The following paragraphs are from a paper on the subject and illustrate why oil shale is so problematic.
...The most direct obvious
environmental impact of an oil shale industry would be the immediate displacement of
ecosystems in land under development. Surface retorting, which requires underground or
surface mining would strongly alter the local ecology and current land uses. Strip mining
would require some of the largest open-pit mines in the world. Around 1.5 tons of spent
oil shale is produced for every one barrel of retorted oil (Albulescu and Mazzella, 1987),
so a surface retorting operation of a million barrels per day would require more than half
a billion tons of raw shale to be mined and disposed of each year. Furthermore, the
retorting process increases the volume of the shale by 15-25 percent so that the pit or
mine from which the shale was removed cannot store all of the waste product (US DOE,
2004). Both surface and underground mining would require piling this material above
ground, thereby creating an unnaturally elevated landscape and likely causing decadelong
displacement of preexisting flora and fauna (RAND).
This new landscape would not only be reshaped but would also become
toxic and would alter both runoff patterns and groundwater quality. Spent shale has a
higher salt content than raw shale and contains small concentrations of arsenic and
selenium which can be mobilized by water that infiltrates tailings piles (Harney, 1983).
Shellâs in-situ method is often touted as a clean alternative because it does not require
surface mining or waste piles, but this approach can still cause groundwater
contamination. The âfreeze-barrierâ would only protect groundwater during production;
once the kerogen has been removed the hydraulic conductivity of the remaining shale
increases allowing groundwater to flow through and leach salts from the newly toxic
aquifer (RAND). Because the Green River formation lies within the greater Colorado
River drainage basin, any surface or groundwater contamination will not only affect the
local population but will likely have a significant impact on water quality for the millions
of downstream users.
In addition to likely groundwater contamination, large-scale development
would also require tremendous quantities of water to be used in production operations.
Water is required at various stages of the mining, retorting, and refining processes. The
U.S. Water resources council estimated consumptive water use of around three barrels of
water per barrel of shale oil production (Water Resources Council, 1981). Water
resources from the Colorado River Basin are already very tightly regulated and are in high
demand from a growing population in the arid Southwest. A recent agreement with
California water districts will return roughly 8 million acre-ft/year to the Upper Basin
(Bunger and Crawford, 2004). A one million bpd oil shale industry would consume the
entirety of these reallocated water rights (Sura, 2005) â water that could alternately be
used to support a combination of municipal supply, irrigation, ecosystem restoration, and
recreation â and would likely diminish the quality of previously available water supplies.
http://srb.stanford.edu/nur/GP200A Papers/elliot_grunewald_paper.pdf
