Natural Gas Midstream
Classification of Methane Emissions from Industrial Meters, Vintage vs New Plastic Pipe, and Plastic-lined Steel and Cast Iron Pipe Last Reviewed
May 2018


Gas Technology Institute (GTI), with project partners AECOM, GHD Services, Inc., and Washington State University will improve the characterization of methane emissions from the natural gas distribution system. The project will focus on emissions from industrial meters in the natural gas distribution system, differences between vintage and new plastic pipelines, and gather data to compare steel and cast iron pipelines with and without plastic liners. The project team will conduct an unprecedented assembly of existing and new field data on methane leaks that will feed advanced statistical methods to offer a new perspective on methane emissions, the metrics/categories used to estimate emissions, and techniques used to curb those emissions.

Gas Technology Institute, Des Plaines, IL 60018

To meet the Nation’s Climate Action Plan goal of reducing emissions 40-45% below 2012 levels by 2025 requires a comprehensive understanding of the emissions profile from the entire natural gas infrastructure to enable cost-effective and efficient identification and control of methane emissions. This project will contribute to one piece of the research needed to provide input into a cohesive strategy for greenhouse gas reduction. The EPA Greenhouse Gas Inventory (GHGI) estimates are used to drive environmental policy and regulations at the federal level, which directly impacts individual natural gas customers, rate payers. By reducing uncertainty and improving the characterization of methane emissions from the gas industry, appropriate regulations will be made, the cost of compliance will be reduced, and the savings will be passed on to the rate payers.

The research will have a significant impact on the national estimates of methane emissions from the natural gas industry. It is intended that the improved Emissions Factors and activity data will be incorporated into EPA’s annual GHGI. The proposed project will also identify specific metrics to be tracked at a company level so operators can prioritize the repair of their non-hazardous leaks to maximize the reduction of methane emissions. Studies have shown fat-tailed emissions can be responsible for up to 50% of total emissions. By identifying these leaks, operators can more efficiently reduce the environmental impacts of their system. The results from the study will also improve the activity data estimates for specific sources such as industrial meters and distribution pipelines. This can help individual companies develop targeted leak repair programs for non-hazardous leaks to optimize emissions reductions. Specifically, the data collected on emissions from cast iron and unprotected steel with plastic liners will help determine if this is an effective practice for reducing leaks. It could then be made into practice in the field and possibly support the creation of a different classification for this type of pipeline to promote the use of these liners as a method of reducing emissions. A reduction in leaks also improves safety for customers and the public.

Accomplishments (most recent listed first)

  1. Developed field sampling standard operating procedure and have shared with DOE and partners.
  2. Developed standardized digital data collection software to streamline data collections across field teams.
  3. Identified industry partners to facilitate field sampling.
  4. Assembled data available on industrial meters; new and vintage plastic pipe; and plastic-lined steel from several industry partners.
  5. Completed 10 weeks of industrial meters sampling; visited nearly 330 separate sites, some contained multiple meters in all 6 regions nationally.
  6. Completed 9 weeks of underground pipeline measurements, examined leaks from new vs. vintage plastic pipes, and sampled 70+ leaks in 5 of six regions nationally.
  7. Conducted 1 trip to survey for leaks on a total of 10,031ft at 17 individual sites of steel and cast iron mains with cured-in-place plastic liners and found no leaks.
  8. Data organization and analysis has begun.

Current Status (May 2018)
GTI is wrapping up the extensive field data collection section of the project. At this point, GTI has completed all 10 planned weeks of industrial meter measurements in all 6 regions nationally. Planning has begun on revisiting previously sampled meters at three industry partners to examine changes over time. Overall, GTI has visited over 400 individual industrial meter sites, conducting detailed leak surveys and component counts. During seven of the sampling weeks, GTI focused on maximizing the number of sites visited, only quantifying leaks that indicated 45% LEL concentration or higher. For three of the sampling weeks, GTI quantified every leak that presented at 100 ppm or higher to better understand all leaks coming from this category. Additionally, GTI has completed 9 of 10 weeks of measurements of new vs. vintage plastic pipe in 5 of 6 regions nationally, and has already scheduled the final week of measurements in June 2018. GTI has visited 270+ sites and quantified 170+ individual leaks. GTI conducted one field campaign to survey 10,031 ft of cast iron and steel mains lined with cured-in-place-plastic liners and did not locate any leaks on the specific segments of plastic lined pipe. The lack of leaks on these segments, coupled with few or no leaks in partner companies records of leaks on these types of pipe, has caused GTI (with the approval of DOE) to shift focus away from these types of pipe for this project. Finally, GTI has begun setting up the basic statistical analyses of the data and will be developing advanced statistics by the end of 2018.

Project Start: October 1, 2016
Project End: June 30, 2019

DOE Contribution: $1,090,719
Performer Contribution: $272,727

Contact Information
NETL – Gary Covatch ( or 304-285-4589)
Gas Technology Institute – Christopher Moore ( or 847-768-0688)

Additional Information: