Coal has powered communities and industries in the U.S. for generations. However, with that legacy comes a challenge: how to responsibly manage the byproducts that are left behind. One of the most significant byproducts is coal combustion residuals (CCR), commonly referred to as coal ash.
Coal ash contains fine particles that are often stored in large basins or ponds near power plants. Over time, these sites can accumulate not only dry ash but also significant amounts of pore water. The water trapped within the ash itself, as well as stormwater and groundwater seepage. Managing that water is where coal ash dewatering comes into play.
What is Coal Ash Dewatering?
Coal ash dewatering is the process of removing water from coal ash basins, ponds, or impoundments. By lowering the water content in the ash, utilities and engineers make these sites safer, more stable, and easier to close in accordance with environmental regulations.
At its core, dewatering reduces the risks associated with ash impoundments, including:
- Structural instability – Water-saturated ash is heavy and can compromise berms or dam structures.
- Groundwater contamination – Excess water can carry trace elements from ash into groundwater systems.
- Long-term liability – Leaving ash wet creates long-term environmental and compliance risks.
Why does it matter?
Coal ash dewatering isn’t just a technical task; it has broad implications for safety, environmental health, and regulatory compliance.
Protecting People and Communities
Lowering water levels reduces the risk of impoundment failures, which can lead to catastrophic spills. Dewatering helps ensure these sites remain stable and secure.
Safeguarding Groundwater
By removing and controlling water within and beneath ash basins, dewatering prevents contaminants from leaching into groundwater sources that supply drinking water to nearby communities.
Meeting Regulatory Requirements
Federal and state regulations require utilities to manage coal ash responsibly. Dewatering is often a critical step in closing coal ash ponds in compliance with EPA’s CCR Rule and related state programs.
Paving the Way for Safer Closures
Dewatering enables the effective capping, remediation, or repurposing of coal ash sites. In short, it serves as the foundation for long-term solutions.
Coal ash dewatering may sound like an engineering detail, but it’s a critical step in protecting communities, preserving water resources, and ensuring compliance as utilities close legacy coal ash sites.