# EXXONMOBIL PIPELINE CO — Notice of Probable Violation

- **operation:** document
- **citation:** CPF 520135007
- **title:** EXXONMOBIL PIPELINE CO — Notice of Probable Violation
- **source type:** enforcement
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** historical
- **official:** true
- **published on:** 2013-03-25
- **effective on:** Not available
- **summary:** CLOSED notice of probable violation citing 195.402(e)(2), 195.402(e)(4), 195.403(a)(3), 195.452(i)(1), 195.452(i)(2).
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-enforcement-520135007.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-enforcement-520135007.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-enforcement-520135007
- **source url:** https://primis.phmsa.dot.gov/enforcement-data/case/520135007
**body:**

Notice of Probable Violation involving EXXONMOBIL PIPELINE CO. PHMSA's enforcement data identifies the cited regulations as 195.402(e)(2),  195.402(e)(4),  195.403(a)(3),  195.452(i)(1),  195.452(i)(2). The case was opened on 2013-03-25 and is reported as closed as of 2015-07-09. Proposed civil penalty: $1,700,000. Assessed civil penalty: $1,045,000. Open the official case record for notices, responses, orders, and the latest status.

Official case documents:

520135007_closure letter_07092015.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_closure%20letter_07092015.pdf

520135007_closure letter_07092015_text.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_closure%20letter_07092015_text.pdf

520135007_Decision on Petition for Reconsideration_06122015.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_Decision%20on%20Petition%20for%20Reconsideration_06122015.pdf

520135007_Decision on Petition for Reconsideration_06122015_text.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_Decision%20on%20Petition%20for%20Reconsideration_06122015_text.pdf

520135007_Final Order_01232015.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_Final%20Order_01232015.pdf

520135007_Final Order_01232015_text.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_Final%20Order_01232015_text.pdf

520135007_NOPV PCP PCO_03252013.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_NOPV%20PCP%20PCO_03252013.pdf

520135007_NOPV PCP PCO_03252013_text.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_NOPV%20PCP%20PCO_03252013_text.pdf

520135007_Operator Petition for Reconsideration_02122015.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_Operator%20Petition%20for%20Reconsideration_02122015.pdf

520135007_Operator Request for Hearing and Response to Notice_04242013.pdf: https://primis.phmsa.dot.gov/enforcement-documents/520135007/520135007_Operator%20Request%20for%20Hearing%20and%20Response%20to%20Notice_04242013.pdf

520135007_Final Order_01232015_text.pdf

JANUARY 23, 2015
Mr. Gerald S. Frey
Global Pipeline Manager & President
ExxonMobil Pipeline Company
800 Bell St., Room 741-D
Houston, TX 77002
Re: CPF No. 5-2013-5007
Dear Mr. Frey:
Enclosed please find the Final Order issued in the above-referenced case. It makes findings of
violation, withdraws one allegation, and assesses a reduced civil penalty of $1,045,000. It
further finds that ExxonMobil Pipeline Company has completed the actions specified in the
proposed compliance order to comply with the pipeline safety regulations. The penalty payment
terms are set forth in the Final Order. This enforcement action closes automatically upon receipt
of payment. Service of this Final Order is made pursuant to 49 C.F.R. § 190.5.
Thank you for your cooperation in this matter.
Sincerely,
Jeffrey D. Wiese
Associate Administrator
for Pipeline Safety
Enclosure
cc: Mr. Chris Hoidal, Director, Western Region, PHMSA
Mr. Bob Hogfoss and Ms. Catherine Little, Hunton & Williams LLP,
Bank of America Plaza, Suite 4100, 600 Peachtree Street, N.E., Atlanta, GA 30308
CERTIFIED MAIL – RETURN RECEIPT REQUESTED



U.S. DEPARTMENT OF TRANSPORTATION
PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION
OFFICE OF PIPELINE SAFETY
WASHINGTON, D.C. 20590
___________________________________
In the Matter of )
ExxonMobil Pipeline Company, ) CPF No. 5-2013-5007
)
)
)
Respondent. )
___________________________________ )
FINAL ORDER
On July 2, 2011, pursuant to 49 U.S.C. § 60117, a representative of the Pipeline and Hazardous
Materials Safety Administration (PHMSA), Office of Pipeline Safety (OPS), initiated an
investigation of the records and procedures of ExxonMobil Pipeline Company (EMPCo or
Respondent) following a failure of its Silvertip Pipeline in Laurel, Montana, that occurred on
July 1, 2011. EMPCo is a subsidiary of Exxon Mobil Corporation and operates approximately
3,800 miles of pipeline transporting crude oil, refined petroleum products, and highly volatile
liquids in Texas, Louisiana, and Montana.1
As a result of the inspection, the Director, Western Region, OPS (Director) issued a Notice of
Probable Violation, Proposed Civil Penalty, and Proposed Compliance Order (Notice) to
Respondent on March 25, 2013. In accordance with 49 C.F.R. § 190.207, the Notice alleged five
violations of the pipeline safety regulations, proposed a civil penalty of $1,700,000, and
proposed certain corrective action.
EMPCo responded to the Notice by letter dated April 24, 2013 (Response). In its Response,
Respondent contested four of the five alleged violations and requested a hearing. In advance of
the hearing, Respondent submitted additional written materials on July 8, 2013 (Pre-hearing
Submittal). OPS also submitted additional materials. In accordance with 49 C.F.R. § 190.211, a
hearing was held on July 17, 2013, in Lakewood, Colorado, before a Presiding Official from the
Office of Chief Counsel, PHMSA. After the hearing, Respondent submitted additional materials
on August 23, 2013 (Post-hearing Brief). Pursuant to § 190.209(b)(7), the Director submitted a
written evaluation of Respondent’s response material and recommendation on September 20,
2013.
1 This information was reported by EMPCo for calendar year 2013 pursuant to 49 C.F.R. § 195.49.



CPF No: 5-2013-5007
Page 2
BACKGROUND
On July 1, 2011, the Silvertip Pipeline operated by EMPCo experienced a failure where the
pipeline crosses the Yellowstone River in Laurel, Montana.2 The failure resulted in the release
of approximately 1500 barrels (63,000 gallons) of crude oil into the river.
The Silvertip Pipeline is 69.6 miles in length and runs from the Silvertip Station near production
fields in Elk Basin, Wyoming, to the ExxonMobil refinery in Billings, Montana.3 The pipeline
also takes crude oil from an intermediate pump station in Edgar, Montana. The pipeline runs
south to north on a 5% to 7% downward slope. The pipeline can drain by gravity into the
refinery in Billings. Pumps at the Edgar station are used to boost flow rate and to pull crude oil
out of tankage.
The pipeline crosses four rivers. At each of the river crossings, the pipeline has a remote
controlled valve (RCV) on the upstream side of the crossing and a hand operated valve on the
downstream side.4 The RCVs are equipped with a relief valve and bypass line to protect the
pipeline from pressure surges caused by the rapid closure of valves and other abnormal hydraulic
events.
The Silvertip Pipeline crosses beneath the Yellowstone River immediately before the pipeline
reaches a terminal facility in Laurel, Montana, about 20 miles upstream from the end of the
pipeline. The pipeline crosses the Yellowstone approximately 800 feet east of the Highway 212
bridge.5 Before 1991, the pipeline crossed the river at the bridge span, but EMPCo was required
to move a portion of the pipeline so that it crossed under the river to accommodate rebuilding of
the bridge.6
At the location of the Yellowstone crossing, the Silvertip pipeline is 12.75-inch outside diameter,
0.500-inch wall thickness, Grade B seamless pipe manufactured by U.S. Steel.7 When the
pipeline was re-routed beneath the river in 1991, it was installed using an open cut crossing
technique, placing the pipeline in a rock cobble trench at least 6 feet below the river bed. The
pipe also had a 1-inch concrete weight coating.
2 EMPCo and OPS were in general agreement on most of the background facts. The primary
disagreement regarded the significance of historical flooding on the Yellowstone River, as detailed below.
3 OPS Pipeline Safety Violation Report (Violation Report) (Apr. 19, 2013), Exhibit A-1 – Accident
Investigation Report (Investigation Report) at 2 (Oct. 30, 2012).
4 Terms “upstream” and “downstream” refer to relative directions on the pipeline. Upstream is in the
direction of the beginning of the pipeline and downstream is in the direction of the end.
5 Violation Report at 2.
6 Post-Hearing Brief at 2.
7 Pre-hearing Submittal Exhibit 8 (Kiefner Report) at 2.



CPF No: 5-2013-5007
Page 3
A. Historical Flooding of the Yellowstone River
According to OPS, the Yellowstone has historically been prone to seasonal flooding, including
increased erosion and scouring since 1991.8 OPS asserted that at the time of the failure, these
problems were common knowledge in Laurel and had worsened in 1991 when the Highway 212
bridge was rebuilt in a way that constricted water flow of the Yellowstone, increasing the
velocity and scouring of floodwaters. OPS pointed to information maintained by the United
States Geologic Survey (USGS), including data from a water gauge approximately 20 miles
downriver from the Silvertip crossing.9 The USGS had determined the “flood stage” at this point
of the Yellowstone River is a water level of 13.5 feet at the gauge.
Between 2008 and 2010, the river typically rose during the spring runoff and summer snow melt
and then fell a short period of time later. There were instances when the river would rise
multiple times during the same high water season, but water levels would usually drop within a
week or two. In 2011, the Yellowstone rose and stayed high for more than a month. The
Yellowstone reached the flood stage as measured by the water gauge three times in 2011: on
May 25, June 25, and July 1, the date of the Silvertip failure.10
Seasonal flooding of the Yellowstone had previously affected other pipeline operators in the
area. In June 2009, flooding and river scouring caused the failure of an 8-inch natural gas
pipeline operated by Willison Basin Interstate Pipeline (WBI).11 WBI replaced the 8-inch pipe
with a 16-inch line horizontally drilled at a depth of 40-50 feet below the river. Another 8-inch
pipeline that had been abandoned by ConocoPhillips became exposed and suffered a rupture
sometime between 2009 and 2011.12 After the 2009 WBI failure, EMPCo conducted an inline
inspection (ILI) of the Silvertip Pipeline at the Yellowstone crossing and found no anomalies.13
This was in addition to a prior ILI performed in 2004.
EMPCo acknowledged the Yellowstone is prone to seasonal flooding, but believed the facts
presented by OPS concerning flooding were overstated. EMPCo asserted that federal databases,
including the USGS, indicated that high water events on the river since the pipeline was installed
were less extreme than past levels. EMPCo also pointed to a report by the Yellowstone River
Conservation Council that indicated the period from 1979 to 2007 “was characterized by
minimal floods on the tributaries and no floods on the Yellowstone River.”14
8 Violation Report at 4.
9 Investigation Report at 5-6.
10 Investigation Report at 5-6.
11 Violation Report, Exhibit B-16 at 3.
12 Violation Report 4.
13 Response at 2.
14 Response at 2, referencing Pre-hearing Submittal, Exhibit 4 “Yellowstone River Historic Events
Timeline” at 5.



CPF No: 5-2013-5007
Page 4
Additionally, EMPCo noted that in the past 20 years, three floods had higher levels than the
flood level at the time of the July 1, 2011, failure. The first occurred before 1991 when the
pipeline was installed; the second occurred in 1997; and the third occurred on May 26, 2011.
The 1997 flood, EMPCo asserted, was the highest crest ever recorded for the Yellowstone.
EMPCo stated that the Silvertip Pipeline “survived [these previous] high water events, and the
Company increased monitoring of the river crossing.”15 Additionally, EMPCo indicated that the
OPS Investigation Report acknowledged there was an absence of historical flooding impacts to
this pipeline.16
B. Events Leading up to the 2011 Flooding
Prior to the flooding in 2011, there were numerous contacts between interested stakeholders and
EMPCo concerning the Yellowstone crossing. In August 2010, there was a meeting of Laurel
officials, the U.S. Army Corps of Engineers, EMPCo, Cenex Pipeline Company, WBI, and
Conoco Phillips that took place at Riverside Park, located slightly east of the Highway 212
bridge on the south side of the Yellowstone River. The meeting concerned erosion of the river
bank in that location and the pipelines that ran beneath, including the Silvertip. Laurel officials
hoped to obtain assistance in fortifying the south bank to help protect the park.17
Several months later in October 2010, Laurel officials contacted OPS and expressed concern
about the pipeline crossings downstream of the Highway 212 bridge due to the seasonal
flooding. OPS relayed this information to EMPCo. In December 2010, EMPCo conducted a
depth of cover survey at the Yellowstone crossing at the request of OPS, and reconfirmed the
findings from a prior survey that the pipeline was “buried in rock and cobble at least five to eight
feet below the riverbed.”18 EMPCo submitted the survey report to OPS on January 29, 2011.
The survey indicated that the Silvertip “met the required minimum depth of cover for new
pipelines, and that the bottom of the river had not changed significantly since the last crossing
survey performed in 2002.”19 OPS staff advised EMPCo at the time to “maintain vigilance with
respect to the annual flooding of the Yellowstone River especially in the vicinity of their pipeline
crossing in Laurel, MT.”20
On May 25, 2011, the Yellowstone reached flood stage level. Laurel officials again contacted
OPS with concerns over the erosion of the south bank of the Yellowstone. In turn, OPS
contacted EMPCo, which sent employees to Riverside Park in response. On this date, EMPCo
shut down the Silvertip for five hours, assessed site conditions, and evaluated data. When no
15 Response at 2.
16 Pre-hearing Submittal at 2, citing Investigation Report at 12.
17 Investigation Report at 3.
18 Investigation Report at 3.
19 Investigation Report at 3-4. The minimum depth of cover for a new pipeline under a river is four feet.
Respondent indicated the depth of cover survey was actually performed in 2001. Response at 2.
20 Investigation Report at 4.



CPF No: 5-2013-5007
Page 5
anomalies were detected, the Silvertip was restarted and EMPCo began daily monitoring by
driving by the location to observe the general area. WBI decided to shut down its pipeline
crossing at the Yellowstone because of the floodwaters.21
One week later, on June 1, 2011, Laurel officials sent photographs of the Yellowstone to EMPCo
with a recommendation that EMPCo come and assess the situation.22 EMPCo responded via
email that the depth of cover at the south bank had been determined to be 12 feet. On June 6,
2011, OPS inspected EMPCo’s integrity management program and most recent ILI data from
2009, finding no actionable pipeline anomalies at the Silvertip’s Yellowstone crossing.
The Yellowstone reached the flood stage again on June 25 due to snow melt.23 Laurel personnel
began reinforcing the Yellowstone banks on both the north and south sides. They again
contacted OPS with concerns over the Silvertip crossing. OPS contacted EMPCo, which shut
down the Silvertip for a second time, visited the site, and assessed the situation. EMPCo
performed a depth of cover survey in Riverside Park from the south bank of the Yellowstone to
RCV 4462, which is the closest upstream valve south of the river crossing. The depth of cover at
this point was between 6.7 feet and 8.5 feet. Additionally, on June 25, 2011, EMPCo placed
sandbags around RCV 4462 in case the park flooded.24
C. Silvertip Pipeline Failure
On July 1, 2011, the Yellowstone River reached the flood stage for the third time in six weeks.
At 10:40:43 p.m., Mountain Daylight Time, EMPCo’s Operation Control Center (OCC) in
Houston, Texas, received an alarm indicating a pressure drop at RCV 4462, the remote valve
immediately upstream of the Yellowstone River crossing.
25 Controller A, who was in charge of
the console at the time, did not see the alarm. At 10:41:14, approximately 30 seconds after the
first alarm, the controller noticed a second alarm which indicated a booster pump at Edgar
Station had automatically shut down because of low suction pressure. The Edgar Station is
approximately fourteen miles upstream of Laurel. Believing there might be a leak, Controller A
shut down the pumps and RCV 1066 at the beginning of the Silvertip Pipeline at 10:50:39 p.m.
He then closed RCV 1067, located approximately one-half mile downstream of the Yellowstone
River at the Laurel facility.
Three minutes later, Controller A notified a supervisor, who reviewed the trends and alarm logs.
At 11:07:32 p.m., the supervisor ordered Controller A to re-open RCV 1067 to allow oil to drain
into the Billings refinery. The supervisor then called the First Line Supervisor in the field, who
requested a senior technician be added to the call. A discussion ensued as to what caused the
Edgar Station pumps to have low suction. After the discussion and review of the relevant data,
21 Violation Report at 5.
22 Investigation Report at 4-5.
23 Investigation Report at 5.
24 Investigation Report at 5.
25 Notice at 1-2.



CPF No: 5-2013-5007
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the supervisor noticed the low suction pressure alarm had been preceded by a pressure drop at
RCV 4462. At 11:36:51 p.m., the Supervisor ordered RCV 4462 closed, which stopped the
gravity flow of oil into the river. Approximately 56 minutes had passed since the first alarm was
received until RCV 4462 was closed, resulting in a total of about 1500 barrels of crude oil
released into the river.
OPS sent investigators to the scene of the failure. On July 5, 2011, a Corrective Action Order
(CAO) was issued by PHMSA.
26 The CAO required EMPCo to take specific actions before
restarting the Silvertip Pipeline. It also required EMPCo to complete additional safety measures
before the next flood season, including replacement of the pipeline crossing at the Yellowstone
River with a horizontally drilled line.
The OPS Investigation Report indicated the pipeline failed as a result of a submerged
“guillotine” break in the pipeline near the south shore of the Yellowstone River caused by debris
caught on the exposed pipe during flooding, which gradually increased external stress on the
pipe until it failed.27 EMPCo’s failure report, prepared by Kiefner & Associates, Inc., similarly
concluded that the Silvertip “failed at a girth weld as a result of the effects of external loading
that occurred due to exposure to flood conditions.”28 The report concluded further that “the
failure mechanism was fatigue crack growth adjacent to a girth weld, followed by ductile
fracture of the remaining section due to tensile overload.”29 Ultimately, the cracks were caused
by “vortex-induced vibration of the exposed pipe in the river current.”30
The Notice issued on March 25, 2013, alleged that Respondent committed five violations of the
pipeline safety regulations in 49 C.F.R. Part 195, as follows:
Item 1: The Notice alleged that Respondent violated 49 C.F.R. § 195.452(i)(2), which states:
§ 195.452 Pipeline integrity management in high consequence areas.
(a) Which pipelines are covered by this section? This section applies to
each hazardous liquid pipeline and carbon dioxide pipeline that could
affect a high consequence area . . . .
(i) What preventive and mitigative measures must an operator take to
protect the high consequence area?—(1) General requirements. An
FINDINGS OF VIOLATION
26 ExxonMobil Pipeline Co., CPF No. 5-2011-5017H , 2011 WL 10796851 (Jul. 5, 2011). Prior
enforcement decisions can also be viewed on PHMSA’s website at http://www.phmsa.dot.gov/
pipeline/enforcement (follow link for enforcement since 2002 and then for Actions issued by year).
27 Violation Report at 3-4.
28 Pre-hearing Submittal Exhibit 8 (Kiefner Report) at 1.
29 Kiefner Report at 1.
30 Kiefner Report at 1.



CPF No: 5-2013-5007
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operator must take measures to prevent and mitigate the consequences of a
pipeline failure that could affect a high consequence area. These measures
include conducting a risk analysis of the pipeline segment to identify
additional actions to enhance public safety or environmental protection . . .
(2) Risk analysis criteria. In identifying the need for additional
preventive and mitigative measures, an operator must evaluate the
likelihood of a pipeline release occurring and how a release could affect
the high consequence area. This determination must consider all relevant
risk factors, including, but not limited to:
(i) Terrain surrounding the pipeline segment, including drainage
systems such as small streams and other smaller waterways that could
act as a conduit to the high consequence area;
(ii) Elevation profile; . . .
(iv) Amount of product that could be released; [and] . . .
(vii) Physical support of the pipeline segment such as by a cable
suspension bridge; . . . .
The Notice alleged that Respondent violated § 195.452(i)(2) by failing to conduct a risk analysis
of its pipeline considering all the relevant risk factors. Specifically, the Notice alleged that
Respondent prepared a risk analysis of the Silvertip Pipeline in July 2010 to evaluate the
likelihood of a pipeline release and possible consequences, but failed to consider the risk of
flooding and river bottom scour, as well as certain risk factors relevant to the Yellowstone River
crossing. The risk factors that Respondent allegedly failed to consider included the terrain
surrounding the pipeline segment; the elevation profile of the pipeline; the amount of product
that could be released in a spill; and the physical support of the pipeline segment in the river.
The Notice also alleged that Respondent should have considered additional factors listed in
Appendix C to 49 C.F.R. Part 195, such as potential natural forces inherent in flood zones and
subsidence areas. The Notice alleged the risk of flooding, channel migration, and river bottom
scour on the Yellowstone River was a known threat given its history, including at least one prior
pipeline failure in the area caused by flooding and impact to other pipelines.
EMPCo responded that it had complied with all requirements in the regulation concerning
preventative and mitigative risk analysis.31 Specifically, it asserted that its 2010 written integrity
management program addressed natural forces such as flooding. Respondent also asserted that
an integrity threat assessment conducted in 2009 considered the threat of weather-related and
outside forces such as flooding. Based on the threats identified by that integrity assessment,
Respondent maintained that its risk analysis considered all of the relevant risk factors, including
those specified under § 195.452(i)(2).32
In addition, Respondent argued that the effects of the July 1, 2011, flood were unforeseeable.
EMPCo noted that seasonal flooding on the Yellowstone River had never before impacted the
31 Pre-hearing Submittal at 7.
32 Pre-hearing Submittal at 6-7, referencing Exhibits 9 and 10 and Violation Report Exhibit B-7.



CPF No: 5-2013-5007
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Silvertip Pipeline despite several floods with higher levels than the one that caused the failure.
Respondent noted that it had assessed the pipeline before the failure and found it had adequate
depth of cover with no known anomalies. EMPCo also referenced the OPS Investigation Report
which acknowledged “Based on the lack of historical flooding impacts to this pipeline since [it
was installed in] 1991, EMPCo may not have known that the river bottom could change
sufficiently to undermine their pipeline.”33
A. Applicable Standards for Identifying P&M Measures
Under the pipeline safety regulations in 49 C.F.R. Part 195, pipeline operators must develop,
implement, and follow a written integrity management program (IMP) for each hazardous liquid
pipeline that could affect a high consequence area (HCA). 34 An operator’s IMP must include,
among other things, identification of additional actions that can be taken to protect the HCA.35
These are known as preventative and mitigative (P&M) measures.
To identify appropriate P&M measures for each pipeline, an operator must conduct a risk
analysis that evaluates “the likelihood of a pipeline release occurring” on the segment and the
potential consequences to the HCA.36 The risk analysis must include consideration of all risk
factors relevant to the likelihood of a release and potential consequences. The regulation lists a
number of risk factors that must be considered, including, but not limited to: the terrain
surrounding the pipeline segment, including drainage that could act as a conduit for the product
to reach the HCA; the elevation profile; amount of product that could be released; and the
physical support of the pipeline segment.
Appendix C to Part 195 provides additional guidance for implementing an IMP, including
guidance on risk factors. The guidance lists both mandatory and additional factors for operators
to consider when identifying measures to prevent and mitigate the consequences of a pipeline
failure. The factors listed include, among other things, potential natural forces in the area, such
as natural forces in a flood zone.37
Both parties acknowledged that seasonal floods were known to occur on the Yellowstone River
at the location of the Silvertip Pipeline crossing. Evidence also demonstrates that during 2008
through 2011, water level of the river rose each year during June and July. During those years,
water level would rise from a typical non-flood height of approximately 2 feet to a seasonal flood
height of 11 to 12 feet.38 During the 2011 season, the height exceeded 14 feet. Flooding is
33 Pre-Hearing Submittal at 2.
34 § 195.452(a)-(b). “High consequence areas” include commercially navigable waterways, as defined in
§ 195.450, and areas that are unusually sensitive to environmental damage, as defined under § 195.2.
35 § 195.452(f)(6).
36 § 195.452(i)(2).
37 49 C.F.R. Part 195, Appendix C (I)(B)(12).
38 Violation Report, Exhibit B-21. Respondent submitted a report titled “Yellowstone River Historic
Events Timeline” from 2008, which stated that 1998-2007 was “characterized by minimal flooding on



CPF No: 5-2013-5007
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known to PHMSA as a potential threat to buried pipelines, and PHMSA has communicated to
operators precautions that should be taken when flooding occurs.39 At this particular location,
flooding had previously caused at least one other pipeline to fail, the WBI gas pipeline failure in
June 2009.40 Taken together, all of this information was sufficient to notify Respondent that
flooding should be analyzed as a potential threat to its pipeline.
Respondent contended that certain information caused it to believe flooding could not impact its
pipeline. For example, EMPCo’s pipeline had survived prior flooding events without damage,
including two floods with a higher water level than the flood that ultimately caused the failure.
EMPCo had also performed a depth of cover survey in 2010, which detected cover over its
pipeline had not changed significantly since the last crossing survey. In its written submissions,
EMPCo also noted that the OPS Investigation Report stated that “based on the lack of historical
flooding impacts to this pipeline since 1991, EMPCo may not have known that the river bottom
could change sufficiently to undermine their pipeline.”41
PHMSA disagrees that this information alleviated Respondent from having to analyze the
possibility that flooding could cause a failure. 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.
B. Whether Respondent’s Risk Analysis Complied with Applicable Standards
PHMSA reviewed the evidence in the record to determine whether Respondent had prepared a
risk analysis that considered the threat of flooding and relevant risk factors. This review
included Respondent’s Silvertip to Billings 12” Crude Preventive & Mitigative Measures
Analysis Summary (2010 P&M Analysis).42
2010 P&M Analysis. The 2010 P&M Analysis described Respondent’s 69.6-mile Silvertip
It noted the location of block valves, elevation at each station, type of product
Pipeline. tributaries, and no floods on the Yellowstone River.” For the purpose of the report, however, only floods
with a 10% or less probability of occurring were identified. The report did not analyze seasonal flooding.
39 OPS has published Advisory Bulletins related to the impacts of flooding on pipeline systems. See
Advisory Bulletin ADB-93-03, 58 Fed. Reg. 41321 (Aug. 3, 1993); Advisory Bulletin ADB-94-05, 59
Fed. Reg. 55152 (Nov. 3, 1994). See also Potential for Damage to Pipeline Facilities Caused by Flooding
(ADB-11-04), 76 FR 44985 (Jul. 27, 2011); and Potential for Damage to Pipeline Facilities Caused by
Flooding (ADB-2013-02), 78 Fed. Reg. 41991 (Jul. 12, 2013).
40 Violation Report, Exhibit B-16 at 3.
41 Post-hearing Brief at 2-3, quoting Investigation Report at 12.
42 Violation Report Exhibit B-7. The P&M Analysis is dated July 7, 2010.



CPF No: 5-2013-5007
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transported, line fill capacity, flow rate, and maximum operating pressure. The entire length of
the pipeline was identified as potentially affecting an HCA. Three potential integrity threats to
the Silvertip Pipeline were identified: third-party damage, manufacturing, and external corrosion.
The document then identified and evaluated different P&M measures to address those three
integrity threats.
Besides third-party damage, manufacturing, and external corrosion, the 2010 P&M Analysis did
not identify other threats that could affect the likelihood of a pipeline release. In particular, the
Analysis did not consider the threat of flooding in evaluating the likelihood of a release.
PHMSA also finds several other deficiencies in the 2010 P&M Analysis. The risk analysis
mentioned the types of “nearby HCAs, which include HPOP, OPOP, Drinking Water and USA-
ECO” but did not define them or identify specific HCAs like the Yellowstone River.43 There
was no mention of the terrain surrounding the pipeline near the Yellowstone River or the
possible consequences of a failure at the crossing. In addition, while the elevation of the entire
pipeline is noted, the elevation profile is not evaluated as a risk factor that could impact the
consequences of a failure, such as whether the elevation profile from south to north allows more
product to drain into the Yellowstone than if the pipeline had a flat profile.
There is some discussion of spill size in the section evaluating emergency flow restriction
devices, but only with regard to the threats previously identified. Since flooding is not identified
as a possible failure mode, there is no consideration of the potential amount of product that could
be released as a result of damage at the crossing caused by flooding, such as if there is a
guillotine break in the pipeline. There is also no mention of the physical support of the pipeline
crossing at the Yellowstone River.
For these reasons, PHMSA finds Respondent’s 2010 P&M Analysis did not consider all of the
relevant risk factors in evaluating the likelihood of a release and potential consequences affecting
the HCA. While PHMSA recognizes that Respondent employed certain P&M measures in the
field, including depth of cover surveys and increased patrolling, these measures are not relevant
to this alleged violation, which concerns whether the risk analysis prepared by Respondent
appropriately considered relevant risk factors. Respondent’s other P&M measures are
considered below under Item 2.
In its written submissions and at the hearing, Respondent indicated that additional details of its
risk analysis were contained in other documents, including its 2010 Integrity Management
Program (IMP), 2010 IMP Forms 6.1, 2005 EFRD analysis, 2010 Data Integration and Risk
Assessment Summary, and 2009 integrity threat assessment. Those documents are considered
below.
43 The acronyms presumably refer to the types of HCAs, such as high population areas, other populated
areas, and unusually sensitive drinking water and ecological resource areas.



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2010 IMP Plan. Respondent argued that sections 3 and 6 of its 2010 IMP Plan demonstrated that
it considered time dependent threats such as heavy rains and floods.44
Section 3 of the 2010 IMP Plan discussed the process for data analysis generally, and stated that
segments are to be evaluated with regard to nine pipeline integrity threats listed in ASME
B31.8S.45 Section 6 of the IMP Plan discussed the procedures for evaluating P&M actions. It
described the evaluation process and noted that Form 6.1 should be used to document the
evaluation.
According to Section 6 of the 2010 IMP Plan, the evaluation process required identification of
HCAs and significant threats, including possible causes of failure. Examples of threats given
were third-party damage and corrosion. After identifying HCAs that may be affected and threats
that could cause a failure, Section 6 stated that appropriate risk factors must be considered,
which either increase or reduce risk. The procedure listed a number of risk factors that, at a
minimum, should be evaluated, including: terrain to HCAs and proximity, elevation profile,
waterways, potential volume released, and physical support.
While the procedures in the 2010 IMP Plan indicate the process Respondent should have
followed in performing a risk analysis, the procedures do not, by themselves, show whether this
process was indeed followed for the Silvertip Pipeline at the Yellowstone River crossing. In
particular, the procedures do not demonstrate that Respondent considered the threat of floods.
2010 IMP Form 6.1. The 2010 IMP Form 6.1 was used by EMPCo to document the evaluation
of P&M actions in support of the 2010 P&M Analysis.
46 Respondent submitted two such
forms.47 One was for the identified threat of external corrosion and the other was for the threat
of manufacturing defects. There were no forms identifying other threats that could cause a
pipeline failure, such as the threat of natural forces or flooding.
Both of the forms submitted include evaluation of the risk factors relevant to the identified threat.
Risk factors such as terrain to the HCA, pipeline profile, potential product spillage, and physical
supports were all considered, but since their consideration was limited to the two identified
failure threats, these factors were not considered in regard to the threat of natural forces or
flooding.
Accordingly, the forms submitted do not support Respondent’s assertion that its risk analysis
considered the threat of floods and associated risk factors.
44 Pre-hearing Submittal at 6-7.
45 Pre-hearing Submittal Exhibit 9. ASME B31.8S is not incorporated by reference in § 195.452.
46 Violation Report, Exhibit B-7 at 3.
47 Pre-hearing Submittal Exhibit 10 – Preventative & Mitigative Actions Evaluation, dated July 7, 2010.



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Other Documentation. Respondent asserted that its 2010 P&M Analysis relied upon a
consideration of elevation profile performed in 2005.48 Respondent also referenced its 2010
Data Integration and Risk Assessment Summary, which noted the approximate 1150-foot
elevation change between the two ends of the pipeline and the static pressure at the downstream
end.49
Having reviewed the 2005 Emergency Flow Restricting Device (EFRD) Evaluation and related
materials, PHMSA finds Respondent considered the elevation profile of the pipeline, but there is
inadequate consideration of how the elevation profile impacts the consequences of a pipeline
failure at the Yellowstone River. In particular, there is no consideration of how the elevation
profile could result in crude oil draining into the river in the event of a failure at the crossing.
Respondent also contended that its 2009 integrity assessment “considered the threat of weather-
related and outside forces.”50 In connection with this assertion, Respondent cited to its 2010
IMP Plan, which is already discussed above.
C. Conclusion
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.
Item 2: The Notice alleged that Respondent violated 49 C.F.R. § 195.452(i)(1), which states:
§ 195.452 Pipeline integrity management in high consequence areas.
(a) . . . .
(i) What preventive and mitigative measures must an operator take to
protect the high consequence area?—(1) General requirements. An
operator must take measures to prevent and mitigate the consequences of a
pipeline failure that could affect a high consequence area. These measures
include conducting a risk analysis of the pipeline segment to identify
additional actions to enhance public safety or environmental protection.
Such actions may include, but are not limited to, implementing damage
prevention best practices, better monitoring of cathodic protection where
corrosion is a concern, establishing shorter inspection intervals, installing
EFRDs on the pipeline segment, modifying the systems that monitor
48 Post-hearing Brief at 5, citing Violation Report Exhibit B-3.
49 Post-hearing Brief at 5, citing Violation Report Exhibit A-15.
50 Pre-hearing Submittal at 7.



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pressure and detect leaks, providing additional training to personnel on
response procedures, conducting drills with local emergency responders
and adopting other management controls.
The Notice alleged that Respondent violated § 195.452(i)(1) by failing to take appropriate
measures to prevent or mitigate the consequences of a failure on the Silvertip Pipeline at the
Yellowstone River crossing. Specifically, the Notice alleged that Respondent failed to operate
remote control valves (RCVs) installed on the Silvertip Pipeline to prevent or mitigate the
consequences of a failure. In addition, the Notice alleged that Respondent failed to take “any
other” P&M measures to address the threat of failure from flooding, such as implementation of
damage prevention best practices, strengthening leak detection systems, undertaking additional
training for response personnel, or addressing the risk of a guillotine failure.51
In its written submissions and at the hearing, Respondent contested the allegation that it failed to
identify and implement appropriate P&M measures. Respondent contended that its written IMP
Plan addressed P&M measures and that EMPCo had adopted those measures at the Yellowstone
River crossing.52 Respondent contended that it “had employed all of the P&M measures
suggested by PHMSA” under the regulation prior to the incident.53
Respondent explained that the P&M measures it employed included conducting a depth of cover
survey several months before the accident, which determined the pipeline had adequate
protection.54 The measures also included actively monitoring river conditions prior to the
accident, having thicker walled pipe and concrete coating, placing the pipe in a rock trench
deeper than otherwise required,
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