Analysis of Groundwater Vulnerability to Underground Petroleum Tank Leakages: Hydrogeological Risk Assessment, Residents' Knowledge, Attitudes and Practices on Associated Health Risks in Abeokuta Urban, Nigeria

This study analyzed groundwater vulnerability to underground petroleum storage tank (UPST) leakages and assessed residents' knowledge, attitudes, and practices (KAP) regarding associated health risks in Abeokuta Urban, Nigeria. A mixed-methods design integrated hydrogeological vulnerability assessment with a household KAP survey. Nineteen petroleum filling stations and 187 associated groundwater sources were purposively sampled, while 374 household respondents completed a structured questionnaire. Hydrogeological vulnerability was classified using station age, elevation-derived hydraulic gradient, and spatial proximity analysis. Socio-demographic data revealed predominantly female respondents (58.3%), economically active adults (32.1% aged 26–35 years), high educational attainment (53.5% tertiary educated), and long-term residents (66.3% residing >12 years). Knowledge levels were low, with 74.6% exhibiting poor awareness of groundwater contamination pathways; only 43.3% recognized that filling stations affect groundwater quality, and just 25.1% understood associated health risks. Attitude scores were moderately positive (mean 3.19), though 93.0% remained neutral, and protective practices were poor (mean score 1.31 ± 1.12), with only 12.3% treating water and 9.6% reporting contamination. Chi-square analysis revealed a significant but weak relationship between knowledge and attitude while knowledge-practice association was not significant. Vulnerability mapping identified three high-risk (15.8%), nine medium-risk (47.4%), and seven low-risk (36.8%) stations, corresponding to 20 (10.7%), 80 (42.8%), and 87 (46.5%) groundwater sources at risk. Elevation-controlled flow demonstrated that stations positioned downgradient exhibited 76.9-100% at-risk sources. The study concludes that contamination risk arises from the interaction between physical vulnerability, inadequate community awareness and protective practices, requiring integrated regulatory enforcement and targeted community public health interventions to reduce exposure.