Localizing the strategy for achieving rural water supply and sanitation in Nigeria

Water is essential for sustenance of life and determines the overall socio- economic development of any nation. In Nigeria, so many programmes to improve water supply and sanitation situation had been put in place by different administrations. Despite this, the hope of meeting the UN Millennium Development Goals (MDGs) target of safe water supply by the year 2015 is still uncertain. The MDG in water supply and sanitation aims to half the proportion of people without access to potable water supply and basic sanitation. More recent statements of the MDGs refer to the right of communities to have access to an adequate supply of safe water. Safe rural water supply coverage in this context is taken to mean water that does not represent a significant health risk; that is of sufficient quantity to meet all domestic needs; that is available continuously to all of the people and is affordable. There is no gainsaying the fact that the objective of improved rural water supply generally is limited to improved health. This paper therefore examines the extent to which government, implementors, and users are adopting different but interrelated mechanisms to deal with water stress in Nigeria. The paper also identifies the challenges in governance, government policies and priorities as responsible for poor service delivery. More importantly, a policy/institutional framework for sustainable rural water supply and sanitation delivery is developed towards achieving the Millennium Development Goals.Keywords: Rural water supply, sanitation, sustainable development, Millennium Development Goals, Nigeri

Groundwater Quality Assessment and Monitoring Using Geographic Information Systems (GIS) in Port Harcourt, Nigeria

The study evaluated the spatial variation of groundwater parameters in Port Harcourt metropolis using GIS. Thirty two (32) water samples were collected from boreholes from different parts of the study area into a treated and well labeled 1.5 litres plastic bootle. The water samples were then subjected to laboratory analysis for temperature, pH, Calcium (Ca2+), Chloride (Cl-), Total Dissolved Solids (TDS), Nitrate (NO3-), Sulphate (SO42-), Sodium (Na+), Potassium (K+), Magnesium (Mg2+), Electrical Conductivity (EC), Salinity, and bicarbonate (HCO3-). Global Positioning System (GPS) was used to record the latitudes and longitudes of the sampled boreholes. The result from the laboratory was subjected to descriptive statistical analysis in order to determine the mean, range and standard error of each parameter with the use of SPSS. Thereafter the result was imported to ArcGIS to generate the spatial variability maps for some groundwater parameters through the use of kriging in geostatistic module. Surfer 8 was used to generate the 2D and 3D representation of the borehole depths while Idrisi for windows was used to generate the relationship between borehole depth and pH ; and borehole depth and Ca. The result showed that Cl had the highest concentration among the anions with a mean value of 161.49 mg/l and Ca had the highest concentration among the cations with a mean value of 6.53 mg/l. The mean values of the all the groundwater parameters were lower than the WHO standard. Moderately weak inverse relationship was observed between the borehole depth and groundwater pH concentration; and between borehole depth and groundwater calcium concentration. It is recommended that the use of GIS should be encouraged to periodically monitor and assess groundwater quality. Keywords: Borehole, Groundwater, GIS, Geostatistics, Port Harcour

Groundwater Protection As Viable Option For Sustainable Water Supply In Nigeria

The threat of contamination of groundwater due to indiscriminate refuse disposal, bad management of sewage and septic tanks, industrial effluent discharges, leakage of underground fuel pipes and storage tanks and non-point pollution sources in major urban and semi- urban locations across the country are real. The argument to start planning for groundwater protection before there is serious contamination is clear and powerful. Such preventive action is the essence of groundwater protection. The logic of preventing groundwater contamination is clear but our problem or concern is in remediation of groundwater contamination. Although there are many well documented examples of groundwater remediation and good sources of information on how to clean up contaminated aquifers, the need to protect our groundwater supplies cannot be over emphasized. The age long aphorism “ prevention is better than cure” applies here. This is because, once polluted, groundwater supplies are difficult and expensive to purify and the aquifer requires a long time to “heal” naturally. It then constitutes a health hazard to the consumers. This paper therefore addresses the question of how we can protect groundwater from becoming polluted. The paper not only concentrates on the problems of protecting groundwater from toxic chemicals but also discusses ways of protecting groundwater from conventional pollutants. Keywords:Groundwater protection, contamination, pollution, sustainable water supply, Nigeria. Global Journal of Geological Sciences Vol. 6 (2) 2008: pp. 153-15

Hydrogeophysics: An overview of general concepts, applications and future perspectives

Hydrogeophysics is an emerging discipline that holds great promise in characterizing hydrogeological parameters and processes. A tight collaboration between hydrogeologists and geophysicists is necessary to achieve the most appropriate use of geophysics in hydrogeology, mainly for planning the geophysical activities in accordance to the hydrogeological target to be investigated and for the interpretation or translation of the geophysical documents into hydrogeological documents. For this collaboration to be meaningful, it is of great importance to share a common language allowing communication feasible: geophysicists have to know the fundamentals of the hydrogeological process, and hydrogeologists have to know the fundamentals of geophysical methods. This is basically the main objective of this paper, where fundamental concepts of both disciplines, their contributions, the methods available, data integration approaches, and future perspectives as well as the hydrogeophysical challenges are presented. Key words: hydrogeophysics, geophysics, hydrogeology, surface geophysics and hydrogeophysical method

Application of seismic refraction methods in groundwater studies in Calabar Southeastern Nigeria.

Calabar, the Cross River State capital, is underlain by Benin Formation. The formation is partly marine, partly deltaic and partly fluviolacustrine in origin. Seismic refraction surveys in the area show that the aquiferous zone has seismic wave velocity of 700-800ms while the non aquiferous zone has velocity ranging from 400-600ms. The velocity is larger in the aquiferous zone because the density in the water bearing sand is higher. Vertical electric sounding confirms the hydrogeologic boundaries between these zones established by the seismic refraction survey. Key words: Seismic Refraction, Groundwater, Velocity, Vertical Electrical Sounding, Aquife

Evaluation of groundwater resource of Amuwo-Odofin, Lagos State, Nigeria

The geophysical investigation for groundwater resources evaluation at Amuwo-Odofin, Lagos State, Nigeria was carried out. The Direct Current Electrical Resistivity method of geophysical prospecting using the Schlumberger electrode configuration was adopted. The curve types obtained from the field data were 6 – layer HKHA at VES 1 and 5 – layer QHA at VES 2. Quantitative interpretation of the sounding curves revealed that the side is underlain by topsoil, clay, clayey sand and fresh water sand. The clayey sand and fresh water sand constitute the aquifer units within the study area. The study revealed that the groundwater potential in the area is rated medium to high with very good prospect for considerable groundwater yielding capacity. The aquifer occurs at depths of 200m – 230m, and even deeper.Keywords: Groundwater, geoelectric layers, vertical electrical sounding, Nigeri

Risk evaluation and modeling of soils contaminated with Polycyclic Aromatic Hydrocarbons (PAHs) in parts of Bonny Island, Niger Delta, Nigeria

Environmental impact of a recent oil spill incident in Bonny terminal using soil media was studied using a risk-based modeling approach. The establishment of the presence of contaminants of concern (CoC), evaluation/assessment, modeling spilled volume and ascertaining potential health risk associated with the spill incident was carried out. The Contaminant of Concern (CoC) included Total Petroleum Hydrocarbons (TPH) and Polycyclic Aromatic Hydrocarbons (PAHs). Soils and groundwater were sampled in the vicinity of the spill incident and further away into the surrounding communities. Soils were sampled into the depths (0.1 m, 0.5 m,1.0 m, 1.5 m), and the results of sieve analysis revealed that the area is predominantly silty sand in composition. This study also revealed that TPH concentration at all locations and depths exceeded DPR target value of 50 mg/kg. The TPH model revealed that a total volume of 222,500m3 of the spill area exceeded DPR intervention value of 5000 mg/kg. The results of PAH showed that only BS-1, BS-6, BS-8, BS-9 and BS-10 exceeded DPR target value of 1.0 mg/kg at some depths. All other sample depths and locations were within the target limit. The 3-D grid generated for PAH showed that 563,000m3 of the study area exceeded the DPR target value. The 3-D block models generated for TPH and PAH, along with the cross-sections and extracted time slices all showed that the concentration of the Contaminant of Concern (CoC) generally decreased with depth, and the centre of the spill located at the south-eastern part of the survey area. Based on these models, three spill zones were identified; Zone 1-highly contaminated areas (BS-8, BS-9, BS-10); Zone 2 - moderately contaminated areas (BS-1, BS-2, BS-6, BS-7); and low contaminated areas (BS-3, BS-4, BS-5). The entire soil in the area were contaminated with TPH and 47% of the area contaminated with PAH. This study has shown the effectiveness of the use of a model-based approach in quantifying hydrocarbon contamination volumes in the area. There is therefore the need for continuous monitoring of hydrocarbon spills in the area