Hoyes Run is a small meandering stream located near the town of McHenry in Garrett County, Maryland. The Maryland DNR biologists have noted a significant loss of flow along the stretch of the stream adjacent to an active, deep pit limestone quarry during the drier months of the year. This loss of water flow has caused a major impact on the general health of the Hoyes Run native trout population. The WM RC&D in conjunction with the Maryland Power Plant Research Program selected Hoyes Run for a pilot stream sealing project using coal combustion by-products grout in 2003. With the formation of new solution cavities in Hoyes Run in 2010, grouting must be repeated again.