Environmental impact of the oil shale industry

In addition, the combustion and thermal processing generate waste material, which must be disposed of, and harmful atmospheric emissions, including carbon dioxide, a major greenhouse gas.

Experimental in-situ conversion processes and carbon capture and storage technologies may reduce some of these concerns in future, but may raise others, such as the pollution of groundwater.

[3] Disposal of mining wastes, spent oil shale (including semi-coke) and combustion ashes needs additional land use.

[5] The waste material may consist of several pollutants including sulfates, heavy metals, and polycylic aromatic hydrocarbons (PAHs), some of which are toxic and carcinogenic.

[6][7] To avoid contamination of the groundwater, the solid waste from the thermal treatment process is disposed in an open dump (landfill or "heaps"), not underground where it could potentially reach clean ground water.

As semi-coke consists of, in addition to minerals, up to 10% organics that may pose hazard to the environment owing to leaching of toxic compounds as well as to the possibility of self-ignition.

Water concerns are a particularly sensitive issue in arid regions, such as the western part of the United States and Israel's Negev Desert, where there are plans to expand the oil shale industry.

These factory plants provide the atmospheric emissions of gaseous products like nitrogen oxides, sulfur dioxide and hydrogen chloride, and the airborne particulate matter (fly ash).

[16][17] The concentration of air pollutants in flue gas depends primarily on the combustion technology and burning regime, while the emissions of solid particles are determined by the efficiency of fly ash-capturing devices.