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Malawi’s leading mineral sector consultants Akatswiri Mineral Resources in collaboration with Zomba-based Enviroconsult have successfully completed an environmental and social impact assessment (ESIA) study for oil exploration in Blocks 4 and 5, which are held by prospecting firm Rak Gas MB45.

The study, whose report has been submitted to the Department of Environmental Affairs for approval, involved community consultations in districts covered by the two blocks which include Machinga,        Mangochi, Dedza and Salima, and national consultations in the Capital City, Lilongwe.

Rak Gas contracted Akatswiri and Enviro-Consult to conduct the ESIA in preparation for seismic operations which will be conducted in the blocks to identify oil and gas traps.

Project Coordinator Hilton Banda says: “The seismic studies entail using a vibrator truck that sends a signal from the ground and recording truck to detect sediments and their depth. The technology uses geo phones mounted on the cable that transmits a signal to a computer.”

“There was, therefore, a need to undertake the ESIA to assess the environmental impact of the seismic exploration work and develop an environmental management plan that contains mitigation measures.”

Banda, who is CEO for Akatswiri, explains that the ESIA involved studies on Geology and Soils, Air Quality, Water and Hydrology, Waste Management, Noise and Vibrations, Transport and Energy needs, Flora, Fauna, Fish, Habitats and Land use, Archaeology and Cultural Heritage and Social Issues as key parameters that require baseline assessment in order to determine potential impacts and their mitigation approaches.

Geology and Soils

The Akatswiri CEO, who is a seasoned geologist, explains that the team conducted geological field mapping in which major lithological and soil units were mapped and sampled for subsequent mineralogical analysis.

He says the team recorded systematic measurements of structural features, field relations and cross-cutting relationships and in addition to field mapping they used existing geophysical data to interpret structural features which could not be seen on the ground as the ground is mostly covered by sediments.

The area is overlain by recent sediments of lacustrine in nature and has been affected by rift faulting which defines the Malawi Rift Valley. NE and NS trending faults, and shear zones present in the area may render critical insights into the structures which might trigger potential landslides or earthquakes.

The project site is dominated by the presence of marsh and agricultural soils. The soil fertility status is augmented through fertilisation to sustain crop production, and soils are moderately acidic.

“The impact assessment shows that the proposed project will have a low to moderate impact on the geology and soils in the study area,” Banda says.

Air quality

He says the air quality assessment was intended to characterize the existing environment and identify the environmental and social hazards associated with the seismic activities on air quality, assess the magnitude and significance of the risks (the likelihood of the hazard and the severity of the impact) and provide a description of the proposed control techniques to eliminate or mitigate the likelihood of the hazard or severity of the impact and development of plans / procedures to manage consequences of exceptional events.

“The results from the baseline survey show that levels of the major air quality parameters (total suspended particulate matter, SO2, NO2, CO and H2S) were below the guideline values according to Malawi Standards (MS737:2011) and World Health Organisation (WHO) guidelines. However, in most of the cases, levels of methane were noted to be significant, mainly arising from decomposition of livestock excreta,” he says. 

Hydrology and water quality

Banda says in order to assess hydrology and water   quality, water samples were collected from block 4 and 5 from boreholes, shallow wells, rivers and analyzed for physical-chemical parameters: temperature, pH, Total Dissolved Solutes (TDS), Electrical Conductivity (EC), Turbidity, F-, Cl-, NO3-, SO42-, carbonates, Na, Ca, Mg, Cu, Mn, Zn, K, and total hardness.

“The results were compared to the World Health Organization (WHO) and Malawi Bureau of Standards (MBS) standards to ascertain the water quality. Analysis of the data indicates that the major water quality parameters are deemed within guideline limits indicating that the water is generally unpolluted. The impact assessment shows that the proposed project will have a low to moderate impact on water resources in the study area,” Banda says. 

Waste Management

The ESIA Project Coordinator also assures that the   seismic surveys are not expected to generate waste streams with high environmental and social impact.

The common sources of waste streams pointed out in the study include presence of workforce, seismic survey activities and vehicle maintenance wastes.

Banda says the expected non-hazardous wastes include domestic wastes (garbage and sewage) and effluents, paper, line cables while hazardous wastes include pharmaceuticals, waste oils, spilled fuel and lubricants and used batteries. The potential impact of wastes is deterioration of water and soil quality affecting terrestrial and aquatic ecosystem (fauna and flora).

In mitigation, he says Rak Gas will implement a Waste Management Plan (WMP) in line with Open Government Partnership (OGP) guidelines for waste management (OGP, 1993; 2008).

Banda says: “As far as practicable, Rak Gas will use existing sanitary facilities in the target areas (otherwise mobile toilets should be used). Solid wastes will be segregated at source in terms of recyclable, reusable, biodegradable and non- biodegradable, hazardous and   non-hazardous, or disposal as appropriate. The Seismic Team will make sure that it does not leave behind any solid waste during the seismic activities.”

“Buffer zone distances between water and seismic lines, sanitary and biodegradable garbage pits will be observed as per International Association of Geophysical Contractors (IAGC) guidelines in order to protect the surface water bodies. Non-biodegradable, flammable wastes may be burned and the ashes buried with the non-flammable wastes. This burial should be at least one meter deep, with due consideration to the area’s water table.”

“All hazardous wastes will be isolated and collected for disposal in regulated municipal facilities. Although, the likelihood of major impacts from accidental spills is low, it is recommended to ensure that requirements of oil spill and emergency plans must be met before operations commence.”

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