Assessment of Water for Different Uses at Some Localities of the Dakhla Oasis, Western Desert, Egypt

This study aims to assess water resources’ quality, biology, and suitability for different uses at some localities in the Dakhla Oasis in Egypt. Thirty-nine groundwater samples represent the Nubian Sandstone Aquifer with different depths, and 7 surface water samples represent wastewater lakes and canals. Major ions, total salinity, Na%, SAR, EC, RSC, PI, MH, KR, SSP, and Cl⁻ are used for the assessment of the water for different uses. It has been found that all groundwater samples of the study area are suitable for different purposes. Where the values of pH, major ions, TH, and TDS are below the permissible limit, this water is free of fecal coliforms. Based on the findings, the groundwater samples are generally suitable for drinking, with the exception of elevated levels of Fe²⁺ and Mn²⁺ concentrations that exceed the permissible limits. These elements can be treated to meet drinking water standards. The water samples from lakes and canals are not suitable for different purposes where these values are over the permissible limit and biologically contain fecal coliforms. According to the quality map, the groundwater in the area of study is excellent for drinking, livestock, and poultry and highly suitable for industrial purposes; and high to low suitable for irrigation purposes. However, lakes and canal water are not suitable for drinking, for livestock and poultry, industry, or for irrigation. The study reveals that there is a chance of an increase in total dissolved solids of wastewater in the lakes and canals which may pose a risk to soils in the study area. The present study recommends the necessity of finding a quick solution to the wastewater lakes which leads to the loss of large quantities of water and land due to salinization processes.