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Dit cahier bevat een voorstel voor een regionale energiestrategie voor Zuid-West-Vlaanderen: Zuid-West-Vlaanderen energieneutraal in 2050. Het biedt een denkkader over hoe Zuid-West-Vlaanderen de komende decennia met energie moet omgaan. Het cahier formuleert een visie, plus een aantal concrete acties om de visie op korte termijn in de praktijk te brengen. Het is de neerslag van een uitgebreid proces dat Leiedal opstartte, in samenwerking met de regionale energiestuurgroep en thematisch verdiept aan de hand van verschillende expertenworkshops en regionale energiefora.

The gold rush in Burkina Faso has many facets, the most expected one being the economic contribution for the country and local development. Since 2012, gold has become the main exportation product of Burkina Faso, reaching 90% of the total export budget in 2018. On the other hand, mining has many disadvantages such as contamination of land and water, water depletion and health risks linked to the consumption of contaminated food. It is therefore imperative that solutions to environmental problems be found for the "greening" of mining. The focal point of this thesis is a gold mine in the southern part of Burkina Faso in the Boulgou province, and close to the border with Ghana Republic. The site is in the catchment of the Nakambé River. This study has three main objectives: (1) to assess the contamination of soil and water by mining, and this in terms of potentially toxic elements; (2) to assess the exposure to potentially toxic elements linked to the consumption of contaminated foodstuff cultivated on and nearby the mining site; and (3) to investigate phytoremediation as a possible way to control potentially toxic elements in soil and water. Regarding the first objective, soil and water samples were taken for analysis. Total digestion and sequential extraction were performed on soil samples taken within the mining site and at nearby, non-affected control sites. The study investigated the concentration of potentially toxic elements, namely arsenic, cadmium, cobalt, chromium, copper, nickel, lead and zinc. Results of analysis of soil samples were interpreted using enrichment factor and geoaccumulation index. Water samples were taken from the pit lakes and the nearby Nakambé river as a control, and the same potentially toxic elements were analyzed. The investigation revealed a high level of As on the site with hotspots around the processing plant and the tailings storage facility. As, Cd, Co, Cr, Ni and Pb were exceeding the agriculture threshold and were therefore of concern. Cu, Zn and Mn were below threshold for agriculture and therefore not a concern. The subsequent calculation of enrichment factors and geoaccumulation indices expressed strong to extreme contamination for As, Co, Cr, Cu, Ni, Pb and Zn. Water analysis revealed that the pit lakes did not meet World Health Organization criteria for drinking water and reflects the impact of the surrounding mining activities. This study highlighted that mining does have an impact on land and water and that the impact is of anthropogenic origin. For the second objective, four cereal types were sampled in four sites, i.e. the mining site itself and three nearby villages (Songo, Youga and Sighnoguin), and those were analyzed for potentially toxic elements. Also, fish were collected from two pit lakes and from the Nakambé river and analyzed for potentially toxic elements. This was complemented by a dietary intake survey of the local populations living near the gold mine. The survey revealed a cereals consumption of 0.43 ± 0.19 kg/person/day and a fish consumption of 5.34± 2.60 g/person/day. The Hazard Index (HI) related to consumption of cereals exhibited a value higher than unity in all locations considered, expressing a health concern by the combined toxicity of the elements investigated. The Target Hazard Quotient (THQ) of fish consumption was below unity, as well as the HI. The results revealed that Target Cancer Risk (TR) results for As, Ni and Pb from combined cereals and fish consumption were higher than acceptable, expressing a concern of risk of cancer due to the long-term consumption of cereals and fish. Finally, for the third objective, soil phytoremediation was considered in a lab experiment using Leucaena leucocephala which is a (sub)tropical shrub endogenous to Burkina Faso, and treatment of seepage from the tailing’s storage pond was investigated by means of a full-scale constructed wetland populated with Chrisopogon zizanioides (vetiver) and Typha domingensis (southern cattail). With As being the main element of concern, the capacity of L. leucocephala to absorb arsenic has been studied under different conditions: with EDTA supplementation and/or with a growth enhancer containing Mycorrhiza sp. and Bacillus sp. The results showed an effective uptake of arsenic by Leucaena leucocephala while EDTA and the growth enhancer did not cause any additional As uptake by the plant. On the contrary, the treatment with EDTA or growth enhancer reduced the plants’ total biomass production. Accumulation of As in the below ground part makes Leucaena more suitable for phytosequestration than phytoextraction and allows its subsequent use as forage for livestock. In the constructed wetland, spontaneously grown T. domingensis thrived and presented better adaptability than C. zizanioides. Due to its high biomass production, standing stocks (amount of potentially toxic elements accumulated in aboveground biomass per area unit) of As, Co, Cr, Cu, Mn, Ni, Pb and Zn were 3, 7, 4, 7, 14, 7, 5, times higher than in C. zizaniodes. The outcomes on seepage treatment and the contribution of plant uptake towards treatment were not conclusive, as there was an additional and significant backload from the sediments in the constructed wetland. Nevertheless, the use of T. domingensis for gold mine tailing storage seepage treatment element uptake is recommended in combination with uprooting in order to achieve a high level of standing stock removal.