The federal Pipeline Hazardous Materials Safety Administration (PHMSA) has served Sunoco with a sternly-worded “Notice of Probable Violation” about the Dragonpipe (Mariner East pipeline system). A copy is available here. The Notice alleges that Sunoco knowingly operated its anti-corrosion system for Mariner East 1 in a way that did not protect it from corrosion; and that, as a consequence, it also failed to maintain required records showing that its corrosion control was adequate.
The PHMSA inspectors looked at records for a section of ME1 near Morgantown, PA, where a leak occurred in 2017. Inspectors from the Pennsylvania PUC had previously looked at that area and come to similar conclusions (see “Sunoco sat by while ME1 rusted”). The PHMSA Notice essentially confirms what the PUC found and provides additional detail.
The PHMSA inspections took place almost exactly a year ago (March 19 to March 23 of 2018). It’s unclear why the Notice was only issued 11 months later (February 4, 2019). But the inspections found serious maintenance issues.
The inspectors found that Sunoco was out of compliance with the engineering standards for “cathodic protection”, the main anti-corrosion technique for steel pipelines. The technique involves creating a small current through the soil between a buried “sacrificial anode” (a piece of metal that is allowed to corrode so that the pipeline doesn’t) and the pipeline itself. (More detail on cathodic protection is here.)
The voltage measurements Sunoco made were inadequate. To verify that its cathodic protection was working, Sunoco measured a basic voltage called “IR drop”, but failed to consider other voltage measurements or other factors in the environment which would have indicated whether the measured IR drop value was adequate.
The Notice quotes the relevant standard:
The earth current technique [which Sunoco used] is often meaningless in multiple pipe rights-of-way, in high-resistivity surface soil, for deeply buried pipe, in stray-current areas, or where local corrosion cell action predominates.
Throughout its length, ME1 runs mostly in “multiple pipe rights-of-way”, and the other factors listed in the quote above are present at many locations. It’s clear that Sunoco’s measurements may have been “meaningless” in many cases.
Even Sunoco’s basic voltage measurements failed to meet the required standard. Not only did Sunoco depend on a basic (and often meaningless) voltage measurement, but in some cases even the basic voltage that was measured was out of compliance. The Notice lists nine specific locations where Sunoco measured and dutifully recorded the inadequate voltages. The inspectors asked Sunoco about these readings. They report, “When requested, Sunoco was unable to explain how the data provided demonstrates adequate cathodic protection….” In other words, the pipeline was not protected from corrosion, Sunoco knew that it was not protected, documented that it was not protected, and yet had no explanation for why it was not protected.
Two requirements, but no fine proposed. The Notice contains a description of a “Proposed Compliance Order” which PHMSA will issue unless Sunoco can demonstrate good reasons not to. This Order will require Sunoco to take the following steps:
- Survey the entire pipeline, applying a different and more appropriate voltage measurement at all test points, within 120 days.
- Maintain adequate records of the survey of item 1, and develop a written plan to fix any deficiencies in cathodic protection that are found. This plan is to be delivered within 60 days of the completion of the survey.
These steps will help ensure that the anti-corrosion system is working, but won’t fix existing corrosion.
The Notice mentions that fines of over $2 million could be assessed for violations such as these, but that “We have reviewed the circumstances and supporting documents involved in this case, and have decided not to propose a civil penalty assessment at this time.”
Where does this leave us? The PHMSA investigation confirms what we already knew from the PUC’s Bureau of Investigation and Enforcement (BI&E): Sunoco’s maintenance practices have been negligent. The BI&E complaint also reported lab testing that showed that corrosion caused the Morgantown leak.
But both the BI&E complaint and the PHMSA Notice suggest other troubling issues: Where else along the Dragonpipe has corrosion been going on? When and where will the next leak appear? Will Sunoco detect it? (They didn’t detect the Morgantown one—the landowner did.) Is ME1 leaking even now?
The PHMSA Notice doesn’t address any of these issues. It deals only with Sunoco’s records of voltage for a small stretch of pipeline near Morgantown. The requirements it places on Sunoco will, if adhered to, help ensure better corrosion prevention in the future, but it does nothing about corrosion problems already buried in the ground.