richc - I'm neither for nor against shale gas extraction. The industry needs to submit it's proposed methods to the regulatory authorities and they need to do the actual regulation.
My point is, this is one industry of many that could cause contamination of your water supplies. They will need to be regualted in the same way as any other potentially polluting industry...*(see below)
Regarding groundwater water supplies - there are two very distinct types, although both have strong legal protection.
Your "33%" are largely strategic supplies used by the water companies to feed the mains. These have very high and proactive levels of protection. Each source has a moelled "Source Protection Zone" or SPZ. This models the catchement area and water travel time to each pumped supply borehole. Any Planning Application for these areas activities that are subjected to very close scrutiny, with many activities being prohibited or severley restricted if they are clsoee to a supply borehole.
The same legislation applies to private supply wells, which typically supply a household or small number or houses . The legal protections are the same, but the lower strategic importance inevitably results in a less proactive protection of these supplies. Any application would stilll have to outline how these would be protected - or provided with an alternative main supply.
BTW - All this legal protection is down to good old EU bureaucracy... 
i think the Tories call it "Red Tape"
Ohh, and as for:
Really? you do understand what limited liability means don't you?
Doesn't make any difference to the regultor's ability to take action, just the way that they proceed...
* - many other industries that might be affecting your groundwater, and which are not obvious candidates for pollution in the public's eye...
- the water companies themselves, perhaps??? where do you think leaky sewers go???
farming - large areas of the country have groundwater adversely affected by nitrates, phosphartes and agricultural chemicals
