Abstract. In many parts of the world, groundwater sources are the single most important supply for the production of drinking water, particularly in areas with limited or polluted surface water sources. Fresh water has become a scarce commodity due to over exploitation and pollution of water. Many countries and international organizations, including Wolrd Health Organization, are seeking to promote people's access to safe drinking water. The situation in Yemen is no exception. Although we rely on groundwater significantly in our lives and our survival, we do not manage it in a way that ensures its sustainability and maintenance of pollution. The objective of this study is to determine the suitability of the groundwater in Al Burayhi and Hedran sub-basin (one of the sub-basins of the Upper Valley Rasyan) as a source of drinking water in the shade of the expected deterioration due to natural processes (water interaction with rocks, semi-dry climate) and human activities. Keywords: assessment of groundwater quality, the spatial distribution of groundwater pollution, Al Burayhi and Hedran sub-basin, Taiz and Yemen.

Groundwater is the main source of drinking water in many parts of the world. Groundwater is subject to pollution due to several trace elements and ions that occur naturally or as the result of human activities at critical concentrations. The quality of the groundwater has to be evaluated to avoid or, at least, to minimize negative impacts on human health (WHO, 2011). As Morocco's water resources are limited, Groundwater is exposed to agricultural, industrial, or urban pollution (Belghiti et al.,

Background. Groundwater is an important source of drinking water for human and animal populations and therefore should be protected from pollution. The study area, Sidi Slimane, is in the western region of Morocco, which is a highly important agricultural area. Objectives. The aim of the present study was to assess the suitability of groundwater for drinking in the Sidi Slimane region. Methods. Twenty (20) samples were collected from different locations in the study area in 2015 in order to evaluate the quality of groundwater for human consumption. Collection, transportation and analysis of samples were performed according to the Standard Methods for the Examination of Water and Wastewater of the American Public Health Association (APHA), 2017. The major ions (cations and anions), ammonium (NH4+), pH and electrical conductivity (EC) of the groundwater samples were analyzed. Total dissolved solids (TDS) and total hardness (TH) parameters were calculated on the basis of obtained chemical data. ArcGIS program (version 10.4.1) was used in the preparation of topographic and hydrological maps of the study area. Results. Groundwater showed high concentrations of most parameters of drinking water quality according to Moroccan and international standards. Groundwater was brackish and very hard. The results showed that sodium and chloride ions were the predominant ions. Salinity was present at low depths. The majority of groundwater samples in the study area (18 out of 20) were sodium chloride type, and only 2 samples were mixed calcium-magnesiumchlorine type. Discussion. The obtained results were compared with the Moroccan standards for drinking water. The results show that 100%, 75%, 70%, 70%, 65% and 55% of groundwater samples exceeded the permissible limits for drinking water quality according to the Moroccan standard with regard to sodium, calcium, TDS, EC, chlorine, and nitrate, respectively. Conclusions. Most of the groundwater samples in the study area showed poor drinking water quality. Groundwater quality must be protected by controlling the use of pesticides, fertilizers, manure, and harmful irrigation practices. Competing Interests. The authors declare no competing financial interests

The problem of water pollution affects the whole world including groundwater which is more susceptible to contamination by residues of industry, agriculture and domestic wastewater leading to the emergence of many serious epidemic diseases (cholera, typhoid, amoebiasis,…etc). The purpose of this study is to evaluate the impact of agricultural intensification and discharge of untreated sewage on the physical, chemical and bacteriological water quality of groundwater Maâmora, Kénitra, Morocco. The physicochemical parameters followed are: T°C, pH, EC, NH 4 + , NO 2-, NO 3-, Cl-, F-, HCO 3-, SiO 2 , SO 4 2-, Boron, Dry Residue, Turbidity, Total Hardness (TH), Dissolved O 2 , Oxidisability and total and fecal coliforms of raw water from the boreholes. This study shows that the physicochemical and bacteriological quality of the groundwater which is used as drinking water for the city of Kénitra and adjacent areas is generally good. However, high concentrations of nitrates (NO 3 , NO 2) in

The main objective of this research is to study the quality of water in terms of a physico-chemical analysis of groundwater and the impact of solid waste on the quality of drinking water for residents of the study area, Sana'a Basin. The present investigation was carried out to analyze water samples from Sana'a Basin during the winter season of 2010. Parameters such as pH, conductivity, TDS, alkalinity, sodium, potassium, calcium, magnesium, nitrate, sulfates, phosphates and chloride as well as heavy metals such as Cd, Cr, Cu, Zn, Fe, F, Pb, Ni, Mn, and Zn have been studied. The physico-chemical analysis showed that the selected major ions of the analyzed samples were within the limits of the World Health Organization (WHO) Guidelines and Yemen Standard. The analysis showed that there is a sort of groundwater pollution with some of the selected trace elements. It was found that three samples out of twelve were polluted with chromium; two were polluted with fluoride, two with iron and three with nickel. It was found also that lead in eight samples out of twelve have either slightly higher concentrations than the WHO Guidelines or the permissible maximum level of it. However, on the other hand, according to Yemen Standards limits, Pb concentrations in all samples were within the limits. We can conclude that the groundwater of this region is unsuitable for drinking or human use because of increases in heavy metals according to the WHO Guidelines and the standard specifications of Yemen.