State of Safety: Illinois

PST’s Data Manager James Eager walks us through one state’s pipeline safety track record each month. Click on the “State of Safety” tag at the bottom of the post to see all of James’s entries to date.

This analysis considers all incidents which occurred in Illinois over the 2010-2022 time period, regardless if they fall under state or federal jurisdiction.

Quick Facts

From 2010 to 2022, pipelines in Illinois caused:

• 252 total reported incidents, including:
  • 183 Hazardous Liquid incidents
  • 25 Gas Transmission incidents
  • 43 Gas Distribution incidents
  • 1 Underground Natural Gas Storage incident
• 132 significant incidents
• 20 incidents ending in injury and/or fatality causing:
  • 32 hospitalizations
  • 9 fatalities
• 46 incidents resulting in fire and/or explosion
• 901 evacuations
• Incidents have released:
  • 2,740,302 gallons of hazardous liquids
  • 415,332 thousand cubic feet (mscf) of gas

Incident Breakdown

Illinois’ incident rate trends below the national incident rate and closely to the average of its neighbors (Plot 1). This trend holds among significant incidents alone (Plot 2).

The highest-cost incident was a hazardous liquids spill, as presented in Plot 3. Of the five costliest incidents since 2010, four were liquids – all crude oil lines. Two of these four incidents were due to “other outside force damage”: in one case, damaged and arcing power lines and in another, external corrosion caused by a nearby damaged water pipeline. Of the other three highest cost incidents in the top five, one was an “unknown” cause (which the National Transportation Safety Board, or NTSB, is investigating), one was a “miscellaneous” cause, and the last was due to internal corrosion. The most expensive incident occurred on September 9, 2010 on a pipeline in Romeoville, IL, about 26 miles southwest of Chicago. On Enbridge’s Line 6A, the 34-inch-diameter pipeline leaked over 316,000 gallons of crude oil, costing over $58 million in damages, when adjusted for inflation. The NTSB report on this incident proposes that a water pipeline installed in close proximity to this stretch of Line 6A caused damage to Line 6A when the water pipeline was installed. In addition, the water pipeline disrupted Line 6A’s cathodic protection and sent a jet of water that pushed sand and small gravel into Line 6A, ultimately causing the leak.

Operator Analysis

Of the 139 unique pipeline operator IDs in Illinois, 47 have been responsible for at least one incident since 2010. Twenty-seven of these 47 operate integrity management programs under a different primary operator. In some cases, the relationships between subsidiary and primary are relatively clear, like with subsidiary operators like Enbridge Energy, Limited Partnership and Enbridge Storage (Pakota) LLC. In some cases, the relationship is less obvious, as with Midwestern Gas Transmission Company and OneOK.

The table below presents the three operators with the most incidents for each system in the state of Illinois over the 2010 – 2022 period. The trend column displays their annual incident rate from 2010 to 2022, with a green point at their maximum and an orange point at their minimum. The row labeled “Other” is an average of the other parent operators for each given system in Illinois – including those without any incidents during this period. Significant incidents are presented as a percent of total incidents, and incident rates are given as incidents per 1,000 miles. Finally, releases are reported in thousand standard cubic feet (mscf) for gas incidents and gallons (Gal.) for hazardous liquids.

	Incidents				Cost (K, USD)		Releases
Parent Operator	Total	Percent Significant	per 1K Miles	Trend	Total	per Incident	Total	per Incident
Hazardous Liquids
MARATHON PIPE LINE LLC	37.0	51%	24.65		34,153	923	294,514	7,960
BUCKEYE	28.0	61%	31.78		49,473	1,767	137,058	4,895
ENBRIDGE (HL)	25.0	48%	91.65		76,886	3,075	421,876	16,875
EXPLORER PIPELINE CO	13.0	38%	48.30		3,335	257	12,802	985
BP	10.0	50%	25.43		6,016	602	12,294	1,229
23 Others (HL, avg.)	3.0	34%	325.61		1,002	449	80,944	17,269
Gas Distribution
NORTHERN ILLINOIS GAS CO (GD)	24.0	71%	0.40		9,594	400	21,629	901
WE ENERGIES (GD)	8.0	88%	0.78		26,346	3,293	2,140	267
AMEREN ILLINOIS COMPANY (GD)	6.0	83%	0.21		5,552	925	7,090	1,182
78 Others (GD, avg.)	0.0	1%	0.21		3	3	0	0
Gas Transmission
ENERGY TRANSFER (GT)	6.0	17%	8.73		841	140	93,831	15,639
TRANSCANADA (GT)	5.0	40%	17.66		1,277	255	113,326	22,665
AMEREN ILLINOIS COMPANY (GT)	4.0	100%	3.22		2,995	749	65,206	16,301
40 Others (GT, avg.)	0.2	12%	2.74		168	89	2,579	1,386

To offer a holistic view of the relative responsibility of operators in Illinois, this table can be referenced in conjunction with Plot 4, which looks at each operator’s incident causes. This matrix presents a concerning suggestion: the majority of Marathon and Enbridge incidents are due to equipment failure and incorrect operation. This cause is more easily addressed by operators and suggests significant room for improvement for a couple of major pipeline operators in IL, which were responsible for 62 incidents over the 12-year period analyzed.

Plot 5 sheds some more light on which operators are responsible for some of the state’s worst incidents during this period. Using a grouped z-score of incident releases, we can identify which release sizes were well above average per system in the state during this period – as a z-score of 0 denotes the mean release size per system. The largest relative incident in the state was an Enterprise spill on August 12, 2013 in Erie, IL, which released 772,800 gallons of crude oil due to an apparent manufacturing defect – a “material failure of pipe or weld,” per Pipeline and Hazardous Materials Safety Administration’s (PHMSA) designations. This spill was over twice the size of the aforementioned Enbridge spill – and nearly 10 times greater than the average liquids spill in Illinois – although the damage was not as costly. Other labeled incidents include those more than five times the average release size for their systems and those with multiple fatalities per PHMSA’s reports.

Find all “State of Safety” entries here