This study is an attempt to characterize the distribution and occurrence of iron in the groundwater sources in parts of eastern Niger Delta, Nigeria. The study sites were chosen from the five (5) geomorphologic units that make up the area. Iron is a major chemical issue in groundwater from the area as nearly all the analysis returned a value for iron. Iron concentration was mapped with a view to relating the high occurrence to depth of boreholes. There is no definite relationship between the depth of boreholes and iron content. Therelationship is rather haphazard and probably related to the geologic history of the Niger Delta region. For instance, the boreholes with highest concentration of iron in the area of 10mg/l are located atIdama (Saltwater Swamp) and Umuoji (Coastal Plain Sands) and are 100m and 81m deep respectively. Ahoada (Coastal Plain Sands) has 0.04 from a borehole 65m deep.The deep wells at Onne (264m) has iron concentration of 0.06mg/l, Joinkrama (Freshwater Swamp) has 6.2mg/l from a borehole 176m deep. Toru-Ndoro (freshwater swamp) has 6.2mg/l from 176m-deep borehole while Forupa (Freshwater Swamp) has 0.3mg/l from a borehole 215m. The high iron concentration appears to be more prevalent in the boreholes drilled in Freshwater Swamps/Backswamp/Meander Belt region as well as the mangrove swamps and coastal ridges. Here, the values range from 0.4 – 10mg/l. It was less than 0.4mg/l in 50% of the samples, 0.4mg/l – 1.0mg/lin 22% of the samples and >1.0mg/l in 20% of the samples. The highest value of 10.0mg/l occurs at Rumuokachi and Umuoji while the groundwater from Harry’s Town has 8.0mg/l. The WHO (2008) recommended a range of 0.1mg/l – 0.3mg/l as highest desirable and maximum permissible limits respectively. The implication therefore is that most water boreholes in the study area deliver water with iron in objectionable concentration. Most of the water in its natural state are not fit for human consumption.
