New Interactive Maps Show Size, Location of Leaks on Chicago Natural Gas System

Improved Technology Will Help Utilities, Regulators Accelerate System Upgrades; Initiative Highlights Hidden Climate Risk and Untapped Solutions Opportunity

June 4, 2015
Kelsey Robinson, (512) 691-3404,

(CHICAGO – June 4, 2015) New interactive online maps released today plot the location and size of nearly 350 natural gas leaks beneath Chicago neighborhood streets from underground pipes owned by Peoples Gas. The maps were developed using specially-equipped Google Street View mapping cars, under a partnership between the Environmental Defense Fund (EDF) and Google Earth Outreach that is designed to showcase new environmental sensing technologies.

Leaks like the ones mapped in Chicago generally don’t pose an immediate safety threat, but leaking natural gas – which is mostly methane – has a powerful effect on the climate, packing 84 times the warming effect of carbon dioxide over a 20-year timeframe. Peoples Gas has been under regulatory scrutiny by Illinois Commerce Commission (ICC) and the Illinois Attorney General for delays and cost overruns in its multibillion-dollar program to replace aging pipes. Methods used by EDF to create the maps can be used by Peoples and others utilities to improve their system management.

“Methane leaks are a serious environmental challenge for utilities across the country, particularly in cities with aging infrastructure. Fixing them is an important opportunity to reduce greenhouse emissions quickly and cost-effectively,” said Jonathan Peress, EDF Air Policy Director for Natural Gas. “Programs to fix or replace leaky pipes are crucially important, but they need to operate efficiently and effectively. New technology like the systems we’re demonstrating in Chicago can help find problem spots and prioritize their investments.”

Neighborhoods were chosen as a representative cross-section of the Peoples Gas system. They include Logan Square and Humboldt Park; Dunning; and Norwood Park and Union Ridge on the North Side, along with Washington Heights and an area spanning Back of the Yards, Canaryville, West Englewood and Marquette Park on the South Side. The maps are available at  

Fixes Needed for an Aging System

Chicago’s natural gas system is among the oldest in the country. About 40 percent of Peoples Gas pipes are cast iron or other leak-prone material, and more than 40 percent are over 50 years old. A 2013 state law requires utilities to submit plans for repairing and replacing leaky pipes, allowing them to recover the costs from customers. The recent ICC audit underscores that while proper efforts to repair and replace leaky pipes are essential, program execution needs improvement.

“These maps reflect both a huge need and an major opportunity to protect consumers as well as the environment by using new technologies and better data to find and prioritize repairs,” said Mary Gade, Regional Administrator for the U.S. Environmental Protection Agency under President Bush and former Director of the Illinois Environmental Protection Agency, who is advising EDF on the project. “Knowing leak volumes will allow for smarter, better and more cost-effective pipe replacement programs.”

Methane emissions represent waste of natural gas, a valuable energy resource. Based on 1.4 million readings taken during at least two passes over 1,000 miles of local roadways, EDF found 349 leaks in just the selected areas measured. All were reported to Peoples Gas as soon as they were identified during the data analysis (the maps do not represent real-time conditions).

EDF says it is imperative that gas utilities use state of the art methods for implementing their repair and replacement plans by integrating leak quantification into their regular leak surveys, prioritizing their pipe repair and replacement programs to fix the biggest leaks first after addressing those that pose a safety risk, and reporting yearly on the amount of lost methane prevented through their efforts. 

New Technology Means Better Opportunity

EDF has been working with utilities in markets around the U.S., including New York, Boston and Los Angeles to validate technology to assess leak sizes quickly and inexpensively, offering a valuable new way for both system operators and regulators to focus and accelerate upgrades where they will reduce emissions most effectively.

The technology in this pilot project is newer and more sensitive than typically used by utilities to monitor the safety of their systems. It is designed to find and measure leaks that wouldn’t necessarily turn up or warrant repair on safety concerns alone, but which do add up to a major environmental issue. EDF and researchers at Colorado State University have spent three years testing and fine-tuning the technology, which is built specifically to filter out other kinds of methane emissions, including natural sources, waste dumps, and natural gas vehicles.

“New technology has given us vastly greater ability to make environmental data available for everyone to see, and to use that information to address environmental problems by making better decisions,” said EDF’s Chief Scientist Steven Hamburg. “Methane leaks are a pervasive challenge throughout the natural gas industry. This is a great opportunity to put new science to work in addressing a critically important real-world challenge.”


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