Suitability Assessment of Heavy Metal Concentration in Eniong Creek, Niger Delta, Nigeria for Multiple Uses

Abstract

he heavy metal concentration in Eniong Creek, Akwa Ibom State, Nigeria was assessed in three locations, between March and August 2024. Standard analytical method and water quality assessment indices were applied to evaluate the waters’ suitability to support aquatic biota and for drinking water and irrigation purposes. Water quality standards for drinking, aquatic life and irrigation were used as benchmark values for the assessment. Six (6) heavy metals were appraised and their range of values were: nickel (0.01- 0.09 mg/L), copper (0.01 - 0.08 mg/L), zinc (0.63 - 3.16 mg/L), lead (0.004 - 0.06 mg/L), cadmium (0.01 - 0.04 mg/L) and iron (0.27 – 1.25 mg/L).The mean concentrations of nickel, cadmium, iron, lead (stations 1 and 2) were higher than the threshold values for drinking water and support for aquatic biota. Zinc values also exceeded the limit required for the sustenance of aquatic biota. However, all the metals conformed to irrigation standard except cadmium. The drinking water pollution index (DWWPI), aquatic life water pollution index (ALWPI) and irrigation water pollution index (IRWPI) values were 2.37 - 2.79, 30.93 - 42.50 and 0.56 - 0.68 respectively. The DWWPI and ALWPI values were > 1, indicating poor water quality for drinking and aquatic life support. The level of pollution exacerbated by anthropogenic activities in the watershed could be responsible to observed variations. Hence, this study concluded that water was not potable or suitable to support diverse aquatic biota but can be used for irrigation purposes.