Monthly Archives: November 2015

Hold On …. Coal Ash Complicates Landfill Lifespan Projections

In December 2014, the EPA ruled that coal ash is a nonhazardous material that can be safely deposited in regional landfills along with household and construction waste.

Coal ash is messy substance created during coal-powered electricity production. According to the American Coal Ash Association, about 115 million tons of coal ash were produced in 2013, the most recent figure available.

For regional landfills, adding coal ash to their waste streams represents a lucrative opportunity — maybe.

Utilities now reuse about 40% of their coal ash in products such as cement and drywall, to name a few. They deposit the rest into landfills or ponds they maintain on-site. However, many of these catchalls are being forced to close due to concerns over harmful substances leaching from the ash into surrounding soil and groundwater. That makes regional landfills the next logical choice for disposal.

Regional landfills can profit by charging utilities a gate fee to accept their coal ash. And here’s how that becomes a real Catch-22.

Landfills’ remaining useful lives have always been projected using conventional waste streams that haven’t included coal ash. As an example, here’s the “Solid Waste Managed in Virginia During Calendar Year 2014,” which lists current lifespan projections for Virginia landfills.

Many landfills are mature sites with only enough airspace remaining to last (in Virginia, for instance) an average of 27.2 years. To suddenly add millions of tons of coal ash to the waste stream could deplete their airspace many years sooner. This could result in communities facing waste disposal crises they never saw coming as their existing regional landfill becomes tapped out.

So what’s a landfill to do?

One win-win solution is for regional landfills to accept the coal ash as beneficial reuse material, but rather than using up scarce airspace for disposal, to divert the ash into fill for macroencapsulated berms that can be constructed around the landfill’s perimeter. Macroencapsulation renders the coal ash completely inert and harmless for generations to come, creates more airspace for the landfill, and staves of the crisis of capacity. Both problems solved.