A Preliminary Assessment Of The Impact Of Solid Wastes On Soils And Groundwater System In Parts Of Port Harcourt City And Its Environs, Rivers State, Nigeria

Soil and groundwater samples from four refuse dumpsite locations in Port Harcourt city and its environs were studied to assess the impact of solid wastes on soils and groundwater system in the area. The study shows significant abundances of Cu, Pb, Zn in soils, in the following ranges Cu: 0.0055-2.31%, Pb: 0.002-3.08%, and Zn 0.001-1.93%. This shows that the soils are contaminated to hazardous levels when compared with acceptable standards. The concentrations of these metals are found to decrease with depth in the soils. However, groundwater in the area is potable and not polluted by the chemical species studied (pH, Fe, Zn, Cd, Cu, Pb, Mn, Cl and N03). It also shows low levels of BOD, COD, TDS, Hardness and coliforms. The metal enrichments in the soils owe their origin to the refuse dumps as well as other sources like dissolution from parent rocks, buried oil pipes and fuel reservoirs, geochemical processes operating within the groundwater system, and atmospheric precipitation. The tolerable concentrations of the parameters in groundwater can be explained by the geologic control on the movement of chemical species in the soils. KEY WORDS: Solid waste, impact, soil, groundwater, Port Harcourt. Global Journal of Environmental Sciences Vol.4(1) 2005: 23-3

Diplog analysis of paleocurrent and depositional energy of Miocene reservoir sands in the northwestern Niger Delta

Dipmeter log is an invaluable tool in the description of paleocurrent and depositional energy associated with subsurface sediments due to its high depth resolution and uniqueness as a method for studies of this kind. Interpretation of dip patterns and variations in dip amounts, in conjunction with composite log and biostratigraphic data, shows that the Lower to Middle Miocene sand reservoirs identified in two onshore wells in the Niger Delta were deposited under high to low energy conditions. The paleocurrent directions are mainly to the southwest, northwest, and southeast. Transporting water currents, waves, tides, and longshore currents dictated both paleocurrent directions and depositional energy. The interaction of these nearshore influences and the resulting pattern of sedimentation of the reservoir sands reinforce the conclusions drawn from studies conducted on Quaternary sediments along the Nigerian southwest coast and on Cretaceous sediments in the adjoining Anambra Basin. The levels of depositional energy deduced are indicative of the bathymetry of the reservoirs and their petrophysical properties. High-energy deposits occur in shallower water depths than the low energy deposits and are likely to be better sorted and more permeable. High variability in energy levels in some sand zones have been shown to correlate with depth intervals having repeated sequences of very thin reservoir sands often separated by minor shale beds. KEY WORDS: Dips, paleocurrent, energy, deposition, reservoir Global Jnl of Pure and Applied Sciences Vol.10(4) 2004: 635-64

Evaluation Of Corrosion And Encrustation Potentials Of Groundwater Wells In Calabar Area, Southeastern Nigeria

This article presents results of groundwater quality assessment based on some corrosion-encrustation index parameters (CEIP) and drinking water standards. The CEIP concentration results indicate that the hydrogen ion concentration, pH ranges from 5.4 to 7.6, total iron, Fe varies from 0.02 to 3.0mg/l; Manganese Mn concentration was found to be from 0.01 to 1.0mg/l; the total dissolved solids TDS content of 13.0 to 273.7mg/l; Dissolved oxygen DO of 0.4 to 6.2mg/l; Hydrogen sulphide H2S of 0.01 to 2.5mg/l; Chloride Cl of 2.6 to 16.2mg/l and bicarbonate HCO-3 ranged 20.5 to 80.9mg/l while total carbonate hardness TCH ranged from 2.4 to 8.5mg/l. Corrosion is accelerated from a combination of any two factors such as high concentration of H2S >2.0mg/l; DO >2mg/l; pH 500mg/l; TDS >1000mg/l and HCO-3 >50mg/l. Encrustation is promoted when TCH >100mg/l; pH>7; Mn >0.1 and Fe >0.3mg/l. Interpretation of these CEIP analytical results based on these background values indicate that the groundwater is acidic. Acidic water causes corrosion of pumps, pipes and screens made of iron and steel. On the other hand, encrustation is never a major problem, although it is not completely absent in the area. The high total iron and manganese content greater than the above threshold values are the causes of encrustation in some localities while the high acidity, dissolved oxygen and bicarbonate are the causes of corrosion in Calabar area. Ways of minimizing the problems of corrosion and encrustation in the water industry of Calabar area have been suggested. Keywords: Corrosion, Encrustation, Index Parameter, Calabar.Global Journal of Geological Sciences Vol. 6 (1) 2008: pp. 1-

Hydrogeological And Geotechnical Investigations Of Gully Erosion Sites In Calabar Area, Southeastern Nigeria

For many years, gully erosion and landslides are posing a serious threat to human existence, agricultural land, infrastructure and socio-economic activities in Calabar and its environs. Consequently, hydrogeological and geotechnical studies of gully erosion sites were carried out in order to provide information on the genesis and continual expansion of gullies in the area. The results indicate that gullies are located in the upper aquifer of the Benin Formation (Coastal Plain Sands). The estimated hydraulic parameters of the sand obtained from granulometric analysis give hydraulic conductivity K ranging from 3.6 X 10-5 to 2,25 X 10-2 cms-1, with a mean of 2.4 X 10-3 cms-1. specific discharge Vd varies from 1.8 X 10-7 to 1.13 X 10-4 cms-1 and average linear groundwater velocity Va ranging from 6.0 X 10-7 to 3.75 X 10-4 cms-1. The geotechnical results further indicate that the liquid limit LL ranges from 24.0 to 54.0%. The plasticity index PI varies from 10.1 to 29.0% with a mean of 16.9%. The optimum moisture content OMC ranges from 8,3 to 14.3% while the silt- clay fraction ranges from 4.0 t0 34.0 with mean of 26.2%. The maximum dry density MDD of the soil ranges from 1810kgm-3 to 2050kgm-3 while the shear strength test show values of cohesion C in the range 13kgm-2 to 32kgm-2 in an angle of internal friction, Φ ranging from 120 to 170. The implication of these data is that gully erosion is partly enhanced by the low shear strength and plasticity index of the soils. In addition, the values of hydraulic parameters suggest high seepage forces and pore pressure. These will tend to reduce the shear strength of the soil and enhance its erodibility. Recommendations were also made on how to control erosion in the area. Keywords: Gully erosion, upper aquifer, hydraulic parameters, geotechnical, Calabar.Global Journal or Pure and Applied Sciences Vol. 14 (4) 2008: pp. 423-43