The Mariner East 2 (ME2) pipeline, currently being built by Sunoco Pipeline (Energy Transfer Partners), is a massive 350-mile long pipeline that, if completed, will carry 275,000 barrels of propane, ethane, butane, and other hydrocarbons per day from the shale gas fields of Western Pennsylvania to a petrochemical export terminal located on the Delaware River.
ME2 has faced numerous challenges from concerned citizens since Sunoco first announced plans for the project in 2014. Fights over taking private property by eminent domain, eyebrow raising permit approvals with known technical deficiencies, as well as nearly a hundred drilling mud spills — inadvertent returns (IRs) — at horizontal directional drilling (HDD) sites since work began in 2017.
This article and the accompanying map brings us up-to-date on the number, location, and status of ME2’s HDD spills. We also summarize the growing list of violations and settlements related to these events. Finally, we highlight the most recent concerns related to ME2’s construction: sinkholes emerging along the pipeline’s path in karst geological formations.
Map of ME2 Updated HDDs, IRs & Karst
The map below shows an updated visual of ME2’s IRs, as of the DEP’s latest tally on March 1, 2018. Included on this map are HDDs where DEP ordered Sunoco reevaluate construction sites to prevent additional spills. Also identified on this map are locations where Sunoco was ordered to notify landowners in close proximity to certain HDDs prior to additional drilling. Finally, the below map illustrates how sinkholes are not a problem unique to one site of construction but are, in fact, common to many areas along ME2’s route. These topics are discussed in greater depth below.
Open the map full-screen to view additional layers not available in the embedded version below.
HDDs & Inadvertent Returns – Redux
In July 2017, the PA Environmental Hearing Board granted a two week halt to ME2’s HDD operations. The temporary injunction was in response to petitions from the Clean Air Council, Mountain Watershed Association, and the Delaware Riverkeeper Network following IRs at more than 60 sites that contaminated dozens of private drinking water wells, as well as nearby streams and wetlands. FracTracker first wrote about these issues in this prior article.
Despite these issues, and despite Sunoco being cited for 33 violations, ME2 was allowed to proceed under an August 7th agreement that stated Sunoco must reevaluate their HDD plans to minimize additional spills. These studies were to include re-examining the site’s geology and conducting seismic surveys. Sites for reevaluation were selected based on factors such as proximity water supplies, nearby streams and wetlands, problematic geologic conditions, and if an IR had occurred at that site previously. Of ME2’s 230 HDDs, 64 were ordered for reevaluation — 22 of these were selected due to prior IRs occurring at the site.
The DEP mandated that Sunoco’s reevaluation studies be put out for public comment. A table of which HDD studies are currently out for comment can be found here. DEP’s settlement also required Sunoco to notify landowners in proximity to certain HDDs prior to commencing construction due to elevated risks. Of the 64 HDD sites under review, Sunoco must notify 17 residents within 450ft of an HDD site, and 22 residents within 150ft of other sites. The HDD reevaluation sites are shown on the FracTracker map above. Below is an illustration of one site where Sunoco is required to notify landowners within 450ft.
One issue residents have raised with these notifications is that Sunoco is allowed to offer landowners the option to connect their homes to a water buffalo during drilling as an alternative to using their groundwater well. The catch is that, if their well does become contaminated, they would also waive their right to have Sunoco drill them a new replacement well.
In January 2018, the DEP again suspended ME2’s construction, this time indefinitely revoking their permits, due to even more IRs. DEP also cited Sunoco for “egregious and willful” permit violations —mainly executing HDDs at sites where they had no permission to do so. The DEP noted of their decision that, “a permit suspension is one of the most significant penalties DEP can levy.”
Nevertheless, Sunoco was again allowed to resume construction on February 8, 2018, after paying a $12.6 million fine. The DEP press release accompanying the decision assured the public that, “Sunoco has demonstrated that it has taken steps to ensure the company will conduct the remaining pipeline construction activities in accordance with the law and permit conditions, and will be allowed to resume.”
A few weeks later, Sunoco ran a full-page advertisement in the Harrisburg Patriot-News, shown above, lauding their safety record. Among other notables, the piece boasts, “State and federal regulators spent more than 100 inspection days during 2017 on the Mariner East project, more inspection days than on any other pipeline in Pennsylvania.” Critics have noted that the inordinate number of inspections are due to the comedy of errors associated with ME2’s construction.
Karst Formations & Sinkholes
Which brings us to the current ME2 debacle. Last week, the PA Public Utility Commission (PUC) ordered a temporary shutdown of Mariner East 1 (ME1), another natural gas liquids pipeline owned by Sunoco/ETP. ME1 was built in the 1930s and its right-of-way is being used for most of ME2’s route across the state. This latest construction setback comes in the wake of numerous sinkholes that emerged beginning in December along Lisa Drive in West Whitehead Township, a suburb of Philadelphia in Chester County.
The most recent of these sinkholes grew into a 20ft-deep, 15ft-wide chasm that exposed portions of ME1 and came within 10ft of a house. It is worth noting that, until only a few days ago, ME1 was an operational 8in pipeline with a potential impact radius (aka “blast zone”) of some 500ft. The PUC ordered that Sunoco must now run a line inspection on ME1 for a mile upstream and a mile downstream from the sinkhole sites along Lisa Drive, seen in the image below. Note the proximity of these sinkholes to Amtrak’s Keystone rail lines (connecting Pittsburgh to Philadelphia), under which ME2 also runs. The Federal Railway Administration only recently learned of the sink holes from a nearby resident.
The Lisa Drive sinkholes are being credited to Sunoco executing an HDD in an area known to have karst geological formations. Sunoco has been ordered by the PUC to conduct more geophysical testing and seismic analyses of the area because of this. Karst is often called the “Swiss cheese” of geology — notorious for caves, sinkholes, and underground rivers. As these geological formations change shape, pipelines can bend and settle over time, ultimately leading to potentially dangerous gas leakages or explosions. For instance, the 2015 Atex-1 pipeline explosion in Follansbee, WV, was ultimately determined by the Pipeline and Hazardous Materials Safety Administration (PHSA) as having been caused by ground settling. That explosion released some 24,000 barrels of ethane, burning more than five acres of surrounding land.
The US Geological Survey (USGS) maintains fairly detailed maps of rock formations for most states, including formations known to have karst. In PA, there are a number of “carbonate” rock families known for karst features and settlement issues: limestone and dolostone, and, to a lesser extent, shale. Meanwhile, the PA Department of Conservation and Natural Resources (DCNR) has maintained a record of karst “features” — sinkholes and surface depressions — documented since 1985. A great explanation of the different types of karst features can be found here.
Underestimating the Risks
What is concerning about the Lisa Drive sinkholes is that Sunoco had supposedly already conducted additional karst geological reviews of the area as part of the August DEP settlement, subsequently ranking a nearby HDD (#PA-CH-0219) as “low risk” for running into karst issues—despite knowing the HDD runs through a karst formation with sinkholes and surface depressions in the area. For the HDD that runs the length of Lisa Drive (#PA-CH-0256), the study rated its risk as “very low.” These two HDDs are shown below, along with the area of ME1 now under structural review.
The likely result of these inaccurate assessments led to two IRs at Lisa Drive, one in October and another in November 0f 2017. DEP’s writeup of these events note that the total volume of drilling muds spilled remains unknown because Sunoco didn’t report the incident. Then, only a month later, sinkholes emerged in the same locations. An image of the November HDD IR is shown below.
It is important to note two additional things of Sunoco’s karst study, an except of which is seen in their map of the West Whiteland area below. First, Lisa Drive is just on the edge of a karst limestone formation. USGS data suggest the location is actually mica schist, but the USGS data is also only a rough estimate of different formations. This underscores why pipeline companies must be required to conduct detailed geotechnical analysis of all HDD sites at the onset of their projects.
The other notable aspect of Sunoco’s study is that it does not fully represent all rock formations known to have karst features. In Sunoco’s map, we see orange shading for limestone, but this does not include dolostone that underlies the many surface depressions and sinkholes surrounding West Whiteland. FracTracker’s map includes these formations for greater accuracy.
Interestingly, as Anya Litvak of the Pittsburgh Post-Gazette observed in her reporting on the Lisa Drive incident, Sunoco’s updated karst assessment ranked the entire route of the ME2 pipeline through the state as “low to very low” risk for potential issues. Furthermore, Sunoco has tried to downplay the Lisa Drive incident, stating that “all areas have been secured,” and that additional incidents are unlikely to occur.
But the overall relationship between Mariner East 2’s IRs, HDD sites, and known karst features tells a very different story than Sunoco’s about the potential risks of ME2. In addition to the concerns about new sinkholes near Lisa Drive, FracTracker found the following in our analysis:
- 7 sinkholes and 386 surface depressions are within 1,500ft of a ME2 HDD site.
- Of the 230 HDDs, 87 are located in carbonate rock areas (52 in limestone/dolostone, 35 in shale).
- Of the 99 IRs, 39 have occurred in carbonate rock areas (23 in limestone/dolostone, 16 in shale).
In other words, nearly half of the IRs caused by ME2 HDDs were located in areas known to have karst formations. Worth noting is that an additional 15 occurred in sandstone formations, also known to cause settlement over time. The remaining IRs are split across nine other formation types.
Considering that the DEP’s current review of Sunoco’s ability to safely execute future HDDs are based on the same karst study that missed the Lisa Drive HDD and ranked nearby HDDs as a “low” risk, one can only assume that additional spills will occur. There are many more HDD sites yet to be drilled, and also not likely studied fully for potential karst risks. As illustrated by the continuing saga of spills, violations, and omissions, it is clear that Sunoco has not maintained a high standard of construction in building ME2 from the onset.
We thank Eric Friedman from the Middletown Coalition for Community Safety for supplying photos of the Lisa Drive site used in this article.