Water quality issues in West and Central Africa : present status and future challenges (original) (raw)
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Journal of Environmental Protection, 2013
The CSIR Water Research Institute undertook water quality monitoring and assessment of the Southwestern and the Coastal Rivers Systems of Ghana from 2005 to 2008 for the Water Resources Commission of Ghana (WRC) under WRIS II Project, a Danish Government Funded Project. The Southwestern and the Coastal Rivers Systems cover approximately 30% of the total drainage basins of Ghana. A total of 19 surface water stations were selected for the monitoring programme. The Adapted Water Quality Index (WQI) was to be used as a tool to classify the overall ambient water quality at the 19 different stations. The index classified water quality into one of four categories: good (Class I, >80), fairly good (Class II, 50-80), poor (Class III, 25-50), and grossly polluted (Class IV, <25). This paper presents the Water Quality Index approach to the assessment of water quality of the waters in the different stations during the period of study. These ten water quality parameters were used to determine the water quality index (WQI): Dissolved Oxygen (DO % Saturation), Biochemical Oxygen Demand (BOD), Ammonium Nitrogen (NH 4-N), Faecal Coliform (FC), pH, Nitrate as Nitrogen (NO 3-N), Phosphate as Phosphorus (PO 4-P), Total Suspended Solids (TSS), Conductivity and Temperature. Evaluation of the waters with the WQI indicated that most Ghanaian waters are currently in Class II, the fairly good water quality state, but with variations in this range within the seasons and stations, and from one water body to the other. Potroase in the Densu basin had the best water quality during the study period while Nsawam had the poorest. Efforts should be made to prevent further pollution of the waters to improve their quality.
Hydrogeology Journal, 2017
Groundwater resources are important sources of drinking water in Africa, and they are hugely important in sustaining urban livelihoods and supporting a diverse range of commercial and agricultural activities. Groundwater has an important role in improving health in sub-Saharan Africa (SSA). An estimated 250 million people (40% of the total) live in urban centres across SSA. SSA has experienced a rapid expansion in urban populations since the 1950s, with increased population densities as well as expanding geographical coverage. Estimates suggest that the urban population in SSA will double between 2000 and 2030. The quality status of shallow urban groundwater resources is often very poor due to inadequate waste management and source protection, and poses a significant health risk to users, while deeper borehole sources often provide an important source of good quality drinking water. Given the growth in future demand from this finite resource, as well as potential changes in future climate in this region, a detailed understanding of both water quantity and quality is required to use this resource sustainably. This paper provides a comprehensive assessment of the water quality status, both microbial and chemical, of urban groundwater in SSA across a range of hydrogeological terrains and different groundwater point types. Lower storage basement terrains, which underlie a significant proportion of urban centres in SSA, are particularly vulnerable to contamination. The relationship between mean nitrate concentration and intrinsic aquifer pollution risk is assessed for urban centres across SSA. Current knowledge gaps are identified and future research needs highlighted.
Summary The daily waste generation in Addis Ababa catchments is estimated about 0.252kg/capita/day and 65 % (1,482m 3 )/day of municipal waste is collected. There is an increasing concentration of heavy metal pollution, coliform and pathogen pollution in the surface and ground water. The nitrate concentration in surface water is higher than the accepted normal concentration of 10 mg/l. Irrigation with polluted water increased accumulation of heavy metals in the soil. Consequently, irrigating with polluted Akaki River has increased As and Zi considerably high.
Impacts of Surface Water Quality in the Awash River Basin, Ethiopia: A Systematic Review
Frontiers in Water, 2022
Water quality impairment, due to anthropogenic activities and limited enforcement capacity, is a rapidly growing threat to water security as well as public health in developing countries. Cumulative effects of deteriorating water quality undoubtedly put pressure on public health and socio-economic developments. For example, most industries in Ethiopia discharge their effluent directly into freshwater systems without any treatment process. The problem is severe for rivers such as the Awash that pass through major cities. Although there were a few studies that looked into the issue, there is a lack of comprehensive water quality impact assessment on agriculture, health, and socio-economics. This article systematically summarizes current research on water quality issues in the Awash River Basin to generate comprehensive information that captures the water quality status of the river and impacts of water contamination, and identify information and management gaps. Results showed that wa...
Applied Water Science, 2018
Freshwater resources are continually decreasing in quality and quantity. Approximately, 1% of this freshwater is accessible in lakes, river channels and underground for domestic use. The study reviewed literature on water resources with focus on freshwater, the quality of our freshwater in terms of physical, chemical and biological variables, the main mechanisms of management, and the challenges associated with these mechanisms as well as blending integrated water management with the indigenous or traditional management of water resources for sustainable development and peaceful coexistence. Also the review offered potent recommendations for policy makers to consider sustainable management of freshwater resources. A total of 95 articles were downloaded from Google scholar in water-related issues. The search took place from June to September 2017, and research articles from 1998 to 2018 were reviewed. Basically Ghana is made up of three discharge or outlet systems, namely the Coastal River Systems which is the least and Volta constituting the largest and with the SouthWestern been the intermediate. Also, freshwater resources usage can be put into two main categories, namely ex situ (withdrawal use) and in situ or in-stream use, and could also be referred to as the consumptive and non-consumptive use, respectively. With the exception of localised pollution engineered by illegal mining and other nuisance perpetuated by indigenes, the quality of water (surface and groundwater) in Ghana is generally better. The review outlined high microbial contamination of water as almost all surface waters are contaminated with either E. coli, faecal coliforms or total coliforms or all. However, these contaminations were more prevalent in surface water than groundwater.
Nitrates in Rural Communities Water Sources in Uzouwani, South Eastern Nigeria, West Africa
The levels of nitrate, phosphate, sulphate, chloride, Dissolved Oxygen, (DO) Biochemical Oxygen Demand (BOD) and some physical parameters of the water resources in a typical rural community in Nigeria were assessed in this report. The study was aimed at finding out the impact of agricultural activities on the various water bodies-streams, hand dug shallow wells and lakes/ponds in a setting with 97% of populace engaged in agriculture. Standard methods were used in the determinations. Results of the study showed that 61.5% of the water bodies studied had nitrate overload. Sulphates were within the recommended limit while the level of phosphates was also higher than the set limit. Chloride, TDS and pH were all within the recommended level. Organic matter load in the waters were significant as shown by decreased values of DO. Although epidemiology records of effects of excess nitrate consumption in the studied area were nonexistent due to some factors, it is not unlikely that health ris...
Assessment of Surface Water Quality in Côte d'Ivoire
Bulletin of Environmental Contamination and Toxicology, 1996
The water systems in Côte d'Ivoire is composed of four main rivers and three lagoons. The rivers cut across the geographic regions from the north to the south to the Gulf of Guinea. Most of the lagoons are narrow, salty and shallow and are parallel to the costline. These lagoons become broad estuaries where the larger rivers empty. Rivers and lagoons serve as important waterway for the transportation of goods and people. They are also important source of animal proteins in form of fish. Above all, the water systems represents a source of domestic water supply for rural as well as urban communities. With the development of commercial agriculture, the improvement of food production, and the need to protect human health against insects vector of disease the use of chemical fertilisers and pesticides has markedly increased in the country. These chemicals released in the environment may reach surface and groundwater where they may persist for long periods. A number of studies have been done on the pollution of water systems in Africa. Ayayi So and Osibanjo O. (1981) reported on water quality of some Nigerian rivers. reported the presence of organochlorine pesticides and PCBs in the River Nile. In 1978, Greichus, Y.A. and al. investigated Lake Nakuru in Kenya for the presence of insecticides, PCBs and metals. But until now no study has been conducted to determine the amount and the fate of pollutants in the water systems in Côte d'Ivoire. This work aims at establishing a base-line levels of various pollutants.
Assessment of surface waters and pollution impacts in Southern Ghana
2021
Illegal mining and inappropriate use of agrochemicals have exacerbated surface water pollution in Ghana. The quality of water has changed, and knowledge of their current condition is important for formulating policies to conserve the country’s water bodies. This study assessed the quality of surface waters in Ghana’s Pra River Basin. A survey of 344 local farmers randomly sampled was conducted and a physicochemical analysis of 33 water samples collected from 25 rivers in the basin. Boreholes are the main source of drinking water for 85% of farmers, and they assessed water quality by its appearance. Rainwater provides over 50% of the water needed by the respondents for domestic use. River water was mainly used for crop production and only secondarily for domestic use. At more than 80% of the sampled sites, pH, Fe and P were above the WHO recommended values, while Pb was exceeded at 30% of the sites. Cu, Hg, As and Fe were above permissible levels for irrigation, especially near the mining areas. The poor quality of river water makes it unusable despite its availability. A more effective and efficient land-use policy focusing on buffer zone protection is recommended to minimise water quality degradation in the basin.