Appraisal of Environmental Impact Assessment Costs in Major Infrastructure Projects in Lagos State

Environmental impact assessment (EIA) is a statutory requirement for major construction and infrastructure projects in Nigeria, yet the cost implications of EIA processes and their management remain poorly understood among construction professionals. This study appraises the cost structure and management of EIA processes in major infrastructure projects in Lagos State. A mixed-method design was adopted, with 76 quantity surveyors, environmental consultants, and project owners forming the respondent group. Structured questionnaires and review of EIA cost reports from 20 projects provided the data. Analysis involved descriptive statistics and content analysis. Findings reveal that EIA costs in Lagos State infrastructure projects typically range from 0.5% to 2.8% of total project value depending on project type, with transport and industrial projects incurring the highest proportional EIA expenditure. Many project quantity surveyors inadequately provision for EIA costs in preliminary estimates, leading to budget surprises during project development. The study finds that delays in Federal Ministry of Environment approval processes add programme and cost risk to projects. Recommendations include the development of EIA cost planning benchmarks for Nigerian infrastructure project types, integration of environmental cost planning as a standard pre-contract quantity surveying service, and advocacy for streamlined EIA approval timelines. This research adds to the environmental cost management literature in South West Nigeria. Keywords: environmental impact assessment, infrastructure projects, Lagos State, cost management, quantity surveying