Existing federal regulations for the control of deep well waste injection are critically reviewed from the view point of basic hydrogeological design principles. It is shown that the Federal Environmental Protection Agency's Guidelines and Standards for Environmental Pollution Control in Nigeria (FEPA Guidelines) provide no explicit guidance for the procedure. They are therefore deficient and ineffective. On the other hand, the Environmental Guidelines and Standards for the Petroleum Industry in Nigeria (EGAS) that are published by the department of Petroleum Resources, lack precision with respect to well design, injection zone characterisation and materials specifications. Monitoring well requirements and specifications are also vague and inadequate. It also appears that several EGAS stipulations were violated at the controversial Ozoro waste injection project. These include but are not limited to the lack of an environmental impact assessment and a DPR facility permit. The fact that the Federal Ministry of Environment exonerated the project operator of any wrongdoing in spite of these violations is indicative of a lack of harmony in the enforcement of EGAS and the FEPA Guidelines. The net result of this is that when the Ozoro project was unceremoniously abandoned, closure, post closure monitoring and other essential procedures were either abandoned or not initiated. The aquifers which underlie the project area therefore remain exposed to contamination from waste that had already been injected. This issue requires immediate attention.
Because of the tremendous potential that deep well injection has for waste management in the chemical, manufacturing and petroleum industries, it is recommended that a harmonised and comprehensive guidance document for the control of deep well waste injection that takes cognisance of all hydrogeologic and hydrogeochemical considerations be developed
In 1999, a deep well waste injection project was initiated at Ozoro, Delta State. The project which had been unceremoniously terminated by its operator apparently because of feared communal agitation attracted considerable controversy and media attention. The host community continues to express concern that toxic waste has been dumped on them, a claim which is denied by the operator of the facility.
This is interesting because relevant federal statutes and guidance documents do exist to regulate the disposal of industrial and toxic waste. Disposal through injection into subsurface geologic formations is a method that is recognised and indeed recommended in these regulations. However these formations may also serve as freshwater reservoirs. It is these fresh water sources that the regulations as much as possible seek to protect from contamination. The Ozoro problem therefore provides a rare opportunity for close scrutiny of the existing regulations with respect to their relevance and effectiveness in achieving this objective not only in Ozoro but also in other sedimentary basins in Nigeria, many of which possess geological formations that can also be used as repositories of industrial and toxic wastes.