Heavy metal pollution in the water resources of Morogoro Municipality.

Heavy metal pollution in the water sources of Morogoro municipality was studied. These water sources include Morogoro river and its tributaries Kikundi, Kilakala and Ngerengere river and several wells. Morogoro and Ngerengere rivers receive urban runoff water from residential, commercial an agricultural areas of the Morogoro municipality as well as industrial discharges of various types. Water and sediment samples from ten sampling locations along the Morogoro river, Kikundi and Kilakala streams and Ngerengere rivers were drawn between the upstream part and the downstream end of the urban municipality. Well-water samples were obtained from five selected locations within the municipality. The concentration of the heavy metals cadmium, lead, manganese and zinc measured in river water samples were within the stipulated water quality criteria of World Health Organization and Tanzania Bureau of Standards while that of iron exceeded the limit set by these standards. Water samples from the five wells within the municipality indicate that the concentration of cadmium, iron and zinc in the waters conform to the guideline on water quality criteria of both World Health Organisation and Tanzania Bureau of Standards. The concentrations of lead and manganese in the well-waters were found to exceed the Tanzania Bureau of Standards guidelines for drinking water. The analyzed river sediment samples who wed that these heavy metals were present in significant concentrations in the sediments. Thus heavy metals were deposited into the sediments. The study has revealed that urban runoff, agricultural, industrial effluents and other municipal activities contribute to pollution of the rivers and wells by heavy metals.