Groundwater hydrogeology and quality in Helwan area and its vicinities in Egypt

Abstract

ABSTRACT The study area includes Helwan city and its vicinities, south of Greater Cairo, between latitudes 29° 40ʹ and 29° 56ʹ N and longitudes 31° 15ʹ and 31° 24ʹ E, east of the River Nile. The main objective was to properly manage groundwater to protect it from deterioration. The hydrogeological and hydrochemical aspects were discussed, and the hazardous impacts of industrial, domestic and agricultural wastes on groundwater quality were evaluated. The main aquifer consists of Quaternary sediments of medium to coarse sand and gravel with clay intercalations. The average aquifer thickness is dominantly about 50 m, locally may increase near the Nile and becomes thinner eastward. TDS is more than 1000 mg/l in most groundwater samples increasing eastward reaching more than 3000 mg/l. High sulfate contents are caused by dissolution of highly soluble minerals as gypsum, mixing with sulfur water from springs and excess application of sulfate fertilizers. Groundwater in the southeast contains nitrate more than 50 mg/l which is high for drinking. Some groundwater and surface water samples contain high iron, manganese, aluminum, cadmium, chromium, copper, lead, nickel, selenium, and vanadium exceeding the drinking water guidelines and could affect sensitive crops. Microbiological pollution is also threatening groundwater in the area causing many diseases for people and animals. Mixed groundwater genesis indicated from domestic and industrial wastewater, excess irrigation water and sulfur water from springs.