Environmental assessment of heavy metals in surface and groundwater at Samarra City, Central Iraq

Abstract

Urban Samarra City is characterized by high population density and wide variation in land use, has led to many environmental problems, for this purpose the environmental assessment became an urgent need for surface and ground water at study area. Three water samples from Tigris River   and six  groundwater samples were collected and analyzed for heavy metals  as Fe, Mn, Zn, Cd, Cu, Co ,Pb, Ni, Cr, As, Mo, Hg, Al, Li, Be, Se, V, U, Sr. Most heavy metal concentrations have shown higher level than standards, such as  Fe, Mn, Cd, Pb, Ni, Cr, As, Mo, Hg, Al ,Li ,Be, Se, V,  that might be due to anthropogenic activities such as  agricultural and the heavy  use of fertilizers, besides other activities among them industrial  .

     All water samples have higher concentration level of Uranium except (SW1, SW2, SW3, GW1) might be due to military activity. On the other hand all samples were polluted in Co except SW2, GW4, high value of Co may be caused by industrial processes and oil product spills.

     Physical and chemical properties values which have obtained in this study are pH, EC, TDS, TSS, DO, BOD,COD and  turbidity. Water analyses reveal unacceptable values for physical and chemical parameters according to WHO standard and IQS2009 limits for drinking water, BOD, EC have shown high values in all surface and groundwater samples. Whereas, high values of TDS, COD and turbidity only in ground water samples.

     The water is not drinkable according to Water Quality Index (WQI) all values are above 100 and, in the sequence (GW1>GW5>GW4>GW3>GW6>GW2), the water quality index of surface water (SW3>SW2>SW1). Mixing of the shallow groundwater and Tigris River water show various patterns affected by other factors such as the aquifer recharge and evaporation, especially at the shallowest parts.