This research paper deals with the hydrological and hydrochemical and bacteriological characteristics of Wadi El-Arab catchment area. The study area covers an area of about 267 km2 and lies between 208 –230 East, and 210230 North (Palestine Grid). The outcropping rocks in the area are sedimentary rocks of the Upper Cretaceous, Lower Tertiary and Recent deposits. The average annual rainfall in the whole catchment area ranges between less than 200 mm to more than 800 mm. The runoff ranges between 1.44 million cubic meters (MCM) to 72.89 MCM. A dam was constructed on Wadi El-Arab catchment area in 1987, with a total capacity of  about 20 MCM to collect flood and base flow for irrigation in the Jordan Valley area. There are more than 20 groundwater wells were drilled in the catchment area and six major springs; most of the wells water are used for irrigation purposes. The average discharge of the springs ranges between 0.81m3/h and 592.2m3/h and the yield of the wells range between 3 m3/h and 6000 m3/h. Water samples from the six springs and seven wells have been collected to study the influence of Irbid Wastewater Treatment Plant (WWTP) effluent on the groundwater quality and to classify the water of springs and wells quality according to their chemical composition furthermore, to study the quality of the springs and wells chemistry and bacteriologically. The results show that the chemical constituents and physical parameters of the studied springs and wells are within the permissible limits according to the World Health Organization (WHO) and Jordan Standards, and they are suitable for domestic and drinking water purposes. The classification of springs and wells water based on hardness: all springs and wells are classified as very hard water. According to the U.S Salinity Laboratory Classification, the springs and wells water were classified into two groups: Barruqa, Wadi Zahar Springs and Wadi El-Arab Well (6) are classified as C2-S1 while other springs and wells are classified as C3-S1. The bacteriological analyses indicate that the studied wells are non-polluted by total coliform and faecal coliform.