Over the past few weeks, Sunoco’s work near the Lincoln Highway (Business Route 30) in Exton has caused sinkhole after sinkhole. The company has responded by sending in one cement truck after another to fill them, and that is still going on as I write this. The sinkhole count is up to 7 (or 8, depending on exactly how you count).

At the same time, the Mariner East 1 and so-called Mariner East 2 (the cobbled-together “Frankenpipe”) continue to operate in close proximity to the sinkholes. In addition, there is an Enterprise pipeline nearby, also carrying highly-volatile natural-gas liquids.

It’s a very dangerous situation. Any one of these sinkholes could expand further, removing the ground supporting one or more of the pipelines. Or the shifting ground could cause a pipeline to bend. If the stress on the pipe is great enough, it will rupture, spewing its contents into the air. In the event of a rupture, we know from the risk assessments that have been done on this pipeline that a huge flammable cloud would form within minutes. There would be no opportunity for warnings or evacuations. Once the cloud reached a source of ignition (a car, a doorbell, an air conditioner) it would all burn instantly, with hundreds of casualties. Depending on the wind direction, the Chester County Library, the Exton Mall, or hundreds of other commercial buildings and residences could be enveloped in that flammable cloud.

The diagram below shows the general location of the sinkholes. They line the pipeline right-of-way from Lincoln Highway, at the point where it is crossed by the Chester Valley Trail, to Valley Creek. (One sinkhole is actually in the creek itself.)

sinkhole location exton 7-14-20
Within the past few weeks, Sunoco’s pipeline work has triggered at least seven sinkholes in the area shown in red. The sinkholes are very close to active pipelines carrying highly-volatile, explosive materials.

Details about the location of the sinkholes and the dates when they appeared are given in the diagram below.

This aerial view shows the locations and dates of multiple sinkholes between Lincoln Highway and Valley Creek. The ones numbered 4 and 5 are within a few feet of an active valve station.

Note the presence of the valve station, which makes the situation even worse. If it were to be damaged, it might be impossible to close the valves. The contents of many miles of pipelines in both directions would have to burn off. It would be many hours before anything could be done.

This is the kind of dangerous situation that caused the Public Utility Commission to shut down Mariner East 1 at nearby Lisa Drive in March of 2018. But this time the sinkholes are more numerous and extensive, and this time there are three active pipelines (not just one) in the vicinity.

Although the PUC is aware of the situation, it has not acted. It needs to shut these pipelines down until the safety and stability of the underlying geology can be assessed.

Please contact the PUC, the Chester County commissioners, and your state representatives and stress the urgency of this situation. They need to act immediately.

Chester County Commissioners:

  • Josh Maxwell, joshmaxwell@chesco.org
  • Marian Moskowitz, mmoskowitz@chesco.org
  • Michelle Kichline, mkichline@chesco.org

At the PUC:

Your representatives in Harrisburg: https://www.legis.state.pa.us/cfdocs/legis/home/findyourlegislator/