Environmental Impact of Produced Water and Driiling Waste Discharges from the Niger Delta Petroleum Industry

Exploratory discharge of produced water and drilling cuttings from oil and gas production has become a major source of pollutant to the biota. The aim of this study is to review previ-ous research on the environmental effect of such exploratory wastes with emphasis on the Niger Delta region. Drilling waste is composed of Aliphatic Hydrocarbon, Polynuclear Aro-matic Hydrocarbon (PAH) and heavy metals such as cadmium, chromium, lead, mercury, ar-senic, copper, Iron, lead, manganese, zinc, barium and strontium among others which are toxic to the environment. The composition and characteristics of naturally occurring chemical substances in produced water (PW) are closely associated to the geological characteristics of each reservoir. The toxicity of produced water effluent can be reduced when treated before discharging into the sea. Sulphide reducing microorganism which are associated with pro-duced water pose threat to the environment. Barite and bentonite present in most drilling fluid were found to reduce plant growth. Studies in some part of the Niger delta have shown high level of some heavy metals associated with exploratory waste with concentrations higher than world health organization (WHO) standard; these have negative impact on the environment such as massive destruction to aquatic lives and agriculture.