Sustainable Mining Site Remediation Under (Semi) Arid Climates in the Middle East and in Northern Africa: The Djebel Ressas Mine in Tunisia as an Example of the Orphaned Mines Issue

Abstract

Humans have mined a large number of sites for minerals, ores and other natural resources over the past centuries. When looking at a practical benefit of applying quality targets to the brownfield site remediation of an Orphaned Mine, the costs directly correlate with the planned target levels. The main problem seems to be the flue dust and mining waste deposits (Alayet et al. in J Appl Remote Sens 11(1), 2017 [1]), so the research follows the three pillars of sustainable development: 1.In order to remove heavy metals contents (Pb, Cd, Zn, Cu, and As—see Table 4 for an overview) safely from a former mining village (cf. Achour et al. in Assessment heavy metals (Pb, Zn, Cd) and metalloids (Sb, As) mobility in carbonated soils contaminated by mining wastes (Northern Tunisia). The poster can be downloaded from: https://www.researchgate.net/publication/335608443_Assessment_Heavy_Metals_Pb_Zn_Cd_and_Metalloids_Sb_As_mobility_in_Carbonated_Soils_Contaminated_by_Mining_Wastes_Northern_Tunisia, (2019) [2] on a regional scale), measures have to be taken for protecting local water reservoirs (E, environmental).2.The reuse of the deposits as material for road construction needs to be studied and decided in terms of costs versus benefits (E, economic).3.Once the topsoil is exchanged with less contaminated soil, after a proper site remediation, the use of the former deposit area for gardening and agriculture should follow health and safety criteria (cf. Béjaoui et al. in Health risk assessment in calcareous agricultural soils contaminated by metallic mining activity under mediterranean climate. CSAWAC CLEAN: Soil Air Water 44(10):1261–1427, 2016 [3, Ghorbel in Contamination métallique issue des déchets de l’ancien site minier de Jebel Ressas: modélisation des mécanismes de transfert et conception de cartes d’aléa post-mine dans un contexte carbonaté et sous un climat semi-aride. Evaluation du risque pour la santé humaine. Thesis, University of Toulouse, France, 4]): Some of the inhabitants grow deep-rooting vegetables on site (S, social) that accumulate heavy metals. Proposed Solutions: A.Control the spread of heavy metals into the towns and villages of an affected area, and into agricultural land, and monitor it—for example via biomarkers.B.Exchange the topsoil in areas where people grow vegetables, especially deep rooting species. At best, utilize a local workforce to create more jobs.C.Additionally, extract heavy metals and stabilize the affected soil by adapted plants. Their leaves and stems accumulate metals that the roots extract. The biomass can be harvested (as a kind of mining) to prevent recontamination of the soil on site.D.Define and try to meet quality targets, e.g. to re-settle certain species in the area. This chapter gives a clear benefit of applying realistic quality targets for orphaned mines’ brownfields. For its site remediation, the main limiting factors are the costs, as “Contra” arguments. So the targets should be re-adopted during the site remediation. For example, practical solutions allow stronger releases of heavy metals after the remediation, compared with the original targets.