Watch Part One: "Toxic Waste Spill in North Carolina"

Coal ash, which contains many of the world's worst carcinogens, is what's left over when coal is burnt for electricity. An estimated 113 million tons of coal ash are produced annually in the US, and stored in almost every state — some of it literally in people's backyards. With very little government oversight and few safeguards in place, toxic chemicals have been known to leak from these storage sites and into nearby communities, contaminating drinking water and making residents sick.

In the final part of our series, VICE News travels to Pennsylvania, home to the largest coal ash pond in the country, which continues to leak dangerous pollutants out into the community.

Watch "Showdown in Coal Country"

Watch "Petcoke: Toxic Waste in the Windy City"

Read "Green Groups Say Another Coal Ash Spill Remains Likely, One Year After North Carolina Accident"