The collective footprint of these pads over the region, however, will be smaller. Vertical wells can be drilled with 40-acre spacing. Proposed Marcellus drilling regulations have the horizontal wells limited to 640-acre spacing. The NY DEC
predicts that the footprint of multiwell pad for horizontal drilling in the Marcellus will be 3.5 acres on average.They also predict that the average multi-well pad will take up 7.4 acres including access roads.An aerial survey of existing Marcellus
well pads in Pennsylvania shows an average footprint of 3.1 acres per well pad, plus 5.7 acres cleared for access roads and other associated infrastructure for each pad. This is a total of 8.8 acres per well. The average footprint of a vertical well pad is smaller, less than one acre according to the aerial survey of Pennsylvania.13 The NY DEC estimates that
one vertical well covers 4.8 acres, including access roads. With vertical wells spaced at 40 acres, there could be 400 wells in 25 square miles, with footprints covering 1,920 total acres, using NY DEC estimates. With multi-well horizontal pads,
there would be 25 in 25 square miles, with footprints covering 185 total acres using NY DEC estimates or 220 using Pennsylvania data. These estimates include access roads.