November 2001

Applying the Risk Analysis Process to the Aggregate Industry

Applying the Risk Analysis Process to the Aggregate Industry

By William H. Langer

Editor’s Note: This article is the eleventh in a 12-part series focusing on how geology can lessen the “surprises” and help overcome the challenges posed by nature during the process of aggregates extraction.

When I was a kid, my buddies and I used to explore the woods around the little town where I grew up. In the clearing on the other side of the woods was our secret fishing hole—a place we were certain only we knew about. We figured the only other people that ever visited the place were Indians (I know, Native Americans, but we didn’t know any better back then) who used to fish there hundreds of years before us. We made a pact never to tell anybody else about that secret place.
Years later, I went to college in the same town where I grew up. One of my geology assignments involved the study of the production of local natural resources, and to my dismay, I learned that my ancient secret Indian fishing hole actually was an abandoned gravel pit. Something magical had taken place in that pit. Nature, left to its own devices, had miraculously healed the scars created by gravel extraction and left in their place a cool, clean pond surrounded by wetlands in the middle of a meadow—in today’s vernacular, a place “bursting with biodiversity.”
John Gunn, The Limestone Research Group, University of Huddersfield, UK.

Biodiversity, which is a shortened form of biological diversity, is the term given to the variety of life on Earth and the natural patterns it forms. Billions of years of evolution, shaped by natural processes including the influence of humans, created the biodiversity we experience today. Biodiversity is often described in terms of the variety of plants, animals and micro-organisms and the ecosystems that those organisms occupy, such as deserts, forests, wetlands, mountains, lakes, rivers, agricultural and city landscapes. In each ecosystem, living creatures, including humans, form a community, interacting with one another and with the air, water and soil around them. It is the combination of life forms and their interactions with the rest of the environment that has made Earth a uniquely habitable place for humans and all other life forms.
Ken Ursic and others from the Cliff Ecology Research Group (CERG) in Guelph, Ontario, Canada, documented what my buddies and I, as kids, casually discovered—that nature, in some situations, can successfully rehabilitate a site without any help from humans. CERG studied the Niagara Escarpment and recognized natural cliffs as special places that provide refuge for rare species of plants and animals. They also inventoried vegetation on the walls of 18 quarries abandoned from 20 to 100 years ago and discovered that many of the older quarry walls naturally revegetated in such a way as to replicate the biodiversity of natural landforms.
Nature can do even better with a little help from its human friends. John Gunn and others from the Limestone Research Group in the United Kingdom demonstrated that the natural reclamation process of abandoned quarries can be accelerated through a process called landform replication. Through carefully designed blasting, referred to as restoration blasting talus slopes, buttresses, and headwalls can be created that can be revegetated to produce landform and plant assemblages similar to those that occur on natural valley sides.
We live in an environment that has been shaped by the activities of people. Those activities have changed almost every part of the Earth. Because of the close ties between aggregate and activities of people, the industry has operations almost everywhere there are people. Consequently, the large amount and tremendous variety of land that is managed by the aggregate industry gives the industry the opportunity to play a very important role in conserving and restoring biodiversity. The industry can conserve biodiversity by employing operational practices that minimize adverse effects on the environment and maximize the positive ones, and can restore biodiversity with ecologically designed reclamation projects.
Increasing numbers of aggregate producers throughout the developed world have “biodiversity programs” of one sort or another. One major aggregate producer has formed a partnership with the World Wildlife Fund to develop a strategy for the ecological restoration of quarries. Some aggregate producers have policy statements that include strong emphasis on protecting the environment, including addressing issues related to biodiversity. Many major aggregate producers made significant efforts to reclaim operations in a manner that increases biodiversity, and some of those producers have web pages that describe their efforts. Almost all major aggregate producers can point to some successful restoration projects that address biodiversity.
At the 1992 Earth Summit in Rio de Janeiro, world leaders agreed on a comprehensive strategy for “sustainable development”—meeting our needs while ensuring that we leave a healthy and viable world for future generations. One of the key agreements adopted at Rio was the Convention on Biological Diversity. This pact between the vast majority of the world’s governments sets out commitments for maintaining the world’s ecological systems while achieving economic development. Three main goals were established by the Convention: 1) the conservation of biological diversity, 2) the sustainable use of the Earth’s components, and 3) the fair and equitable sharing of the benefits from the use of natural resources. If someone asks the question, “What is the aggregate industry doing to address these goals?” the truly enlightened aggregate producers can proudly answer that their operations are “bursting with biodiversity.” 

William H. Langer is a geologist with the Mineral Resources Team of the U.S. Geological Survey.