Quarrying Activities and its Environmental Health Implications among Inhabitants of Ndarugo Area, Kiambu County, Kenya


Mining can be described as the extraction of valuable minerals as well as the removal of other of geological materials from the earth. Mining is an activity that has been carried out since the prehistoric times, where stone and other metals were extracted from the earth. The process of mining has to prove profitable to the miner seeking to gain from the extract, and involves prospecting for the extracts, analyzing the profitability of the mine, the process of extraction and finally but not in all cases the reclamation of the land. For many years, these mining processes have led to adverse negative environmental effects either during the mining process or long after the mines have been closed. Stone as one of the valuable mineral extract has always been used since the beginning of civilization to make early tools and weapons (Hartmann &Howard, 1992)

Mining techniques are divided into two excavation types, which include surface mining and subsurface mining. In the current times, surface mining is more common. In relation to extraction of rocks, surface mining is employed, and a technique known as open pit mining is used. Surface mining began in the mid sixteen centuries, and has been continually employed throughout the world; although it is majorly employed in the North American continent, where today, surface mining is much more common, and produces, for example, 85% of minerals (excluding petroleum and natural gas) in the United States, including 98% of metallic ores (Hartmann, 2002). This technique is used when the deposits of the useful rock are found near the surface. The open pits that produce building materials and dimension stones are commonly referred to as quarries. Extraction of materials using this method involves the use of heavy equipment that moves the earth and other huge machines that extract the final product, which in itself results to negative effects to the surrounding environment through noise, dust, and vibrations that are as a result of the activity, where also in some cases additional logging of forests is done in the vicinities of the mines to create room for the storage of debris and soil excavated.

Stone has always been used for building and decorations because of its resistance to weather and for its aesthetic appeal. For example, India’s use of stone for construction purposes can be traced back to 3200 B.C. The country’s many innumerable temples and ancient palaces have been carved out of locally available stone. One of the most famous buildings, the TajMahal at Agra, portrays a long age tradition of stone architecture in the country (UNESCO World Heritage Centre, n.d.).

Stone being an important component in the construction of homes is often demanded in large quantities, especially in our country Kenya. The demand for quarried aggregates is enormous (George, Ndegwa, Oguta & Calvince, 2003). Developmental activities in Kenya that involves the construction of homes, factories and schools among other developments underpin the necessity of quarrying as an activity in the country. The quarrying and aggregate production industry is therefore a major player in the important role of steering the nation’s economy through the provision of essential building materials and providing employment opportunities. Housing demand in Kenya supports the fact that there is an enormous reliance on stone aggregates, and bearing in mind that the population growth is placed at 4.2% per annum, which accelerates urban migration gives a projection of an annual increase of housing units, which currently stands at 206,000 units annually (CAHF, 2012).

Areas like Ngong and Mwiki supply Nairobi’s area with building stone and are home to artisanal stone quarrying, however Juja Township is also another location in Kenya that is home to the industry, and has seen exponential growth in the recent years, since the quarries in the area became active in the 1940’s and late 1950’s. During those early times, there were seven stone quarries that were in operation, however, the number has increased to the present 207 quarries. The quarries are distributed along the Ndarugo river, with the largest quarry covering 20 ha of land and the smallest 0.01 ha (George et al., 2003). The quarries relatively vary in depth ranging from 2- 50 m deep.

The quarries are undeniably of economic significance; however they are also a source of environmental problems throughout their whole phase of operation. Both active and abandoned quarries are a threat to the surrounding environment, and more significantly result to the degradation of land, drainage problems and visual intrusion because many are not rehabilitated after use.

Mining and quarrying

Mining just like agriculture is one development feat by the human race, which marked the start of early civilization. It is one of the basic industries that fuelled civilization, and as a fact being second from agriculture as the agrarian revolution commenced in 1500 B.C and it in the 1700 B.C has continually supplied all the basic resources that are in use by modern civilization (Hartmann & Howard, 1992). According to Madigan, mining has played a chief role in the existence of the human race (Madigan, 1981), whereby the term mining is in its broadest terms to mean the extraction of any naturally occurring minerals, be they in gas, liquid or solid state.

Many important cultural eras are earmarked by the development of mining, and the derivatives of the activities associated with the industry. The eras can be outlined as; Stone Age (prior to 4000 B.C.E), the Bronze Age (4000 to 5000 B.C.E), the Iron Age (1500 B.C.E. to 1780 B.C.E), the Steel Age (1780 to 1945), and the Nuclear Age (1945 to the present). There are many uses of minerals, for different purposes and occurring in different ages by the human race.

Active and abandoned mines and quarries have been a source of negative environmental effects which have led to erosion, formation of sinkholes, and contamination of soil, groundwater, and surface water, and also the loss of biodiversity. All these problems arise from contamination of the chemicals used in mining and the neglect of environmental awareness while operating the mines and quarries. Increasingly, there are abandoned quarries and mines throughout the world because of low running reserves and this leaves so many open pits after the extraction process is finished, where many of the mining companies are reluctant to properly rehabilitate a site after they have exploited it fully. In the United States alone, there are more than 560,000 abandoned mines on publicly and privately owned land (Kertes, 1996). These open mines are a danger to those that may want to explore them, especially to those people that do not have the proper knowledge and skills on how to approach them safely, and this forms a majority of the population (DOI, 2007).

Minerals have also been a great source of wealth that has enabled many countries with the rich abundance of the natural resources accumulate wealth and form great economies. Those countries that do have them obtain valuable currencies from the countries that do not have. It has also been estimated that only a fraction of 1% of the earth’s surface is underlain with mineral deposits that can be exploited for monetary value (National Mining Association, 1998).

In the modern times, the consumption of minerals has been on the rise, as the society is drastically changing because people are relying now more on airplanes, trains and vehicles for transportation; mobile phones, computers and radios for communications; heavy machinery and fertilizers for agricultural output; industrial minerals for home building; and nuclear plants, and coal for electric power. This kind of use for industrial services has led to the over exploitation of minerals. However, this kind of use has spurred a lot of public reaction, where people have become more aware of the need to conserve energy, minerals and the environment. Countries like the United States have compelled their mining industry to endorse a policy that favours the extraction of minerals in a more sustainable manner (National Mining Association, 1998).

Mining in Kenya is however not that large, and it is dominated by exploitation of non-metallic minerals such as soda ash, diatomite, gypsum, limestone, fluorite, constructional stone and sand harvesting. The large percentage of mining in the country is done by the artisanal miners, which accounts to about 70-80% (Osumo, 2001). Majorly the type of activity under quarrying in Kenya is the extraction of stone. This activity is a very significant activity in the country under the informal sector or popularly known as the Jua Kali sector. It involves a number of stakeholders that include land owners, quarry owners, concession holders (who lease land and extract stone for sale) and quarry workers who constitute both the skilled and unskilled. The sector is believed to employ over 40,000 workers nationally, where in Nairobi alone it employs 10,000 people (Asher & Sam, 1999).

The country has a very great demand for stone because of the ever growing construction industry, and stone from mechanized quarries is in high demand. Many of these quarries are found in Juja, but recently those that that serve Nairobi (the Ngong division of Kajiado district, approximately 13 kilometers southwest of Nairobi) have been surveyed, and according to Asher & Sam (1999) the results have revealed that the local stone reserves can sufficiently supply stone for the next 50 years.

The bio-physical and socio-economic effects of quarrying activities

The process of quarrying is greatly related to the negative environmental effects of the activity. There are several processes that are involved in quarrying and they include; clearing of overburden of soil, drilling, blasting, splitting and dressing of stone. The process uses various tools for extraction which are categorized into two, namely, hand tools and machine tools. The hand tools include; jacks, levers, hammers, and chisels for extraction; and hammers, chisels (including pneumatic), drills, saws, grinding stones and polishing powder for stone-working (Shadmon 1989). On the other hand, machine tools include: jack-saws, saws, wire-saws, and chainsaws, mechanical chisels for extraction; and guillotines, saws, planers or fraisers, grinders and polishers for manufacturing (Shadmon 1989). Every stage in the operation of a mine has its negative consequences, which are:

  • Clearance of the overburden leads to the destruction of vegetation, destruction of fauna habitats, loss of scenery, enhancement of soil erosion;
  • Drilling leads to the generation of dust, and generation of noise; Blasting causes ground vibrations, fly rock generation of dust, generation of noise, surface land disruption, and explosive fumes (gases);
  • Splitting causes flying stones pieces, while Stone dressing causes the generation of dust (Mines and Geology).

The bio-physical effects are associated with the environmental impacts because the fact that many of the quarry sites are uncontrolled and that insufficient techniques of mining are used, it produces a degradation of both land and stone reserves. In many cases there is lack of resource allocation planning in quarry land, a situation that results to quarry sites being located haphazardly without any proper development and guidance. In the end there is a myriad of mineral surface workings that show a lack of resource and environmental management (Savery, 1997).

Artisanal stone quarries are also known for the high waste to recovery ratio, which is influenced by among other factors, the natural formation of the rocks and the method used to extract the stones. The situation is such that the estimated amount of stone wasted in the country ranges from 50 – 90%. The situation is influenced by use of manual mining techniques, although blasting is also used in areas where the rock is much harder before the stone is split and sized.

These wasteful methods of both quarrying and processing of the stones aggravate the situation (Agevi & Ogero, 1990). There is also aesthetic pollution, which happens if there is no screening of current operations and proper restoration of abandoned mines. Visual aftermath of quarrying is equal to the poor utilization of resources in small-scale artisanal quarrying (Savery, 1997). Introduction of potentially discordant features into the landscape also result to visual intrusion and affect the landscape character e.g. quarry face, plant, lighting and quarry face.

Another effect is that quarries can contribute to air pollution in a number of ways that include; ammonium nitrates form the fuel mix used in blasting and from engines, dust from the quarry or the roads that lead to the quarry site, as well as the dust and fumes from the lorry traffic and dust from the blasting process may cause discharge of pollutants to the atmosphere. Dust is one of the most visible, invasive and potentially irritating impact associated with quarrying. Dust concentrations, potential impacts and deposition rates tend to decrease rapidly away from the source (Howard and Cameron, 1998). However, its visibility tends to raise concerns that are not usually directly proportional to its impacts on human health and the environment (Howard & Cameron, 1998).

Noise is another of the effects which is as a result of the use of explosives, processing equipment and earth moving equipment and the situation is worsened with quarries being at close proximities to each other. The impact of noise on the sound receiver is often from the source which is characterized by the rhythm, pitch of noise, beat and distance (Langer, 2001). The use of explosives may also trigger ground vibration which is also a cause of disturbance. In cases where rivers are located near river or other drainage systems, they lead to water pollution which is also another effect and can be attributed to the amount of lead in oil, petroleum spills and waste metals on soil without treatment, in the quarry mining and transportation machinery. Quarries can also be a cause for water table alterations, where the quarries go deep enough to affect ground water aquifers. Formation of dams at quarry sites is also a common feature in abandoned quarry sites (Agevi & Ogero, 1990)

The socio-economic effects

Quarrying is undeniably a valuable source of building materials worldwide, but it raises problems in land use by the communities that are found around areas where such activities take place. A study conducted in the Niagra escarpment on quarrying, revealed that there is a struggle between the industry, the quarry operators who are in charge of producing the construction materials and the local communities that have new uses and value for the same land (Sandra & Andes, 2005).

In Kenya, studies on the socio-economic effects of artisanal quarrying have been conducted. The studies have focused on resource utilization, restoration and respiratory dusts created by lorry traffic, and are aimed at improving productivity and environmental sensitivity of artisanal quarrying (Savery, 1997; Agevi and Agero, 1990; Mjaria, 1997; Ng’ang’a, 1997; Ng’ang’a and Agevi, 1990; Wells, 1996).

In a report tabled by Ng’ang’a (1997) after a workshop of artisanal quarrying stakeholders, quarrying was presented as being a significant economic activity in the construction sector, as well as providing a livelihood for land owners, quarry owners, concession holders, quarry workers, and people in the transport industry. Another report by Kenya Quarry and Mine Workers Union (1996), it indicated that the sector was providing a livelihood for about 200,000 people in the country.

Constraints facing the expansion of the industry, in meeting both the existing and potential demand for dimension stone, have been captured in a report titled socio-economic and institutional survey of stone quarrying in Kenya by Agevi and Agero (1990). There are potential risks associated with quarrying that cannot be ignored, but have been underplayed in many of the reports, and include health risks. Quarries located near residential areas have been connected to posing health issues especially because of the clouds of dust produced. A certain report in Palestine indicated that the locals living near quarries were suffering from increased levels of asthma and acute bronchial infections (Foundation of Middle East Peace, 1998)

Mitigation measures for the management and control of quarrying activities

The extraction of materials from the earth’s crust inevitably impacts on the surrounding natural and social environment. Particularly, the removal of soil and changes in topography of the area are likely to affect local ecosystems and watersheds. However, throughout the years these impacts have been successfully addressed and mitigated through the development and implementation of effective quarry rehabilitation plans. In many of the cases, effective implementation of a well-designed rehabilitation plan has resulted in significant environmental and social benefits, an example in our country being Bamburi Cement Mines in the coast (CSI, 2011).

The CSI through its published work by the WBCSD indicates that quarrying activity carries with it the obligation to rehabilitate both the site and, wherever necessary, the surrounding area while operating and upon completion of operations. The success of rehabilitation also carries commercial benefits for the operating companies. The license to operate for both the industry as a whole and for individual companies is dependent on ensuring that land used for quarrying purposes is rehabilitated in an effective and responsible manner, taking into account the needs and expectations of stakeholders, and the influence of regional and local planning requirements. Those that adopt the best practices in this regard have a greater expectation in realization of the significant benefits, which includes long-term sustainability of their operations and competitive advantage, which far outweigh the short-term financial costs that are a result of undertaking a rehabilitation program (CSI, 2011).

CSI ESIA guidelines also points out principles that guide an effective rehabilitation plan are as follows:

  • The post-closure land use needs to be clearly assessed when initiating a quarry rehabilitation plan, even if this can evolve over the lifetime of the quarry. A quarry rehabilitation plan needs to be based on a clear set of objectives reflecting the legislative requirements (as the highest priority), and encompassing the local social, economic and environmental (including biodiversity) considerations for the future use of the site. The objectives will be technically and financially sustainable.
  • Legal compliance must be the minimum requirement when establishing each quarry rehabilitation plan. The rehabilitation guidelines should never be in conflict with, but should always complement and go beyond legal compliance.
  • The rehabilitation plan will ensure the site is left in a safe and stable condition. The safety of the rehabilitated quarry includes the stability of slopes, roads and raw materials piles. Safety should always be considered as paramount for the rehabilitation plan.
  • Stakeholders should be listened to, and relevant stakeholders need to be involved at all stages. The quarry rehabilitation plan must address stakeholder expectations, and be aligned with, or leverage from, the stakeholder view, experience, culture and customs.
  • An assessment of the baseline conditions enables identification of the impacts and measurement of the changes that may arise as a result of quarrying activity. The assessment of baseline conditions includes air and water, flora and fauna, site safety, landscape integration, human activities and cultural heritage.
  • The rehabilitation plan shall be developed prior to the commencement of mining for new sites, but should also be developed for operating quarries, where such a plan does not already exist. It should be aligned with the mining plan. Depending on the objectives and priorities set, the development and monitoring of management plans for biodiversity should, at a minimum, be considered as a supplement to the quarry rehabilitation plan, and in other cases, as core parts of the plan.
  • A monitoring plan and appropriate corrective measures (if necessary) should be included in the rehabilitation plan, thereby ensuring the documentation and measurement of performance against the objectives.

Other mitigation measures have been explored by many scholars and organizations and are as outlined below:

  • Classification of protected areas is an effective mitigation measure and if there is a need to designate such areas, then the classification of the protected areas by the International Union for Conservation of Nature and Natural Resources (IUCN) is one of the prominent systems that exist for such purpose.
  • There was a resolution that was passed on October 2000 by the world congress in Amman, Jordan, that recommended the member states to prohibit by law, all explorations and extraction of mineral resources in protected areas that corresponded to the IUCN protected area management categories.
  • EIA’s and ESIA’s are another mitigation measure where there are internationally accepted tools that have enabled mining companies to adequately factor in environmental and social considerations in investment decisions. For many of the companies internationally they have become an integral part of investment assessment methodologies that had previously been focused largely on financial criteria. There has been a re-emphasis on the use of impact assessment instruments that came as recommendations of the UN conference on Environment and development in 1992, which as a result reinforced the aspirations of the Berlin guidelines of 1991 on environmental stewardship. The impacts of assessments cover the effects on flora and fauna and on human health, as well as broad socio-economic impacts of mining both directly and indirectly.
  • Public participation is another very important part of regulating the environmental and social impacts of mining activities and an effective mitigation measure, which ensures sustainability by ensuring overall management of exploiting mineral resources, is held to accountability. There are key benefits that do arise from public participation, where the decision on whether a project has a significant impact on the environment as well as social effects and should be allowed to proceed is based on the local knowledge that is often valuable information often missed by the experts and it also legitimizes the project that would otherwise prove to be a problem because of social tensions when the project is externally imposed.
  • It is also now law that whenever anyone is carrying out an environmental and social impact assessment, that they include a public participation component. This is supported by the fact that many of the African countries provide for the right to a clean environment in their constitutions. This kind of provisions can actually found claims of a right of a member of the public to be heard before any decisions are made on projects that could have significant adverse effects on them.
  • Last but not least is access to information as outlined in Principle 10 of the Rio declaration that states that “each individual shall have the appropriate access to information concerning the environment that is held by public authorities, including information on hazardous material and activities in their communities and the opportunity to participate in decision making processes. States shall facilitate and encourage public awareness and participation by making information widely available”, expresses the relationship between access to information and participation in decision making. This is also further expressed in the UN Economic Commission for Europe “convention on access to information, public participation in decision making and access to justice in environmental matters (the Aarhus Convention), which is widely regarded as a model of public participation regime (UNECE, 1998).
  • In South Africa, their promotion of access to information act (2000) and its regulations establish a scheme to facilitate access to information held by public and public institutions. To monitor and enhance the implantation of the act, the South African human rights commission is assigned that responsibility.

Policy and legal framework governing mining in Kenya

a.) National Environment Policy, 2012: Revised Draft 5 of July 2012

The policy aims to provide a holistic framework to guide the management of the environment and natural resources in Kenya. Its core goal is to advance better quality of life for present and future generations through sustainable management of the environment and natural resources.

b.) The National Minerals and Mining Policy: Revised Final Draft 2010

The objectives of this draft policy that is awaiting parliament’s enactment covers several facets of mining in Kenya such as the regulatory framework, stimulation of investment in the mining sector in Kenya, ensure harnessing of minerals contributes optimally to vision 2030 and national development. Additionally, the policy also recognizes the need to bring into the mainstream the small scale artisanal mining sector.

c.) Draft National Education for Sustainable Development Policy, 2011

This is a policy document prepared by the ministry of environment and mineral resources on November 2011 (Ministry of Environment and Mineral Resources, 2011, p. 14). Education of the general public around the mineral rich areas is critical for them to understand the benefits, opportunities and effects of the mining activities. This policy is crucial in preparing the people for a resettlement exercise and in order to receive less resistance.

d.) Mineral Development Policy

This policy covers the National Development Plan of 1994-1996, titled Resource Mobilization for Sustainable Development. The National Environment Action Plan Committee (NEAP) is established under Section 37 of EMCA. This cross-sectoral committee is responsible inter alia, for the development of a five year national environment action plan. The national environment action plan shall contain among other aspects analysis of the natural resources of Kenya and their distribution, quantity and various uses. It shall also recommend legal and fiscal incentives for business that incorporate environmental requirements into their planning and operational processes as well set out

e.) Legal framework Governing Mining Activities

The Mining Act Cap 306 of 1940 is outdated and does not apply to standard mining regulation procedures. The industry wants to see a new law that aims to remedy the problems by stating the timeframes and procedures to be followed when access to land is unreasonably denied. The current Mining Act, which dates back to the 1940s, has been termed as a major block in the development of the mining industry.

f.) Environmental Management and Co-ordination Act no. 8 of 1999

The policy process culminated into the Draft Sessional Paper No. 6 of 1999 entitled “Environment and Development.” The legislative process gave forth the Environment Management and Coordination Act (EMCA) (Act No. 8 of 1999) as Kenya’s first framework environmental law. Both the Draft Policy and Act added to a large number of existing sectoral laws and policies dealing with various facets of the environment, such as water, forests, minerals and many others (Government of Kenya, 2012, p. 7).

g.) National Land Policy Of 2007

To address this problem, the Government has come up with a National Land Policy 2007 whose vision is to guide the country towards efficient, sustainable and equitable use of land for prosperity and posterity. This policy will ensure that all land is put into sustainable and productive use. The policy has so far received Cabinet’s approval and is currently waiting for enactment by the legislature.

h.) The Kenya National Environment Action Plan (NEAP) report of June, 1994

This policy is covered in the Draft Sessional Paper on Environment and Development of 1996, Sessional Paper No.1 of 1994 on Recovery and Sustainable Development to the Year 2010, and the Report of the East African Cooperation Meeting of National Environment Institutions of November, 1997. This policy was updated in 2009 by the National Environment Management Authority (NEMA) in a document titled the “The National Environment Action Plan Framework 2009 to 2013.

i.) Trade Policies

Although most of the minerals are exported in their raw form, the government policy is to encourage value addition within the country for higher returns, support of industrialization and employment creation.

j.) Resettlement/Land Acquisition Policy Framework of the Government of Kenya

The objective of the policy is to outline the manner in which the people in areas where minerals have been found to be relocated to other areas.

k.) Land Reclamation Policy

This policy was not drafted by the ministry concerned with mining and minerals in Kenya rather it is a product of the Ministry of Water and Irrigation. Nevertheless, it has been included here since it affects the mining sector especially on the aftermath of mining activities and not on the onset of mining. For instance, in mining from limestone and even sand, huge holes are left behind that become hazardous to the environment.

l.) National Occupational Safety and Health Policy (June 2010)

This policy aims at promoting safe and healthy environment in places of work especially mining sector which not only uses dangerous chemicals in extraction of minerals but also exposes the workers to health hazards like dust.

Theoretical and Conceptual Framework

Theoretical framework

The theory guiding this study is the systems theory. This section reviews the theory with a view to bringing out the salient attributes that would enable this study to fit in. Similarly, the concept of land degradation is also incorporated to further buttress the effect of mining within the system. The general systems theory developed by Bertalanfy (1951), argue that the natural geology consist of mutually related subsystems and the destruction of one of the subsystem lead to the modification of the entire system. The environment is the sum total of all the external factors that influences the life of an organism, here the physical environment which comprise the land is considered. Consequently in the strive for economic growth, the physical and social environments are subjected to pressure that affect the entire system. He emphasized that real systems are open to, and interact with, their environments, and that they can acquire qualitatively new properties through emergence resulting in continual evolution. Thus rather than reducing an entity e.g. (environment) to the properties of its parts or element e.g. (land, social and economic setup), system theory focuses on the arrangement of and relations between the parts which connect them into a whole.

The systems theory conceptualizes land degradation and negative social and economic effects as the response of the mining to the demand of the environment. The theory sees land degradation as well as negative social and economic effects as an output of the mining. Land degradation such as loss in vegetation cover, changes on the landscape and negative social effects such as health related issues is seen as the reaction of the mining to environmental demands and pressures. The theory shows that the relationships that unite the part to form a whole have a lot of influence on the behavior of the whole.

Man affects his environment as he responds to the changing condition set by the environment and the environment responds to human manipulation, thereby creating a state of dynamic equilibrium that continues to adjust and readjust in space with time (Olofin, 1989). The systems theory was chosen against other theories because, the world is made up of components and the components are interrelated. Nothing is independent on its own. A change in one will have repercussions on the other parts. With respect to this study therefore, because man depend on the mining and the mining is being done on the land, the environment is in turn affected by such activity and land degradation sets in. The relationship between the two is that the mining as an input was converted into land degradation as the output in this case. The three interrelated components resulted into land degradation. Land is one of the major resources in both developed and developing countries, and forms the basis of economic sustenance. Degradation is therefore the diminution of the biological productivity expected of a given tract of land (Ayuba, 2005). Land degradation which includes degradation of vegetation and soil has been identified as a major problem in Africa (FAO, 1980). From the foregoing therefore, the systems theory sees land degradation as the output of the mining.

Conceptual framework

Human beings are part of the biosphere or its ecological component and play a central role in modifying and interfering with the physical environment through their activities. Human systems tend to influence these activities, whereby socio-economic aspects that include demography, knowledge, economic development and lifestyle among others, directly or indirectly influence what we do. These in turn lead to the development of man-made systems that are strongly influenced by human beings, and includes the development of physical structures, public infrastructure, parks, man-made lakes, mines and rock quarries, so as to satisfy the needs and wants in society. Quarrying as one of the developments interacts with the aspects of the physical environment or otherwise the natural systems that includes physical phenomena that do not originate from human activities; including water, air and climate. The ecosystem as part of the natural system is also affected. Human beings as the sole generator of these effects are also affected, where the effects on the physical environment can also impact on the socio-economic aspects of quarrying, including loss of lives, poor health and diseases, accidents, reduction of land for other land uses, and destruction of built structures.

Quarrying as an activity that involves the extraction of earth materials for economic value, takes place within the physical environment and therefore has impacts both on the physical and socio-economic environment, however there are also positive aspects of mining which determine whether quarrying will continue.

The conceptual framework is a synthesis of components from a developed conceptual framework for integrated monitoring, namely Integrated Environment and Health Monitoring (IEHM) framework developed by WHO (world health organization), 2010 with that of a theoretical framework by Law and Smith on the principal components of the environment. The synthesis has modifications in line with the researcher’s conceptualization of quarrying as an activity that has both socio-economic and environmental impacts (see figure below).


In assessing the environmental impacts of quarrying activities in reference to Ndarugu area, Kiambu county, it can be deduced that; in an effort by quarry owners who seek to exploit minerals through quarrying activities, for the highly demanded stone commodity, there are numerous abandoned quarries that have been put to no use. This is because there is a general reluctance by the owners to restore or to rehabilitate the abandoned quarries. For the active quarry sites, there are numerous negative environmental impacts both bio-physical and socioeconomic which affect both the people living in close proximity to the mining sites and the workers who work in the sites. This has led to the development of many risks both health wise and exposure to risky sites that leaves the community highly affected. However this is not only limited to active sites but also abandoned quarries have hugely contributed to the degradation of the environment as well as posing numerous risks associated with open pits.

Several mitigation measures have been laid out to mitigate mining activities at worldwide level and also locally in the country with Agenda 21, The National Environmental Action Plan, National Environmental Policy and also rehabilitation plans that have been successful, but the issues to do with artisanal or small scale quarrying have not been properly addressed and the policies and legislative frameworks go silent when it comes to issues of concern to quarrying. This has resulted to a blatant disregard of the environment in a highly unregulated industry, where those that assume the role of controlling the sector, who being the local authority have no capacity in terms of skills and manpower to affect control in the sector.


Short term recommendations

  • The quarry owners should adopt methods that are less wasteful
  • There should be use of technologies that are user and environmental friendly
  • Rehabilitation of quarries should be emphasized after use
  • Adoption and emphasis of use of safety equipment to reduce accidents and health risks around the worksites
  • Community members, landowners and concession holders be involved in finding viable solutions to the problems posed by quarrying
  • Promotion of environmental awareness campaigns and technical training programs to add value to how the locals respond to the quarrying process and negative environmental impacts

Long term recommendations

  • Quarrying activities should be under one government department under the newly established Ministry of Environment, Water and Natural resources. The quarrying activities in the country are currently licensed by the local authority that do not have the capacity to do so. They operate from revenue collection and land allocation only without any regard of the actual activities carried out. They are unable to assess the quantity and production capacity and hence duration of quarrying to go hand in hand with development plans. They are unable to assess the environmental degradation and rehabilitation program thereof required after the quarrying.
  • The government should re-establish mining cooperative societies for the small scale and artisanal mining. This is because individuals may not be able to handle the environmental issues and the mines rehabilitation.


Agevi and Ogero B.B. (1990).Stone quarrying in Kenya: a socio-economic and institutional survey. Nairobi, Kenya: Intermediate Technology and Development Group Mining Program.

Asher Shadmon, Sam G. (1999). Training and policy guidelines for artisanl quarrying.ITDG.

Ashurst, J. and Dimes, G. (1977).Stone in building: its use and potential today. London: The Architectural Press.

Ayuba, H.K. (2005).Environmental science.An introductory text.Apani publisher.

Bertalanfy, L. (1951). An outline of general systems theory. British Journal of Philosophy of Science theory, 1: 143.

CAHF. (2012). Housing Finance in Africa – a review of some of African’s housing finance markets. Finmark Trust.

CSI. (2011).Guidelines on quarrying rehabilitation: biodiversity and land stewardship. Switzerland: Roto Presse SA.

FAO.(1980). Natural resources and the human environment for food and agriculture.

Environment Paper No. I. Rome. File:///A:\Population and Land degradation(Text).htm.

George M. Ndegwa, Oguta B, Calvince O. (2003).Impacts of quarrying on water quality alongNdarugu river of Thika District. Kenya: JKUAT.

Government of Kenya.(2012).ACT NO. 8 of 1999 – Environmental Management and Coordination Act. Nairobi: Government Printers.

Government of Kenya.(2010).The National Minerals and Mines Policy. Nairobi: Government Printers.

Hartmann Hl. (2002).Introductory to Mining Engineering.

Hartmann, Howard L. (1992).SME Engineering Handbook, Society for Mining, Metallurgy, and

Exploration Inc.

Hornbostel C. (1991).Construction Materials: Types, Uses and Applications (Second Edition.). New York: John Wiley and Sons Inc.

Howard Bob and Cameron Ian.(n.d.). Dust Control: Best Practice Environmental Management in Mining.

ILO.(1999).Social and labour issues in small-scale mines. Report for discussion at the Tripartite Meeting on Social and Labour Issues in Small-scale Mines Geneva. International Labour Office.

Kertes N. (2007).U.S abandoned mine count still a mystery-General Accounting Office Report. American Metal Market.

Logging of forests and debris dumping.(n.d.). Retrieved from Ngm.nationalgeographic.com

Ministry of Environment and Mineral Resources.(2010).draft national education for sustainable development policy. Nairobi: ministry of environment and mineral resources.

Ministry of Environment and Mineral Resources.(2012).National environment policy, 2012. Nairobi: ministry of environment and mineral resources.

Mjaria J. (1997).The artisanal stone quarry workers in Nairobi region: Baseline survey report. Nairobi, Kenya: Intermediate Technology and Development Group.

National Enviromnent Magamenet Authority (2009).NATIONAL ENVIRONMENT ACTION PLAN FRAMEWORK 2009-2013.airobi: National Environment Management Authority.

Noranha I. (1998).The small-scale Indian laterite stone quarry and working sector: A case study of Goa. New Delhi: Tata Energy Research Institute.

Olofin, E.A.(1989).Human response to the natural environment in the Kano region. Kano and Some of Her Neighbours. ABU Press.

Saevery S.P.A. (1997).Training and policy guidelines for artisanal quarrying: Report on field study research in the Nairobi region of Kenya (Working paper). ITDG/University of


Savery S. (1997).Report on field research in the Nairobi region of Kenya (Unpublished report).ITDG/University of Bath/ODA.

Shadmon A. (1989).Stone: An Introduction. New York: The Bootstrap Press.

Shadmon A. (1993). Dimension Stone-its impacts on environment and constructional applications-the role of engineering geology.

UNECE. (1998). Convention On Access To Information, Public Participation In Decision Making and Access to Justice in Environmental Matters. Aarhus.

UNESCO World Heritage Centre.(n.d.). Taj-Mahal – UNESCO World Heritage Centre. Retrieved from Whc.unesco.org

Wells J. (1996).Artisanal stone quarrying in Kenya: a market study.

Leave a Comment Here