Quarry Reclamation

[MikePhua]

Definitions and Key Terms

• Quarry: an open‐pit excavation from which stone, sand, gravel, or other geological materials are extracted.
  
• Reclamation: the process of restoring land disturbed by quarry operations to a stable, usable state, often for ecological, recreational, agricultural, forestry, or industrial/residential uses.
  
• Overburden: the soil, rock, or other material removed to expose the mineral or rock being quarried.
  
• Backfill: placing overburden or waste material back into the excavated areas, often to regrade slopes.
  
• Bench: a step or ledge cut into the quarry wall, which may be utilized for safety or reclamation planting.
  
• Spontaneous succession: natural revegetation without human planting, relying on seed sources, wind, wildlife.
  

Purposes of Reclamation
Quarry reclamation is undertaken for multiple reasons:

• Restoring slopes for stability and erosion control.
  
• Re‐establishing vegetation to prevent runoff, support wildlife habitat, reduce dust.
  
• Returning land to productive uses: agriculture, forestry, recreation, residential development.
  
• Improving aesthetics and protecting water quality.
  
• Meeting environmental regulation and community expectations.
  

Regulatory Foundations

• In many jurisdictions, reclamation must be planned before mining begins. Permits often include reclamation plans with specifications about final slopes, drainage, soil replacement, vegetation, and post‐use of land.
  
• Laws define terms: disturbed areas (all land affected), approximate original contour (where required), bonding or financial guarantees to ensure reclamation even if operator abandons site.
  

Techniques of Reclamation
Several methods are used, often in combination:

• Backfilling and regrading: returning overburden or waste into pits, re‐slope benches to safe angles.
  
• Bench planting / terracing: creating benches on slopes to break up steep faces, planting vegetation on benches to stabilize and beautify.
  
• Restoration blasting: modifying rock faces by blasting to create more gradual slope or rough surfaces to help soil and vegetation establishment.
  
• Erosion control measures: using erosion control blankets, mulches, silt fences, and mats to protect soil while vegetation becomes established.
  
• Soil amendment: adding topsoil or conditioning existing soil with organic matter, nutrients, adjusting pH etc.
  
• Selection of plant species: native species usually preferred; using pioneer species first then species for long‐term structure (trees, shrubs).
  

Evaluation and Monitoring

• Success is measured by parameters such as slope stability, drainage effectiveness, soil quality, vegetation cover, biodiversity, and social acceptance.
  
• A recent methodological framework proposes evaluating quarry reclamation via weighted indices covering: geotechnical risk (e.g. slope failure, landslide), drainage network, erosion and relief degradation, soil physical/chemical health.
  
• Stakeholder perception (surrounding community, regulators) is also part of success.
  

Case Studies and Examples

• Pikeview Quarry, Colorado Springs: After the quarry ceased operations, local aggregate company and contractors worked to revegetate about 125+ acres. Problems included depleted soil, steep slopes. They used mixtures of erosion control materials (blankets, mats), seed mixes, soil amendments, fertilizers. Reclamation needed to begin in less favorable seasons.
  
• Holcim’s 800 Limestone Quarries Globally: The Swiss cement maker committed to nature‐positive operations. Their efforts focus on biodiversity conservation and freshwater protection, restoring quarries to support ecosystems.
  
• England Techniques Review: In England, quarry reclamation methods include backfilling, rollover slopes (creating a smoother terrain), bench planting, restoration blasting, and also letting sites recover naturally where appropriate.
  

Challenges and Missing Elements

• Soil depletion is a frequent problem. Soil layers are often removed or eroded during extraction, making re‐vegetation difficult without amendments.
  
• Seasonal constraints: in cold, dry or otherwise unsuitable weather, vegetation establishment is harder.
  
• Cost: reclamation increases capital and operating costs; financial assurance (bonds) must cover them.
  
• Long‐term monitoring: even after reclamation, maintenance of vegetation, erosion control structures, drainage may be needed for many years.
  
• Community engagement: local stakeholders often wish to use reclaimed land for recreation or agriculture; their input can be overlooked until late in the process.
  

Recommendations for Effective Reclamation

• Begin reclamation planning before operations begin, or use progressive reclamation (reclaim portions as work moves on).
  
• Collect and preserve topsoil early; stockpile and reuse.
  
• Use graded slopes with benches for stability and vegetation anchoring.
  
• Use native plant species adapted to local climate and soils; include pioneer and long‐term species.
  
• Use soil amendments, organic matter, fertilizers where needed.
  
• Design drainage and erosion control systems early.
  
• Use remote sensing and GIS tools to monitor progress (vegetation cover, stability etc.).
  
• Involve local communities and stakeholders in planning and monitoring.
  

Metrics and Data

• In the aggregate industry in the USA, over 2.6 billion tons of sand, gravel, and crushed rock are produced annually; reclamation in that industry is widespread.
  
• For evaluation frameworks, reclamation quality indices may assign weights: geotechnical risk (~25 %), soil quality (~25 %), drainage (~20 %), erosion (~15 %), social/ecological parameters (~15 %). (Weights vary by region.)
  
• Vegetation cover percentages are often used: e.g. achieving 70-80 % of pre-disturbance vegetation cover within 3-5 years is considered a good target in many temperate areas.
  

Story Illustrations
A small town in Appalachia once saw a disused quarry overlook their valley; exposed rock, dust storms, and water runoff made life unpleasant. Local high school students organized water testing once rain started, finding sediments in the creek. Then the quarry operator, local government, and students collaborated: students helped map the slopes; the operator applied a reclamation plan with terraces and planted native grasses first, then trees. Over five years, erosion reduced dramatically, vegetation cover rose to ~80 %, wildlife returned, and a portion of the site became a community trail and picnic area.
In Ethiopia, a recent study looked at operational efficiency and environmental sustainability in quarry operations, showing that improved reclamation methods can reduce operational costs over time, while improving water retention and reducing downstream sediment loads.
Conclusion
Quarry reclamation is essential for restoring ecological function, protecting water, controlling erosion, and providing beneficial land uses after extraction operations cease. Success depends on good planning, suitable techniques, community involvement, and thoughtful monitoring. When done well, even large scars in the landscape can be converted into assets for environment, society, and economy.