The 44 ash ponds are at power plants and hold both fly ash and bottom ash from the burning of coal in those plants, as well as scrubber sludges from pollution-control equipment.

The 115 coal impoundments are at mines or coal wash plants and generally hold coal “fines” that are essentially coal dust and other material that is left over after coal is shipped from the mine, typically after having been washed.

Some of the significant differences:

The material in the ponds is not the same in terms of chemical composition.

Since they’re next to power plants, the ash ponds tend to be in areas that are flatter than the coal impoundments, which, especially in eastern Kentucky, may be in remote mountainous areas where a breach of the impoundment could send stuff pouring down a narrow valley and potentially pose more of a threat.

On the other hand, there often are more folks living in the vicinity of the ash ponds, especially at older power plants, which tend to be nearer cities. The new plants are more typically in rural areas.

The regulation is also different. The ash ponds are under the jurisdiction of the Division of Waste Management and, if they have a wastewater discharge point, the Division of Water. The coal impoundments are overseen either by Division of Mine Reclamation and Enforcement or Abandoned Mine Lands, and also the Division of Water.

The issues and problems with each are distinct and unique to each – not saying one or other is bigger cause for concern – they’re just different and should not be lumped together. Worth noting that there has not been an ash pond failure in Kentucky in recent memory – can’t say the same for coal impoundments – biggest one in recent years was the huge one in Martin County in 2000, but spills from coal impoundments occur regularly.