The Environmental Defense Fund and Google Earth Outreach are using specially equipped Google Street View mapping cars equipped to locate and measure methane released from thousands of leaks in the natural gas lines beneath cities across America. But in Mesa, they found just a few small emitters. That’s because the city-owned utility and others around the state have been proactive in replacing and maintaining older, leak-prone pipes.
“We are proud of Mesa’s high standards when it comes to keeping our natural gas lines above safety and environmental requirements,” said Frank McRae, energy resources director for the city of Mesa. “The results illustrate our dedication to safety and reliability for our customers and the city.”
The city has a history of high standards regarding leak detection and safety. For example, Mesa Energy Resources played an active role in the development of the federal Gas Distribution Integrity Management Program, which the city adopted in 2010, a year before the required deadline.
All utilities are required to monitor their lines and quickly fix leaks that pose a safety threat. But smaller or more remote leaks can – and often do – go undetected or unrepaired for long periods. This doesn’t usually pose a safety risk, but the escaping 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. Over time, those emissions can do a lot of damage; reducing them can have an immediate benefit to the climate.
“Methane leaks are a serious environmental challenge for utilities everywhere, and a waste of customer resources. Fixing them is a quick way to dramatically reduce greenhouse emissions,” said Mary Gade, a former state and federal environmental official now working with the Environmental Defense Fund (EDF) on the mapping project. “Mesa has done a good job keeping up with the investments needed to protect their system. The city is setting a good example for others around the country.”
But even cities like Mesa have room to make further progress. To further reduce pipeline leaks, for example, EDF says that Arizona utilities should be required to use state-of-the-art measurement and detection technology, conduct more frequent leak surveys, and make the results publicly available.
The Mesa City Council recently committed to improving its data practices and openness as one of the first cities selected for the Bloomberg Philanthropies “What Works Cities” initiative, making this an opportune time to consider using better data acquisition and analysis tools to advance utilities’ leak management efforts in Mesa, and throughout Arizona.
“Arizona has a strong regulatory framework for leak repair and management. But better data can help ensure that utilities are investing their resources more cost effectively, and getting the biggest bang for their customer dollars,” Gade said. “Leaks that are a safety threat should always be fixed immediately, but after that, utilities should be tackling those with the greatest emissions, which pose the most serious threat to the environment.”
Early detection of natural gas leaks benefits both customers and the environment, and has the potential to reduce the need for costly and disruptive emergency repairs. Utilities in New York and California are already publishing dynamic maps of their natural gas leaks. Publically sharing geographically-attributed leak data can help regulators and ratepayers track utility performance, and ensure cost-efficient emission reductions.
The researchers in Mesa collected 600,000 data points driving 200 miles of roadway in and around the city, and found just three leaks. Google cars took readings in March and April 2016. The maps therefore represent a snapshot, and may not reflect current leaks due to repairs or other changes.
New technology means better opportunity
The mapping project was developed in collaboration with scientists at Colorado State University and Google Earth Outreach. EDF has been working with utilities in cities around the U.S. to demonstrate technology to detect leaks and assess leak sizes quickly and more efficiently.
The technology in this pilot project is newer and more sensitive than devices typically used by utilities to detect leaks on their systems. It has the capability to find and measure leaks that wouldn’t necessarily turn up or warrant repair based on safety concerns alone, but which do add up to a major environmental issue and costs to ratepayers. EDF and researchers at Colorado State University spent four years testing and fine-tuning the technology.
– Kelsey Robinson is communications manager of the Oil and Gas Program for the Environmental Defense Fund.