ASSESSMENT OF THE LEVEL OF PHYSICOCHEMICAL AND MICROBIOLOGICAL CONTAMINATION OF GROUNDWATER IN PARTS OF BIR NASSER AND BIR AHMED WATER FIELDS IN TUBAN DELTA IN ADEN AND LAHEJ GOVERNORATES - YEMEN

The objective of this study is to assessed the of groundwater pollution, in some of  Bir Nasser and Bir Ahmed waters fields, in Tuban delta, which are considered as the main sources of drinking water and household purposes for consumers in Aden Governorate. In this study, 20 groundwater samples have been collected from the fields of Bir Nasser and Bir Ahmed, in the period from February until July 2021. The evaluation of groundwater quality in the study area was based on 19 parameters such as: Temperature (T), Turbidity, Hydrogen Ion Concentration (pH), Electrical Conductivity (EC), Total Dissolved Solid(TDS), Total hardness(TH), Total Alkalinity (TA), Calcium(Ca2+), Magnesium (Mg2+), Sodium (Na+1), Potassium (K+1), Iron (II) (Fe2+), Sulfates (SO42-), Chloride (Cl-), Fluoride (F-), Nitrate (NO3-), Nitrite (NO2-), Total Coliform (TC) and Fecal Coliform (FC). Groundwater suitability for a drink and domestic purposes was compared with the World Health Organization specifications (WHO 2004) and the Yemen's ministry of water and environment standards (YMWE,1999). The results showed that most of the physical, chemical and biological parameters are higher than the permissible limit by (WHO 2004), with the exception of pH and nitrite, which were found below the standard limit. Reasons for the high parameters values of some study areas were the presence of the investigated wells near the population centers that use cesspits to dispose of waste water, as well as the closeness of the wells to the agricultural lands that use chemical and animal fertilizers, in addition to random drilling of wells, and excessive pumping for groundwater. Therefore, there is a need for appropriate treatment measures before the consumption of these waters by the populace to avoid long term accumulated health problems of these pollutants.