PHMSA Incident Risk Analysis
Center for Excellence in Risk Management
Updated 2020-10-26
Incident Data Analysis
Natural Gas Transmission
In this section we are going to explore the past ten years of Natural Gas transmission incidents to try and identify any trends. The first metric is the expected loss (EL). EL is the average loss per mile in a year. EL is arrived at by aggregating all the losses reported by the total mileage each year. All dollar amounts are inflation adjusted.
The source incident data from PHMSA: PHMSA Flagged Files
Mileage is derived from Annual Report Data: PHMSA Annual Report Data
For each incident in the database a CoF was calculated based on the inflation adjusted property damage, number of injuries and fatalities. With the goal of providing a unified system of measure all injures and fatalities were assigned a value of a statistical life (VSL). The fatalities were multiplied by 10 million dollars in accordance with DOT guidance and each injury was counted as one-third of a VSL. The overall results can be seen in the first histogram. The vertical lines represent a P50 and and P95 event. These are the values that would be the 50th and 95th percentile of incidents.
Value of a Statistical Life Guidance:DOT VSL Guidance
Since PHMSA has not updated the threshold for incident reporting since 1984, they subdivide all the incidents into a category they call, “Significant” and “Serious”. Significant incidents are incidents that would of exceeded $50,000 in 1984 inflation adjusted dollars and “Serious” includes the Significant criteria plus any injury or fatality. The significant and Serious incidents provide a consistent metric of the number of incidents per year since they are accounting for inflation.
The definition of Serious and Significant incidents can be found here: PHMSA Serious and Significant incidents
The following is the CoF for all incidents broken out by the cause.
It is evident from the Significant Histogram that the P50 and P95 shifted to the right. The p50 shifted from 148 to NA thousand dollars.
The table below is all natural gas transmission incidents reported to PHMSA since 1986. It is searchable by company name and it can be filtered or sorted on any column. The units for Cost and CoF are thousands of dollars.
The following bar graphs represent the frequency of failure for natural gas transmission aggregated by year.
The following information is the average number of fatalities per incident. The inverse of this number would be the number of incidents before a fatality would be expected. The average since 2010 is 0.028 fatalities per incident.
| Year | Fatality Rate |
|---|---|
| 2010 | 0.093 |
| 2011 | 0.000 |
| 2012 | 0.000 |
| 2013 | 0.000 |
| 2014 | 0.008 |
| 2015 | 0.042 |
| 2016 | 0.032 |
| 2017 | 0.028 |
| 2018 | 0.009 |
| 2019 | 0.008 |
| 2020 | 0.013 |
Hazardous Liquids
Incident History of Hazardous Liquids reported to PHMSA.
In this section we are going to explore the past ten years of Hazardous Liquids incidents to identify any trends. The first metric is the expected loss (EL). EL is the average loss per mile in a year. EL is arrived at by aggregating all the losses reported by the total mileage each year. All dollar amounts are inflation adjusted.
The source incident data from PHMSA: PHMSA Flagged Files
Mileage is derived from Annual Report Data: PHMSA Annual Report Data
For each incident in the database a CoF was calculated based on the inflation adjusted property damage, number of injuries and fatalities. With the goal of providing a unified system of measure all injures and fatalities were assigned a value of a statistical life (VSL). The fatalities were multiplied by 10 million dollars in accordance with DOT guidance and each injury was counted as 1/3 of a VSL. The overall results can be seen in the first histogram. The vertical lines represent a P50 and and P95 event. These are the values that would be the 50th and 95th percentile of incidents. These results are influenced by two incidents with a combined CoF of 6 billion dollars.
Value of a Statistical Life Guidance:DOT VSL Guidance
A better measure of risk might be the expected loss normalized to the volume transported since the consequences of a Hazardous Liquid incident are directly related to the volume spilled.
Hazardous Liquid Consequence of Failure by incident classification.
Since PHMSA has not updated the threshold for incident reporting since 1984, they subdivide all the incidents into a category they call, “Significant” and “Serious”. Significant incidents are incidents that would of exceeded $50,000 in 1984 inflation adjusted dollars and “Serious” includes the Significant criteria plus any injury or fatality. The significant and Serious incidents provide a consistent metric of the number of incidents per year since they are accounting for inflation.
The definition of Serious and Significant incidents can be found here: PHMSA Serious and Significant incidents
| Year | Fatalities | Rate |
|---|---|---|
| 2010 | 1 | 0.057 |
| 2011 | 0 | 0.000 |
| 2012 | 3 | 0.165 |
| 2013 | 1 | 0.053 |
| 2014 | 0 | 0.000 |
| 2015 | 1 | 0.049 |
| 2016 | 3 | 0.145 |
| 2017 | 1 | 0.047 |
| 2018 | 0 | 0.000 |
| 2019 | 0 | 0.000 |
| 2020 | 4 | 0.182 |
Distribution of Bbls Released
Distribution of consequences relative to the spill size. The units on Costs and Consequences are thousands of dollars.
Frequency of Failure for Hazardous Liquid incidents
A comparison of the distribution of Natural Gas vs. Hazardous Liquid Consequence of Failure.
Data table of all Hazardous Liquid incidents since 2010. Searchable by Company and it can be sorted or filtered on any column.
Gas Gathering
Note: The only incidents in the PHMSA data are ones that happen on jurisdictional gathering which is a small percentage of the overall gathering mileage. Incidents reported on gathering pipelines account for about 6% of total natural gas incidents.
In this section we are going to explore the past ten years of Natural Gas Gathering incidents to identify any trends. The first metric is the expected loss (EL). EL is the average loss per mile in a year. EL is arrived at by aggregating all the losses reported by the total mileage each year. All dollar amounts are inflation adjusted.
The source incident data from PHMSA: PHMSA Flagged Files
Mileage is derived from Annual Report Data: PHMSA Annual Report Data 
For each incident in the database a CoF was calculated based on the inflation adjusted property damage, number of injuries and fatalities. With the goal of providing a unified system of measure all injures and fatalities were assigned a value of a statistical life (VSL). The fatalities were multiplied by 10 million dollars in accordance with DOT guidance and each injury was counted as 1/3 of a VSL. The overall results can be seen in the first histogram. The vertical lines represent a P50 and and P95 event. These are the values that would be the 50th and 95th percentile of incidents.
Value of a Statistical Life Guidance:DOT VSL Guidance
Since PHMSA has not updated the threshold for incident reporting since 1984, they subdivide all the incidents into a category they call, “Significant” and “Serious”. Significant incidents are incidents that would of exceeded $50,000 in 1984 inflation adjusted dollars and “Serious” includes the Significant criteria plus any injury or fatality. The significant and Serious incidents provide a consistent metric of the number of incidents per year since they are accounting for inflation.
The definition of Serious and Significant incidents can be found here: PHMSA Serious and Significant incidents
Table of Natural Gas Gathering incidents that is searchable by company name and allows for sorting and filtering on any field. Costs and CoF are in thousands of dollars. Any filters that are greyed out indicates there is nothing to filter on because all the values are the same.
Distribution
In this section we are going to explore the past ten years of Natural Gas Distribution incidents to identify any trends. The first metric is the expected loss (EL). EL is the average loss per mile in a year. EL is arrived at by aggregating all the losses reported by the total mileage each year. All dollar amounts are inflation adjusted.
The source incident data from PHMSA: PHMSA Flagged Files
Mileage is derived from Annual Report Data: PHMSA Annual Report Data
Consequence of Failure for all Natural Gas Distribution Incidents.
For each incident in the database a CoF was calculated based on the inflation adjusted property damage, number of injuries and fatalities. With the goal of providing a unified system of measure all injures and fatalities were assigned a value of a statistical life (VSL). The fatalities were multiplied by 10 million dollars in accordance with DOT guidance and each injury was counted as 1/3 of a VSL. The overall results can be seen in the first histogram. The vertical lines represent a P50 and and P95 event. These are the values that would be the 50th and 95th percentile of incidents.
Value of a Statistical Life Guidance:DOT VSL Guidance
Natural Gas Distribution CoF for Significant incidents only.
The following histograms are the CoF broken out by cause. The vertical represent P50 and P95 events as before.
Since PHMSA has not updated the threshold for incident reporting since 1984, they subdivide all the incidents into a category they call, “Significant” and “Serious”. Significant incidents are incidents that would of exceeded $50,000 in 1984 inflation adjusted dollars and “Serious” includes the Significant criteria plus any injury or fatality. The significant and Serious incidents provide a consistent metric of the number of incidents per year since they are accounting for inflation.
The definition of Serious and Significant incidents can be found here: PHMSA Serious and Significant incidents
Frequency of Failure for Distribution
| Year | Fatality Rate |
|---|---|
| 2010 | 0.092 |
| 2011 | 0.112 |
| 2012 | 0.102 |
| 2013 | 0.077 |
| 2014 | 0.170 |
| 2015 | 0.040 |
| 2016 | 0.087 |
| 2017 | 0.154 |
| 2018 | 0.055 |
| 2019 | 0.079 |
This is a table of Distribution incidents. Cost is the direct cost that is reported to PHMSA and CoF is the Cost plus the monetized cost of any injury or fatality. The Cost and CoF are reported in units of thousands of dollars.