Water Quality and Environmental Impact Assessment of a Tropical Waterfall System

摘要

To provide information on the water quality and productivity of waterfalls, monthly samples were taken from three sites along the 6817.7m long Agbokum waterfalls for 24 months (January 2007-January 2009) during wet and dry seasons. Apart from pH, Cadmium (Cd), Chromium (Cr) Ammonium (NH4+), Lead (Pb), alkalinity, Surface Temperature, Air temperature, water velocity and rainfall, all other environmental parameters showed significant variation between sampling sites. Most parameters including water discharge (1496.5±82.9), dissolved oxygen (9.6±0.2), conductivity (69.0 ± 18.5), calcium (16.9±1.2), magnesium (2.5±0.04), silicon (2.5±0.04), Iron( 0.08±0.02), Manganese (0.8±0.2), Total solids(178.6±8.8) and Total hardness (74.5±4.3) were highest in waterfalls region (midstream) of the river. Deleterious levels of Fe, Pb, Cd and Mn, above recommended levels, in the waterfalls region of the river and in the wet samples coupled with the acidic nature of the wet samples poses potential health hazards to the aquatic organisms and the inhabitants of the area that use this water resource directly for domestic purpose without treatment. The results indicate a deteriorating water quality of Agbokum waterfalls with the waterfalls region and wet season being most critical in the effective management of the water body.