INTRODUCTION
I have decided to take the position of an environmentalist for this topic for several reasons. There is a lot of research that shows that global warming is becoming a big problem and I feel that as South Africans, we need to look at developing more sustainable and renewable energy sources and move away from using fossil fuels.
After doing all the research for this project, I was really shocked at how much damage we are doing to the water systems in our country through the process of open cast coal mining. I understand that mining does create jobs and it is necessary at this present moment in time, but the sooner renewable energy sources are developed, the better for the world.
In the following report, I will discuss different types of open cast coal mining, the effects of open cast coal mining on the environment as well as the financial implications of associated with environmental management.
OPEN CAST COAL MINING
What is open cast coal mining? A simple answer to this question is that when a coal seam is found less that 50m - 80m from the surface of the earth, then the coal is mined from the surface of the earth. There are several different methods of doing this. These are open pit mining and strip mining.
The types of mining mentioned above begin on the earth's surface and keep exposure to the surface until the mine is closed. These types of mines can reach depths of 600m or more and because of this, the sides are generally stepped or benched for safety reasons.
Because of this type of mining and because of the fact that sometimes the depth of the mines can go below the water table, the effects on the environments are great.
Open pit mining: - This method is used when a steeply dipping seam or seams, or a pipe or the coal makes up the country rock. In this case, the whole ore body is mined, and no overburden (top covering of rock) is put back into the void (hole).
This method also uses a lot of drilling and blasting to remove the rock to be loaded and taken to a treatment plant.
Strip mining: - This method is used when the seam is horizontal or gently dipping. In this case, a strip of earth is cleared of the top soil and overburden and mined. When the first strip is cleared of all the coal, a second strip is prepared, but with this strip, the overburden is placed in the void of the first strip. When the second strip is cleared of coal, then a third strip is prepared and the overburden in placed in the void of the second strip and so on.
Unfortunately, during this type of mining there is an increased risk of contamination to ground water because rainwater falls into the pit and spoil piles.
These types of mines are rehabilitated during the mining process and because the final strip has no overburden to fill it with, it can be used as a lake or establish a wetland once all the flora is well established and the ground water is back to an acceptable quality.
ENVIRONMENTAL IMPACT
In 2007 there was an article in the Mail & Guardian called “Mining Industry Must Clean Up its Act”. There were many interesting facts in this article that I feel everyone should know about. Although this article is a few years old, I still think that it's very important important and relevant.
According to this article, Eskom intends to double the electricity output in the next 20 years. In a Bill introduced in Parliament in May, the landowners don't need to give permission for the plans to mine on their property. What is shocking is that at the time of the article, there were 114 mining related applications for coal on farms in Mpumalanga's Great Lakes District.
This land includes ancient peat lands and a water catchment area classified as “irreplaceable” by provincial conservation authorities. Chrissiesmeer in Mpumalanga's Great Lakes District includes the largest freshwater lake in the country and it has several hundred pans surrounding it. This would be one of the reasons it is classified as an “Irreplaceable water resource” the other reason would be that it is home to at least 215 bird species.
Dr Pretorius - secretary of the Mpumalanga Lakes District Protection Group has calculated that the mines will produce 23 million tons of coal between 4 and 10 years. One of Dr Pretorius's biggest concerns is that acid water from the mines will find its way into the Chrissiesmeer system because of decanting; this will lead either into the Vaal River or the Komati River.
A report by Terence McCarthy from the school of geosciences at Wits University states that both ground water and surface water in the area will be permanently contaminated by mining. McCarthy goes on to say “No matter what precautions are taken, the mine[s] will inevitably contaminate the lake - either rapidly if decant occurs or more slowly if decant water is adequately contained.”
I am very lucky to have spoken to Richard Thomas of Sound Mining Solutions (Pty) Ltd who was able to give me an actual report done for a company who wanted to start a mine in the Mpumalanga area.The report dates back to 2008, but the information is still relevant.
Due to confidentiality reasons, the names of the mining company and the names of the people who drafted the report may not be used in my project - this was specifically asked of me by Mr Thomas, but Mr Thomas can be contacted to verify the information used.
Section 5 of the report deals with the environment and potential environmental impacts. There are many studies done on all aspects of the environment namely: -
I have decided to focus on soil and land capability, biodiversity, surface and ground water, air quality and the socio-economic issues.
Soil and land capabilities
There are many different types of soil in this area. They are predominantly light textured, sandy loam to sandy clay loams in nature. The rooting depths vary between 2 and 15m with the majority of the soils mapped having a moderate to high erodibility.
The irrigation potential of the arable soils can be described as moderate to good, and the remainder of the soils don't drain properly - therefore, the land capability ranges from large areas of grazing lands with smaller areas of arable and wetland potential. It must be noted that far more of the land is being used for crop farming in the project area than the amount of land that is classified as arable land.
Approximately 1100ha of land will be disturbed by the project.
Biodiversity
The proposed project falls within two vegetation types - the Rand Highveld Grassland and the Eastern Highveld Grassland. Both of these vegetation types are classified as endangered.
There are vegetation units including natural grasslands, artificial grasslands and exotic plantations. Some of the natural grasslands, including the wetlands associated with these systems are considered to be of high conservation importance and ecological functions - these are sensitive environments.
Protected and endangered plant species and species with traditional medicinal value also occur on the project site, as well as alien and invasive plant species.
Red Data or localized species are habitat specific. This makes the search and rescue efforts and relocation of these species difficult and often unsuccessful. The animal life which is associated with the vegetation has the potential to occur in and or adjacent to the proposed project area, and a number of these are Red Data Species.
If the mining project is not properly managed, the development of this project has the potential to damage this biodiversity and cause impacts of high consequence.
Surface Water
The proposed project area is located in the Limpopo and Orange River catchment. There are two main river systems in the area of the project site, namely the Wilge River which flows in a northerly direction just to the east of the project site, and the Bronkhorstspruit which also flows in a northerly direction to the west of the project site.
The project site is drained by two tributaries of the Wilge River. These tributaries are both non-perennial although water is observed in the spring fed tributary for most months of the year.
Wetlands occur within the project area and are associated with specific soil and wet grassland types. As part of the wetlands, two pans occur in the north west section of the eastern section of the project site.
Surface water quality in the area ranges from marginal to ideal water quality - this water is used for livestock and crop watering and for limited domestic use.
The proposed project infrastructure layout impacts on two minor non-perennial drainage lines. If the surface water systems are not managed, significant pollution could be released into the environment.
Groundwater
The investigation in this area showed that the water levels varied from between 0.3 and 28m below ground level. Most of the boreholes are used for domestic and agricultural purposes.
The groundwater quality in the area is of good quality with the only regular non-compliant parameters being nitrate and fluoride.
Local elevations in nitrate are attributes to possible human/agricultural impact from pit latrines and use of nitrogen-containing fertilizer.
There are two aquifer systems here. he Karoo system which is a minor aquifer system, and then a major aquifer system which is a deeper dolomitic aquifer zone which is beneath the Karoo system. The target coal seams, however, all occur above the dolomitic aquifer system.
If not managed properly, the proposed project is likely to have unacceptable impact on both the ground water levels and ground water quality in and around the project site. The emphasis is on measures to prevent discharge of contaminated water, measures to capture and treat contaminated water and to conserve the impermeable geological zones that separate the coal seams and upper aquifer from the deeper dolomitic aquifer.
Air quality
The Mpumalanga Highveld region already has a problem with air pollution. Elevated sources of emissions in the region are associated with potential for both regional and more widespread impacts on air quality.
The pollutants of concern include particulates, sulphur dioxide and nitrogen oxides. Sources of these pollutants include: - power stations, industry, mining operations, dust from both paved and unpaved roads, wind erosion of exposed open areas and stockpiles; domestic fuels burning; biomass burning; vehicle exhaust emissions; and informal refuse burning.
Dust emissions due to unmanaged on-site operations are normally found 1 - 2km of mining operations, and therefore, in terms of this proposed project, the receptor sites are the neighbouring farms, farm owners and farm workers.
The mine will generate both small inhalable dust particulates and larger fallout dust. The main contributors to dust emissions will be unpaved roads, blasting, wind erosion of exposed areas and stockpiles, wind erosion from the mine residue disposal facility, materials handling and crushing operations.
In the unmanaged scenario, the study predicts that there will be unacceptable off-site impacts.
Socio-Economic
This project will have both positive and negative economic benefits that will impact on the local area, the greater region and South Africa as a country.
The positive benefits are that there is a form of capital investment, employment, support services and foreign exchange income.
The negative benefits include involuntary relocation of people, informal settlements and associated problems of crime and security, as well as the potential negative impact on the value of surrounding land.
FINANCIAL MATTERS
In the Mail & Guardian article of 30 July 2007, it says that tourism in the area between Ermelo and Carolina is still in the beginning stages. The Matotaland Tourism Association says that the tourism industry contributes at least R4million per year and gives 50 jobs to the local economy.
The report obtained from Mr Thomas has a table in it indicating the costs involved for the construction of the Mine Residue Disposal Facility and the return Water dam. Also, the Costs relating to environmental management, monitoring and reporting are in another table.
I have included these tables in my project as they were accurate figures at the time that the report was done in 2008.
In total, the cost, excluding VAT two years ago would have been R48 778 953.94.
estimated construction costs for MRDF and return water dam estimated initial envirOnmental set-up costs
CONCLUSION
Mining.The world has come to rely on fossil fuels, oil, coal and gas. The cost to the environment cannot be ignored anymore.
I researched many articles, newspapers, mining magazines, environmental books and the internet and I keep coming up with the same messages. I would like to take this opportunity to quote a few headlines: -
“Mining devastating SA's farms”
Thousands of South Africans are employed in mines and the unemployment rate would increase drastically if all the coal mines were to close overnight. I am not suggesting that at all. What I am saying is that when the mining managers are not managing the operations properly, and the environment is put at risk, then something has to change because if it doesn't, we won't have the natural resources to sustain us - like water and food and clean air.
Take the R48 000 000 needed to clean up the environment and use it towards building something more sustainable like solar or wind powered energy plants.
BIBLIOGRAPHY
These are the websites that I browsed to get my information.
OPENCAST MINING OF HARD ROCK AND ROCK CRUSHING OPERATIONS...
File Format: Microsoft Word - View as HTML
IMPACT AND ASSESSMENT TABLE; OPENCAST MINING OF COAL. SUMMARY OF ENVIRONMENTAL IMPACT ASSESSMENT (SECTION 5) AND MITIGATION MEASURES (SECTION 6)...
www.bullion.org.za/.../Impact%20Guide/...%20Environmental%20Impacts%20Associated%20with%20Mining/... - Similar
http://www.google.com/search?ie=UTF-8&oe=UTF-8&q=open+cast+mining&domains=bullion.org.za&sitesearch=bullion.org.za
DEPARTMENT OF WATER AFFAIRS & FORESTRY WATER QUALITY STATUS REPORT...
File Format: Microsoft Word - View as HTML
The expansion of mining activities in the Ermelo area to provide coal for... The Waste Discharge system, which will be implemented in the near future,...
www.fishingowl.co.za/WCweb/word/Ria%20Munnikreport.doc - Similar
Chapter 6 - Mining Methods
File Format: PDF/Adobe Acrobat - Quick View
means of surface mining methods. Strip mining, open-pit, opencast mining and quarrying are the most common mining methods...
www.bullion.org.za/.../Chapter%206%20-%20Mining%20Methods.pdf - Similar
http://www.bullion.org.za/Departments/Environment/Downloads/Impact%20Guide/PDFs/Output/Output/Chapter%206%20-%20Mining%20Methods.pdf
1 THE HIDDEN DRAGON: NITRATE POLLUTION FROM OPEN-PIT MINES - A...
File Format: PDF/Adobe Acrobat - Quick View
by C Bosman - Related articles
water supply was found near an open-pit mine, which was identified as the..... have various different sources, great care should be taken with the design...
www.iaia.co.za/Conference_2009/_.../Papers/Bosman_Carin.pdf - Similar
High-density processing of coal
File Format: PDF/Adobe Acrobat - View as HTML
Processing of the coal will furthermore improve the quality of the coal delivered to.... for coal processing in South Africa is dense-medium separation....
www.sacoalprep.co.za/.../18_High%20density%20processing%20of%20coal_J%20de%20Korte.pdf
http://www.sacoalprep.co.za/Conference2009/03_The%20effective%20use%20of%20coal%20in%20Sasol_SJ%20Mangena.pdf
http://www.businessday.co.za/articles/content.aspx?id=97670
http://www.timeslive.co.za/news/article275637.ece?service=print
http://www.businessday.co.za/articles/content.aspx?id=99529
http://www.environment.co.za/pop_printer_friendly.asp?TOPIC_ID=1091
http://www.rsc.org/education/teachers/learnnet/jesei/chemweat/home.htm
Richard Thomas, Mining Engineer. Sound Mining Solutions. 011 234 7152 (W)
Science Project: Chemical Systems - Carbon Dioxide & Fossil Fuels - Dillon Botha (Grade 11)
