Water quality and hydrogeochemical characteristics of groundwater around Mt. Meru, Northern Tanzania

Abstract

Climate change and population growth around Mt. Meru experienced lower availability of water for domestic and agricultural uses. Reduction in quantity of water is compounded by lack of information on water quality which could lead to undesired health risks and agricultural effects when such water is used for irrigation. Thus, major ions from 54 different water types (springs, streams, dug wells, boreholes, and lakes) were used to assess hydrogeochemical characteristics and suitability of water for domestic and agricultural purposes. Results showed dominance of the major cation and anion in the order of Na + > K + > Ca 2+ > Mg 2+ and HCO 3 − > CO 3 2− > Cl − > SO 4 2− > NO 3 − > F − , respectively. It is revealed that Mt. Meru is the recharge zone. Geology, water-rock interaction time, and climatic conditions control water chemistry. Major freshwater aquifers were found to be fractured mafic volcanics, breccia, and tuff. Lahars, due to their susceptibility to weathering, were found to host groundwater of low quality. The suitability of water for domestic and irrigation purposes was moderate, in order of lakes < dug wells < boreholes < streams < springs. Fluoride was found to be the major natural contaminant affecting water quality for domestic purposes with mean value of 17.6 mg/L, while elevated Na + (mean = 118 mg/L), K + (mean = 59 mg/L) and HCO 3 − (mean = 390 mg/L) relative to other ions were found to affect water quality for irrigation purposes. In some few cases, anthropogenic pollutions were recognized through NO 3 − and Cl − .

Consumer awareness and production practices of farmers on antimicrobial residues in chicken eggs and Chinese cabbage in Dodoma, Central Tanzania

“…The high frequency of using well water for vegetable irrigation could be due to its accessibility and cost-effectiveness [ 59 ]. However, most farmers’ inability to keep domestic animals from accessing water sources suggests that animal excrement containing antimicrobial residues could contaminate water sources as previously reported [ 60 ].…”

Quality assessment and hydrogeochemical characteristics of groundwater in Kerzaz and Beni Abbes along Saoura valley, southwest of Algeria

“…During their journey, the chemical composition of groundwater evolves through the crossing of different geological faults according to several modifying phenomena (Mansour 1993); according to its chemical composition, we can classify them in families using the logarithmic diagram of Piper which is composed of two triangles representing the distribution of the anions and that of the cations, respectively, and a rhombus representing a synthetic distribution of major ions. This diagram reveals similarities and differences among water samples because those with similar qualities will tend to plot together as groups (Todd 1980;Makoba and Muzuka 2019).…”

Hydrochemical Characterisation of High-Fluoride Groundwater and Development of a Conceptual Groundwater Flow Model Using a Combined Hydrogeological and Hydrochemical Approach on an Active Volcano: Mount Meru, Northern Tanzania

“…The main challenges for groundwater quantity are depletion of shallow aquifers due to over-pumping, climate change, conflicting land uses, and uncontrolled urban development [1][2][3]. The main challenges for groundwater quality are high F − concentration [3][4][5][6][7], contamination from domestic sewage from on-site sanitation, industrial effluents, leachates from solid waste dumpsites, leaking fuel filling and waste oils [2], and saltwater intrusion (saltwater pollution) in coastal areas due to over-pumping of the aquifer [2,8].…”

“…The East African Rift System contains some of the regions with the highest F − concentrations in the world: Kenya, Tanzania, and Ethiopia [9]. High F − concentrations exceeding the WHO health-based guideline for drinking water (1.5 mg/L) [10] have been reported in both the surface and groundwater in Tanzania [2][3][4][5][6][7]11], Ethiopia [12,13], and Kenya [14][15][16]. The regions are rich in highly weathered Na-K-rich volcanic rocks with low Ca-Mg content.…”

“…This study identified two potential aquifers in the area, both containing significant concentration of F − . Additionally, the study by Makoba and Muzuka [7] on the northern and southeastern flanks of Mount Meru found that surface and groundwater chemistry are controlled by geology, water-rock interaction time, and climatic conditions. This study found that the aquifer composed of fractured mafic volcanics, breccia, and tuffs shows low total dissolved solids (TDS) and F − values compared to the aquifer composed of lahars, which are susceptible to weathering and hence lead to high TDS and F − values.…”