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Environmental Impact Assessment - Enviro Dynamics Namibia

Environmental Impact Assessment - Enviro Dynamics Namibia

Chapter

Chapter 7:Environmental Impact AssessmentStatus (+ or -)Significance (no mitigation)MitigationSignificance (with mitigation)Confidence levelNature of the impactExtentDurationIntensityProbabilityStatus (+ or -)Significance (no mitigation)MitigationSignificance (with mitigation)Confidence levelNegativeLow – concentrations of large sulphur bacteria is assumed to be low orabsent.No mitigation necessaryLow – concentrations of large sulphur bacteria is assumed to be low orabsent.Medium - the assessment is based on assumptions that are arrived frompublicly available data, while data directly from the target areas arelimited. An initial survey is needed to confirm the assumptions.The anaerobic bacterium Clostridium botulinum type E might proliferate inthe dredged area if the system turns anoxic, and may pose a health risk tohumans and wildlife when entering the food chain.Specific mine site - Target areas are 22 x 8 km in size but only a maximumof 3 km 2 per annum will mined, which amounts to a total of 60 km 2 after 20years of mining (the period for which the mining licence is issued).Short term – if the system turns anoxic this will be of long term orpermanent duration, but C. botulinum proliferation is linked to periodicmassive die-offs of fish and other aquatic life that might occur duringextreme events such as H 2 S eruptions. Once bacteria proliferate they mayenter the food chain by ingestion of contaminated sediments from thedredge area.Serious effects – botulism caused by the bacteria can be lethal to humanand wildlife.Improbable – no in situ contamination of fish populations by the bacteriumhas been reported for southern African fish populations. Literature datasuggest that the distribution of the bacteria is limited in deeper salinewaters. If the bacteria are a problem in Namibian waters, it is unlikely thatthe addition of 60 km 2 of anoxic seafloor will add any measurable risk ofbacteria proliferation to the already large areas of anoxic zone.NegativeLow – proliferation of bacteria is assumed to be a rare probabilityNo mitigation necessary but this should not indemnify the fishing industryfrom complying with any regulations regarding C. botulinum contaminationLow – proliferation of bacteria is assumed to be a rare probabilityMedium – very little is known about the natural life-cycle of the bacteriaand this assessment is based on data from the northern hemisphere.Nature of the impactExtentDurationIntensityHigh suspended sediment concentrations near the sea bottom generatedby the drag head and subsequent re-deposition of the material causessmothering effects.Dredge area – sedimentation effects will only be relevant along a narrowstrip around the dredge site as any re-depositions inside the dredge areawill have no impact since the animals are removed.Very short term – smothering of a particular area occurs only during thedredging activity, maximum dredging activity per area is assumed to be

Chapter 7:Environmental Impact AssessmentProbabilityStatus (+ or -)Significance (no mitigation)MitigationSignificance (with mitigation)Confidence levelNature of the impactExtentDurationIntensityProbabilityStatus (+ or -)Significance(no mitigation)MitigationSignificance (with mitigation)Confidence levelNature of the impactExtentDurationIntensityProbabilityHighly probableNegativeLow – very small extent, very short duration and low intensityNo mitigation necessaryLow – very small extent, very short duration and low intensityHigh – studies on draghead plumes have shown that the affected area isvery smallRe-deposition of particles in the overflow plume causes smothering ofbenthic organisms, particularly in the depo-center on the continental slopeLocal to regional – the fines (

Final - Enviro Dynamics Namibia
Environmental Management Plan - Enviro Dynamics Namibia
Chapter 0 - Cover Summary.pdf - Enviro Dynamics Namibia
Cover Summary - Enviro Dynamics Namibia
Environmental Management Plan - Enviro Dynamics Namibia
Marine Benthic Study.pdf - Enviro Dynamics Namibia
Fisheries - Enviro Dynamics Namibia
Water Column Study.pdf - Enviro Dynamics Namibia
Water Column Study - Enviro Dynamics Namibia
Comment Responses - Enviro Dynamics Namibia
chapter 1. introduction - Enviro Dynamics Namibia
Draft Social Impact Assessment - Enviro Dynamics Namibia
Marine Benthic Study - Enviro Dynamics Namibia
Chapter 6 - Public Consultation.pdf - Enviro Dynamics Namibia
Chapter 5 - Socio-economics.pdf - Enviro Dynamics Namibia
Chapter 2 - Legislation and Policy.pdf - Enviro Dynamics Namibia
Appendix 1a - Fish and Fisheries Study - Enviro Dynamics Namibia
Sandpiper Project - Enviro Dynamics Namibia
Appendix 1d - Jellyfish Study.pdf - Enviro Dynamics Namibia
Environmental Management Plan - Enviro Dynamics Namibia
Enviro Dyanmics presentation - Enviro Dynamics Namibia
EIA DRAFT MAIN REPORT.pdf - Enviro Dynamics Namibia
Groud Water Impact Assessment - Enviro Dynamics Namibia
Wetland & Fish Ecology - Enviro Dynamics Namibia
Hydrology and Flood Evaluation - Enviro Dynamics Namibia
Final Environmental Scoping Report MTC.docx - Enviro Dynamics ...
mitations Impacting Environmental Assessments
Environmental and Social Impact Assessment of the ... - AECEN
Impact Assessment Environmental and Societal Impacts