Physicochemical assessment and bacteriological studies of hand-dug wells of major markets in south western, Nigeria

Rapid population in developing nations has imposed stress on groundwater resources, thus the need to assess physicochemical and bacteriological impact of microbes on hand-dug wells along some major markets in Ibadan Southwestern Nigeria. Water samples from hand-dug wells were measured sequentially, and total dissolved solute (TDS), pH, electrical conductivity (EC), salinity, and temperature were measured in situ. Water samples were analyzed at a Microbiology Laboratory. Most probable techniques used for micro-organism analysis were in three stages: presumptive test used for confirmation of Escherichia coli, confirmed test for total viable bacteria count (TVBC), and complete test to reconfirm the presence of coliform. Presumptive test showed high rate of E. coli in most of the hand-dug wells with (37.5 %). Confirmed test revealed Staphylococcus aureus to be 25 %, followed by Proteus vulgaris (14.6 %), Bacillus species (12.5 %), Pseudomonas aeruginosa (8.3 %), and Klebsiella spp. (2.1 %) respectively. Total viable bacteria counts are 500 to 192,000. Physicochemical results (total dissolved solute (TDS), pH, electrical conductivity (EC), salinity, temperature) when compared with WHO (2006) and SON (2007) revealed all the parameters to be within the permissible limits except pH (5.8 to 9.56), and high values of the parameters were caused by organic matter. High E. coli in the study area revealed influence of human and animal fecal that coul

Profiles of Problematic Soils and Spatial Distribution: Implication on Foundation Construction in Parts of Kosofe Lagos, Southwestern Nigeria

Geotechnical data were complemented with geophysical investigation and employed to delineate problematic soils in parts of Kosofe Lagos, Southwestern Nigeria. The study area was chosen because of known issues regarding cracks in buildings and differential settlement of infrastructures founded on soils in the area. The aim is to generate profiles and maps of the spatial distribution of the subsurface soils to aid in foundation planning. Forty-eight borehole logs and nine Vertical Electrical Soundings were compiled to delineate the different subsurface lithology which include peat, clay and sand. The results showed that the peat layer has maximum thickness of about 18.25 m but absent in some boreholes. This is underlain by clay unit with thickness ranging between 2.50-28.50 m. Sand unit constitute the third layer delineated with maximum thickness of 14 m. There is a general thickening of peat soils in the northern parts, especially around the streams in the area, which is instructive on the role of stream in the formation of the peat. The clay on the other hand is thickest around the northeastern and southeastern parts. The soil profiles generated reveal that the area is underlain by thick peat and clay having significant lateral, vertical variation and rapidly changing lithological facie over short distances. The extensive occurrence of these poor engineering soils calls for adequate engineering precaution in designs of building foundations

Southwestern Nigeria 1

Petrographic and geotechnical properties of Lateritic Soil