Influence of illegal artisanal small-scale gold mining operations (galamsey) on oil and grease (O/G) concentrations in three hotspot assemblies of Western Region, Ghana

This study determined the contamination levels of oil and grease (O/G) across nine (9) galamsey operations under different environmental media (background soil, surface drainage, slurry/sludge and galamsey wastes) in three galamsey hotspot assemblies (Tarkwa Nsuaem, Amenfi East and Prestea Huni Valley) within the Western region of Ghana. Triplicate samples each of the four environmental media for the nine galamsey types (Washing Board, Washing Plant, Anwona, Dig and Wash, Dredging, Underground Abandoned Shaft, Underground Sample Pit, Chamfi and Mill House) were collected and analysed using n-hexane extractable materials in acidic medium by extraction and gravimetry to determine O/G concentrations. From the comparison of mean ranked concentration of O/G, using Kruskal-Wallis Test, the observed differences in the ranking was significant across all four media. The O/G concentrations for Anwona, Chamfi, Mill House, Washing Board and Washing Plant galamsey recorded exceedances when compared to the Ghana EPA Effluent Guideline Value of 100 mg/L for water and The New Dutch Lists' Target and Intervention Value of 50 mg/kg and 500 mg/kg for solid/semi-solid materials. Consistently and for all environmental media types, the levels of O/G across the galamsey types were in the descending order of: Washing Board, Chamfi, Anwona, Mill House, Washing Plant, Underground Sample Pit, River Dredging, Dig and Wash, Underground Abandoned Shaft and Control Sample (non-galamseyed areas). In general, the surface drainage medium was predominantly found to be the most impacted upon medium from hydrocarbons by seven of the nine galamsey operations (Washing Board, Anwona, Chamfi, Mill House, Dredging, Dig and Wash and Underground Sample Pit). This was followed by slurry/sludge, background soil and waste media in that order. Expectedly, there were no exceedances for the Reference or Control Samples (non-galamseyed areas).

Mercury contamination of soil and water media from different illegal artisanal small-scale gold mining operations (galamsey)

Environmental media contamination with mercury, because of illegal artisanal small-scale gold mining (popularly called galamsey), is a major concern in Ghana; yet specific details as to how such contaminations are influenced or distributed across different galamsey operations have been lacking. We monitored mercury levels across nine different galamsey operations (Washing Board, Washing Plant, Anwona, Dig and Wash, Dredging, Underground Abandoned Shaft, Underground Sample Pit, Chamfi and Mill House) in three hotspot assemblies (Tarkwa Nsuaem, Amenfi East and Prestea Huni Valley) of the Western Region of Ghana. Triplicate samples each of background soil, surface water/drainage, slurry/sludge and galamsey waste materials (totaling 160) were obtained and analyzed using Atomic Absorption Spectrophotometer (AAS) to determine total Hg concentrations. From the comparison of mean ranked concentration of mercury, using the Kruskal-Wallis Test, it was realized that the observed differences in ranking was significant for all four environmental media considered. Thus, the poor handling, usage and disposal of mercury from the different galamsey activities did result in elevation of harmful quantities of mercury into the environment. Overall, the highest median value obtained for mercury was recorded at the Mill House galamsey sites and within slurry/sludge medium. This was followed by Chamfi, Washing Board, Washing Plant, Anwona, Dig and Wash and Dredging in descending order, with the Underground Abandoned Shaft and Underground Sample Pit galamsey types recording values below detection limit. In terms of their contribution to mercury contamination to the environment, Mill House, Chamfi, Anwona, Washing Board and Washing Plant galamsey types recorded the highest mean rankings. Overall, key priority information required for influencing reclamation and cleanup policy decisions for mercury, for the many affected wastelands across the country, can be derived from this paper.

Spatial distribution patterns of illegal artisanal small scale gold mining (Galamsey) operations in Ghana: A focus on the Western Region

Recently, there have been efforts by stakeholders to monitor illegal mining (galamsey) activities, foster their formalization and reclaim the many abandoned wastelands in Ghana. However, limited information exists on the locations, abundance, scope and scale of galamsey types, which hinders the development of effective policy response.

This study attempts to map and analyze the distribution patterns, abundance, activity statuses and the extents of nine (9) galamsey types within eleven (11) Municipal and District Assemblies (MDAs) of Ghana's Western Region. It explores the utility of field-based survey, using the Open Data Kit (ODK) system, ArcGIS and Google Earth Imagery to map and visualize different galamsey types under a hostile working environment. A total of 911 galamsey sightings, of which 547 were found in clusters (corresponding to approximately 7106 individual operational units) and 364 in stand-alone mode. Overall, a total of 7470 individual galamsey operations were encountered in 312 different communities (towns and villages).

Operationally, the Alluvial Washing Board, Mill-House and Chamfi were found to be the three most popular and practiced galamsey types. The three main galamsey hotspot districts (out of the 11) are the Tarkwa Nsuaem (294 sightings and 3648 individual galamsey sites), Amenfi East (223 sightings and 1397 individual galamsey sites) and Prestea Huni-Valley Districts (156 sightings and 1130 individual galamsey sites). In terms of their activity statuses, 199 abandoned operations (entailing 1855 individual operations), 664 active (entailing 5055 individuals operations) and 48 semi-active (comprising 560 individuals within clusters) galamsey operations were sighted at the time of the study.

While galamsey is generally acknowledged to be widespread in Ghana, the results suggest a scale that probably surpasses any previous estimate or expectation. The findings will adequately inform the prioritization of reclamation efforts.