>>I understand that shale mining may cause contamination without proper controls. I am not seeing justification for the statement that it readily pollutes.
>>
>>Drilling a water well and using a gas powered pump may cause groundwater pollution, but that does not mean that it readily does.
>>
>>What am I missing?
>
>You're reading the statements without reading between the lines. These are the same companies that claimed to be able to drill in the gulf without incident (gulf oil spill and many others), to be able to ship oil without incident (Valdez and others), and to be able to pipe oil without incident (Alaska pipeline spills and others). In everything they say they can do safely, there have been enormous spills that have permanently polluted our lands and water.
>

I find the bolded statements above to be factually incorrect.

This report lists the 39 companies involved in oil shale and tar sands mining.
http://www.unconventionalfuels.org/publications/reports/SecureFuelsReport2010.pdf

Of those, there are 3 who are currently involved in the Gulf.
Anadarko, Chevron and Shell.

Please provide proof that any of these 3 claimed that their activities would have no "incidents".

Just a head's up. Not even the governmental agency in charge of regulation would claim that. ;)
BOEMRE Proposed rule change 2008.
http://www.boemre.gov/federalregister/PDFs/74FR28639.pdf
30 CFR Part 250
The MMS believes that requiring operators to implement a Safety and Environmental Management System will reduce the risk and number of accidents, injuries, and spills during Outer Continental Shelf activities.

BOEMRE Code of Federal Regulations regarding bonding for oild drilling activities.
http://www.gomr.boemre.gov/homepg/lsesale/bonding/30cfr_regulations.html

>Shale mining is significantly harder to do without pollution than anything else they already can't do without polluting.

Even if it is "significantly harder" that does not mean impossible nor unmanageable.

I'll acknowledge that the Exxon Valdez spill is taking significantly longer to clean itself up than originally expected, but that is a far cry from "permanent". In contrast the gulf spill is cleaning itself significantly faster than expected.