In 2007, Katmai National Park personnel discovered hydrocarbon contamination near the subsurface of Naknek Lake while acquiring sand to replace a septic system.  According to the National Park Service (NPS), from 1975 to 1993, the NPS made deliveries of diesel fuel to this area and filled fuel tanks by way of a fill port. The diesel contamination was likely associated with these fueling activities.  To remediate the site, the NPS mixed and applied 1,000 pounds of RegenOx, physically breaking down diesel hydrocarbon chains in the soil.  After treatment with RegenOx, concentrations of diesel-range organics were reduced by approximately 90% across the stockpile.  Read more about this case here.