Henry's Knob is a mountain and Superfund Alternative Site in York County South Carolina at 1,120 ft (340 m) above sea level.

At the time of its discovery, the deposit of kyanite on the mountain was the world's largest[2] United States Environmental Protection Agency (EPA) testing has determined that approximately 450 residences in the vicinity relying on well water are affected by groundwater contamination from the former mine.

While some efforts have been made to repopulate the site with vegetation, little cleanup of the dangerous minerals (including Manganese) has been done.

The agency asked ABB to conduct an investigation of the Henry's Knob site and surrounding area to identify pollution, including the nature and extent of acid mine drainage that has entered the environment as a result of previous mining activities.

The investigation work plan is on file at the Clover Public Library, along with other documents pertaining to the site.