 With 70% of in-place reserves typically remaining in the ground at the time of oil field abandonment, this research has enduring economic and societal importance.The Bureau's environmental research group conducts a wide range of basic and applied research in groundwater resources, vadose zone hydrology, coastal studies, near-surface geophysics, and geologic mapping.The group also has programs that relate energy and the environment, including a major initiative in geological sequestration of greenhouse gases.