PST’s Data and GIS Analyst 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.
With over 70,000 miles of transmission, distribution mains, and liquid pipelines, Ohio ranks fourth-highest in the United States for pipeline mileage. Let’s take a closer look at Ohio’s safety record and the operators involved.
From 2010 to 2021, Ohio has had:
- 188 total incidents including:
- 79 Hazardous Liquid incidents
- 48 Gas Transmission incidents
- 59 Gas Distribution incidents
- 114 significant incidents
- 15 incidents ending in injury and/or fatality
- 50 incidents resulting in fire and/or explosion
- 2,645 total members of the public evacuated
- Incidents have released:
- 1,088,159 thousand cubic feet (mscf) of gas
- 362,726 gallons of hazardous liquids
Compared to its neighboring states and the rest of the U.S. Ohio appears to be more incident prone than average (Plot 1). Furthermore, Ohio’s relatively volatile yearly incident counts don’t suggest a particularly clear trend in any direction, while Ohio’s neighbors seem to have leveled off in recent years, after an increase in incidents during the early 2010s. However, given Ohio’s relatively extensive pipeline mileage, it is useful to look at the rates of incidents per distance. When we compare Ohio’s incident rate with the average for its neighbors and the rest of the country, we get a more holistic picture of Ohio’s relative safety record (Plot 2). Along with incident rates, we can also keep tabs on the raw incident counts discussed above by displaying those numbers as the size of the points in the two following plots.
Based on incident rates per mile, Ohio seems to be about on par with its neighboring states. Furthermore, both Ohio and its neighbors appear to fare better than the national average. Even when looking at significant incidents (Plot 3), Ohio generally appears to perform better than the rest of the country. However, the volatility in year-to-year incidents is even more prevalent among significant incident rates in Ohio. We should expect some volatility when comparing a single state to group averages, as these grouped averages tend to compensate for volatility in trends. Despite this, Ohio’s significant incident rate seems to be especially unpredictable from year-to-year: ranging from nearly two significant incidents to less than half an incident per thousand miles.
From the map of Ohio’s incident locations and cost, it is apparent that despite relatively fewer miles of liquids pipelines, incidents occur at a similar frequency to gas transmission and distribution lines and are similarly costly. This trend is fairly common across the U.S. and appears quite clearly in Ohio.
Between 2010 and 2021, 31 unique operators bear responsibility for pipeline incidents in Ohio. These 31 subsidiary operators are grouped under 20 parent operators, with a few remarkable trends among the operators at hand. The table below presents the three most incident-prone parent companies for each system and their summary statistics over the past 12 years. The trend column displays their annual incident rate from 2010 to 2021, 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 Ohio. Finally, releases are reported in thousand standard cubic feet (mscf) for gas incidents and U.S. Barrels (BBL) for hazardous liquids.
|Parent Operator||Total||Significant||per 1K Miles||Trend||Total||per Incident||Total||per Incident|
|COLUMBIA GAS OF OHIO INC||30||73%||1.50||17,993||600||150,809||5,027|
|PIEDMONT NATURAL GAS CO INC||5||100%||0.88||1,707||341||7,757||1,551|
|Others (GD, avg.)||2||67%||1.35||643||255||409||180|
|Others (GT, avg.)||2||82%||19.97||3,552||1,240||40,242||14,872|
|MARATHON PIPE LINE LLC||13||31%||15.51||2,364||182||303||23|
|Others (HL, avg.)||2||74%||27.99||733||615||759||270|
Notably, the trend lines show that six of the nine highlighted operators have had their worst year more recently than their best year in terms of incident counts. It is also apparent that Questar distribution, Kinder Morgan transmission, and Energy Transfer liquids are some of the worst of the bunch in Ohio.
There are a couple of instances where surprisingly, the “other” operators appear to show higher than expected rates of incidents per mile. In general, this was due to a relatively low mileage for these companies. For example, in the gas transmission system, AK Steel Corp operated 9.8 miles of pipeline on average between 2010 and 2021. A single incident during this period resulted in a rate of 102 incidents per 1,000 miles, which heavily drove the average rate for “other” operators up.
These types of instances are similarly visible in Plot 5, where we examine the release size and damage cost of incidents by their operator and system. The gray dot in the upper right of the “Gas” plot is a single Enbridge incident – their only Ohio incident from 2010 to 2021. On January 21, 2021 a compressor station exploded and caught fire in Summerfield, Ohio, injuring two and evacuating four people. The subsidiary operator was Texas Eastern Transmission, LP; they currently run nearly 1,000 miles of gas transmission pipelines in Ohio.
Plot 5 also shows us that Energy Transfer seems to have the broadest range of incident size and cost among liquids operators. They are however certainly one of the worst in the state given the frequency of highly costly incidents.