The Large Volume Leak (LVL) Study
Innovative Solution Developed to Cut Emissions from Natural Gas Leaks in Half.
Activists and Utilities Ready to Enact it in Massachusetts
By: Audrey Schulman, President of HEET
Boston, MA, September 25, 2017 — A practical plan to cut emissions in half from underground natural gas leaks is announced by an unconventional coalition of environmentalists, academics, for-profits and gas companies. If this approach is enacted statewide, the emission reductions will be equivalent to cutting in half the emissions from all of the state’s stores and businesses.[1]
The pipes under Massachusetts streets are the second oldest in the country and prone to leaks. The gas emitted is over 90% methane, a greenhouse gas dozens of times more damaging than carbon dioxide. A 2015 Harvard/Boston University study[2] estimated the total amount of leaked gas in Greater Boston at 2.7% of all the gas in the state.
Half of the total emissions from underground natural gas leaks comes from just 7% of leaks.[3] The Energy Omnibus Bill passed last year in Massachusetts requires these “environmentally significant” large volume leaks to be repaired.
However, gas companies have always been mandated to focus on public safety rather than the volume of leaks. Therefore, they had no scalable, proven method ready to figure out which leaks were “super-emitting” in order to fix them. A coalition of environmentalists, academics and for-profits, worked together with the state’s three largest gas companies (National Grid, Eversource and Columbia Gas) on a research study to quickly develop an initial method. In a highly unusual step, the three largest utilities shared information and worked closely with the environmentalists.
The research showed that one practical way to find the large volume leaks is to measure the gas-saturated surface area over the leak. Any leak where the gas has spread for more than 2,000 square feet is likely to be large volume. In addition, the coalition also created an inexpensive, easy-to-use device — the FLUXbar — that allows for comparison of the leaks to provide feedback for continual improvement.
“This research is excellent and the results will be of interest to engineers across the gas industry,” said Neil Proudman, Vice President of New England Gas Operations for National Grid.
The environmentalists and gas companies will be sharing their recommended action plan that includes: a) initially identifying the large volume leaks through the size of the leak footprint, b) data transparency about the results, c) using the FLUXbar for verification initially and d) an independent panel reassessing the methods and results annually.
Steve Bryant, the President of Columbia Gas, predicted that this innovation, “will allow us to save the most emissions for the least customer cost.”
“This diverse, knowledgeable group of partners is breaking ground on a way to address emissions from gas leaks,” said Eversource President of Gas Operations Bill Akley.
If the Department of Public Utilities enacts the coalition’s recommended actions, the state could cut the emissions from leaking pipes in half for the least cost and disruption. The end result will be a replicable national and international model for rapid reduction of methane emissions in our communities.
Some of the many organizations /people involved in the study:
● NGOs: HEET, Mothers Out Front, Sierra Club of Massachusetts
● Government: Metropolitan Area Planning Council
● Academics: Boston University Professor Nathan Phillips, Zeyneb Magavi
● For-profits: Gas Safety Inc., Millibar, MultiSensor Scientific
● Utilities: Columbia Gas, Eversource, National Grid
This research was funded by the Barr Foundation, Putnam Foundation, and many individual donations.
[1] Estimate of methane impact based on McKain et al. total emissions estimate, divided by estimate of contribution from underground distribution system, and scaled to the 20 year impact of methane.
[2] McKain et al., Methane Emissions from Natural Gas Infrastructure in use in the urban region of Boston, Massachusetts, PNAS, Jan 2015.
[3] Hendrick et al., Fugitive methane emissions from leak-prone natural gas distribution infrastructure in urban environments, Env. Pollution, Jan 2016.
