Managing Environmental Risks of Abandoned Industrial Sites in the South West Zone of Nigeria

This study examines the professional management of environmental risks associated with abandoned industrial sites in South West Nigeria, with specific reference to decommissioned textile mills and chemical facilities in Ogun, Oyo, and Lagos States. The collapse of Nigeria's industrial sector since the 1980s has left numerous large-scale facilities in states of partial or complete abandonment, with potential for contaminated soil, groundwater, asbestos-containing materials, and legacy chemical stockpiles to create ongoing environmental risks for adjacent communities. A risk inventory was developed for twelve identified abandoned industrial sites using desk-based research, site reconnaissance assessments, and engagement with state environmental agencies and corporate liquidation records. Risk was evaluated using a tiered prioritisation matrix based on hazard severity, pathway completeness, and receptor sensitivity. Results classify five sites as high-priority requiring immediate investigation, four as medium-priority, and three as low-priority. The most serious risks are identified at three former chemical manufacturing sites in Lagos and Ogun States where liquid waste containment has failed and community groundwater use is confirmed. State environmental agencies possess limited capacity to investigate or manage these sites due to legal uncertainty over ownership of abandoned properties and absence of dedicated contaminated land regulatory frameworks. Federal-level environmental liability legislation does not clearly assign responsibility for orphaned sites. Recommendations include developing a national contaminated land register, establishing a Polluter Pays fund for orphaned sites, and conducting immediate Phase II investigations at the five highest-priority abandoned sites. Keywords: abandoned industrial sites, contaminated land, environmental risk, South West Nigeria, legacy pollution.