Here's a great visual on the water disparity between Palestinians and Israelis: http://visualizingpalestine.org/system/visual/en/VP-WB-Water...
And another on the discriminatory water supply: http://www.btselem.org/water/discrimination_in_water_supply
Second, when looking up information about this, it seems that about 150 million m^3/year of of in total is pumped from the aquifer, while it seems that overall, Israel gets (...very vaguely) about 2 billion m^3/year from other sources (desalinization plants, for example, were aiming to supply 500 million m^3/year by 2015, no idea what the current status is). In short, it seems the West Bank is going to need to import water from somewhere to match Israel's consumption. (Also, information on this seems /very/ sparse and disjoint. I'd appreciate finding a good, well cited source...)
Also, note that there are multiple aquifers that seem to be referred to as 'mountain aquifers': There's the larger, Western mountain aquifer, which extends from a few miles from the coast, through Israeli territory, well into the West Bank. In terms of area, it's hard to say since different maps seem to draw it at different sizes, but at a guess it seems that it's split 50/50 between the West Bank/Israel, and according to one map, the Israeli side is cheaper/easier to extract. And there's the much smaller Eastern Mountain Aquifer, which is mostly contained within the West Bank, although it seems to have some corners peeking out in the north and south near the Jordan river.
While Israel does control nearly 100% of the access to that aquifer and uses it as a political bargaining chip for various agreements and negotiations with the Palestinians it doesn't seem to employ a policy that prevents individuals from access to water.
P.S. I also find it odd that they've decided to use the WHO recommended numbers instead of quoting the ones from the UN water report which although isn't a fluff peace for Israel does states that a large disparity between the water usage on both sides is oddly due lower usage of showers and lavatories especially in the more nomadic parts of the west bank than is due to lack of access to water. Based on the UN water report the average water usage per person in the Ramallah is 141 liters, so in a city where they got multiple showers and toilets per apartment and houses with pools the water usage seems to be very simmilar to Tel Aviv...
Because if so. Well they don't have to actually share it do they?
Just saying it, I have no sides... No flamewars, ok?
I don't want a flamewar either :) just trying to trying to be the grain of salt.
"In modern times, the territory is generally and almost universally known as part of the West Bank."
Israel (or rather individual Israelis), on the other hand, seems to have a significant focus on improving quality of life for themselves.