cap and cover system
nounPronunciation: /kæp ənd ˈkʌvər ˈsɪstəm/
A multi-layered engineered barrier installed over contaminated mine waste to prevent infiltration and control gas emissions. Typically includes clay, synthetic materials, and soil layers.
Full Definition
A cap and cover system is a multi-component engineered barrier designed to isolate contaminated mine waste from the environment while providing a stable foundation for final land use. The system typically consists of several layers including a foundation layer over the waste, a low-permeability barrier layer (often clay or geosynthetic materials), a drainage layer to manage infiltrating water, a protection layer to prevent damage to underlying components, and a final cover soil layer to support vegetation. The design must account for settlement, freeze-thaw cycles, root penetration, and long-term material degradation. These systems are commonly used over tailings impoundments, waste rock piles, and other contaminated mine materials where complete removal is not feasible.
Plain English
A thick, layered cover like a blanket that's put over dirty mining waste to keep rain out and prevent harmful gases from escaping, then topped with soil for plants to grow.
In Editorial Context
A complex remediation technology that requires careful explanation of engineering components and long-term performance expectations in reclamation success stories.
Etymology & History
Developed with increased environmental regulation requiring long-term containment of mining wastes rather than simple abandonment.
Evolved from simple soil covers to sophisticated engineered systems as understanding of barrier performance improved.
Usage
"The tailings impoundment closure plan specified a cap and cover system with redundant barrier layers to ensure long-term environmental protection."
Usage note: May be referred to simply as 'cap' in context, but full term is preferred for clarity.
Context: remediation design, environmental compliance, closure planning
Region: international
Also known as
Contrasted with
Don't confuse with
Similar technology used in different waste management contexts with varying design requirements