Is there a downside to drilling underground?
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?
Ten years ago, when horizontal directional drilling was becoming more commonplace and concerns about drilling mud spills were on the rise, the Illinoisbased 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.
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?
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?
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.
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.