Demands on extractive industries have grown, leading to quarries becoming larger, with longer working lives. Meanwhile, public perceptions of the extractives industry have gained greater focus as communities seek to ensure that the impact of nearby operations is minimised, while enhanced environmental awareness has led to the imposition of much tighter planning controls on both new and existing quarries. A sympathetic rehabilitation plan is now an essential part of any permitting application, with quarrying companies often required to post bonds to cover the cost of post-extraction restoration.
A hostile environment
Planning ahead is one of the most critical aspects of successful landscape regeneration. Careful husbanding of materials that are likely to be needed for subsoil and soil replacement is essential, although, as some researchers have noted, soil fertility will not last forever in storage.
Another problem facing limestone quarry operators is that of rock quality. Varying physical or chemical properties can easily be found across a quarry’s reserve block, such that extraction may have to take place in several different areas simultaneously. In consequence, it is usually difficult to work one area out completely before starting its remediation and moving on to focus production on another part of the reserve. As a result, reclamation has to be held back there, unlike a sand-and-gravel or strip-mining operation, where extraction and reclamation can be planned completely sequentially.
The harsh quarry environment also presents challenges to achieving reclamation success. Plants that are introduced often have to re-establish themselves in the face of an infertile growing medium, rock faces that both allow water to run off quickly and trap heat, and the continuing generation of some level of dust.
Changing the focus
Another aspect of reclamation planning is the need for flexibility, as HeidelbergCement found out at its 43 ha. Weisenau limestone quarry, close to Mainz-Weisenau in Germany. With the quarry having been worked for over 100 years, reclamation was first targeted at the creation of agricultural land. However, in 2004, the focus changed to nature conservation and local recreation, and the company began a joint project with the Mainz city authorities over the detailed planning of future work.
In England, meanwhile, Cemex’s Barrington quarry is a major site of scientific interest in its own right, with nationally important exposures of fossils. In consequence, Cemex’s restoration plan includes leaving a section of the final face exposed, so that study access can be maintained after quarrying has been completed.
A critical component
Being able to demonstrate carefully planned restoration that will benefit nature and communities alike is already a critical factor in the permitting process for quarries. With the recently published Saint Index survey having shown that quarrying ranks at, or close to, the bottom of public approval ratings for new developments, being able to provide clear evidence of the benefits that can be achieved through sympathetic restoration can be a significant factor in winning public confidence.
For the full report from Simon Walker, please see the June 2009 issue of World Cement.
Author: Simon Walker is the Principal of I.E.T.S Ltd, providing research and editorial services to the international minerals industry.
Read the article online at: https://www.worldcement.com/europe-cis/01102009/restoration_planning_for_extractive_industries/