Exploring the Physicochemical Characteristics and Microbial Dynamics of Water Systems Surrounding Lemna Dumpsite in Calabar Municipality, Nigeria

This study assessed the physicochemical characteristics and microbial dynamics of water systems surrounding the Lemna dumpsite in Calabar Municipality, Nigeria, to determine contamination levels and associated public health risks. A descriptive and analytical design was adopted. Primary data were obtained through field sampling of surface and groundwater, laboratory analyses, structured questionnaires, and interviews, while secondary data were sourced from literature and environmental reports. Water samples from Obot Obu, Effanga Bassey, Dan Achibong, Borrow Pit Beach, and Sandmining Beach were analyzed using standard methods. Data were treated with descriptive statistics, comparison with WHO and NESREA standards, thematic analysis, and multiple regression. Results indicated marked deterioration in water quality. pH ranged from 5.9 to 6.8, dissolved oxygen from 3.7 to 5.0 milligrams per litre, total dissolved solids from 580 to 710 milligrams per litre, electrical conductivity from 1230 to 1520 microsiemens per centimetre, and turbidity from 7.2 to 11.0 NTU. Heavy metals, including lead (0.03 to 0.07 milligrams per litre), and nitrate levels (58 to 78 milligrams per litre) exceeded permissible limits. Microbial counts were also elevated: total coliforms (29 to 55 CFU per 100 millilitres), E. coli (16 to 25), Salmonella spp. (5 to 10), Pseudomonas aeruginosa (8 to 15), and Giardia lamblia (2 to 5). Regression analysis showed a strong relationship between contamination and health risks (R = 0.739; R² = 0.546; F = 210.387, p < 0.001), indicating that over 54% of health variations were explained by pollution. The study concludes that water sources are unsafe and recommends improved waste management, routine monitoring, provision of safe water, and public education.