You already know that coal is dirty. But guess what, it’s even dirtier than you think. Here’s why.

• Coal doesn’t stop being hazardous once it’s burned. The mess left behind is called coal ash.
• Coal ash is filled with poisonous contaminants like arsenic, lead, and mercury. While these contaminants are often in very small concentrations, they easily leach and concentrate in run-off from disposal facilities.
• Coal ash is stored temporarily in slurry ponds before being shipped off-site for disposal, while some is stored there indefinitely. Virtually all coal ash slurry ponds are close to power plants, and large power plants are located on large bodies of water (the water is used for cooling). In Minnesota, these include Lake Superior and the Mississippi, St. Croix, and Minnesota Rivers.
• Also worrisome is the industry’s practice of reusing its waste. In 2005, almost 30 million tons of fly ash – with its full contingent of toxins – were reused in roads, roofing tiles, paints, and wood and plastic products.
• Two years ago in Tennessee, a plant’s containment dams failed and huge flows of coal ash slurry poured into nearby waters. And there’s always the danger of it happening again.

You already know that coal is dirty. But guess what, it's even dirtier than you think. Here's why.