When the drilling is finished, water, combined with chemicals designed to reduce friction and serve other purposes, is injected from the surface into the well shaft at very high pressures, thereby fracturing the shale rock formations far below, and making it possible to extract economically the natural gas embedded in the shale.

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But Martens said issuing of permits for shale gas drilling could begin even while regulations are being finished, if the Health Department's review finds the Environmental Conservation Department's impact study adequately addresses health concerns.

WSJ: NY health chief: Longer gas-drilling study needed