Prepared by Bob Ackley of Gas Safety USA
OVERVIEW
The condition of Washington DC’s natural gas infrastructure and the status of gas leaks and repairs are urgent public safety issues. The city’s natural gas infrastructure is older, more prone to leaks, and therefore poses more potential hazards to the public.
According to Washington Gas Light, there have been at least 4,000 gas leaks in DC since 2016. A majority of the leaks have been grade 1 leaks — the most dangerous kind as described under DC and federal law. The utility company has spent an estimated $17.8 million since 2016 to repair leaks throughout the city.
The Pipeline and Hazardous Materials Safety Administration, reported that there were 1,214 miles of gas mains in Washington DC as of December 31, 2017. Compared to the rest of the country, Washington had:
• 17 times more of leak-prone cast iron/wrought iron gas pipelines than the national average, These mains are considered leak prone and slated for replacement. They are prone to cracks caused by earth movement and can create extremely hazardous conditions in a short time frame
•Eight times as many miles of pre-1940 gas mains than the national average
•Three-times as many leak-prone gas service lines than the national average
DC’s Leak-Prone Gas Pipelines
The most leak-prone gas pipelines are those that are made of unprotected bare steel, cathodically protected bare steel, unprotected coated steel, copper, cast iron / wrought iron and ductile piping.
Summary: How DC Compares to the Rest of the Country
Of the 1,214 miles of gas mains that were in Washington DC as of December 31, 2017, the city had:
•Greater percentages of older and the most leak-prone gas pipelines than the national average
• Percentages greater than the national average of service line gas pipes that are made of the most leak-prone materials
• A much smaller percentage of safer plastic gas mains than the national average.
• A smaller percentage than the national avenge of cathodically-protected coated steel mains, bare steel gas mains and unprotected bare steel distribution main pipelines
(Source: U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration)
AN IN-DEPTH LOOK AT THE PROBLEM
The bad news: In 2017 Washington DC had:
17 times more of leak-prone cast iron/wrought iron gas pipelines than the national average
• There are 408 miles of cast iron/wrought iron gas pipelines in Washington DC. This is 17 times greater than the national percentage of such pipelines
• These mains are considered leak prone and slated for replacement. They are prone to cracks caused by earth movement and can create extremely hazardous conditions in a short time frame
800% more of pre-1940 gas mains than the national average
• There are 393 miles of pre-1940 gas mains in Washington; this is almost eight times more than the national percentage (32.32% v. 4.15%)
300% more leak-prone gas service lines
• Washington DC has three-times more leak-prone gas service lines (6,619) than the national average (22% v. 6%)
Three-times the national average of unprotected coated steel
• Unprotected coated steel pipes are substandard and slated for replacement
• There are 57 miles of unprotected coated steel distribution gas mains in Washington DC which represent 4.7% of all main pipelines in the city
• Nationwide, 1.5% of distribution system main pipelines are made of unprotected coated steel
200% more bare-steel gas lines than the national average
• Washington has more than twice the number of bare steel gas service lines than the national average (5.29% v. 2.56%)
A greater percentage of hazardous natural gas leaks
• Washington DC has a greater percentage of hazardous natural gas leaks in its more than 125,000 service lines than the national average (.40% v.24%)
A smaller percentage of safer plastic gas mains than the national average
• There were 403 miles of plastic gas mains in DC, which is 33% of all gas mains in DC
• Nationwide, 57% of all gas mains are made of plastic
The better news: In 2017 Washington DC had:
Fewer cathofically-protected gas mains than the national average
• There are 318 miles of cathodically protected coated steel mains in Washington which is 26% of all distribution gas mains in the city. FThis is less than the national average of 36% of all cathodically-protectedsteel mains.
No cathodically–protected bare steel gas mains
• Cathodically protected bare steel mains are considered substandard and slated for replacement.
• There were 0 miles in DC system compared with .86% nationally
Not as much unprotected bare steel distribution main pipelines as the national average
• Unprotected bare steel is highly susceptible to corrosion, has no cathodic protection and has all been slated for replacement.
• There are 23 miles of unprotected bare steel distribution main pipelines throughout DC which is just shy of 2% (1.89%) of the entire DC pipe system. Nationally 2.73% of all mains are unprotected bare steel.
(Source: U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration)
DC Gas Leaks 