Natural Resources committee  The approach that's being used—it's been tested in Quebec and also in New Brunswick—tends to be liquefied petroleum gas, basically a propane frac. That method offers a number of advantages in terms of management of the flow-back of the fluid, the fluid in this case being propane.

Natural Resources committee  Yes. It's sand.

Natural Resources committee  Yes, that's correct. We use a process called perforating. A tool is put in the well, and at specific intervals that tool fires small charges that perforate the steel casing and the cement, and it basically gives the fluids, and therefore the proppant, an avenue into the shale formation.

Natural Resources committee  That's correct.

Natural Resources committee  It flows. Essentially it seeks a lower pressure environment than the shale, and that lower pressure environment is the surface. The fracturing process creates a pathway from the shale into the well, and the well creates the pathway from the shale to surface. It basically flows because there's a pressure difference between the surface and the reservoir in the shale.

Natural Resources committee  No. It's just...let's call it normal water, which in the summertime would be a little warmer than in the fall. In some parts of Canada where fracturing operations are done in the wintertime, which is generally not the preference, the water supply needs to be heated.

Natural Resources committee  No, I don't think so. Jim may have a better answer, but I don't think so. I don't think the temperature of the water makes any difference. It's just so that it doesn't freeze into a block in a tank or a bit someplace.

Natural Resources committee  It will not. It will stay in the shale. That portion that isn't returned to surface stays in the shale.

Natural Resources committee  No, the nature of gas storage in shale is nothing like that. The fractures that are created are the thickness of a sheet of paper.

Natural Resources committee  The amount of water used varies a great deal from one place to another. Some shale gas developments use no water. Others—and Horn River is an example that people are probably familiar with—use a great deal of water. It's a function of the mineralogy, the geology, the depth, the length of the well, and the number of fracture stages that are being completed in each well.

Natural Resources committee  —in North America over the last 50 years, and this has not been a widespread issue. I don't know the regulatory regime in Pennsylvania, but I can assure you that if you look at western Canada, at Alberta and British Columbia in particular, that's not a commonplace concern.

Natural Resources committee  That is a concern, but I think two things. In Pennsylvania, the issue has been gas migration. This is gas that has migrated from shallow sources in the cement or between the cement and the casing or between the cement and the rock up into aquifers. It has nothing to do with hydraulic fracturing and fracture fluids.

Natural Resources committee  That's correct, but realize also that we've drilled thousands, millions in fact, of wells—

Natural Resources committee  It depends on the methane concentrations in the aquifer. In fact, there's readily available technology that allows the methane to be separated from the water. It's used in western Canada and probably even in Ontario and Quebec and the Maritimes. Basically, it's a separator that separates the gas from the water.

Natural Resources committee  No.