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Philadelphia is a city of old meets new, and Billy Penn will take a look at much of the old. We’re looking to take a deep dive into different facets of the city’s aging — and largely ailing — infrastructure in a new series. We’ll go over the history, the problems and what the city is doing to remedy the situation.

Philly’s gas pipes are old and leaking — in fact, there’s a startling amount of potentially explosive stuff seeping into the ground in these parts. And there’s not much the city can do quickly to fix it.

The amount of pipes Philadelphia has that are made up of an antiquated material is higher than any other utility company in the country, and the city’s sometimes-100-year-old gas mains are springing upwards of 2,000 leaks per year.

These leaks can cause explosions and are slowly pushing greenhouse gases into the atmosphere, contributing to global warming on a huge scale. And the city and the state simply don’t have enough money to quickly take care of it.

The Problem

Philadelphia’s leaky natural gas pipes are some of the worst in the nation, and much of that is due to this: More than half are made of cast iron and unprotected steel — materials utility companies stopped using for new pipes in the ’60s.

According to an investigation by The Pittsburgh Tribune-Review, the feds urged states in the 1970s to replace cast iron pipes because they’re more prone to leakage and make up the vast majority of natural leaks across the country. The highest concentration of these pipes is right here in Philly, where half of the 3,000 miles of pipeline are cast-iron.

The Trib also reported that Philadelphia Gas Works reported 89 leaks per hundred miles of pipelines in 2013, which is somewhere around eight times the national average.

These pipes that can be more than 100 years old in some cases can spring somewhere around 2,000 leaks a year, according to the Inquirer, and can eventually cause gas mains to rupture and blow up buildings or homes in the area.

Here’s a look at what (worst-case scenario) these explosions can cause:

YouTube video

A 2008 study showed the most leak-prone areas include Fairmount, East Oak Lane, Kensington, and Kingsessing.

The leaks taking place daily can cause more than problems with old gas mains — it’s terrible for the environment. Natural gas is made up of methane, a greenhouse gas. The Mayor’s Office of Sustainability estimates that each year, leaky gas pipes release emissions equivalent to that of 120,000 cars.

What the city is doing

There are few people who don’t want these old pipes to be replaced. But at the rate PGW is moving, we’ll all probably be dead by the time the city gets rid of its last cast iron pipes. And like anything else, it comes down to money.

For every mile of pipe replaced in Philly, it costs about $1 million. When The Trib asked former Gov. Tom Corbett about replacing cast iron pipes across the state, he basically said ¯\_(ツ)_/¯ and asked where that estimated $11 billion would come from. (For perspective, that’s close to the amount of money the state spent on education in total last year.)

So currently, PGW is replacing about 18 miles of pipe per year based on what it can afford. At that rate, it’d take more than 80 years to replace everything. But that process could have been expedited had the city gone through with its plan last year to privatize PGW.

Connecticut-based UIL Holdings, the company that was going to buy PGW from the city for nearly $2 billion last year, claimed it could ramp up the replacement process and cut the time it would take to replace the pipes in half. This promise came as the group launched an ad campaign aimed at City Council called “fix-the-system-or-cross-your-fingers.” Scary.

But if you remember, the sale of PGW never went through. Mayor Michael Nutter was all like “let’s sell this thing!” and City Council was all like “you didn’t keep us in the loop about this!” and no public hearings were held and everything fell through. The public utility company is left to continue its glacial pace of replacement.

By the numbers

3,024 – miles of natural gas mains

1,500 – approximate number of miles of natural gas mains that are made of cast iron and unprotected steel, an antiquated material used to create mains

2,000 – approximate miles of gas mains considered “at-risk”

3 – number of PGW explosions in the last 35 years

11 – number of people who died in those explosions

120,000 – number of cars equivalent to the amount of emissions released annually from Philly’s leaking pipes

1.86 billion – dollars UIL Holdings offered to buy PGW from the City

89 – number of leaks per 100 miles of pipe in 2013 (eight times the national average)


PGW has been serving the city since 1836, when 40 natural gas lights were lit on 2nd Street for the first time by employees of Gas Works. By 1897, the United Gas Improvement Company had signed a 30-year contract with the City to manage PGW.

Photo: Philadelphia Gas Works

Throughout the 1900s, natural gas took hold as a more popular cooking fuel than coal as Philadelphia Gas Works continued to merge with smaller gas companies throughout the city. In 1955, the Northern Liberties Gas Company (it was a thing) became the last one to merge with PGW.

In the 1960s, most utility companies stopped creating new mains with unprotected steel and cast iron and by the 70s, federal regulators began urging utility companies to replace the old systems.

By 2009, PGW launched the state’s largest natural gas conservation program that was designed to help 100,000 residents become more energy efficient. Today, PGW continues its gas dominance in the region, but it really can’t quickly replace the old lines that are springing leaks throughout the city.

The money

Cash money is really at the heart of all of this mess that Philly has found itself in. It doesn’t have anywhere near enough capital to replace the leaking gas mains that it should, and the state is just as broke and unable to help.

As the clock ticks on the danger associated with thousands of miles of leaking mains throughout the city, the state is grappling with a massive budget deficit but is still urging Philadelphia to replace its leaky gas mains — especially since it didn’t sell off PGW to a company that would have expedited the replacement and paid the city to do it.

In fact, the PUC is threatening asking the city to forgo the $18 million annual fee it now receives from PGW “to reduce the impact on ratepayers of an upgraded main-replacement program,” according to the Inquirer. Some council members complained the move is punishment for not selling PGW.

Anna Orso was a reporter/curator at Billy Penn from 2014 to 2017.