Dr. Charles N. Alpers is a Research Chemist with the U.S. Geological Survey’s California Water Science Center in Sacramento, California. Dr. Alpers has many publications related to the environmental legacy of historical mining including: acid mine drainage; sulfate minerals; mercury contamination and bioaccumulation; and arsenic speciation and bioavailability. His current projects include quantification of erosion and sediment sources at Malakoff Diggins State Historic Park in Nevada County, California; investigation of mercury transport, methylation, and bioaccumulation at the Cache Creek Settling Basin in Yolo County, California; and geochemistry and mineralogy related to extreme mine drainage (including negative pH) at the Iron Mountain Mine Superfund Site in Shasta County, California.