plies or groundwater at levels dangerous to human health, and residue transport and handling can also produce airborne particulate matter that poses an inhalation risk beyond the mine area (NRC, 2006b).
In areas that have active or historical oil and/or gas development, there are a variety of environmental impacts that directly or indirectly impact human health. These include waste materials and pollutants generated during drilling and production as well as leakage and inadvertent spills during later parts of the petroleum life cycle.
Drilling and production result in the discharge of produced waters,2 drill cuttings, and drilling muds that have the potential for chronic effects on benthic communities, mammals, birds, and humans. Although the petroleum industry is now highly regulated and most of the waste products are recycled on site or disposed of in licensed injection wells, historically this material was abandoned on site in unlined pits or “tanks” (see Figure 6.1) that now require remediation to prevent further groundwater con-