A comparative evaluation of two rehabilitation options employed to rehabilitate industrially generated elemental seepage on a coal mine
Mining has a very long history in South Africa and together with the mining activities comes environmental degradation. The mining sector makes use of a number of different procedures and products that causes this degradation of the environment. One of the products harming the environment which are critical for mining activities to commence is explosives. The environment is protected by law in South Africa; it is required that the environment must be rehabilitated after the mining of an area has stopped. Similar environmental laws are also applicable to other industries that can cause harm to the environment. Land in South Africa, and all over the world, is an important asset for ecosystems and people alike. This makes the rehabilitation of degraded land and ecosystems of the utmost importance. In most cases where land was degraded by human activities, human intervention is needed to rehabilitate the area. This is mostly to speed up the process and to make sure future harm to the environment is minimalised. Scientific research is undertaken in order to set up guidelines and procedures for the rehabilitation of degraded sites. The aim of this research is to ensure that each site, with its site specific problems, has the chance to be rehabilitated to the best possible state. Environmental impacts created by human activities were not always a concern and in numerous historical cases the environment was degraded without any thought of the implications. As an example, the effluent from industries was often not disposed of in an environmentally friendly way; this is discussed further in this study. In this study, an explosives manufacturing company (EMC) leased land from a coal mining company for a period of twelve years. The explosives manufacturing plant was erected on top of a watershed within the borders of the coal mining site. Effluent from the manufacturing plant was disposed of by means of a "soak-away" which entails dumping the effluent and wash water into the soil where the contaminants penetrates the soil and soaks away. This resulted in a series of problems with the soil fertility and caused the vegetation on the site to deteriorate and eventually die off completely which left the area denuded from any vegetation in certain areas. After an assessment of the area, a company specializing in the rehabilitation of degraded land drafted a rehabilitation plan. This plan is explained and examined in this study. The rehabilitation and monitoring was done by the same company that compiled the remediation plan and the site was deemed to be successfully rehabilitated in 2008. The success of the rehabilitation however was short lived (approximately 2 years), since the site again showed signs of denudation in 2010. Intervention was needed once again and a site visit was conducted in 2010 (by a different rehabilitation company) after which a different rehabilitation plan was drawn up and implemented. This study entails the evaluation of the different rehabilitation procedures implemented by the two companies in question and explains the different views of each. The main objective of each of the rehabilitation companies was to rehabilitate the site to the predetermined state were neither the coal mine nor the EMC faces any liability in terms of environmental law. In the case of the first company, this was attempted by removing the contaminants from the growth medium after which the soil was ameliorated with different biological inoculants and chemical ameliorants. The site was then reseeded for vegetation establishment with the long term goal of creating a self-driven vegetation cover. The site was rehabilitated and monitored after the second rehabilitation attempt and all the findings indicate that the rehabilitation of the site was successful. The second plan entailed removing the contaminants which the first attempt failed to remove due to a possible lack of understanding regarding the underlying geology of the site. The second procedure also used better amelioration techniques that provided a better result.