Studies on environmental impact assessment of wastewater pit in Izombe flow station, South-Eastern Nigeria

Abstract Three (3) wells were sunk with a hand -operated light cable percussion rig to maximum depth of 15.00 to 21.00m. The static water levels recorded after drilling for each well were 8.00m for borehole 1 (BH 1), 4.40m for BH 2, and 5.00m for BH 3. The soil stratigraphy reveals a uniform correlation in the three (3) boreholes of medium to very coarse grained sand and gravelly sand. The lower layers are coarser, so that there appears to be a downward coarseness of the grains. There is also a downward decrease in the shade of brownish colour. In BH 1, there is an upper stratum of dark brown, medium grained, friable sand to a depth of about 9.00m. This is underlain by light brown, very coarse grained, gravelly sand. BH 2 and BH3 display similar profiles of overlying dark brown, medium grained, friable sands of about 3.0m in thickness. This is followed by light brown, coarse grained sands to depths of about 15.00m. Light brown, very coarse grained, gravelly sands extend from this depth to the maximum drilled depth of 21.00m. Results also reveal that the soil is non-plastic and fall within the soil classification group of SP under the Unified Soil Classification System. Permeability tests of the samples are moderately high values as expected for the sandy soils and range from 7.83 x 10 -1 cm/s to 8.92 x 10 -1 cm/s. The hydraulic gradient between BH 1 and BH 3 is about 6% or 1m in 16m (1:16) while that between BH 1 and BH 2 is about 7% or 1m in 14m (1:14). Since the hydraulic gradient between BH 1 and BH 2 is slightly higher, more rapid effluent discharge is expected towards BH 1. This may explain the higher concentration of crude oil contamination of the groundwater, particularly within the region of the waste pit

Correlation of Mechanical Properties of Some Rocks in South-Eastern Nigeria

Abstract- The mechanical properties of five different rock types from south-eastern Nigeria were determined through uniaxial compressive strength (UCS) test, point load strength test, impact strength index test and natural density test. The results were correlated by using correlation coefficient and regression analyses. The equation of the best-fit line, and the correlation coefficient were determined for each regression. Among the four rock properties correlated in terms of drillability (penetration rate) of percussive or rotary drilling rig, the uniaxial compressive strength, the impact strength index and natural density are found to be the dominant properties affecting penetration rate of rotary drills. Index Terms- uniaxial compressive strength, impact strength index, natural density, point load, correlation coefficient R I