Basement and alluvial aquifers of Malawi: An overview of groundwater quality and policies

This paper highlights the quality of groundwater in basement and alluvial aquifers of Malawi through literature assessment. Groundwater in these aquifers serves about 60% of Malawian population. Alluvial aquifers yield high groundwater in excess of 10 L/s and more mineralized than basement aquifers. The values from literature are presented as ranges. The geochemical quality of both aquifer types are classified as good. However, in some cases values higher than maximum permissible limits (MPL) are worrisomely apparent. Significant levels for some elements have been demonstrated. Although groundwater policies and instruments are available, more groundwater research, monitoring, data archiving is needed.Key words: Alluvial aquifer, basement complex, groundwater quality, borehole water, shallow wells, Malawi

Water quality changes due to abattoir effluent: A case on Mchesa Stream in Blantyre, Malawi

Abattoir effluent is known to degrade the quality of receiving water bodies. This study assesses the impact of effluent from Shire Valley Abattoir on the physico-chemical parameters of Mchesa Stream in Blantyre. Water samples were collected from five sampling sites along Mchesa Stream located at progressive distances from the discharge point. Sampling was done three times over a period of four months (June to September 2008). The physico-chemical parameters tested were: pH, biochemical oxygen demand (BOD), dissolved oxygen (DO), suspended solids (SS) and electrical conductivity (EC). The mean values of the measured parameters were as follows: BOD (381.1 mg L-1); DO (3.6 mg L-1); SS (312.8 mg L-1); pH (7.6); and EC (105.6 μs cm-1). The highest concentrations of BOD and SS were 612.3 mg L-1 and 477.3 mg L-1 respectively and were obtained at a point of effluent discharge into Mchesa stream. One-way ANOVA showed significant deviation from WHO standards for BOD, SS and DO (p < 0.05). This study shows that effluents from the Shire Valley Abattoir have partially contributed to the pollution of Mchesa Stream to levels which pose health and environmental hazards to the surrounding communities.Key words: Abattoir, effluent, water quality, physico-chemical parameters, Mchesa stream, hazard

Public participation in Malawi’s environmental impact assessment (EIA) process

Since the adoption of the Environmental Management Act of 1996, Malawi has been using environmental impact assessment (EIA) as a tool for predicting and assessing the impact of development projects on the environment. This study assessed the extent of public participation in Malawi’s EIA process. Desktop study of relevant documents such as EIA and environmental audit reports, policies and laws, books, journals and internet articles was done. Further information was obtained from relevant stakeholders through interviews and questionnaires. This involved fifteen respondents divided into three categories: five NCE members, five TCE members and five EIA practitioners. This study reveals that public participation is not adequate at most of the key stages of the EIA process in Malawi which puts the human and ecosystem health at risk. There is an urgent need to enforce the EIA provision as stipulated Malawi’s Environmental Management Act. Effort should focus on public awareness and human resource capacity development so that the EIA process is diligently executed and that enforcement and follow-ups are properly done by the Department of Environmental Affairs which is a lead agency on environmental issues in Malawi.Key words: Public participation, environmental impact assessment, Malawi, enforcement

Spatial variation of volatile organic compounds and carbon monoxide in Blantyre City, Malawi

This study assessed variations of ambient volatile organic compounds and carbon monoxide (CO) levels in Blantyre City, Malawi. Volatile organic compounds and carbon monoxide measurement was done using the Multi-Gas Monitor between August and December, 2010. Rapid urbanization and lack of standard enforcement on air pollution as well as lack of data on pollutant levels in the city prompted this study. The study focused on methane volatile organic compounds and non-methane volatile compounds besides carbon monoxide. Results of the analysis showed that non-methane volatile compound levels were highest at public bus terminuses with 12.40 ± 0.83 ppm, and lowest for industrial locations (2.16 ± 0.09 ppm). However, all points registered zero (0.00) ppm for methane volatile organic compounds. Similarly, mean levels of carbon monoxide were highest at public bus terminuses with 10.92 ± 0.74 ppm, and lowest for industrial locations (1.11 ± 0.13 ppm). With the exception of Ginnery Corner, all the sampling points had levels of both parameters within the air quality standards. The study revealed a spatial and diurnal variation of the pollutants in all sampling points. It further revealed that the sources of these pollutants are diverse with vehicular emissions being the main  source for Masauko Chipembere highway.Key words: Air pollution, ambient, permissible limit, urban, vehicular emission

Air quality assessment of carbon monoxide, nitrogen dioxide and sulfur dioxide levels in Blantyre, Malawi: a statistical approach to a stationary environmental monitoring station

Air quality in urban areas is a cause of concern because of increased industrial activities that contribute to large quantities of emissions. The study assess levels and variations of carbon monoxide (CO), nitrogen dioxide (NO2) and sulfur dioxide (SO2) in Blantyre, Malawi using a stationary environmental monitoring station (EMS). Results show that CO level (2.47 ± 1.23 mg m-3) were below the Malawian limit value (10.31 mg m-3). Although, NO2 (4.02 ± 2.47 mg m-3) and SO2 (8.58 ± 2.88 mg m-3) were significantly higher than allowable Malawian Standards (0.52 and 0.23 mg m-3, respectively). Discernible variations in hourly, diurnal, monthly and seasonal CO, SO2 and NO2 were apparent. Independent t-test confirmed that day time values were higher than those at night (p < 0.05). Thus, variations in local weather affect the disparity in hourly and diurnal values. Analysis of variance (ANOVA) confirmed significant variations in monthly observations. Moreover, independent t-test showed that wet season CO (2.32 mg m-3), SO2 (5.10 mg m-3) and NO2 (9.41 mg m-3) levels were higher than dry season values (CO = 2.32 mg m-3; SO2 = 3.42 mg m-3; NO2 = 8.13 mg m-3). A hierarchical cluster analysis (HCA) divided the 10 months into three groups based on distribution of CO, SO2 and NO2, air temperature, wind speed and wind direction. Furthermore, factor analysis (FA) showed that air temperature had significant contribution to variations in mean values of CO, SO2 and NO2 for the entire study period. The study shows a need for constant urban air quality monitoring in Blantyre and all urban areas in Malawi. It is recommended that the experimental site widen the scope of the study by utilizing the flexibility of the EMS. Key words: Air pollutants, principal component analysis, developing countries, environmental monitoringstation, Kaiser normalization

Comparison of plant nutrient levels between compost from Sky loo and Fossa alterna toilets

Recent scholars have highlighted the benefit of harvesting compost from eco-san toilets for application as plant nutrients. However, levels of nutrients in eco-san compost may vary depending on the type of toilet and also the type of top soil in a particular geographical region. This study compared levels of nitrogen, phosphorous, potassium, calcium and sodium between compost from Sky loo and Fossa alterna toilets. Samples were collected from Zimora and Ng’ombe villages in Chikhwawa district, southern Malawi. Statistical analysis using SPSS showed significantly higher levels of nitrogen, calcium and moisture in compost from Fossa alterna toilets than in Sky loo (p < 0.05). However, there were no significant differences in the levels of potassium in the two types of eco-san compost studied. This study has revealed that compost from Fossa alterna is generally a richer source of plant nutrients than that from Sky loo thereby presenting poor, local communities in sub-Saharan Africa with a cheaper alternative to commercial fertilizer.Key words: Eco-san toilets, compost, Malawi, plant nutrients, soil quality