Another Spill into the Yellowstone – Are we learning anything?


Many rivers to cross
But I can’t seem to find my way over

                                                ~Jimmy Cliff


Dear Readers: An unfortunate deja-vu-all-over-again moment occurred recently: another pipeline ruptured at a crossing of the Yellowstone River in eastern Montana.

First, there was the Silvertip spill….

You may remember that after the ExxonMobil Co.’s Silvertip Pipeline ruptured and spilled 1,500 barrels of oil into the Yellowstone River in 2011, I got a letter from my friend King Fisher of Riparian Ranch asking about the rules that govern pipelines crossing rivers. It was clear by then that the Silvertip spill was caused by the pipeline being damaged by riverbed scour and debris and he was understandably confused about the existing rule requiring operators to bury their pipelines a minimum of only four feet when they construct pipelines across rivers of at least 100 feet in width. He wondered whether there were other rules, and what they might be. 

I answered that letter in the Trust’s newsletter in January of 2013 (at pages 4-6). Here are the highlights of that response:

  • The current rules require pipelines crossing rivers that are wider than 100 feet to be buried at least 4 feet at the time of construction. A separate rule requires lines that cross navigable rivers to be checked at least every 5 years “to determine the condition of the crossing”. There is no rule requiring any specific depth of cover to be maintained after installation, unless the pipeline is one where a spill could affect a “high consequence area,” say, for example, the drinking water supply of a small city that takes its water directly from, say, the Yellowstone River.
  • The 2011 amendments to the Pipeline Safety Act included a directive to PHMSA to undertake a study of liquid pipeline incidents at river crossings to determine if depth of cover was a factor, and to make recommendations for any legislative action to improve the safety of buried pipelines at river crossings. No regulatory action was required of PHMSA.
  • PHMSA produced its report describing its data management challenges (it doesn’t have a database, geographic or otherwise that shows the crossings that are subject to the 100 foot crossing/4 feet deep rule); and describing the pipeline failures at crossings in the last 20 or so years (well, at least some of them). In an NTSB document not cited in PHMSA’s report to Congress, a chart shows that 6 of Exxon’s pipelines in the San Jacinto floodplain ruptured or were undermined for up to 120 feet in the 1994 flood event; most of these were not included in the PHMSA analysis.

Then there was the Bridger spill – Another spill into the Yellowstone River last month

The Bridger pipeline failed at its crossing of the Yellowstone River, spilling approximately 1,000 barrels of crude into the river. Complicating response, investigation and recovery is that the river is entirely frozen over, but with ice of varying thickness from day to day, creating safety concerns for responders and physical limitations on recovery operations.

Initial reports were that the pipeline was buried at least 8 feet under the bed of the river. Then we learned that was an assessment from 2011. Then we learned that sonar showed much of the pipeline crossing the river was exposed on the riverbed, and some of it was suspended above the bed, entirely exposed. Although we do not yet know the reason for the pipe’s failure, clearly the lessons of the Silvertip (and a USGS study showing parts of the Missouri River scouring to depths of up to 40 feet) had not been learned – that rivers change all the time and quickly, that riverbeds move a lot of sediment, and quickly.

My 2013 reply to King Fisher was written before PHMSA had fulfilled its second obligation under the 2011 Act: to determine whether the depth of cover requirements are inadequate and if so, to make legislative recommendations. I suggested staying tuned to find out what PHMSA would do, and raised concerns about some of the options open to it:

The risk is that PHMSA either: a) decides to change the depth of cover at installation rule, creating a political sideshow that exhausts safety advocates’ energy arguing over the number of feet or inches it should be raised, completely ignoring the fact that the installation rule makes very little difference over time if there are no maintenance of cover rules or viable, enforceable integrity management rules to require operators to manage for the risk of riverbed scour; or b) decides to argue that the operator’s obligations under integrity management rules to identify and mitigate the risks of riverbed scouring are sufficient, regardless of the 4-foot depth of cover at installation requirement, and therefore the depth of cover rules don’t need to be changed. 

Unless PHMSA opts for: c) an enforceable and enforced maintenance of cover rule for all crossings that is based on a study of the specific location and characteristics of each crossing; and d) actually enforcing integrity management obligations of operators to design for and mitigate against the risk of riverbed scour before an incident occurs, this smart pig is not optimistic about improving the safety of crossings at rivers.

So, how did PHMSA do?

Well, to some extent it remains to be seen, but there is recent reason to hope for improvement.

When PHMSA reported to Congress with the second half of its homework assignment – do you have legislative recommendations? – PHMSA reported that it believed that its existing legislative authority was adequate to protect pipelines at river crossings. PHMSA has yet to publish ANY substantive proposed changes to its safety regulations since the 2011 reauthorization, and until those major proposed rulemakings are released, we won’t know whether PHMSA intends to change the depth-of-cover-at-construction rule or to propose any new rules requiring maintenance of cover to some depth.

But just last week, in the midst of the awful news about the Bridger spill into the Yellowstone, PHMSA released its Final Order on ExxonMobil’s appeal of the fine imposed for its Silvertip spill. In the order, PHMSA responded to the operator’s (EMPCo’s) arguments that they had complied with the regulations relating to adequate risk assessments and integrity management measures to manage the identified risks:

The fact that flooding had not previously caused an integrity issue for Respondent’s pipeline does not mean future flooding could never cause a failure. One of the purposes of the integrity management regulations is to anticipate the possible threats to the pipeline in the future. Given that flooding is a threat in general and that flooding had caused integrity issues for other pipelines at the same location, it was not reasonable for EMPCo to assume seasonal flooding would never impact its own pipeline. At a minimum, the Operator had a duty to evaluate the likelihood of a pipeline release occurring from flooding. [Order at page 9.]

The order continues by analyzing the documents in the record to determine if such a risk analysis had been made, notes that the 2010 Preventive and Mitigative Measures Analysis identified only three risks to the line — third-party damage, manufacturing, and external corrosion — in spite of the fact that the entire line had been identified as one which could affect a high consequence area, and further noting that the presence of the Yellowstone River or the risk of a failure at its crossing was never mentioned.

The good news

The Conclusion of the PHMSA order on this violation is this:

Given the history of flooding and impact to other pipelines at this location, the threat of flooding was relevant to the likelihood of a release occurring on Respondent’s pipeline. Respondent did not evaluate the likelihood of a release caused by flooding of the Yellowstone River and failed to consider risk factors relevant to flooding. Accordingly, PHMSA finds Respondent violated § 195.452(i)(2) by failing to conduct a risk analysis of the Silvertip Pipeline that considered all risk factors relevant to the likelihood of a release on the Silvertip Pipeline and potential consequences affecting the Yellowstone River. [Order at page 12.]

This suggests that PHMSA may, in fact, be choosing Option D from my response to my friend King Fisher: d) actually enforcing integrity management obligations of operators to design for and mitigate against the risk of riverbed scour before an incident occurs.

Well, okay, technically, they haven’t yet enforced those obligations before an incident occurs as far as we know, but this is at least a start. Most importantly, it should certainly put every other operator on notice, whether they’ve had a flooding/riverbed scour/earth movement failure or not, that PHMSA will enforce the operators’ obligation to adequately assess those risks and to integrate sufficient preventive and mitigative measures into their integrity management programs to protect against failures. Unfortunately, PHMSA didn’t do that when they inspected the Silvertip a year or so before the Yellowstone rupture. When regulators enforce those obligations in routine inspections of integrity management programs independent of (and hopefully before) any incidents, that will indeed be good news.

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