ASSESSMENT OF GROUNDWATER QUALITY IN WEST MALLAWI DISTRICT, SOUTH MINYA GOVERNORATE, EGYPT, USING WATER QUALITY INDEX (WQI) AND IRRIGATION PARAMETERS

ABSTRACT
The current study used the WQI index and various irrigation quality parameters to evaluate the groundwater quality of the Oligocene and M. Eocene aquifers in the west Mallawi District, south Minya Governorate for drinking and irrigation uses. To do that, twenty-seven groundwater samples representing both aquifers were chemically examined for major cation, anion, pH, TDS, EC, and trace elements. The water quality index and irrigation water parameters like Na%, SAR, RSC, KR, MH, and PI were computed and used for irrigation suitability assessment. In addition to creating and interpreting the spatial variation maps of major ions and WQI for the Oligocene and M. Eocene aquifers.
Results of the spatial distributions of TDS, major ions, and WQI values of the groundwater samples of both aquifers indicated that the groundwater is acceptable for consumption, except in the eastern portions of the Oligocene aquifer, where the values of TDS, Na⁺, SO₄^-2, and Cl^- exceeds the permissible limits and the groundwater samples fall under the poor water classification (WQI > 50). The concentrations of trace elements (Fe, Mn, Li, V, Zn, and Al) in the groundwater of both aquifers were within acceptable limits for drinking. The areal distributions of EC, TDS, SO4^-2, and Cl^-, as well as Kelly’s ratios, plotting of Na% and SAR versus EC revealed that the groundwater of the M. Eocene aquifer and 87.5% of water samples of the Oligocene aquifer were categorized as good to a permissible for irrigation, while 12.5 % of water samples of the Oligocene aquifer are deemed unfit for the same purpose. According to the computed RSC, PI, and MH values, the groundwater of the M. Eocene and Oligocene aquifers show values below the recommended limits for irrigation.