The lessons of Mariner East 2

Pa. regulators were braced for water woes and complaints. But they didn't expect all those spills.


The Mariner East 2 pipeline, which spans 303 miles, is the largest project that Pennsylvania environmental regulators have ever dealt with. They know they will be judged by how they handle this project.
(Andrew Rush/Post-Gazette)

The Mariner East 2 pipeline project has had hundreds of spills of drilling mud since construction began last year. It has fouled drinking water, created sinkholes in backyards and left other neighbors unscathed. Sunoco Pipeline L.P. has been accused of setting the standard for “what not to do when constructing a pipeline properly.” But some pipeline experts have a different message: This is normal.

Anya Litvak 
Laura Legere 

Since February 2017, a feat of audacious engineering has been unfolding across southern Pennsylvania. The Mariner East 2 pipeline, spanning 303 miles, crossing 570 wetlands and more than 1,200 streams — the largest project that state environmental regulators have ever dealt with — has put the Department of Environmental Protection in the crosshairs of what, from the sidelines, can feel like a moral judgment.

Among the 29,000 public comments that DEP reviewed were calls by citizens to reject the permits outright — because the pipeline would contribute to climate change; because they thought it unfair that a private company can claim land by eminent domain; because Energy Transfer Partners, which merged with Sunoco last year, is the same outfit that battled protesters at the Standing Rock Reservation in North Dakota and had a record of violations in Pennsylvania.

Others — union members, landowners, small businesses — wrote imploringly of jobs and innovation and energy independence. All development has risks that must be weighed against the benefits, they argued.

How regulators and Sunoco assessed that risk was a moving target throughout the permitting and construction process, which, because of delays, is not expected to be done until 2020.

When the DEP issued the necessary permits for Sunoco to begin construction in February 2017, the agency put out fact sheets for the public carefully explaining what it could and could not do:

The DEP could... The DEP could not...
make sure that public waterways weren't damaged by the pipeline. regulate private drinking water wells.
require Sunoco to protect soil from sliding down hills as a result of construction activities. direct the company not to build on hills.
ask Sunoco to estimate the risk of spills in certain drilling jobs. independently assess whether those estimates were valid.

Granting a permit is rarely a yes-or-no decision, they explained. It is a process of working with companies to get their applications into a shape good enough to say yes.

Mariner East 2 was a “high priority” project for the DEP and Gov. Tom Wolf’s administration. The pipeline is meant to connect Pennsylvania’s gas riches to the world. At full buildout, its twin pipes and associated storage facilities will be able to ship 700,000 barrels of natural gas liquids each day through 90,000 tons of epoxy-coated steel under cornfields and coal mines and suburban backyards to customers mostly across the sea in Europe.

The $5 billion project is not the first to cross the state or even the first to follow a similar route: The largely adjacent pipeline now known as Mariner East 1 was built in the 1930s to move oil in the opposite direction. Its reversal and expansion in 2014 foreshadowed some of the challenges that came into focus with Mariner East 2.

As future projects follow in this one’s choppy wake, pipeline companies and Pennsylvania regulators will inevitably be measured by the lessons they learned — or missed — this time.

How is this pipeline different from all other pipelines?

A right-of-way where workers are installing a section of Mariner East 2 pipeline project, Friday, Sept. 28, 2018, Union.
(Andrew Rush/Post-Gazette)

Most of the Mariner East 2 pipeline is laid in a trench a few feet deep. But this pipeline is different in that Sunoco also proposed more than 100 sites where it would bore a tunnel underground and string the pipeline through it. Those tunnels could be dozens of feet below the surface. Many are thousands of feet long.

The method — called horizontal directional drilling, or HDD — is meant to avoid disturbing sensitive or populated areas and to bore under roads and railroad tracks. Ideally, it should allow pipelines to be inserted far below a lake or neighborhood without the bother of excavation.

“Think of it as an angioplasty” as opposed to open-heart surgery, said Samuel Ariaratnam, an engineering professor at Arizona State University and an expert on trenchless construction who consulted for Sunoco on the Mariner East 2 project. “From an environmental perspective, it’s way better,” he said. “And you know the patient is up and working the next day.”

Usually it is environmental advocates who tout the virtues of horizontal drilling at public hearings, urging companies to consider this more costly alternative to plowing through wetlands or wildlife habitats.

The technology has become more popular and more refined as pipelines continue to get closer to population centers. Pipelines are built to connect the supply to the demand, and with the development of the Marcellus and Utica shales in Appalachia, both sides of the equation are in populated areas.

Still, Sunoco’s decision to use the horizontal drilling technique at so many crossings along the Mariner East 2 pipeline is unusual.

The similarly sized 300-mile Atlantic Sunrise pipeline — which runs through Pennsylvania and four other states — used horizontal drilling only seven times to cross water bodies, including the Conestoga and Susquehanna rivers.

Energy Transfer Partners used horizontal directional drilling technology at 67 crossings of its 713-mile Rover Pipeline, which dips into Pennsylvania in Washington County.

Read part 1: Unstable Ground

Is there a downside to drilling underground?

Pipeliners work on the Mariner East 2 pipeline project on a right-of-way near the property of Jeff and Michelle Seaman, Wednesday, Oct. 3, 2018, in Union.
(Andrew Rush/Post-Gazette)

Horizontal directional drilling is susceptible to a particular kind of spill — known as an inadvertent return — in which lubricating mud erupts through weak spots in the rock during boring.

The company said in its permit applications that its bores would travel through bedrock, to avoid areas with underground pockets and fractures or loose soils that could disrupt the drilling and carry the mud out of the bore.

In September 2016 — after Sunoco had submitted four versions of its application materials, which then-waterways manager Domenic Rocco described that summer as being “loaded with inconsistencies and lack[ing] sufficient detail” — the DEP asked for an analysis explaining the risk of such a spill at each drilling site.

At first, Sunoco said 11 of the 143 crossings had a “medium” risk, based on the presence of gravel or other geological complexities near a wetland or drinking water reservoir. A few months later, it added another three sites to account for geology in eastern Pennsylvania with eroded limestone voids and places with past spills.



At medium-risk sites, drilling paths were redesigned to be deeper and longer, and inspection plans called for more vigilance.

None of the sites was identified as high-risk for spills — a designation that might have required the company to more dramatically reengineer its route. The rest were deemed to be at low risk.

When construction began, spills to waterways or dry ground followed soon after. They happened more than 230 times by DEP’s count — recurring multiple times at some sites in the past two years.

Are these spills unusual or just the status quo?

Pipeline workers clean up a mud spill in West Whiteland Township, Chester County, in November 2017. Courtesy of Eric Friedman.

Ten years ago, when horizontal directional drilling was becoming more commonplace and concerns about drilling mud spills were on the rise, the Illinois-based nonprofit Gas Technology Institute commissioned a study.

The term “inadvertent return” is meant to separate unintentional flows from the intentional ones — the drilling fluid and rock cuttings that are supposed to come back out of the bore. Those are collected in pits near the hole.

The study involved a survey of 54 horizontal directional drilling installations. It found half had experienced the less-welcome spills.

Eric Skonberg, president of Texas-based Trenchless Engineering Corp. and an author of the study, said the results are well known in the industry. Mr. Skonberg said, “If you ask the contractors how often it happens, they would say probably 50 percent of the time. But the owners of the pipelines said 10 percent.”

Most of the time, the spill involves a manageable quantity of non-toxic liquid that leaves no lasting impact. “And, yes, you can plan for it,” he said.

Whether Sunoco knew about the study isn’t a mystery. In April, Sunoco spokeswoman Lisa Dillinger told the Philadelphia Inquirer that Sunoco’s rate of inadvertent returns was 37 percent, “which is below the industry average of 50 percent.”

Pennsylvania regulators, on the other hand, said they did not.

“The expectations from us were that there (were) not going to be inadvertent returns,” said Mr. Rocco, who is now acting program manager.

Do you appreciate good journalism? If you do, consider subscribing.

Support journalism. Subscribe today.

If you are a loyal subscriber, thank you for your support.

He said that while the DEP made Sunoco draft a plan for cleaning up spills should they occur — and the mere existence of such a plan was already an improvement over Sunoco’s work on Mariner East 1, one DEP official testified at an administrative hearing earlier this year — Mr. Rocco stressed they weren’t expecting anything close to the number of spills that materialized.

Whether that was a failure of communication or foresight isn’t clear.

When asked if Sunoco’s rate of spills and drilling problems is just a normal side effect of putting in a major pipeline, Mr. Ariaratnam said: “Yes. Absolutely.”

“You expect to have inadvertent returns,” he said. “I reviewed all the documents and plans. I think they’re doing a great job.”

Last week, Ms. Dillinger said that “inadvertent returns are not unexpected” during horizontal drilling, but stressed that “steps are taken to protect the environment during our construction.”

How did Sunoco evaluate the risk of spills?

Work on a Mariner East 2 pipeline right of way in Union Township. Courtesy of Jeff Seaman.

In August 2017, after violations mounted and a state environmental judge shut down construction, Sunoco was required by a legal settlement to reevaluate its plans for horizontal drilling at 63 sites. The company has submitted reassessments for 27 sites — all of which were originally designated as low risk.

In the new reviews, Sunoco often came to entirely different conclusions.

Some of the original designs were now described as posing “a high risk” or “an increased risk,” or as “susceptible to the inadvertent return of drilling fluids.”

A design for crossing under the Juniata River in the center of state “could fail.” It was “very possible” that a planned bore path in Chester County, west of Philadelphia, could have intercepted a water-rich fracture and affected local wells.

Nearly all of the reassessed crossings required a redesign and new DEP approvals. Most were realigned to send the pipeline deeper underground. Several were converted into open trenches or conventional bores that are more intrusive on the surface but pose fewer risks to water supplies at some sites.

Even that didn’t stop the spills.

Since November, there have been spills at 10 of the reassessed sites, including one site where a 30,000-gallon spill of drilling muds reached a wetland in Berks County. Sunoco had said a redesign of its plans there was unnecessary.

Who protects groundwater?

Pipes for the Sunoco Mariner East pipeline are placed in South Lebanon Township, Pa., in July 2017.
(Jeremy Long/Lebanon Daily News)

If the DEP finds that an activity is polluting water, it can shut work down and require water supplies to be restored after damage.

But no Pennsylvania law gives DEP the authority to set standards for water quality in private wells, to keep an inventory of their locations or to set rules for how such wells should be built.

That meant that even though Mariner East 2 would be skirting hundreds of wells used by homeowners for drinking, bathing and washing clothes, the state couldn’t say exactly where those wells were or how vulnerable they might be during construction.

In an email to other DEP officials in January 2017, Mr. Rocco relayed a complaint from a Delaware County resident whose private water well had been affected by renovation of Sunoco’s older Mariner East 1 pipeline.

“Though we don't regulate it,” he wrote, “this private well issue has the potential to really blow up.”

Mr. Rocco’s solution — the one DEP ultimately adopted — was to apply “a bunch of special conditions if we decide to move forward with permit issuance,” conditions that put the responsibility on Sunoco to resolve any water supply complaints to the satisfaction of the well’s owner.



In the first entry on 10 pages of special conditions, DEP required Sunoco to give three days notice to all public and private water supply owners that might be affected by water quality changes caused by the company’s work.

During the planning stages, the company had already notified 146 public water systems with possible groundwater wells or surface water intakes within a mile of the project’s corridor. After permits were issued, Sunoco tested nearly 500 private water wells within 150 feet of drilling sites.

The special conditions signaled that DEP and Sunoco anticipated some water supplies might be damaged.

But it took more than a dozen polluted wells — along with lawsuits from environmental groups and a state legislator in the last two years — for regulators and the company to concede that damage was more of a certainty than a risk.

Within five months of the permits being issued, Sunoco’s construction disrupted an aquifer serving 15 water supplies in a suburban neighborhood in Chester County. The company was forced to expand the distance from drilling worksites — from 150 feet to 450 feet — where it had to alert private well owners and offer water testing before, during and after drilling.

In February 2018, Sunoco and DEP formalized a precautionary requirement that the company should offer to pay for temporary water for all properties with water wells within 450 feet of directional drilling sites during construction, often in the form of a bulk water holding tank hooked to the home’s plumbing.

In April and May, Sunoco acknowledged the best thing was for people nearby to stop using their wells during pipeline drilling.

“Non-use of the water wells during drilling activities is the best protective measure,” a company consultant wrote in a reevaluation of its plans to drill through the groundwater zone near 11 private water wells in Chester County in May.

If drilling mud is non-toxic, is it safe?

A mud spill at an apartment complex in Media. Source: Clean Air Council court documents.

The lubricating muds used during pipeline drilling are not toxic to humans, although a large enough spill in a stream or wetlands can hurt aquatic life.

Bentonite, the main ingredient, is approved by the U.S. Food and Drug Administration as a food additive. It is used in cosmetics, detergents and medicine, an environmental scientist named Paul Chrostowski testified at a Public Utility Commission hearing in May.

But the additive may play a role in disrupting the underground cracks and conduits that allow water to flow through aquifers to wells.

Ira Daniel Sasowsky, a geosciences professor at the University of Akron, testified at the same administrative hearing that bentonite is used to thicken the drilling fluid.

“Bentonite can also be used to plug holes, if you’re using just a lot of bentonite,” he said. “So it would only be under that latter circumstance where I think you would completely block up the flow of the aquifer.”

Mohammad Najafi, a professor of civil engineering at the University of Texas Arlington, said in an interview that drilling fluid remains in liquid state only while it’s agitated. Left alone, it solidifies, which forms a helpful seal around pipelines. However, it is possible, he said, that it could solidify in natural fractures and change groundwater flow.

Pipeline construction can also disrupt aquifers by opening new channels for the water.

When Sunoco’s drilling in Cumru Township, Berks County, sent dirt or drilling mud into five water wells and caused a sixth to go dry between July and October 2017, the company recommended cleaning out the wells to restore the flow of clean water and injecting grout around the pipeline’s exit holes to stop water from escaping the aquifer.

DEP concluded Sunoco was to blame for “altering the long-standing water elevation conditions under the hill” where the pipeline path was drilled, Andrea Blosser, then a section chief in DEP’s waterways program, wrote.

“Even if the grouting does work,” she wrote, “it may take years for the drained groundwater to return to predrill elevations.”

Is Sunoco a bad actor?

A right-of-way where workers are installing a section of Mariner East 2 pipeline project, Wednesday, Oct. 3, 2018, Union.
(Andrew Rush/Post-Gazette)

John Quigley, who was secretary of DEP until May 2016, told the Engineering New Record trade publication in January that “no one else comes close to Sunoco’s poor track record.”

“Basic engineering and scouting of the route — it doesn’t appear that was ever completed properly.”

DEP’s currently leadership was slightly more diplomatic.

In April — after the Mariner East 2 pipeline had been stopped, restarted and fined $12.6 million for “willful and egregious violations” — DEP Secretary Patrick McDonnell said in an interview with the Post-Gazette that this project “had some of the toughest conditions of any permit.”



“The reality is that they were not meeting those permit obligations,” he said.

As of last week, the project had more than 70 permit violations, according to the DEP. When asked about noncompliance last week, Ms. Dillinger noted only one instance, when Sunoco initiated a horizontal underground drilling operation on a site that was permitted for trenching.

“That was rectified about eight months ago,” she said. “We are committed not only to following the strict guidelines set forth in our permits but to employing the highest levels of construction expertise and to preserving and protecting the environment in which we conduct our work.”

DEP initially found comfort in requiring that a professional licensed geologist be present at each horizontal directional drilling job to monitor the pressure in the bore and how much liquid was coming back out.

But several months into construction, DEP noted that the process wasn’t working as intended and that on at least two occasions, the geologists reported they were instructed not to talk to the drillers.

Mr. Rocco said in October that he has seen improvement in Sunoco’s approach in recent months.

What did we learn?

A launch pad for a horizontal directional drill that will burrow under railroad tracks to install the Mariner East 2 pipeline project, Thursday, Aug. 30, 2018, in Nottingham.
(Andrew Rush/Post-Gazette)

DEP is taking steps to make many of the lessons learned from Mariner East a feature of all future pipeline permitting in Pennsylvania.

A legal settlement with environmental groups in July requires regulators to develop new policy documents for everything from how pipeline companies should communicate with residents before starting work to how they should look for underground hazards.

Mr. Rocco noted a stakeholder group will be assembled to focus specifically on horizontal directional drilling guidance. As an example, he said, the group might discuss whether 450 feet is an appropriate radius for the protection of private water wells.

Policies to be developed through this process will not have the full weight of law, and some improvements will require the Legislature to act.

The Mariner East 2 pipeline is still not finished. Landowners in its path are already wondering about Mariner East 3.

Author: Anya Litvak 
Author: Laura Legere 
Media: Andrew Rush
Design: Sam Underwood