B:
Biological Indicators of Watershed Health: Benthic Macroinvertebrates: Aquatic Worms - This web site includes information on aquatic oligochaetes which are generally found in soft mud bottoms, and in high numbers are considered indicators of very poor water quality. [Environmental Protection Agency (EPA)]

D:
Drilling Waste Management Information System - Provides technical and regulatory information on practices for managing drilling muds, cuttings and wastes [Department of Energy (DOE), Argonne National Laboratory (ANL), National Energy Technology Laboratory (NETL)]