The sample size at household and community level was defined according to the estimated number of residents of each block of the camps, approximately targeting 3% of the households. The water samples were analyzed in laboratories of Water and Environment Institute at Al Azhar University, Gaza, Palestine. Chemical analyses were performed for major ions content using standard methods [10]. Electrical conductivity and pH were measured directly in the field using a portable instrument called Electrochemistry made by CIBA-CORNING. Sodium and potassium were analyzed using a Flame Photometer and nitrate was determined by a cadmium reduction method, followed by spectrophotometric measurement at 540 nm wavelength. The calcium and magnesium were determined with EDTA, while titration with mercury nitrate was used to determine chloride. For alkalinity, a titration with 0.01 N sulfuric acid was used and a turbidity method was employed for the sulfate analyses [11]. Bacteriological analyses of water samples were analyzed for total coliform and fecal coliform in duplicate samples. Total coliform and fecal coliform bacteria were enumerated by the membrane filter method using m-FC agar. 250 ml of the water sample was filtered through a sterile membrane filter of 0.45 mm [12].