Last year, Pennsylvania and West Virginia contributed nearly half of the more than a billion gallons of frack waste that were injected into underground wells in Ohio.

Both suits requested that the Navy provide funding for medical monitoring of the families’ health condition as a result of the toxic exposure. They also sought a large-scale health study to determine whether PFAS contamination caused unusual levels of illness in the community — and to what extent.

The pipeline will carry volatile propane, ethane and butane, which has raised fears of many who live near it — even though explosions are rare. As part of StateImpact Pennsylvania’s “Mariner East 2: At what risk?” series, we put together this video to explain what those substances are and how they act both inside the pipeline and if they got out, and how you should respond if there’s a leak.