Ground Water Conditions and Spatial Distribution of Lead and Cadmium in the Shallow Aquifer at Effurun- Warri Metropolis, Nigeria

Abstract

A water table head distribution map of the shallow Benin Formation aquifer in the Effurun-Warri area has been drawn from dug well data and used to define groundwater gradients as well as identify directions of groundwater movement in this densely populated urban setting. Water samples from forty dug wells were also screened for the presence of lead and cadmium and results showed a variation in concentration from not detectable to 0.04mg/l for each metal. Iso-concentration contours for lead in groundwater suggest that enrichment may be from two sources: wastes from the refinery and petrochemical industrial complex on the northwestern edge of the city and secondly from leachates associated with the many unregulated waste dumpsites. Lead appears to be constrained from spreading eastwards from the industrial complex area by the south and westwards trending groundwater gradient. The city wide prevalence of elevated levels of cadmium is also probably due to leachates from unregulated dumpsites as well as the mixing of groundwater as suggested by existing gradients. Potential implications of the findings for public health, local and regional water quality monitoring are discussed.

Urbanization and Major Ion Hydrogeochemistry of the Shallow Aquifer at the Effurun - Warri Metropolis, Nigeria

“…Deep regional groundwater flow in the Niger Delta region is reportedly in the west and south west direction (Ophori, 2007). In the Effurun -Warri area local flow in the shallow aquifer is controlled by a south westerly trending groundwater mound that extends from the Effurun GRA towards the neighborhood of Ekurede -Itsekiri and from which mound groundwater flows northwards, westwards, southwestwards and even eastwards (Akpoborie et al, 2014).…”

“…Therefore, evolution of groundwater chemistry in the shallow aquifer underlying the city appears to be driven by such factors as the infusion of dumpsite leachate that is an important source of bicarbonate, chloride and sodium ions into the system; direct recharge from mildly acidic and low pH rainwater (Efe, 2005, Olobaniyi & Efe, 2007, flood water and storm water from drains and gutters (Gobo, Amangabara & Agobie, 2014;Egboh, Nwajei, & Adaikpoh, 2000), untreated sewage and finally, the complex ground water flow patterns (Akpoborie et al, 2014) that exist in the area. Omo-Irabor, Olobaniyi, Oduyemi and Akunna (2008) have also stressed the influence of anthropogenic factors in the determination of water chemistry in the Niger Delta region.…”

“…However, Warri River and tributary creeks are perennial gaining rivers (Akpoborie, et al, 2014)) and there is no evidence of heavy groundwater withdrawals in any part of the city that has caused a reversal of existing gradients. Indeed, the Warri River and its tributary creeks carry predominantly fresh water (Aghoghovwia, 2011;Ogbeibu, Chukwurah & Oboh, 2011).…”

“…Thus the objective of this paper is to provide a description of the major element geochemistry of groundwater using geo-referenced data and against which future evaluations and trends in this highly vulnerable and rapidly expanding urban environment may be compared. The results reported herein constitute part of a groundwater evaluation study, partial results from which have been reported by Akpoborie, Uriri and Efobo (2014).…”

Lithological Identification and Underground Water Conditions in Jeddo Using Geophysical and Geochemical Methods

“…It lies between latitude 5.583 • N and 5.600 • N and longitude 5.710 • E and 5.716 • E (Figure 1). The area is characterized by tropical equatorial climate with a mean annual temperature of 32.8 • C and an annual rainfall of 2673.8 mm [1]. It is an established fact that the annual temperature and amount of rainfall is highly variable from year to year [2].…”