Oil shale, which is an organic-rich fine-grained sedimentary rock, contains significant amounts of kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be extracted. Kerogen requires more processing to use than crude oil, which increases its cost as a crude-oil substitute both financially and in terms of its potential environmental impact. US Secretary of the Interior Ken Salazar and Bureau of Land Management Director Bob Abbey announced today that they will take a fresh look at commercial oil shale rules and plans issued under the previous Administration and, if necessary, update them based on the latest research and technologies, to account for expected water demands in the arid West and to ensure they provide a fair return to taxpayer.