rawette, Ronkh, and Ross Béthio sites, then on January 9, 2025, at Mboubène bridge, Kassak, and Mboundoum sites. For the first campaign, three (03) surface water samples were taken, one (01) per site, and for the second campaign, three (03) samples were taken, one (01) per site. The six samples were packaged in 500 mL polyethylene bottles and transported in a cooler to the CERES LOCUSTOX laboratory in Dakar for physical and chemical analysis (turbidity, major ions, and heavy metals). The results obtained show values of 127 NTU, in accordance with the (150 NTU) for the Ross Béthio site, and high values of 240 and 320 NTU respectively for Rawette and Ronkh sites. For the second campaign, the turbidity values comply with the above standard (Mboubène 27.74 NTU and Mboundoum 70.28 NTU), except for Kassak site with a value of 164 NTU. For heavy metals, copper (Cu) and arsenic (As) showed minimum concentrations of 0 and maximum concentrations ranging from 0.194 to 0.0162 mg/L, respectively, following a spatio-temporal variation that complied with the values established by the standard. Lead (Pb) was detected in all samples during the two campaigns, with concentrations ranging from 0.029 to 0.317 mg/L, exceeding the threshold values established by the standard. Only cadmium (Cd) and zinc (Zn) were completely absent in both campaigns. These metals probably originate from agro-industrial activities upstream of the study sites and gold panning, motor pump repairs, and runoff during the rainy season. This contamination could be avoided by treating waste in accordance with the waste standards in force in Senegal.

Keywords:
Heavy metals SEQ Waterborne diseases Senegal River Delta

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References:

[1]	Saliou Kamara, "Hydraulic developments and management of a largely anthropized hydrosystem: the Senegal River delta" 2013.
[2]	Doods and King, "Relationship between trihalomethane compounds and congenital malformations" 2001.
[3]	Nieuwenhuijsen, Mellah-J Toledano, Paul Elliot, "Relationship between trihalomethane compounds and congenital malformations" 2001.
[4]	ANSD, "Regional economic and social situation”
[5]	ANSD, "www.ansd.sn/taxonomy/term/8," 2023. [Online]. Available: https:// www.ansd.sn/ taxonomy/ term/8? page=1. [Accessed June 18, 2025].
[6]	OMVS, "State of the environment in the Senegal River basin" 2011.
[7]	Mohamed Talla Cissé, Soussou Sambou, Yaya Diémé,"Effect of the Manantali dam on changes in the hydrological regime of the Senegal River in the upper basin: a statistical approach" Science and Global Change, vol. 20, no. 111, pp. 104-111, 2009.
[8]	(OLAC), "hydrographic-network/lake-de-guiers" 2021. [Online]. Available: hydrographic- network/lake-de-guiers. [Accessed January 27, 2025].
[9]	Patrick Triplet, Ndèye Astou Sané, Rokhaya Wade,"Management plan for the three backwaters" 2019-2023.
[10]	Abdoulaye Faye, "Water and physical environment in the Gorom-Lampsar basin" 1989-1990.
[11]	Saer Gaye, "Modeling of flow propagation in the delta's hydraulic axes: application of the SIC model validated by the HEC-RAS model" 2015.
[12]	Société Grenobloise d'Etudes et d'Applications Hydrauliques, "Hydrology of the Senegal River delta (left bank of the river)," 1964.
[13]	Papa Malick Ndiaye, "Evaluation, calibration, and analysis of current and future trends in reference evapotranspiration in the Senegal River basin," 2021.
[14]	Adrien Coly, "Towards integrated management of the Senegal coastline and river basin," 2002.
[15]	Boubacar Cissé, "Drainage water from irrigated areas in the Senegal River delta: drainage systems and water quality," 2011.
[16]	Mor Talla Sall, "Study of irrigation/drainage practices in the irrigated perimeter of the Senegalese sugar company: proposal for improvement," 2005.
[17]	Mame Ramatoulaye Faye, "Contribution to improving access to water for irrigated agriculture in the face of the proliferation of aquatic plants, including Typha australis, in the Senegal River Delta: the case of the CSS”
[18]	Awa Niang, "Development of Lake Guiers from 1824 to the advent of the great dams on the Senegal River: a geographical perspective. Climate and development," 1999.
[19]	ANSD, "Regional economic and social situation," 2019.
[20]	Penda Diop, "Towards a participatory multi-use water resource management strategy in the Senegal River Delta: decision-making processes and regulatory tools around Lake Guiers," 2017.
[21]	SCOPELA, "Standing vegetation report," 2014.
[22]	Souleymane Gueye, "Study of the evolution of the Lake Guiers region," 1999.
[23]	PGIRE 2, "Characterization of inland fishing and aquaculture in the department of Dagana and the ponds of the departments of Matam and Kanel in the Republic of Senegal," 2016.