Conventional and unconventional wells in PA

Over 1.2 Million Pennsylvanians Within 1/2 Mile of a Well

Aging well in McKean County, PA. Source:

One of the potentially troubling aspects of oil and gas development is that there are usually people who live in the vicinity of the wells. Pennsylvania now has over 8,000 active unconventional wells; there are any number of issues that can occur with these modern, industrial-scale sites, including road degradation, contaminated water, and health impacts, among others. In addition, there are over 93,000 of the smaller, conventional wells in operation throughout the Commonwealth. While these garner far less attention than their unconventional counterparts, they are also prone to producing similar impacts, not to mention that since many of them are older wells, they not only have potentially been subject to deterioration and occasional neglect, but were constructed during a period with less stringent requirements than are currently expected.

Petroleum engineers are now capable of drilling horizontally for tens of thousands of feet. For the most part, however, this technology is employed to maximize production, rather than to ameliorate impacts on people who live near the product. But who are these people? To help to answer this question, the FracTracker Alliance calculated the number of people living in a half-mile radius around active wells in the state.

More than 1.2 million Pennsylvanians live within the impact area.

Of the 93,754 wells that have been drilled in the state since 1950 that have not yet been plugged, the Pennsylvania DEP only has location data for 79,118 of them. All but one of the 14,636 missing locations are for wells that are categorized as Conventional. While one must presume that there is some overlap in coverage within the half-mile zone, the extent of this region – and therefore the population that lives within it – cannot be determined.

Fig. 1. PA Populations Near Oil and Gas Wells. Click here to access written description and additional map tools.

To maximize the reliability of our calculations, this map was created using a custom Albers equal-area projection centered on Pennsylvania. A half-mile buffer around each well type was created, and the resulting layer was clipped to Census tract data. The ratio of the smaller clipped area to the full Census tract area was calculated, and that ratio was then multiplied by the population totals from the 2010 Census to obtain our population estimates of the half-mile zone. The area in the study area is larger than six states, while the calculated population is larger than that of eight states.

Of the 79,118 active oil and gas wells in PA for which location data are available, we determined the area and estimated the population within a half mile radius. Note that some regions are with a half-mile of both conventional and unconventional wells.

Fig. 2. Number of people in PA near oil and gas wells (79,118 active wells for which location data are available). Note that some regions are with a half-mile of both conventional and unconventional wells.

The county most impacted, in terms of area, for unconventional wells is Bradford, with 353 square miles (See Figure 2). Washington County had the most people living in the zone, however, with 20,566. For conventional wells, the drilling landscape is the largest in Indiana County, affecting 761 square miles, while Erie County has the most people in the half-mile zone, with 212,900. When considering all wells together, the numbers are almost identical to conventional wells. Indiana County leads with 762 square miles, while the drill zone in Erie County represents 211,903 people, or 76% of the county’s population in 2010.

3 replies
  1. Matt Kelso
    Matt Kelso says:

    Upon request, we have also calculated the PA population within a one kilometer radius of wells. Our estimates show that 202,603 Pennsylvanians live within 1 km of an unconventional well, 1,343,436 within 1 km of a conventional well, and 1,463,619 are within a km of any active well (drilled but not plugged). You can see totals by county on this map.

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  1. […] instance, there are about 1.2 million Pennsylvanians living within a half mile of one of the state’s nearly 80,000 oil and gas wells, but there is no […]

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